370 FXUS65 KPUB 252208 AFDPUB Area Forecast Discussion National Weather Service Pueblo CO 308 PM MST Wed Nov 25 2020 .SHORT TERM...(This evening through Thursday) Issued at 247 PM MST Wed Nov 25 2020 ...A mainly dry Turkey Day, with temperatures around seasonal levels... Current water vapor imagery and upper air analysis is indicating increasing westerly flow aloft across the region, as shortwave ridging is being pushed east by eastern Pacific energy digging across the Pacific Northwest at this time. Satellite imagery is indicating clear skies across the state, with some mid and upper level moisture spreading across across the Great Basin at this time. Satellite imagery is also indicating snow cover steadily melting through the afternoon, with some patchy snow still visible south and west of Pueblo, from near the Reservoir back to the Wet Mtns, as well as along and south of Highway 50 between Fowler and La Junta and between Las Animas to just south of Lamar. Snow is also hanging tight across the central San Luis Valley. Snow cover has kept temperatures cooler than surrounding areas, with Alamosa just now getting above freezing as of 2pm, with La Junta at 41F and Lamar at 47F, compared to Springfield and Limon at 54F and the Air Force Academy at 51F. Tonight and Thanksgiving Day...Latest models remain consistent with PacNW system splitting as is continues to translate across the Intermountain West tonight. The main part of the system continues across the Northern Rockies through the day tomorrow, as secondary energy, now digging down the backside of the system across the PacNW Coast, cuts off an upper low across the southern Great Basin by 00Z Friday. The increasing west to southwest flow aloft across the region tonight will allow for breezy conditions to continue at the peaks overnight, with lee troughing across the I-25 Corridor keeping enough westerly downslope across the higher terrain west of the corridor to keep temperatures in the 20s to lower 30s overnight across the "banana belt" while valley locales will likely see lows in the teens and 20s, save for the San Luis Valley where lows look to be in the single digits to the teens. Passing northern Rockies wave will bring increasing clouds to the region through the day tomorrow, with best lift and moisture associated with the system staying north of south central Colorado. At any rate, will likely see a few snow showers spreading into the central mountains through the late afternoon hours, with any accumulations remaining light and staying across the higher terrain north of Cottonwood Pass. The passing wave will also send a weak front across eastern Colorado through the late morning, with breezy northerly winds of 10-20 mph, strongest across the far southeast plains, expected to become easterly upslope through the afternoon hours. This will limit heating across the area, with highs in the 40s to lower 50s expected across the plains, and mainly in the 20s and 30s across the higher terrain. .LONG TERM...(Thursday night through Wednesday) Issued at 247 PM MST Wed Nov 25 2020 Low confidence forecast beginning Saturday, with large operational model differences and high ensemble spreads. Not much in the way of precipitation expected, but that could change depending on which model, if any, plays out. Thursday night through Saturday...greatest confidence in the forecast during this period, although, there are model differences even for this portion of the forecast. For Thursday night, a weak upper disturbance is forecast to track south across Colorado helping to generate a few light snow showers from the La Garita range, north into the Central Mountains. Not anticipating much in the way of accumulations, with a dusting to may be a patchy inch north of Cottonwood Pass. On Friday, a stronger upper level low is forecast to drop south out of Utah, and track east across the Desert Southwest through Saturday. Both the ECMWF and GFS are pretty far south with storm track, with snow across the San Juan and Southern Sangre de Cristo ranges on Friday and possibly into Friday night. Snow accumulations will be light at 1 to 3 inches, with locally higher amounts possible near the New Mexico border. Both the GFS and ECMWF keep the Plains dry as the upper system tracks to the south. The NAM is the outlier, with a bit further north track. It does bring a quick shot of rain or snow Saturday morning across southern portions of the Plains. For now, have low pops on the Plains late Friday night into Saturday morning. Overall confidence on the Plains is currently low, and pops may need to be adjusted down some. A cold front is expected to arrive Saturday night, with strong north winds expected across the Plains. Temperatures will be on the cooler side, with 40s and 50s across the region. Sunday...big model differences here! The GFS drops a sharp trough south across Colorado, bringing with it a chance for precipitation over the Mountains, Palmer Divide and west of I-25. Nothing is suggesting much in the way of rain or snow, but a couple inches would be possible based on the GFS solution. The ECMWF has nothing coming through on Sunday, with weak energy well to the east. The NBM came in dry like the ECMWF, so at this time, went that route. But, there could be a low potential depending on which solution pans out, for precipitation over the Mountains and Palmer Divide on Sunday. Monday into Wednesday...very low confidence out this far. The GFS takes an upper level low and parks it over the Four Corners region through much of next week. The ECMWF is much slower in developing the upper low, but then swings it east across the region by mid week. The GFS would bring a couple of rounds of mountain snowfall for next week, while the ECMWF holds off for much of the period. For now, the forecast will likely be on the drier side, but that could change depending on how the model solutions evolve over the next few days. Mozley && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 247 PM MST Wed Nov 25 2020 VFR conditions expected at COS. PUB and ALS over the next 24 hours, with increasing mid and high levels clouds expected through the day on Thursday. Generally light diurnal wind regimes expected at the taf sites, with low level upslope flow developing at COS and PUB late Thursday morning and early afternoon. With snow cover still melting across the San Luis Valley, there could be enough low level moisture to support fog development at ALS later tonight. However, with mid and high level moisture increasing across the area within the increasing southwest flow aloft, models are not as conducive for widespread fog, and will not include in the taf at this time. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...MW LONG TERM...MOZLEY AVIATION...MW