Area Forecast Discussion
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
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661 FXUS65 KPUB 212158 AFDPUB Area Forecast Discussion National Weather Service Pueblo CO 358 PM MDT Sat Sep 21 2024 .KEY MESSAGES... - Widespread showers/scattered thunderstorms across most of southern Colorado this evening and overnight, then precipitation intensity/coverage begin to fade early Sunday morning. - Snow levels drop down to around 9000 feet early Sunday morning, though most accumulating snow (5-10 inches) will stay across the higher peaks at/above 10kft. - Below average temperatures throughout the majority of the week, returning to normal by the end of the week. - Dry conditions are expected throughout the week. && .SHORT TERM /THROUGH SUNDAY/... Issued at 352 PM MDT Sat Sep 21 2024 Currently, upper low over nern AZ at mid-afternoon, with expanding area of showers and thunderstorms over much of the region as upward vertical motion increases across srn CO. Strongest storms so far today have been over the San Luis Valley, where weak instability (CAPE around 500 J/KG) and strong wind shear/upward motion were generating some fast moving convection. Hail threat with these storms will be limited by weak instability, but will need to watch for at least a low end severe wind threat across the Valley through 00z given storm motions of 50-60 mph. For the remainder of the afternoon into the evening, shower and thunderstorm coverage will expand across the area as low approaches, with HRRR suggesting a rather robust band of thunderstorms crossing the mountains 23z-03z, then impacting the I-25 corridor and eastern plains 02z-07z. Will continue with high pops and a mention of thunderstorms all areas, as strong forcing will overcome weak instability and keep tsra chance going until at least midnight. Snow levels hangs out between 9-10k feet through the evening, though wouldn`t be surprised to see stronger convection drive it lower toward 8k feet at least briefly, though accums should remain mainly over the peaks. After midnight, low passes overhead with vertical motion gradually diminishing from sw to ne as main deformation zone shifts into nrn CO. Overnight QPF, starting at 00z, will range from a half inch to slightly over an inch over much of the higher terrain, while valleys and I-25 corridor see numbers around a half inch. Plains should see a quarter to half inch overnight, perhaps a little heavier far southeast corner if stronger convection over ern NM/wrn TX can hold together as it comes north this evening. Overall, made only a few minor changes to ongoing forecast, as previous set of grids appear to have a good handle on things. Sunday, upper low gradually shifts out of Colorado into nwrn KS by late afternoon, though moisture and instability will linger across the area. Still a good deal of showers early in the morning over the eastern mountains and plains, with most activity then weakening/ ending by noon. A few showers/weak storms could re-fire over mainly the mountains in the afternoon as mid-level lapse rates remain rather steep, though not expecting anything particularly strong or widespread. It will definitely fell like fall across all the area temperature-wise, with max temps only in the 50s/60s at lower elevations, 40s/50s mountains. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... Issued at 352 PM MDT Sat Sep 21 2024 The closed that has been impacting the short term forecast continues its journey towards the northeast, but a lingering trough will still be overhead at the beginning of the long term forecast period, which will bring some light rain below 12kft and light snow above 12kft over the easter San Juan Mountains. The strong low pressure system brought cold air over the region and that will continue during the overnight where low temperatures will be in the 30s and 40s over the mountain valleys and the plains. Currently it doesn`t seem that any frost products will be needed, but it is close, so we`ll need to keep monitoring. Below average temperatures are expected throughout the majority of the week over the plains and mountain valleys. On Monday the high temperatures will be in the upper 60s to low 70s over the plains and mountain valleys. A weak shortwaves will begin to pass over Colorado, once again bringing light snow over 12kft and rain below 12kft over the eastern San Juan Mountains. Otherwise dry conditions and light winds everywhere else. Tuesday through Saturday: The rest of the will have some influence from a tropical system that will be impacting the U.S. South, therefore there is some uncertain, depending on the tropical system`s path. Overall, the flow over Colorado is expected to be fairly weak with ridging aloft developing over the western half of Colorado with northerly winds over the eastern half. There isn`t precipitation being resolved for the rest of the forecast period, just dry conditions with temperatures reaching closer to seasonal by the end of the week. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1133 AM MDT Sat Sep 21 2024 Upper level low across nrn Arizona at midday will move north and east across south central Colorado through the evening, then continue into northeastern Colorado on Sunday. This system will develop widespread precipitation, with showers and thunderstorms spreading north and east across the central Rockies through tonight. At the taf sites, lowering VFR cigs and vcsh 18z-20z, then more widespread showers and areas of MVFR cigs/vis from 20z until at least 08z. Risk of tsra this afternoon at KALS and will carry a 20z-24z tempo, while at KPUB and KCOS, tsra threat is later in the period generally in the 00z to 04z timeframe. After 08z, precip trends back toward vcsh, though with plentiful moisture and weakening winds, prevailing MVFR cigs are likely at all sites, with a risk of IFR 10z-18z, especially at KALS if significant precip occurs Sat evening. && .PUB WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until noon MDT Sunday for COZ058-060- 082. && $$ SHORT TERM...PETERSEN LONG TERM...SKELLY AVIATION...