Area Forecast Discussion
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
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957 FXUS65 KPUB 191025 AFDPUB Area Forecast Discussion National Weather Service Pueblo CO 425 AM MDT Thu Sep 19 2024 .KEY MESSAGES... - Another dry day with frost possible again in the San Luis Valley tonight. - Warm and breezy conditions for Friday, with spotty critical fire weather conditions and isolated convection across the plains. - High confidence (70-90%) in a cool and wet weekend with widespread rain and mountain snow likely Saturday through early Sunday. - Lower confidence (10-20 percent) in stronger storms across the SE Plains on Saturday. && .SHORT TERM /THROUGH TONIGHT/... Issued at 421 AM MDT Thu Sep 19 2024 Cool front is dropping southward through the plains, evident in area radars early this morning. This will bring some minor cooling (perhaps a degree or two cooler than yesterday) across the plains as winds shift out of the east then southeast by afternoon. Out west, little change is expected from yesterday with dry and warm fall temperatures returning. Winds will become breezy in the afternoon, especially in and near the mountains, but gusts overall should stay under 25 mph which should limit any critical fire weather concerns in spite of low afternoon humidity values across the lower elevations. There will be a wave of high cloudiness lifting northward across the area this afternoon and evening, but the forecast area will remain dry. Clear skies overnight tonight will lead to another crisp fall morning across southern CO, especially mountain valleys. We could see another frost for the San Luis Valley, but with Frost Advisories already in effect this morning, will let later shifts issue additional headlines if necessary. -KT && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Issued at 421 AM MDT Thu Sep 19 2024 Friday-Friday night...Latest models are in good agreement on slowly increasing southwest flow aloft across the Rockies through the day on Friday, as a seasonably strong upper low digs across the West Coast and into Western Arizona by 00Z Saturday, which is a tad slower and a tad further west than was forecasted 24 hours ago. Southwest flow induces lee troughing across the plains on Friday, with breezy south to southwest winds again leading to some spotty critical fire weather conditions, mainly along and west of the I-25 Corridor, with southerly flow expected to increase low level moisture further east across the plains. This will lead to the potential for a few afternoon and evening showers and thunderstorms, with NBM mean CAPE of 200-600 j/kg across the far southeast plains. Friday also remains the last day for above normal temperatures for a while, with highs in the mid 80s to mid 90s expected across the plains, and mainly in the 60s and 70s across the higher terrain. Saturday-Sunday...Operational and ensemble model data are coming into much better agreement with timing and location of the upper low across Western Arizona lifting out into the Four Corners region Saturday afternoon. This system remains progged to continue out across south central Colorado Saturday evening before continuing into northeastern Colorado by Sunday afternoon. With that said, increasing moisture and uvv ahead of the system will develop rain showers across south central Colorado by mid morning, with the potential for waa showers developing across the southeast Plains through the late morning and early afternoon. The latest NBM data indicates mean CAPE across the plains of 400-900 j/kg with enough shear for the development of supercells. However, with the slower ejection of the upper low, there may not be enough uvv or instability to develop strong storms across the southeast plains. Time will tell. The latest SPC Day 3 outlook has a marginal risk across much of eastern New Mexico, with the marginal risk inching into southeastern portions of Las Animas county into southwestern portions of Baca county. The expected movement of the upper low will lead to widespread precipitation across south central Colorado spreading north and east across the eastern eastern and plains Saturday afternoon and evening before precipitation lifts north and east into northeastern Colorado Saturday night and Sunday, with some wrap around precipitation continuing across the Pikes Peak and Palmer Dvd region through the day Sunday. Latest qpf has increased across the area with 1/2 to 1 1/2 inches possible by Sunday morning, greatest amounts over and near the higher terrain along and north of Highway 50, as will as across the far southeast plains. Snow levels look to lower to between 10-11K ft Saturday night, with latest model data supporting several inches of snow across the higher peaks (generally above 12K ft), across the Central Mtns into the Pikes Peak region by Sunday morning. Later shifts may need to go with early season winter weather highlights for the highest zones. While precipitation totals remain in flux with the eventual track of the passing system, temperatures will definitely cool to well below seasonal levels through the weekend, with coolest day expected to be Sunday, with highs in the 60s across the lower elevations and mainly in the 40s and 50s across the higher terrain, save for 30s at the peaks. Monday-Thursday...A generally cool and unsettled northwest flow pattern remains in the offing for early next week. This will keep chances of precipitation, especially over and near the higher terrain, along with temperatures at and below seasonal levels into the middle of the work week, with warmer and drier weather returning into the end of next week, as upper level ridging builds back across the Rockies. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 421 AM MDT Thu Sep 19 2024 VFR conditions expected over the next 24 hours. North winds at KCOS and KPUB this morning will shift around from the east then southeast in the afternoon but speeds should stay under 20 kts. Light winds at KALS will increase out of the southwest and gust up to 25 kts in the afternoon. Winds will become light and diurnally driven tonight at all 3 terminals with some passing high cloudiness from late afternoon through the evening. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... Frost Advisory until 8 AM MDT this morning for COZ069>071. && $$ SHORT TERM...KT LONG TERM...MW AVIATION...KT