200 FXUS65 KPUB 131107 AFDPUB Area Forecast Discussion National Weather Service Pueblo CO 407 AM MST Thu Feb 13 2025 .KEY MESSAGES... - Critical fire weather conditions are likely across the San Luis Valley today, where a Red Flag Warning has been issued from 11 AM through 6 PM. - Snow moves in over the high country through the afternoon and evening hours, with snowfall rates increasing drastically after sunset. Winter Weather highlights go into effect at 8 PM this evening. - Heavy wind driven snow continues for the mountains Friday and Saturday with heaviest falling across the eastern San Juans through Friday. - Damaging winds possible southern I-25 corridor late tonight into Friday afternoon. && .SHORT TERM /THROUGH TONIGHT/... Issued at 303 AM MST Thu Feb 13 2025 Wind chills are in the teens to low twenties below zero across our plains. As of 3 AM, La Junta`s wind chill is at -20F. Temperatures are in the single digits below zero across our plains, with some of our mountain valleys and higher terrain locations still near and just above zero. Alamosa is actually one of our warmest spots on the map early the morning, which is not typical for them this time of year. They are sitting at +10F as of 2 AM! Skies are clear for most areas, with some lingering scattered lower decks still persisting over El Paso and northern Pueblo counties thanks to continued weak upslope. Dewpoints are in the single digits and low teens below zero. The San Luis Valley is experiencing poor overnight humidity recoveries, with most locations still seeing relative humidity values around the 40% range early this morning. This will set the stage for critical fire weather conditions across the Valley today. Today.. Brutally cold temperatures stick around through the early morning, but we begin to warm quickly under sunny skies. Cold Weather Advisories are valid through 8 AM across portions of our plains. Our flow aloft transitions from northwesterly this morning to southwesterly by this afternoon, as our next system approaches from the west. This will mean increasing temperatures for most areas, especially for locations south of highway 50, where southwesterly downsloping winds will kick in earlier in the day. Mostly clear skies are expected on our plains, with highs ranging from 40s across our southern plains, to 30s further north. Mountain valleys will also warm into the 40s, but will be windy today, especially across the San Luis Valley. Minimum relative humidity values also look to drop into the low teens across the valley through much of the afternoon. The combination of low humidities, gusty winds, and dry fuels will lead to critical fire weather concerns across the San Luis Valley this afternoon. For this reason, a Red Flag Warning was issued valid through 6 PM. The good news is that humidity values increase rapidly through the evening, as our next system begins to usher in beneficial moisture to the region. Snow showers look to kick off over the San Juans, La Garitas, and western Sawatch Mountains through the late afternoon and early evening hours. Tonight.. As the upper-level trough makes it`s way into the Great Basin late tonight into Friday morning, snowfall rates increase drastically over the high country. The heaviest snowfall looks to fall in the early morning hours of Friday over the San Juans, with snow chances spreading eastward across the high country through the night. Winds also increase tonight, with gusts in excess of 60 mph possible over the higher terrain, and gusts in excess of 50 mph over lower elevations. Cross-sections show the potential for inverse shear across our southern mountains after midnight tonight, though strongest jet support remains off to our south through this timeframe. For this reason, went with a high wind watch for now, and just for Huerfano and Las Animas Counties. This may need to be expanded in time or space at a later time as models come into better agreement with the setup for potential mountain wave early tomorrow morning. Overnight lows will remain cooler than normal for areas along and north of highway 50, and will be a bit warmer, with temperatures generally in the upper 20s and low 30s further south where winds remain elevated. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Issued at 303 AM MST Thu Feb 13 2025 Southwest flow increases on Friday with heavy snow continuing across the Continental Divide, spilling over into the western slopes and higher peaks of the Sangre De Cristo range through the day. Have hoisted Winter Weather Advisories and warnings for most of the mountains, though most of the moisture will get wrung out before impacting the Wets and Pikes Peak and Rampart Range. Southwest to westerly orographic flow through this event will be most favorable for the eastern San Juan mountains where 1 to 2 feet with locally higher amounts will be possible. Higher crests of the La Garitas, the Sawatch range and the higher Sangre De Cristo mountains will see a foot or more with considerable wind driven snow expected. Some moderate snow accumulations will be possible over the lower sangres Friday into Friday night but this should stay mainly confined to the west facing slopes and higher passes. Have opted for Winter Weather Advisories for these lower areas...though should see a tight gradient in snowfall amounts down the eastern slopes given strong downslope flow. Remainder of the valleys could see up to an inch as showers spill off the adjacent higher terrain. Otherwise it will remain dry and windy for the plains on Friday which will allow temperatures to rebound into the 50s to lower 60s. Cross sections show a brief mountain wave signature possible across the southern I-25 corridor early Friday morning from Colorado City to the Raton Pass before deep mixing takes over with the trough passage. Any showers moving off the mountains into the adjacent lower elevations may also help with higher level momentum transport, bringing the potential for wind gusts in excess of 60 mph into the lower elevations. HREF shows up to 70 percent probabilities for high winds greater than 58 mph spreading into portions of Huerfano and western Las Animas counties, which maximize overnight into Friday morning. Have hoisted high wind watches for this area. Otherwise, could see gusts up to 50 mph across the southern San Luis Valley and southern plains south of highway 50 during the day as the surface low deepens and pushes eastward into KS during the afternoon. Cold front drops south through the plains Friday evening with snow showers possible along and behind it into Saturday. Doesn`t look like a heavy event but could see some half inch to 1.5 inch amounts as winds shift around from the east on Saturday providing some shallow upslope in and near the mountains. Highest of these snow totals will fall across the Palmer Divide. Central mountains will continue to pick up snow on Saturday as another impulse in more favorable northwesterly orographic flow translates across the region. Temperatures will be cooler all areas. Precipitation ends Saturday night with dry and warmer conditions returning for Sunday and Monday as flow aloft transitions back to westerly ahead of the next system dropping in from the Pacific Northwest. Monday will be the warmest day ahead of another cold front which will move through the area Monday night. Cold and light snow may revisit the region for mid week as an arctic airmass gets driven south through the norther/central plains. Long range models differ with how far west the cold air gets in CO...with EC the coldest and GFS the warmest. National Model Blends definitely lean warm and dropped temperatures back several degrees through mid week. If the EC cluster verifies, may need to cool high temperatures off even more. -KT && .AVIATION /12Z TAFS THROUGH 12Z FRIDAY/... Issued at 406 AM MST Thu Feb 13 2025 For KCOS and KPUB..VFR conditions are expected at both TAF sites through the next 24 hours. Clear skies persist through the beginning of the period, with mid and upper-level cloud cover moving in generally after 18Z. Winds look to remain light and mostly easterly through the day today, with a transition back to westerly overnight for KPUB tonight. For KALS..VFR conditions persist through around 03Z this evening, before chances for vicinity snow showers and the potential for lowered ceilings begin to encroach on the station. Chances increase after 18Z, so have left mention on snow on station out of the TAF until that timeframe. South winds gusting in excess of 20kt remain in place through the overnight hours, which will lead to blowing snow tonight and early tomorrow morning. Ceilings and visibilities will likely come in lower for the next period as chances for snow on station increase through Friday.. && .PUB WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 8 PM this evening to 5 PM MST Saturday for COZ058-059-061-064-072-074. Winter Storm Warning from 8 PM this evening to 5 PM MST Saturday for COZ060-066>068-073-075. Red Flag Warning from 11 AM this morning to 6 PM MST this evening for COZ224. Cold Weather Advisory until 8 AM MST this morning for COZ084>086-089-093>099. High Wind Watch from this evening through Friday afternoon for COZ087-088. && $$ SHORT TERM...EHR LONG TERM...KT AVIATION...EHR