030 FXUS63 KDTX 180900 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 500 AM EDT Mon May 18 2026 .KEY MESSAGES... - Warm and humid conditions will exist today and Tuesday. This brings the risk for severe weather each day, mainly during the afternoon and evening hours. Thunderstorms will be capable of producing damaging winds, large hail and isolated tornadoes. - Cooler and drier conditions expected Wednesday and Thursday. && .AVIATION... VFR conditions will prevail through the morning hours as southwest winds strengthen. Breezy conditions expected by late this morning through the afternoon with 25 to 30 knot gusts. A broken line of rain and thunderstorms is then expected to take shape this afternoon to the early evening with main timing between 19Z and 01Z. MVFR to possible IFR conditions will accompany the thunderstorms. Once the line passes, a period of clearing in lower clouds will develop before lower scattered clouds may build back in toward sunrise tomorrow. D21/DTW Convection... A broken line of rain and thunderstorms is expected between 20Z and 01Z. Period of MVFR to possible IFR conditions will accompany the thunderstorms. .DTW THRESHOLD PROBABILITIES... * Moderate for thunderstorms this afternoon. * Low for ceilings aob 5000ft through this morning. Moderate with thunderstorms this afternoon. && .PREV DISCUSSION... Issued at 307 AM EDT Mon May 18 2026 DISCUSSION... Warm frontal boundary responsible for the prolific hail producing supercellular activity across portions of the Saginaw valley and northern thumb late Sunday will finally ease north of the region this morning as higher magnitude warmth increases influence within deepening southerly flow. Benign conditions ensured thru late morning as stability holds under modest capping. Influx of higher quality moisture will commence during this time, establishing a notable moisture gradient from west to east by early afternoon /dewpoint of mid 60s west to upper 50s east/. This affords a moderate level of diurnal boundary layer destabilization for at least western sections. Given an afternoon temperature of middle 80s, mlcape projection of upwards of 1500-2000 j/kg will peak across the Saginaw valley and down through the Highway 23 corridor. This leaves a receptive downstream environment for potential reorganization/ expansion of any MCV governed remnant nocturnal convective activity spilling downstream. A fairly strong model consensus exists on this scenario, targeting lower Michigan for a mid-late afternoon increase in coverage. A broader threat window locally between 19z and 01z with dependence on pace of the MCV. The background wind field remains modest, but subject to a localized meaningful increase both across the lower levels and with greater depth as the feature moves through. Supportive environment to offer a risk of both large hail and damaging wind gusts, with greater overall potential with westward extent. A focused area of higher SRH does materialize as low level flow backs briefly with a slight shift in the pressure gradient orientation. Therefore, cannot completely discount the possibility for a more organized, rotating updraft to present a brief, isolated tornado threat. Outside of the convective window, forecast continues to highlight gusty southerly conditions reaching 30 to 35 mph at times today. The seasonably warm and humid conditions will exist again Tuesday ahead of a cold front. A more muddled early day picture in terms of both cloud cover and precipitation chances, as a portion of the model solution space suggest possible activity prior to 18z owing to some combination of the ongoing moisture advection and remnant midwest convection leftover from tonight. Degree and pace of destabilization certainly still subject to change. Assumption for at least a weakly unstable environment timed favorably with an evening cold frontal passage will present an opportunity for deeper updrafts to organize within a sufficient background deep layer wind field along the frontal zone. The SPC Day 2 outlook maintains a slight risk designation to highlight the associated strong wind and large hail threat for the late Tuesday period. Warm sector environment will again become diurnally gusty, with winds reaching 30 to 35 mph from the south at times. Notably cooler post-frontal environment arrives Wednesday. This will occur with the backdrop of increasing low to mid level ridging, ensuring a stretch of dry and stable conditions lasting into Thursday. Low level thermal trough marked by 850 mb temperatures of lower single digits, lending to below average readings during this time. Coldest conditions Thursday morning as the surface high centers locally - lows dipping into the 30s in some locations. Dry conditions likely to hold under a modest warming trend Friday, as the next system organizes upstream. This system will introduce the next chance of rain Friday night into Saturday. MARINE... A warm front releases north across Lake Huron this morning, with southerly winds expanding across all local waters. Strong low level jet winds will struggle to mix down over the open waters where cool water temperatures maintain stable over-lake conditions. Gusty southwest flow will thus be confined to the nearshore waters, aided by warmer water temperatures and land influence. Frequent gusts today and Tuesday are expected to hold between 25 and 30 knots, but an isolated gust to 35 knots over Saginaw Bay cannot be entirely ruled out. Small Craft Advisories are in effect for today and will be needed Tuesday as well. More localized wind/wave impacts arrive with thunderstorm activity this afternoon-evening, and again Tuesday when a cold front sweeps through the area. There is potential for some of these storms to be strong to severe with all modes of severe weather in play. The cold front comes through Tuesday night, followed by high pressure filling in mid-week to support a quieter and more seasonable late May pattern. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...Small Craft Advisory from 10 AM this morning to 10 PM EDT this evening for LHZ421-422-441>443. Lake St Clair...Small Craft Advisory from 10 AM this morning to 10 PM EDT this evening for LCZ460. Michigan waters of Lake Erie...None. && $$ AVIATION.....AA DISCUSSION...MR MARINE.......MR You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.  276 FXUS63 KLSX 180903 AFDLSX Area Forecast Discussion National Weather Service Saint Louis MO 403 AM CDT Mon May 18 2026 .KEY MESSAGES... - Widespread showers and thunderstorms are expected throughout the day with heavy rainfall in some locations potentially leading to flash flooding. - A few strong to severe thunderstorms are possible this afternoon and evening with the main hazards being hail and damaging wind gusts. - Additional thunderstorms are forecast late tonight and early Tuesday morning with another round possible along a cold front Tuesday afternoon/evening. && .SHORT TERM... (Through Late Tuesday Afternoon) Issued at 402 AM CDT Mon May 18 2026 A complex of thunderstorms, that as of 09z, is currently positioned near Quincy MO to Warrensburg MO. This activity initiated across KS/NE on Sunday evening and has continued to push southeastward early this morning, with arrival in central/northeast MO expect around 09-10z. Within the last few hours, this complex has become outflow dominant, which has led to a gradual weakening trend from the severe wind gusts it was producing across northwestern MO around midnight. Upstream observations indicate that the gust front has been achieving winds gusts in the 30-50mph range. As a result, the main severe hazard tied to these storms as they move into the area are expected to be scattered wind gusts up to 50mph, along with frequent lightning and heavy rain. In fact, one of the main concerns regarding the short term is now the threat for heavy rainfall and flash flooding, mainly across central/south-central MO and points west. CAMs are in good consensus that the southeastward progress of this thunderstorm complex will continue to slow as it makes its way into the area this morning. Additionally, there are signs that backbuilding of thunderstorms may occur as the remnant outflow boundary/line of convection stall in a west-east orientation, with strong low-level southerly warm/moist advection overrunning this stationary boundary. Analysis of forecast soundings unveils a plentiful amount of uniform CAPE (around 1,500 J/kg) throughout the column, along with warm cloud temperatures with freezing levels around 12-14kft AGL. In addition, PWATs are currently in the 1.4-1.5" range, with the latest HREF indicating values increasing to 1.7-1.9" today, which is near the 99th percentile. Lastly, the HREF LPMM precipitation reveals the potential for a west-east oriented swath of 2-4" with localized pockets of 4-6" possible. Given all of the variables mentioned above, the risk of heavy rainfall has prompted us to issue a Flash Flood Watch for central/south-central MO and portions of east- central MO that is in effect from 12z today through this evening. Regarding the severe weather potential throughout the day, the threat remains for an isolated thunderstorm becoming strong/severe with hazards being hail along with damaging winds. This potential appears to be lower due to the lingering showers and thunderstorms across a large portion of the area, inhibiting solar insolation, and thus, robust destabilization this afternoon. Regardless, given the warm/moist summerlike airmass in place and the continuation of steepened mid-level lapse rates, maintaining sufficient instability, the threat for an isolated severe storm remains. A few locations may be able to clear by this afternoon, allowing the environment to recover and destabilize, and potentially the threat for strong to severe thunderstorms to increase in localized areas. With uncertainty regarding the evolution/coverage of lingering showers/storms, confidence is low regarding the extent of severe weather that may be realized across the area this afternoon and evening. By tonight, the large-scale pattern features a broad mid/upperlevel trough to the west, with an embedded shortwave ejecting northeastward into the Great Plains. This mid-level feature triggers lee-side surface cyclogenesis across the Central Plains/Midwest near a quasi-stationary baroclinic zone. Convection is modeled by high resolution guidance to initiate along this boundary in KS/NE, with quick upscale growth ensuing with eastward progression. The surface low is modeled to lift northeast into the Midwest on Tuesday, which begins to slowly shift the quasi-stationary baroclinic zone southeastward as a cold front. However, this convection is progged by guidance to outrun this slowly advancing cold front out west, and gradually weaken as it approaches the area. This weakening trend appears reasonable since the best deep-layer shear remains displaced to the north and west of the area and forcing for ascent will be limited without convection tied to the boundary. Regardless, this threat for severe weather late Monday night into early Tuesday morning will include the potential for large hail and damaging wind gusts. Additionally, if surges or bowing segments occur, then severe outflow gusts or embedded circulations leading to brief tornadoes may also be possible. Guidance is in fairly good agreement that the cold front will approach northeast MO/west-central IL Tuesday morning with it exiting to the southeast late Tuesday evening. Locations that remain pre-frontal for a majority of the day on Tuesday will have the greatest severe weather threat. The big question that remains is, how quickly will the atmosphere recover from the early Tuesday morning convection by the time the front is working its way through the area. As of now, it appears the severe weather threat will be greatest from east-central MO and points southeastward, as these locations will have the best chance to destabilize in the early afternoon on before the arrival of the front. Regardless, instability and mid-level flow are still forecast to be sufficient enough to support organized storms with potential for large hail, damaging winds, and tornadoes. Any lingering outflow boundaries from morning convection may serve as areas of focus for thunderstorm development in the afternoon ahead of the cold front. Peine && .LONG TERM... (Tuesday Night through Sunday) Issued at 402 AM CDT Mon May 18 2026 Low-level cold air advection within the post-frontal airmass will lead to much cooler conditions for Wednesday, with highs forecast to be around 10-15 degrees below average. Quasi-zonal flow aloft encompasses the region through the end of the week, which should allow for a period of dry conditions until Friday. By the end of the week, the general trend of LREF temperature IQRs is a gradual warmup to temperatures right around climatological normals. Peine && .AVIATION... (For the 06z TAFs through 06z Monday Night) Issued at 1022 PM CDT Sun May 17 2026 Showers and thunderstorms line up from Minnesota through Kansas late this evening. This activity is expected to be the primary source for thunderstorm potential heading into Monday with the main impacts being MVFR visibilities, locally heavy rain, and gusty winds. However, the intensity of this line is in question as it moves southeast through Missouri and into Illinois early Monday morning. Another disturbance drive northeast out of the southern Plains, which could lead to a few showers and isolated thunderstorm ahead of the approaching line. The isolated nature of what develops ahead of the line makes it difficult to pinpoint direct impact to any one terminal and therefore is not mentioned in the TAF at this time. The strategy was to focus on TSRA along the main line and target best potential for TSRA impacts. KUIN has the greatest chances (70-80%). KCOU/KJEF lie at the southern end of theline, where thunderstorms are likely to weaken, but maintain a broad spread of showers with embedded thunder potential. It remains uncertain whether thunderstorms will maintain enough intensity through the metro terminals, justifying the continuation of PROB30 groups to account for TSRA. One trend that will need to be monitored is where outflow stalls Monday. A second, weaker surface low ejects from the Plains along the boundary, which could support showers and isolated thunderstorms over central MO/metro sites through much of the day. It would be reasonable to extend the -SHRA mention with PROB30s for TSRA, if trends continue in this direction. Otherwise, conditions largely vary between MVFR/VFR through the period with MVFR concentrated on relatively more intense SHRA/TSRA. Maples && .LSX WATCHES/WARNINGS/ADVISORIES... MO...Flood Watch through this evening for Boone MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-Moniteau MO- Montgomery MO-Osage MO-Warren MO-Washington MO. IL...None. && $$ WFO LSX  314 FXUS62 KFFC 180904 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 504 AM EDT Mon May 18 2026 ...Morning Area Forecast Discussion... .KEY MESSAGES... - A few scattered thunderstorms are possible this afternoon along the GA/AL border, but coverage will be much less than yesterday. - Warmer temperatures the next few days with highs in the upper 80s to low 90s. - Increased rain chances return from Wednesday into next weekend. && .SHORT TERM... (Today through Tuesday) Issued at 500 AM EDT Mon May 18 2026 Another warm day expected this afternoon as temperatures rise into the upper 80s and low 90s. The best chance for afternoon thunderstorms has shifted to the west, though a few isolated thunderstorms are possible along the GA/AL border this afternoon. Coverage seems to be significantly less than yesterdays storms. Instability will be a limiting factor as well with high pressure keeping a cap on most of the CWA. The forecast for Tuesday is a bit of a carbon copy for today though with increasing afternoon clouds out a head of the cold front that's expected to bring the next round of weather. You can find more information about that system in the long term below. Winds will remain southerly at 5-10mph with some higher gusts in the higher elevations of northern Georgia. Overnight lows will be pleasantly in the mid 60s. && .LONG TERM... (Tuesday night through Sunday) Issued at 500 AM EDT Mon May 18 2026 By Wednesday afternoon and evening, a cold front will push southeastward toward far north Georgia. The highest PoPs will be relegated to these areas in proximity to the frontal forcing with drier conditions initially favored farther southeast. The front makes only limited southward progress by Thursday into north Georgia as upper support departs northeastward from the Great Lakes into Quebec. As such, diurnally-enhanced PoPs should again be highest along/north of the I-20 corridor. Flow aloft then transitions into southwest flow by late week as the front becomes stationary. Weak shortwaves within this flow will enhance convective coverage headed into the weekend, particularly with the aid of diurnal heating. Coverage again will likely be highest across roughly the northern half of the area through this period. The organized severe threat continues to look low given the summer-like weakly sheared environment, a couple of strong to isolated severe storms certainly can't be ruled out. While locally heavy rainfall will also be possible, the lack of a widespread and persistent soaking rainfall will limit the overall impact on the drought through the forecast period. Temperatures remain generally several degrees above normal (highs in the mid to upper 80s to lower 90s on the warmest days and lows in the 60s), though marginally cooler highs are possible late week given increased clouds and convective coverage. && .AVIATION... (06Z TAFS) Issued at 124 AM EDT Mon May 18 2026 Mostly clear skies will continue until after 10Z. Rain from yesterday may result in some low clouds near sunrise. A TEMPO for BKN IFR cigs runs from 10 to 13Z. A CU field with SCT low VFR will form after 15Z. //ATL Confidence...06Z Update... Medium on IFR Cigs. High on all elements. Vaughn && .PRELIMINARY POINT TEMPS/POPS... Athens 90 63 89 65 / 0 0 0 0 Atlanta 88 67 88 68 / 0 0 0 0 Blairsville 83 60 83 62 / 10 0 0 0 Cartersville 89 65 89 65 / 10 0 0 10 Columbus 90 66 90 68 / 0 0 0 0 Gainesville 87 63 87 66 / 0 0 0 0 Macon 90 63 90 66 / 0 0 0 0 Rome 88 63 88 63 / 20 0 0 10 Peachtree City 89 64 89 65 / 0 0 0 0 Vidalia 9064 91 65 / 0 0 10 0 && .FFC WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Vaughn LONG TERM....Vaughn AVIATION...Vaughn  515 FXUS63 KLMK 180909 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 509 AM EDT Mon May 18 2026 .KEY MESSAGES... * Today through Tuesday, temperatures are expected to warm into the mid 80s to low 90s. Some daily max temperature records could be challenged. * This afternoon/evening, showers and/or thunderstorms arrive, especially for our northwestern counties. * A line of strong to severe storms is expected to move through ahead of a cold front on Tuesday, possibly bringing strong winds and hail. The line will weaken as it moves east over the region. && .SHORT TERM /THROUGH TONIGHT/... Issued at 509 AM EDT Mon May 18 2026 Today, a closed low within an upper trough is located near the Four Corners. East of the trough, southwest flow stretch over the Plains before meeting an upper ridge flowing through the Great Lakes and New England regions. The Lower Ohio Valley sits under this ridge with gusty (20-25 mph) southerly winds being driven by a pressure gradient between a surface high over the Southeast and low pressure that stretches from the western Plains into the Midwest. This sit-up is expected to provide lots of sunshine and WAA to drive high temperatures into the mid 80s to low 90s throughout southern Indiana and central Kentucky. By this afternoon, the southern low level winds will not only drive temperatures warmer, but they will also lift precipitable water values to 1.75-2" over western Kentucky north into western Indiana, and as the remnants of the system currently over Iowa drift southeast towards the CWA, it will have this moisture rich unstable environment to work with to bring showers and thunderstorm to southern Indiana. Moisture is expected to quickly drop off south of the Ohio River, so most of the activity is expected to remain in southern Indiana, and the best chances for strong to severe thunderstorms will be in the far northwestern parts of the CWA, including Dubois County, where thunderstorms could develop ahead of the approaching line. With MLCAPE values around 1,600 J/kg, MUCAPE values near 2,300 J/kg, an inverted "V" sounding with LCLs near 1 km, strong winds and hail could be possible. Deep layer shear is weak around 25 knots, so this could possibly help some hail to melt as it fall back through the column, reducing its size. The high PWATs will also likely drive intense rainfall which could cause ponding of water. There is a limited window for any stronger storms as instability is expected to quickly drop to the southeast. Tonight, any remaining showers and thunderstorms are expected to dissipate. Continued WAA with some cloud cover will help limit cooling, keeping low temperatures in the upper 60s to low 70s. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Issued at 509 AM EDT Mon May 18 2026 Tomorrow, ahead of an approaching cold front, temperatures are expected to once again climb into the upper 80s to low 90s with another day of gusty WAA. This is expected to drive very high instability in the area of SPC's "Slight" risk. Some areas over southern Indiana could see MLCAPE values near 2,500 J/kg and MUCAPE values near 3,000 J/kg. This would help an expected line of convection ahead of the front to generate strong gusty winds and possibly large hail before weakening as the system pushes off to the east. Current timing has the line reaching Dubois county during the early afternoon. In the following hours, the line would push east through southern Indiana and central Kentucky. Tuesday night, the cold front is expected to reach our southern Indiana counties, but it could be slow getting through central Kentucky, not making it through the CWA until sometime on Wednesday. The front will slowly veer winds towards the north. Temperatures will remain mild Tuesday night falling into the mid to upper 60s, but Wednesday's highs can be expected to see some relief only making it to the mid 70s near Jasper, Indiana to the mid 80s near Clinton County. This will be near normal for many across the CWA. The slow moving front will keep shower and thunderstorm chances across the CWA through Wednesday, but strong storms aren't expected. On Thursday, highs are expected to be slightly below normal, in the low to mid 70s for most. Far southern Kentucky could see the upper 70s. Enjoy it because temperatures begin to inch back up day by day into the mid 80s by Sunday. Precipitation chances remain low but remain as the front sits south of the CWA. Another low pressure system could swing through on Friday, brining a better chance for widespread rain. && .AVIATION /06Z TAFS THROUGH 12Z TUESDAY/... Issued at 215 AM EDT Mon May 18 2026 VFR conditions are expected to remain through the period at most sites, but HNB and possibly SDF could see a line of late afternoon/evening convection arrive from the northwest before dissipating. This could bring heavy showers and low VFR ceilings for a limited time. All area TAF sites can expect southerly winds to become gusty, gusting to 20-25 knots for most of the day before easing tonight. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ SHORT TERM...KDW LONG TERM...KDW AVIATION...KDW  892 FXUS62 KCHS 180934 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 534 AM EDT Mon May 18 2026 .WHAT HAS CHANGED... The Aviation section was updated for the 18/12z TAFs. && .KEY MESSAGES... - 1) Minor coastal flooding is possible along coastal areas of Charleston and Colleton Counties with high tide this evening and possibly Tuesday evening. - 2) Mostly dry conditions expected through midweek with increasing rain chances to occur late week. && .DISCUSSION... KEY MESSAGE 1: Minor coastal flooding is possible along coastal areas of Charleston and Colleton Counties with high tide this evening and possibly Tuesday evening. Astronomical influences associated with the recent new moon and lunar perigee along with a modest onshore flow will continue to drive elevated tide levels, leading to minor coastal flooding along parts of the lower South Carolina coast this evening. The latest forecast advertises a peak high tide 7.0-7.2 ft MLLW in the Charleston Harbor this evening and 6.9-7.1 ft MLLW Tuesday evening. A Coastal Flood Advisory for Coastal Colleton and Charleston Counties could be for this evening's high tide and possibly again Tuesday evening although confidence in reaching the 7.0 ft MLLW minor flood stage is much more uncertain by then. Astronomical tide levels then begin to fall and the potential for minor coastal flooding will diminish. KEY MESSAGE 2: Mostly dry conditions expected through midweek with increasing rain chances to occur late week. Sfc high pressure and upper level ridging holds tight across the region through mid-week, allowing largely dry conditions to prevail. Model soundings also remain quite capped, so in the off chance that precipitation does develop, expect overall accumulations and severe potential to remain low. Otherwise, look for afternoon highs to warm into the upper 80s to lower 90s under mostly sunny skies, with lows only dipping into the mid to upper 60s. Upper level pattern shifts heading into the latter half of the forecast period, resulting in chances for unsettled weather. As noted in the previous discussion, a decent amount of model uncertainty still exists, making it hard to put too much confidence in any one solution just yet. While details still need to be ironed out, most guidance does showcase a shortwave trough digging across the central/northern Plains by Thursday. Meanwhile, at the sfc, will see a cold front dive southeastward across the Ohio/Tennessee River Valley, sending the aforementioned high pressure into the Atlantic. There are some indications that this boundary could stall across our area through Saturday, which would support increasing moisture and higher rain chances. However, if the ridge remains stronger, the front and better forcing could remain farther to the west and north, resulting in lower rain chances than currently forecast. Do think it is worth noting though, that latest ensemble probabilities for accumulated rainfall > 1" now showcase a 20-60% chance (highest inland). Certainly something to keep an eye on in the coming days. && .AVIATION /09Z MONDAY THROUGH FRIDAY/... 18/12z TAF Discussion: KCHS/KJZI/KSAV: Shallow ground fog at all three terminals will quickly dissipate at sunrise. VFR for the period. Gusty winds will occur with the passage of the sea breeze this afternoon. Shallow ground fog will be possible again at all terminals early Tuesday morning. Extended Aviation Outlook: There are no high confidence concerns. && .MARINE... Through Tonight: The synoptic flow regime will change little through tonight as Atlantic high pressure remains centered well offshore. A easterly flow regime will prevail with east to southeast winds 15 kt or less prevailing. Some local enhancement could occur along the land/sea interface and Charleston Harbor this afternoon with sea breeze. Seas will average 2-4 ft. Monday through Friday: No marine concerns are expected. High pressure to the east will drive onshore east-southeasterly flow each day, with wind speeds mostly topping out in the 10-15 knot range. Each afternoon and evening there could be some local enhancement along the land/sea interface with the diurnal sea breeze. Seas should average 2-4 feet through the period. Rip Currents: Influences from the new moon cycle combined with persistent onshore flow will produce an elevated risk of rip currents through midweek. A moderate risk for rip currents is in place for all beaches through Tuesday. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$  903 FXUS66 KLOX 180935 AFDLOX Area Forecast Discussion National Weather Service Los Angeles/Oxnard CA 235 AM PDT Mon May 18 2026 .SYNOPSIS...18/205 AM. Warmer temperatures are expected this week with some locally breezy Santa Ana winds this morning. The warmest day will be Wednesday with slow cooling the rest of the week along with a return of night and morning low clouds and fog. && .SHORT TERM (TDY-WED)...18/205 AM. The marine layer is about 5000 ft deep and marine layer stratus covers much of the csts and vlys of LA and VTA counties. The low clouds should dissipate earlier than normal as the pressure grads shift offshore. There will be a 10 mb offshore trend in the E/W direction and this will help develop a Santa Ana wind event despite not much in the way of actual offshore flow or upper support. Most of the passes and canyons will have gusty NE winds but the advisory level gusts will be confined to the mtns. Almost all of the csts and vlys will see 4 to 8 degrees of warming today with max temps across the csts and vlys in the 70s and lower 80s. There will be weaker offshore flow on Tuesday but it will hinder any attempt of the marine layer to reform with only the Long Beach area vulnerable to morning low clouds. Any canyon winds that do develop in the morning will be well under advisory criteria. The warming trend will continue with 1 to 3 degrees of warming expected across the csts; 3 to 6 degrees in he vlys and 5 to 8 further inland. The inland areas greater warming trend is due to the lack of cool air advection that will occur today. The max temps across the csts/vlys will be 4 to 8 degrees above normal. Wednesday should be a sunny day with little or no marine layer stratus in the morning. It will be the warmest day for the csts and vlys as max temps there will warm another 1 to 3 degrees. Look for mid 70s to lower 80s across the csts and 80s in the vlys. .LONG TERM (THU-SUN)...18/205 AM. Weak upper level flow will be atop of Srn CA for the xtnd period. There will be few if any weather concerns during the period. At the sfc there will be increasing onshore flow each day. By the weekend there will be moderate to strong onshore flow. The marine layer clouds will also increase in coverage and duration every day. By the weekend there will be a strong enough onshore push to the W that will generate gusty near advisory level gusts in the western Antelope Vly and foothills. The increase in onshore flow and marine layer coupled with slowly falling hgts will bring about a 4 day cooling trend. Friday will have the most noticeable cooling of 4 to 6 degrees. By Sunday max temps will be in the mid 60s to mid 70s across the csts and upper 70s and lower 80s in the vlys. These max temps are 1 to 3 degrees blo normal. && .AVIATION...18/0903Z. At 0835Z at KLAX, the marine layer was 5000 ft deep. The top of the inversion was at 6300 ft with a temperature of 11 C. Good confidence in TAFs for KPRB, KSBP, KSBA, KCMA, KPMD and KWJF. Moderate confidence in the remainder of the TAFs as VFR conds could come as early as 12Z depending on the strength of the Santa Ana winds. KLAX...Moderate confidence in TAF. Cigs will vary between 025 and 040. SCT conds could arrive as early as 14Z. There is a 30 percent chc of an 8 kt east wind component 11Z to 15Z. KBUR...Moderate confidence in TAF. Cigs will vary between 025 and 040. SCT conds could arrive as early as 14Z. && .MARINE...18/204 AM. For the Outer Waters, high confidence in current forecast. Tonight through tonight, high confidence in combination of Small Craft Advisory (SCA) level winds and seas. For Tuesday through Friday, winds and seas are expected to remain below SCA levels. For the Inner Waters north of Point Sal, high confidence in current forecast. For this morning, high confidencein a combinations of SCA level winds and seas. From this afternoon through Friday, winds and seas are expected to remain below SCA levels. For the Inner Waters south of Point Conception, high confidence in current forecast. Through Friday, winds and seas are expected to remain below SCA levels. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...Wind Advisory remains in effect from 7 AM this morning to 3 PM PDT this afternoon for zone 88. (See LAXNPWLOX). High Surf Advisory in effect until 9 AM PDT this morning for zones 340-346-354. (See LAXCFWLOX). Beach Hazards Statement in effect until 9 AM PDT this morning for zones 349-350-362-366. (See LAXCFWLOX). Wind Advisory remains in effect until 3 PM PDT this afternoon for zones 375>380. (See LAXNPWLOX). PZ...Small Craft Advisory in effect until 9 AM PDT this morning for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT early this morning for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Tuesday for zone 670. (See LAXMWWLOX). Small Craft Advisory in effect until 9 PM PDT this evening for zones 673-676. (See LAXMWWLOX). && $$ PUBLIC...Rorke AVIATION...Rorke MARINE...RAT SYNOPSIS...LP/MW weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox  961 FXUS61 KRLX 180936 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 536 AM EDT Mon May 18 2026 .WHAT HAS CHANGED... Aviation Forecast Discussion update. 243 AM update... Portions of our northeast mountains have been clipped with a Marginal Risk for strong to severe thunderstorms late this afternoon into this evening, with the bulk of activity streaming into the Pittsburgh, State College, and Baltimore/Washington forecast office areas. && .KEY MESSAGES... 1) Hot temperatures, reminiscent of mid to late summer, takes center stage for the start of the week amid strong upper level height rises. Peak afternoon temperatures reaching the lower 90s Monday and Tuesday could stir up heat impacts to sensitive populations. 2) Low end chances for diurnally driven showers and storms along the mountains late this afternoon. A strong cold front sweeping through the region Wednesday will bring the return of widespread showers and storms, along with relief from the heat. Daily chances for precipitation rounds out the work week into the weekend. && .DISCUSSION... KEY MESSAGE 1... High pressure centered off the Carolina coast will bolster strong upper level height rises for the Central Appalachians the next two days. This will result in peak afternoon temperatures stemming into the upper 80s to low 90s for areas outside of the higher terrain both today and Tuesday. Heat index levels are not anticipated to reach thresholds warranting headlines this week, however temperatures this hot so early in the season could cause heat sensitivity impacts to vulnerable populations. If spending time outdoors the next few days, ensure you adequately hydrate and take frequent breaks from the heat. A mid week cold front will bring relief from this stretch of hot weather, with temperatures returning to their seasonable norms for the second half of the week. Amid this warm spell, temperature records could be neared at a few sites. More details on climate records can be seen in the Climate Section further below. KEY MESSAGE 2... While robust high pressure to our southeast supplies subsidence and resulting dry weather to most of the forecast area today, a few diurnally driven showers and thunderstorms could sprout within afternoon cumulus fields along the northeast mountains. Low end chance POPs were included for our higher mountain zones late in the afternoon into the evening, with the bulk of convection streaming northeastward into neighboring forecast office territories. This notion reflects nicely with the Marginal Risk for severe weather introduced with this morning's Day One outlook issuance from SPC. Dry weather then settles back into the entire forecast area late tonight through much of the day Tuesday. By Tuesday evening, the risk for strong to potentially severe thunderstorms increases as a cold front sweeps through the Ohio Valley. A long corridor stemming from southwest Texas to the Great Lakes region has been placed in a Slight Risk for severe weather on Tuesday, with lessening potential for eastern Ohio into West Virginia as storms encroach amid weakening instability around sunset. Overnight thunderstorm activity is not out of the question as the onset of precipitation overspreads the forecast area Tuesday night, becoming mostly showers by the predawn hours. The frontal boundary will be draped overhead on Wednesday, with chances for strong to severe storms resuming in the afternoon for locations ahead of the front that can achieve some destabilization. The cold front will struggle to make much progress out of the area due to the strength of the Bermuda high. This will cause the boundary to become stagnant across the Carolinas and Mississippi Valley and eventually retreating back to the north late within the valid forecast period. As a result, unsettled weather triumphs for the second half of the work week and into the weekend, with a steady plume of moisture feeding into the region and maintaining daily opportunities for showers and storms. This will bring mostly beneficial rainfall to our drought stricken forecast area. && .AVIATION /09Z MONDAY THROUGH FRIDAY/... Generally quiet flight conditions this morning aside from river valley fog that has formed around EKN. While additional development could occur around CRW before sunrise, all other terminals should remain VFR. Fog erosion will then lead to widespread VFR conditions through the remainder of the valid TAF period. Afternoon southwesterly breezes possible across the area before decoupling late this evening. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY... FORECAST CONFIDENCE: High. ALTERNATE SCENARIOS: Locally dense fog may bounce in and out of EKN and CRW this morning. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE MON 05/18/26 UTC 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18 EDT 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 12Z TUESDAY... No widespread IFR conditions are expected at this time. && .Climate... Forecast / Record High Temperatures -------------------------------------- Mon, 5/18 | Tue, 5/19 | -------------------------------------- CRW | 91 / 92 (1982) | 91 / 95 (1931) | HTS | 90 / 92 (1962) | 90 / 92 (1996) | CKB | 89 / 92 (1962) | 89 / 90 (1959) | PKB | 90 / 95 (1962) | 90 / 90 (1964) | BKW | 85 / 87 (1996) | 85 / 89 (1996) | EKN | 86 / 89 (1911) | 87 / 93 (1996) | -------------------------------------- && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ DISCUSSION...05 AVIATION...05 CLIMATE...05  965 FXUS65 KPSR 180937 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 237 AM MST Mon May 18 2026 .KEY MESSAGES... - A Wind Advisory remains in effect through 11 AM for portions of Southeast California for strong northerly post-frontal winds. - Coolest temperatures over the next week and beyond are expected today, with high temperatures 4 to 7 degrees below normal, before slowly warming back up and nearing 100 degree highs again this weekend. - Daily dry conditions, with no threat of rain, and seasonal afternoon breeziness are expected through the next 7 days. && .SHORT TERM /TODAY THROUGH TUESDAY/... A potent shortwave trough was seen moving eastward through UT early this morning with a southward and southeastward moving cold front through AZ and SoCal. Strong northerly winds and widespread lofted dust were observed post-front in San Bernardino County. The cold front will continue dropping south through southeast CA and southwest AZ early this morning, with strong northerly post- frontal winds expected through mid-morning. A Wind Advisory is in effect for eastern Riverside and northeast Imperial Counties through 11 AM PDT/MST this morning with northerly gusts up to 35-50 mph expected. Latest HREF shows strongest 850mb winds (>40 mph) occurring through around 3-5 AM PDT/MST this morning. During this time is when the greatest impacts - primarily northerly crosswinds across I-10 and localized blowing dust - are anticipated. While the gradient wind is expected to weaken around the sunrise hours, some areas may see northerly wind gusts pick back up for a few hours after sunrise due to mixing. Otherwise, winds should gradually subside across southeast CA and southwest AZ heading into late-morning and the afternoon. Hazy skies should become evident after sunrise this morning, with all the lofted dust across CA and NV, especially across southeast CA and southwest AZ. Hi-res models depict the cold front stalling out across south- central AZ toward sunrise and mid-morning. So, south-central AZ is not expected to experience any of the strong northerly and northwesterly post-frontal winds. There will still be some breezy southwest winds though late morning and this afternoon, mostly gusting up to 15-30 mph. A narrow band of low level moisture and forcing along and ahead of the front will lead to some lower clouds this morning across south-central AZ, including the Phoenix area, and a few hi-res models still support a brief sprinkle shower. So, a few drops falling in the morning, after sunrise cannot be ruled out, but do not expect any measurable rain. The dip in 500mb heights over the area and push of cooler air from the north will result in cooler surface temperatures today, with below normal high temperatures expected across the region. Highs this afternoon are forecast to mostly be in the 80s across the lower deserts, with only 10-20% chances of reaching 90F in places like Phoenix and Yuma. Heading into tomorrow, the potent trough will have left the region, ejecting through the Plains, but another trailing weak shortwave will follow and keep a large-scale trough pattern in place across the Desert Southwest. This will keep temperatures from rapidly warming back up and while they will warm up from today, highs tomorrow are still forecast to come up shy of daily normals. Most lower deserts will top out with highs in the lower 90s. Winds tomorrow will be even lighter than today for most areas. Although, with the trailing shortwave there will be another enhancement to northerly winds down the Colorado River and southeast CA, with peak wind gusts as high as 20-30 mph in the morning through midday. The lagging shortwave will also help draw scattered high clouds into the Desert Southwest through the day. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Through the rest of the week, global ensembles depict a lasting weak longwave trough pattern across the Desert South, with neutral height anomalies and no significant shortwaves rolling through the region. This will translate to rather seasonal weather conditions, but with a slow day-to-day warming trend. High temperatures are forecast to be near normal through the end of the work week - highs in the middle to upper 90s. Meanwhile morning lows are expected to be near to slightly below normal, largely due to dry air/low humidity and limited cloud cover. It is not until the weekend when odds of high temperatures reaching the 100 degree mark spikes back up to around 30-60%, as the longwave trough across the Desert Southwest breaks down. Conditions will remain dry through this weekend, with no threat of rain, and seasonal wind patterns are expected, with light winds through the overnight and morning hours and afternoon upslope breezes up to 15-25 mph. && .AVIATION...Updated at 0540Z. South Central Arizona including KPHX, KIWA, KSDL, and KDVT: The main aviation concerns will be a brief period of lower clouds (04-05 kft AGL) tomorrow morning. SW winds with around 8-13 kt will continue into the overnight hours. There is still low confidence in winds going SE during the overnight hours and may be more southerly. This shift is expected between 09-11Z. A early shift to SW winds is expected by 14-15Z, with winds picking up speed into the teens during the afternoon. Some occasional gusts into the upper teens are possible during the afternoon and early evening hours. FEW high clouds will gradually move out overnight, with FEW- SCT CU as low as 4-5 kft AGL expected to develop around sunrise, but are only expected to last for a few hours. Then mostly clear skies are expected for the remainder of the TAF period. Southeast California/Southwest Arizona including KIPL and KBLH: Periods of gusty winds will be the main aviation weather concerns throughout the TAF period. At KIPL, wind gusts of 20-25 kts will continue over the next couple hours before decreasing to around 10-15 kt. At KBLH, SW winds with speeds of 10-15 kt will continue for the next couple hours. A cold front will enter the area from the N-NW and switch winds abruptly at KBLH overnight (around 08-09Z) and at KIPL (around 13Z) early tomorrow morning. Brief visibility restrictions, due to blowing/lofted dust, will be possible initially at KBLH as the cold front moves through the area. Winds at both terminals will then remain out of the N-NW for the remainder of the TAF period. Gusts of 20-25 kt are expected at KBLH from the early morning through the early evening. FEW high clouds will clear out overnight with mostly clear skies expected the rest of the TAF period. && .FIRE WEATHER... Elevated and marginally critical fire weather conditions are expected early this morning across portions of southeast CA as a result of strong northerly winds and dry air following a frontal passage. Conditions will improve by late-morning/early-afternoon as northerly winds subside. Elsewhere today, winds will be lighter, but still with peak southwesterly gusts up to 15-30 mph across south-central AZ. Minimum RH values today will be around 5-10% across western districts to 15-25% across eastern districts. Temperatures will be coolest, and below normal, today, which will result lower max mixing heights (up to 6-8K ft above ground level). Temperatures will slowly warm through the end of the week, but remain near seasonal level, and conditions will remain dry. Daily minimum RH values will be around 5-15% each day after today with poor to fair overnight recoveries at 25-50%. After today seasonal wind patterns are expected through the rest of the week, with afternoon upslope breezes up to 15-25 mph and the only exception being another brief enhanced northerly wind down the Colorado River tomorrow morning. There is no rain in the forecast through this weekend. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...Wind Advisory until 11 AM PDT Monday for CAZ560-561-564-568>570. && $$ SHORT TERM...Benedict LONG TERM...Benedict AVIATION...Berislavich FIRE WEATHER...Benedict  162 FXUS66 KPQR 180941 AFDPQR Area Forecast Discussion National Weather Service Portland OR 240 AM PDT Mon May 18 2026 .SYNOPSIS...Dry and benign weather is expected across the region through much of the next week as high pressure builds over the Northeast Pacific, bringing a warming trend. Weak systems aloft may bring enhanced cloud cover on some days, but rain chances are minimal. && .DISCUSSION...Now through Sunday...A weak upper level disturbance passing over the region this morning will maintain high level clouds through late morning, before skies become mostly sunny this afternoon. Concerns for hazardous weather remain minimal through the next week. There is high confidence that upper-level ridging and surface high pressure will build over the Northeast Pacific, with increasing uncertainty in the amplitude and position of the upper ridge later in the forecast. Early in the period, while the ridge is centered well offshore, upper shortwaves within northwesterly flow aloft may produce increased cloud cover, but chances for rainfall remain 5% or less through the middle of the week. On clearer nights, areas of fog are most likely to develop within sheltered valleys. As the ridge axis shifts east, temperatures will trend upward through at least Thursday, reaching the 60s along the coast and upper 70s to around 80 degrees along the I-5 corridor. Later in the forecast period, uncertainty in the evolution and possible break-down of upper-level ridging introduces a similar uncertainty in forecast temperatures. Highs are most likely to continue in the 60s to mid 70s, but the spread of possible outcomes becomes wider: chances of reaching 80 degrees along the I-5 corridor are generally 15-45% Friday and Saturday, but there are also 10-25% chances of remaining below 70 degrees. The next opportunity for widespread rain holds off until late next weekend when there is greater consensus that the ridge breaks down. 36/DH && .AVIATION...A weak upper level disturbance is pushing high clouds across the area this morning within the northwest flow aloft. Marine stratus with MVFR CIGs near KAST is expected to persist through 18z this morning. Elsewhere, predominately VFR conditions are expected through at least 03-06z Tuesday. Though, there remains low chances (10-20%) for MVFR stratus to back build off the Cascades toward inland terminals, except 20-30% at KTTD, between 12-18z this morning. Chances for MVFR stratus increase again near KAST after 03z Tue, and at northern inland terminals after 06z. Light north to northwesterly winds again expected to become breezy this afternoon. KPDX AND APPROACHES...VFR conditions expected through at least 06z Tuesday, though there remains a 10-20% chance for MVFR stratus between 12-18z this morning. High clouds expected to clear out this afternoon. Light northwest winds expected to increase to 8-10 kt by 22z this afternoon. /DH && .MARINE...Northerlies are expected to persist through much of the week as the summer-like pattern settles in. Strongest winds are expected during the afternoon and evening periods as a surface thermal trough strengthens over the southern Oregon coast. A Small Craft Advisory has been issued for the inner coastal waters south of Cape Foulweather later this afternoon into this evening for gusts up to 25 kt. Similar conditions are expected on Tuesday. Seas around 6 to 8 feet are expected through the week as well. Small Craft Advisories are in place for the Columbia River Bar early this morning, and again early Tuesday morning, for strong ebb currents which will produce hazardous conditions to small craft. Strong ebb currents are possible during the morning hours each day this week. /DH && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory until8 AM PDT this morning for PZZ210. Small Craft Advisory from 5 AM to 9 AM PDT Tuesday for PZZ210. Small Craft Advisory from 2 PM this afternoon to 11 PM PDT this evening for PZZ253. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland  190 FXUS63 KEAX 180942 AFDEAX Area Forecast Discussion National Weather Service Kansas City/Pleasant Hill MO 442 AM CDT Mon May 18 2026 .KEY MESSAGES... - Showers and thunderstorms continue across the region this morning, with locally moderate to heavy rainfall possible. - Severe thunderstorms are likely late afternoon into late tonight. - Far NW Missouri and NE Kansas will be under the greatest threat for all severe hazards by late afternoon and early evening. - Storms should congeal into a line of thunderstorms by this evening, and move east southeast through the region late tonight. Once this occurs, damaging wind gusts should become the primary hazard, but a few brief tornadoes may be possible. - Moderate to heavy rain will be possible again with the storms tonight. A flood watch is in effect through almost the entire CWA through 7 AM Tuesday. - Cooler temperatures arrive for Tuesday through Thursday before heating up once more by this weekend. && .DISCUSSION... Issued at 331 AM CDT Mon May 18 2026 A mature mesoscale convective system (MCS) is moving through the CWA this early morning, with a few sporadic 50 to 60 mph wind gusts as well as relatively widespread 1+ inches of rain (isolated pockets have received a bit over 2"). The leading convective portion of the MCS will continue to move off to the east southeast through the next few hours, with CAM guidance suggesting convection stalling out toward the northern edge of the Ozark Plateau by later this morning and continuing into the afternoon hours. With around 1.8 to 1.9" PWATs in this region and the potential for a prolonged period of moderate rainfall, WPC has upgraded the new Day 1 excessive rainfall outlook to a moderate for Linn County KS into Bates and Henry County MO (although 00z SPC HREF guidance keeps the corridor of heaviest rainfall just south of our CWA toward the Lake of the Ozarks and surrounding areas). Attention then turns to the severe and heavy rainfall threat later tonight as the mid/upper trough moves out of the Four Corner regions and ejects across the Central Plains this afternoon and evening with strengthening WSW deep layer flow overspreading the region. Recent CAM guidance suggests that convective initiation should occur by mid to late afternoon along the stalled or slow moving northeast to southwest oriented front across western IA into SE Nebraska and NE Kansas within an environment characterized by moderate to high instability and 40+ knots of deep layer shear. The window for discrete storms will likely be fairly small as deep layer shear vectors are generally parallel to the front, allowing for upscale growth into clusters or line segments. The greatest threat for all severe hazards will be late afternoon/early evening across far NW Missouri (Atchison, Holt, and Nodaway) and NE Kansas (Doniphan) where storms could remain relatively discrete initially. A well developed line is projected to develop along the front by later this evening across NW Missouri into NE Kansas, moving to the east southeast through the late evening hours into late tonight, at which point severe wind gusts should become the primary hazard, although with strong low level bulk shear there will be a threat for QLCS mesovortices, especially considering CAM guidance suggests the potential for bowing segments tonight. In addition to the severe threat, locally moderate to heavy rainfall will be possible yet again with PWAT values ranging from 1.6 to 2". Due to the threat for heavy rainfall this morning and again late tonight, have decided to expand the flood watch to almost the entire CWA through 7 AM Tuesday morning. Cooler temperatures and much more comfortable dew points are expected for Tuesday through Thursday, with daily afternoon highs in themid to upper 60s. There will be a 40 to 50% chance for showers and storms Thursday afternoon and evening, but severe weather is not anticipated. Warmer temperatures and increasing moisture return should arrive by Friday and into the weekend. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 139 AM CDT Mon May 18 2026 A mesoscale convective system (MCS) is moving through the region this early morning, with showers and thunderstorms likely to continue at the terminals through 12z to 14z this morning. Another round of thunderstorms is likely to impact STJ starting around 2z Tuesday and the KC metro terminals by around 4z Tuesday. VFR conditions (broken cloud deck around 4 kft) should generally continue through most of the period, but brief periods of MVFR CIGs will be possible as well as MVFR VIS during periods of heavier rain. Winds will briefly turn northerly with the MCS moving through, but should return to southerly within a few hours, with sustained winds on the order of 15 to 20 knots and gusts up to 30 knots. && .EAX WATCHES/WARNINGS/ADVISORIES... MO...Flood Watch through Tuesday morning for MOZ001>007-011>016- 020>024-028>032-037>040-043>046-053-054. KS...Flood Watch through Tuesday morning for KSZ025-057-060-102>105. && $$ DISCUSSION...WFO EAX AVIATION...BMW