FXUS64 KTSA 190440 AFDTSA Area Forecast Discussion National Weather Service Tulsa OK 1140 PM CDT Mon May 18 2026 ...New SHORT TERM, LONG TERM... .KEY MESSAGES... Updated at 1140 PM CDT Mon May 18 2026 - Severe Thunderstorm Watch in effect for portions of NE OK, near the OK/KS border until 7 AM. Damaging wind gusts will be the main severe hazard. - Numerous showers and storms Tuesday morning into NE OK spreading southward through early afternoon. Severe weather possible along with locally heavy rainfall. - Cooler temperatures Wednesday-Friday with continued low to medium rain chances through the remainder of the week. && .SHORT TERM... (Through Tuesday Night) Issued at 1140 PM CDT Mon May 18 2026 A line of strong and severe thunderstorms has formed across southeast KS, along a southeast-advancing cold front that is currently on the doorstep of the forecast area. The line of convection has produced a distinct outflow boundary that has pushed well ahead of the squall line. As long as this stays true, it will keep any tornado threat just about at zero. Main severe hazard with this line of storms will be damaging wind gusts, with isolated large hail embedded. A Severe Thunderstorm Watch is in effect for Pawnee, Osage, Washington (OK), Nowata, Craig, and Ottawa counties until 7 AM. The line is forecast to reach the I-44 corridor right around sunrise Tuesday, give/take an hour. Latest consensus in CAMs show some weakening of the line as it moves southeast of I-44, though pockets of strong and severe storms will still be possible as the line becomes more diffused. As it moves into southeast OK late in the morning and into the afternoon, the combination of daytime heating and existing outflow boundaries may cause re-intensification in the line; damaging winds would be the main threat if anything severe develops. The severe threat will shift south and east of the area by mid- afternoon, with lingering light to moderate stratiform rain lingering mainly across southeast OK and northwest AR through the remainder of the afternoon. Overall, rainfall amounts will vary from half an inch to around an inch. A few locations may have amounts closer to two inches with pockets of intense cores embedded in the line. Southwest flow aloft with maintain itself through the daytime and evening on Tuesday. Additional scattered showers and thunderstorms are anticipated to develop along the 925-850mb frontal boundary late Tuesday afternoon and evening, mainly across northeast OK and northwest AR. Severe thunderstorms are not expected, but an additional rainfall amount up to half an inch will be possible. Precipitation chances will continue through the end of the short- term period. Substantially cooler temperatures will follow the cold front overnight tonight and during the day Tuesday, with temperatures falling into the 60s and lower 70s immediately behind the front. Temperatures across southeast OK and northwest AR could reach the lower 80s in the afternoon prior to the frontal passage. The front will exit the forecast area sometime around sunset. Cloud coverage should stay thick through Tuesday night and should keep temperatures from plummeting overnight. Regardless, overnight lows will drop into the 50s and 60s by sunrise Wednesday. Mejia && .LONG TERM... (Wednesday through Monday) Issued at 1140 PM CDT Mon May 18 2026 Consensus in model guidance continues to show a series of passing mid/upper-level waves through the remainder of the week, through this upcoming weekend, and even into early next week. As such, there will be daily chances of showers and thunderstorms through the long-term period. At this time, flow aloft is expected to be fairly light and not very supportive of severe weather through at least Thursday and much of Friday. However, PWATs are expected to remain abnormally high through the period and the upper-level waves will likely produce periods of moderate to heavy rainfall at times. One possible instance of heavy rainfall will occur Thursday afternoon/evening and into Thursday night as a couple of shortwaves combine over the area. Another instance of heavy rain is forecast to occur Friday night into Saturday morning as a more potent trough passes to the north of the area. Instability and shear will become a little more defined and a limited severe threat may develop Friday evening/night as storms are expected to initiate off a dryline in western OK Friday afternoon and push eastward into the region later. Better details on timing and severity will come in later days. An active pattern will persist Sunday and Monday, with isolated to scattered precipitation chances each day. Northerly winds and cloud cover (with precipitation chances) will keep temperatures below average through Thursday. Temperatures climb back near seasonal average by Friday before climbing above average by late in the weekend or early next week. Mejia && .AVIATION... (00Z TAFS) Issued at 635 PM CDT Mon May 18 2026 VFR conditions will prevail this evening, with LLWS at all sites until the arrival of a cold front late tonight and Tuesday morning. A line of thunderstorms is expected to accompany the cold front, with reduced ceilings and visibilities and gusty winds. Gusty south winds ahead of the cold front will become north Tuesday, with gusts up to 20 knots through the day. MVFR ceilings will prevail through the day Tuesday following the passage of the cold front. && .PRELIMINARY POINT TEMPS/POPS... TUL 87 67 72 57 / 20 70 70 70 FSM 89 72 79 66 / 20 20 90 50 MLC 88 73 77 62 / 10 30 80 50 BVO 87 61 66 52 / 20 80 40 70 FYV 85 72 77 62 / 40 30 80 60 BYV 85 72 77 60 / 30 30 90 70 MKO 86 71 75 59 / 20 30 90 60 MIO 86 67 72 55 / 40 70 80 80 F10 88 70 75 57 / 20 30 80 60 HHW 87 73 78 65 / 20 30 90 50 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && $$ SHORT TERM...67 LONG TERM....67 AVIATION...05