Area Forecast Discussion
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
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092 FXUS65 KPUB 172336 AFDPUB Area Forecast Discussion National Weather Service Pueblo CO 536 PM MDT Tue Sep 17 2024 .KEY MESSAGES... - Strong to severe storms possible rest of this afternoon and early evening across the plains. - Patchy frost/light freeze possible for central San Luis Valley tonight. - Dry and breezy on Thursday. Spotty near-critical fire weather conditions are expected across the area. - Cooler and wetter conditions this weekend across the area. Best chance of showers and storms will be on Saturday. && .SHORT TERM /THROUGH WEDNESDAY/... Issued at 308 PM MDT Tue Sep 17 2024 Currently At 2 pm, A line of broken storms extended from just west of COS S- sw`d into the southern Sangres. Other additional showers and storms were noted over the CONTDVD region. Over the plains the atmosphere was destabilizing and winds aloft were increasing. SPC has already issued a watch for the region and lasts until early evening. Rest of today into early evening... Storms will continue to progress steadily northeastward. Given the shear, storms will likely move across the region as a broken line. Dewpts were noted in the U40s to lower 50s, and CAPE values were around 500-1000 Js, with the better instability generally east of a line from KLIC to KTAD. Strong forcing was pushing out in advance of a negatively tilted closed low pushing east-northeast out of Nevada. Main severe threat continues to be strong winds, as HRRR guidance continues to show strong gusts with storms, and the environment is favorable for strong gusts given the well mixed lower atmosphere and DCAPE values greater than 1000 Js over the far eastern plains. Overall, activity should move out of the region by early to mid evening. Later tonight through tomorrow... Much drier air will advect in behind this system and dry weather is expected tonight into tomorrow all areas. Only weather concern will be the San Luis valley where temps will be in the 32-34 range and pockets of frost are likely over the central valley floor. Temps tomorrow will be above normal over the plains, with mid 80 to around 90F plains and L70s valleys. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... Issued at 308 PM MDT Tue Sep 17 2024 Thursday... Dry and warm conditions will persist across the area on Thursday as we sit in between two upper lows. Breezy southwest flow will have temperatures remain mostly steady, with highs in the mid-high 80s over the plains while the high valleys remain in the 70s. With the dry airmass remaining in place, Rh values will hover around 15-20 percent through most of the afternoon, while surface winds sit around 10-15 mph. Unless we get more mixing than the models are expecting, which is possible but not likely, critical fire weather conditions will be marginal. Otherwise, the day will be relatively quiet. Friday Onwards... Models have reached better agreement on the track of the next incoming low as we approach this weekend. Friday will largely be a transition day, with high temperatures about 5 degrees higher than Thursday, along with slightly increased moisture from the incoming system. As we move into Saturday, models have continued trending south with the evolution of the upper level pattern, now sending a closed low directly over Colorado. As it moves in, a cold front will push south across the area late Friday night into early Saturday. Along the front, localized convergence and a good amount of monsoon moisture could net us a healthy amount of precipitation. The exact amounts, as well as what kind of precipitation (convective vs more stratiform) we may see will largely be dependent on frontal timing and instability. As of now, the GFS only shows a few hundred J/kg of CAPE over the plains, and the system is moving relatively quickly, so amounts may not be all that high. However, there is still time for these details to become better resolved in the data. There is still a bit of uncertainty amongst the model guidance with regards to the speed of the low as well. The GFS has consistently been one of the faster models, and the Canadian has been largely tagging along the last few runs. However, the EC is currently looking slow compared to the other deterministic guidance by several hours. Additionally, any shift to the N-S extent of the track will have a big impact on precip amounts. High temperatures will drop around 10 degrees as well, in mainly in the 70s to low-80s out east. For Sunday, post-frontal air will cool us off even more, with highs in the 60s-70s across the CWA. Some isolated-scattered POPS remain, but at this point models begin to diverge again on the departure of the low. Most of the better forcing and moisture will be off to our north and east, though if the low intensifies faster we may get some more potent wraparound precipitation into the Palmer Divide. Still plenty of time for those details to be resolved. Models are much less clear beyond that, though the cooler pattern may possibly extend into early next week. && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 535 PM MDT Tue Sep 17 2024 VFR conditions are expected at all three TAF sites, KCOS, KPUB, and KALS, for the next 24 hours. Gusty southerly and southeasterly winds are likely to persist for the next couple of hours, weakening after 02Z this evening as showers continue to push eastward and away from the terminals. Sky conditions are expected to improve throughout this evening, with mostly clear skies persisting through the remainder of the forecast period. Showers and storms are not expected tomorrow. There is a slight chance (<30%) of IFR ceilings and visibilities with stratus and fog at Alamosa tonight through early Wednesday morning, especially given the rain received there today, though confidence was too low to mention in the TAF at this time. && .PUB WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...HODANISH LONG TERM...GARBEROGLIO AVIATION...EHR