Area Forecast Discussion
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
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864 FXUS65 KPUB 291727 AFDPUB Area Forecast Discussion National Weather Service Pueblo CO 1127 AM MDT Wed May 29 2024 .KEY MESSAGES... - Strong to severe storms are likely (60-80% chance) for our plains today, with main risks being hail up to 2 inches, winds gusting to 60 mph, and lightning. - Severe storms possible on the plains Thursday afternoon/evening. - Scattered afternoon storms again Friday/Saturday, though less chance of severe weather. - Generally dry and warmer from Sunday into next week. && .SHORT TERM /THROUGH TONIGHT/... Issued at 345 AM MDT Wed May 29 2024 Currently.. Upslope conditions have developed across portions of El Paso, Pueblo and Fremont counties this morning, as east-southeasterly winds and outflow enhanced moist air have made their way westwards and back into the terrain. Ceilings are around 1,500ft across El Paso County as of 3am. Dewpoints are in the 40s, and temperatures are in the 50s. This extra moisture will help to set the stage for today`s convection. Today and Tonight.. Models show the upper ridge axis passing overhead early this morning, as a trough begins to push into the Northern Rockies later on this morning and into this afternoon. This pattern, along with our influx of moisture, will help to spark a few storms over the high country by around 11 am. Higher storm coverage and intensity will exist over northern and southern portions of our mountain adjacent plains by around 1pm this afternoon. Some models don`t seem to be realizing the amount of moisture that we could be working with today, though CAPE values are still ranging from around 1500 to 3000 J/Kg throughout this afternoon and this evening. 0 to 6km shear is anywhere from 30 to 40 kts as well, with highest amounts further out out on our plains. In many ways, today will be similar to yesterday, with two rounds of storms firing over our southern plains and the Pikes Peak region, and eventually joining up over our eastern plains, and with 2 inch hail and 60 mph wind gusts being our biggest concerns. The main difference will be that today we could see more of a non-zero tornado or landspout threat. 0 to 3km Helicity indexes are not super impressive, but are higher than yesterday, especially over the Palmer Divide later this afternoon and into this evening. Daytime high temperatures will be a couple of degrees warmer than yesterday for most locations. Storms are expected to linger a bit later than they did yesterday for our eastern plains, though most locations should still be dry by midnight. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Issued at 345 AM MDT Wed May 29 2024 Upper level wave swings eastward out of the northern Rockies into the nrn plains Thu, with southern extension of the wave and associated upward motion moving across Colorado during the day. Main question for Thu revolves around the evolution of the surface air mass over the southeast plains, as nrn Rockies wave pushes a cold front through the area Thu morning, with boundary becoming nearly stationary along the CO/NM border in the afternoon. Behind the boundary, northerly winds in the morning gradually turn eastward during the afternoon, leading to increasing low level moisture and instability (CAPE in the 1000-2000 J/KG range) for most of the area east of I-25 through the day. Wrn edge of the deeper moisture/instability still somewhat of a question, as a few CAMs are slower to turn the winds easterly, which would keep deeper moisture/instability closer to the KS border versus farther west near/just east of I-25. If winds turn easterly as progged, 0-6km shear by late Thu afternoon will increase into the 35-45 kt range, which would support fairly widespread severe convection and perhaps a few supercells with large hail. Wind profile still not particularly indicative of a tornado threat due to rather weak low level winds, though a few landspouts may be possible during initial cell development near the frontal boundary along the NM border. Again, best chances for storm initiation will be along the Palmer Divide and Raton Mesa, with perhaps some loose organization into an MCS over the far east early in the evening before activity rolls e-se into KS/OK/TX overnight. Mountains and interior valleys will see scattered showers/thunderstorms, but moisture continues to be rather sparse over the high terrain, suggesting only spotty and light rainfall. On Friday, still some moderate wind shear (0-6km of 30-40 kts) in place across the area, though with cooler surface temps and decreasing mid-level lapse rates, air mass will be considerably more stable (CAPE in the 500-1000 J/KG range), leading to both less thunderstorm coverage and weaker storms in general. Temps warm Sat, but with even less moisture available, afternoon convection will be weak and high based at most locations. Very warm and dry conditions then forecast for Sunday as mid/upper level flow turns more swly ahead of the weak upper trough moving through the Rockies. Could see some mid-upper 90s on the plains by Sunday afternoon, as dryline shifts toward the the KS border and deep mixing develops along and east of the mountains. Continued warm and dry into next week, as heights gradually build over the swrn U.S. and best low level moisture remains just to our east through the period. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 1127 AM MDT Wed May 29 2024 VFR conditions are expected to prevail for all TAF sites (KALS, KCOS, and KPUB) throughout the forecast period. There will be a moderate probability of VCTS for KCOS and KPUB, with only a slight probability of VCSH/VCTS at KALS. If SHRA/TSRA does develop, it could temporarily reduce CIGs and VIS to MVFR/IFR criteria. Outflow boundaries will be possible for both KCOS and KPUB during the late afternoon through early evening hours due to convection, which may cause abrupt windshifts. It could also result in periodic windshifts and increased wind speeds if storms move over station. Winds will be overall diurnally influenced towards throughout the forecast period. -Stewey && .PUB WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...EHR LONG TERM...PETERSEN AVIATION...STEWARD