FXUS65 KPUB 180457 AFDPUB Area Forecast Discussion National Weather Service Pueblo CO 1057 PM MDT Sun May 17 2026 .KEY MESSAGES... - Strong to severe thunderstorms possible northern portions of the southeast plains this afternoon and evening - Critical fire weather conditions continue this evening for the SE mtns/southern plains and return along the southern CO border on Monday with conditions getting close to PDS Red Flag Warning criteria across Baca county - Strong winds southern areas on Monday with blowing dust and a low end chance of high wind criteria for the San Luis Valley and southern I-25 corridor - Snow late tonight through Monday for the Continental Divide mountains and Pikes Peak region with some light accumulations possible - Frost or Freeze possible for the southeast plains Monday night, especially El Paso and Kiowa counties && .UPDATE... Issued at 902 PM MDT Sun May 17 2026 Update to allow today's Red Flag Warning to expire as scheduled. Winds have begun to weaken and have turned northeasterly across much of the warned area. This will continue to help humidity values to improve through the rest of this evening. The warning was allowed to expire as scheduled. && .SHORT TERM /THROUGH TONIGHT/... Issued at 141 PM MDT Sun May 17 2026 Southwest winds continue to increase across southern portions of the forecast area this afternoon with critical fire weather conditions being met along the southern I-25 corridor. Models have trended farther south with the retreating cold front across the southeast plains which calls into question whether Red Flag conditions will materialize across northeast portions of the Red Flag Warning area. Given HREF is still showing around a 30-50% chance of criteria being met across western and southern portions of Kiowa County, have opted to keep the Red Flag Warning intact for now. There may also be some dry lightning and gusty outflows from thunderstorms that could also cause issues across northern sections. Meanwhile, with the digging upper trough out west, and at least some displacement of the frontal boundary back northward, CAMS still suggest best potential for severe thunderstorms this afternoon and evening will be across El Paso county. NAMNest does kick off a couple cells across our far eastern counties which race off to the northeast and diminish, so can't really rule out an isolated severe storm north of highway 50, though cap is holding things at bay farther east for the time being. CAPE up to 1000 J/kg and deep layer shears around 50 kts suggest hail up to around 1 inch and wind gusts up to 60 mph will be the primary risks, with LCLs looking a little high and low level helicity not as great as farther north and east. Will need to monitor the northern portions of the southeast plains closely, as storms could get stronger if they can develop. Right now, the threat looks too conditional. Front surges back into the southeast plains tonight enhanced by thunderstorm outflows to the north. There could be some showers and isolated strong thunderstorms along the boundary with some elevated CAPE, but overall CAMS are not too enthused with this potential even though pattern recognition suggests some low end potential. After midnight, winds begin to shift around from the east with low clouds, stratus and stratiform rain developing along the eastern slopes of the southeast mountains and Pikes Peak region towards morning. Closed low across southern UT fills and lifts out across northwest CO on Monday putting southern CO under the windy sector across the interior valleys and southern portions of the southeast plains. Challenge will be how far north will the front mix as the lee side surface low ejects from northeast NM into southwest KS. Consensus of HREF members is to keep the Red Flag conditions tied to the southern-most border counties with any northward push to the front being defeated by reinforced cooling from precipitation as the system cross the mountains into the adjacent plains. Humidities could get very low across Baca county and we are flirting with PDS Red Flag Criteria. The ingredient coming up short is the winds, with gusts not quite making the 55 mph threshold. 12z HREF probabilities of this are 0%, while QMD NBM only shows up to 20%. So have hoisted Red Flags for now and will let later shifts upgrade Baca to a PDS Red Flag if later runs support this. None the less, extreme fire danger will be in place on Monday across Baca county which will make control of any wildfires extremely difficult. Also concerned about near high wind criteria and blowing dust across the San Luis Valley. NBM shows this but none of the HREF members or the HREF probabilities depict above 0% chance of 58 mph wind gusts. It could get close as the trough axis passes by and downward forcing maximizes. Timing for this is around 16z (10 AM mountain time) for the San Luis Valley. This may loft some dust and reduce visibilities. Any showers that survive as they push off the higher terrain to the west could goose winds up further and result in some locally intense blowing dust. Will need to keep an eye on this for potential Dust Storm Warnings Monday morning. Wind gusts up to 55 mph may spread into the southern I-25 corridor (where humidity levels stay above the Red Flag PDS threshold of 9%) but again, 12z HREF probs for high winds (58 mph or greater) remains around 0% and even NBM probs are 10% or less. So no high wind highlights look necessary at this point but will be re-assessed with next suite of model runs. To the north of the frontal boundary across the plains it will be a cool day with a cloudy start, and clouds may not clear out of El Paso county until late in the day. Stability behind the front on the plains will be high, so any convection that develops over the mountains will likely push eastward and diminish as the forcing from the system lifts off to the northeast. && .LONG TERM /MONDAY THROUGH SUNDAY/... Issued at 141 PM MDT Sun May 17 2026 Once the trough passes by, the cold front will drop through all of the plains again bringing better humidity recovery and much cooler temperatures. In fact, most of the southeast plains may be vulnerable to a frost or freeze late Monday night into Tuesday morning. Northern sections are more likely and have issued Freeze Watches for El Paso and Kiowa counties. Farther south some lingering low clouds may help keep temperatures just above freezing though any partial clearing may leave some areas vulnerable to frost potential. Otherwise cool upslope flow will continue on Tuesday across the plains. Instability develops over the mountains for some isolated to scattered afternoon showers and thunderstorms but these will diminish quickly as they move off into the more stable airmass east of the mountains. More troughing out west moves across CO on Wednesday ramping up precipitation chances across the southeast mountains and plains Wed afternoon and night as the better forcing moves across. Active northwest flow continues through the rest of the week with daily shower and thunderstorm chances across the area. Another drying trend sets in for next weekend as we get some minor ridging and the northern stream storm track shifts northward a bit. Temperatures will climb back into the 80s to near 90 across the plains for next weekend though winds remain fairly light. -KT .Aviation... Gusty southerly winds will pick up at all three terminals this afternoon with directions more southeasterly initially at KCOS and KPUB and more southwesterly at KALS. Wind gusts up to 30 to 35 kts will be possible this afternoon. -TSRA will be possible in and near KCOS which could erratic wind directions from thunderstorm outflows in the afternoon with gusts up to 40 kts possible. This will reinforce a cold front which will drop southward bringing strong north to northeast winds into both KCOS and KPUB between 01-02z. Gusts up to 40 kts will be possible. Meanwhile, winds will gradually slacken off at KALS during the evening hours but settle from a southerly direction around 10-15 kts most of the night. Stratus will fill in rapidly at KCOS and KPUB around 06z with -SHRA and BR possible after 08z as cigs drop into the IFR category. Once winds shift from the southeast, KCOS could see LIFR conditions develop and persist through the tail end of the valid TAF period. KALS will see winds pick up around 13Z from the south to southwest. Gusts up to 45 kts will be possible with restrictions to vis possible in BLDU Monday morning. -KT && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 1056 PM MDT Sun May 17 2026 KCOS and KPUB: MVFR to IFR conditions are expected through the majority of this TAF period due to lowered ceiling heights. With that said though, both KCOS and KPUB, but especially KPUB, will have a period of VFR condition ceiling heights during Monday afternoon. Looking at winds, they are expected to remain around and less than 10 knots tonight, though will quickly increase heading into the late morning and early afternoon hours as a potent storm system swings over the region. Winds are expected to remain elevated then into Monday evening, though will slowly start to lessen in magnitude. Otherwise, dry conditions are expected tonight, though KCOS may experience drizzle to light rain as upslope winds develop. Then during the early afternoon hours, a band of showers and thunderstorms is expected to push eastward off of the higher terrain and across the TAF sites, bringing periods of lower visibility. KALS: VFR conditions are expected over the next 24 hours, though a brief period of MVFR conditions will be possible Monday morning into the afternoon hours due to blowing dust within the San Luis Valley. Looking at winds, they will remain around 10-13 knots tonight, and increase quickly early Monday morning as a potent storm system passes over. In addition, showers may push eastward off the higher terrain and across the San Luis Valley, and a shower impacting the TAF site can not be ruled out. Otherwise, dry conditions will prevail, with mid to high level clouds persisting into Monday afternoon, and then starting to clear Monday evening. && .FIRE WEATHER... Issued at 141 PM MDT Sun May 17 2026 Near PDS Red Flag criteria will be possible Monday across Baca county where humidity levels will approach 6%. Winds may come up shy of the 55 mph gusts needed for criteria to be met, with most models suggesting 50 mph may be the top wind gusts for this event. Regardless, the combination of dry fuels, and windy and dry conditions will lead to a period of Extreme Fire Weather conditions until the front brings better humidity recoveries back into the area between 6 PM and 9 PM Monday evening. A sharp wind shift from the north with gusts up to 40 mph will accompany the front Monday evening. Las Animas will also see strong winds and low humidity but humidity levels will not be as low, staying around 15% near the mountains where the stronger gusts up to 55 mph will be possible around mid day. Blowing dust and poor visibility will be a concern for both areas once the winds kick up. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... Freeze Watch from late Monday night through Tuesday morning for COZ084-085-095-096. Red Flag Warning from 11 AM to 8 PM MDT Monday for COZ230-233- 237. && $$ UPDATE...EHR SHORT TERM...KT LONG TERM...KT AVIATION...SIMCOE FIRE WEATHER...KT