Area Forecast Discussion
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
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827 FXUS65 KPUB 080508 AFDPUB Area Forecast Discussion National Weather Service Pueblo CO 1108 PM MDT Fri Jun 7 2024 .KEY MESSAGES... - Showers and thunderstorms expected on Saturday, with strong to severe thunderstorms likely along and east of the I-25 corridor. - Shower and thunderstorm chances continue Sunday through Tuesday, with the most widespread precipitation Sunday and Monday. && .UPDATE... Issued at 659 PM MDT Fri Jun 7 2024 Dropped severe tstm watch for the plains as main line of storms is well east. Still some weaker convection and even some lightning back west over the higher terrain, so will keep some low pops for storms going a few more hours until most activity ends by midnight. && .SHORT TERM /THROUGH TONIGHT/... Issued at 319 PM MDT Fri Jun 7 2024 Currently.. Satellite and radar imagery depict isolated to scattered showers and thunderstorms across our mountains and portions of our plains. Convection is very high based today, and at first glance looks a bit unimpressive on radar, but it is important to note that many of these smaller cells are producing damaging outflow winds. Area observations are showing thunderstorm outflow winds of anywhere from 45 to 60 mph across Fremont, El Paso, and Pueblo counties as of 2 pm. Temperatures have soared into the 90s and low 100s across the plains this afternoon, though convective cloud cover is starting to limit temperatures for our mountain adjacent plains. Dewpoints are in the 40s for most of our plains, with some low 50s on our far eastern plains. SPC mesoanalysis indicates 2000 J/Kg of DCAPE across the the entire lower Arkansas River Valley for the next 2 to 4 hours. Rest of Today and Tonight.. As storms continue to push south and east across the plains over the next few hours, expecting damaging wind gusts to continue to be the main concern for most locations. The main exception to this will be our far southeastern plains, where convection was slightly later to get going, but, as of 2:30pm, it is starting to ramp up a bit. This area is seeing slightly higher dewpoints, with area observations showing Td in the mid 50s this hour. This area will see more of a threat for hail up to 1 inch in diameter, along with the damaging winds gusting 60 to 70 mph through around 6 pm this evening. High res model guidance suggests that all convection should come to an end or push east by around midnight or so at the latest. Later tonight, models bring a weak cold front across our plains. While this front will not bring much of noticeable change in our winds or temperatures through the overnight hours, it will set the stage for a cooler and more active weekend. && .LONG TERM /SATURDAY THROUGH FRIDAY/... Issued at 319 PM MDT Fri Jun 7 2024 Cold front is expected to push across the region late tonight into early Saturday, providing some relief with the heat. However, highest temps on Saturday are still expected to reach the 80s to low 90s over much of the area. Quickly turn attention to returning thunderstorm chances along with the risk of severe weather Saturday afternoon into the evening, especially across the plains. General synoptic pattern looks to remain the same, however, guidance in fair agreement with showing a more defined short wave trough pushing across the region during the day Saturday. This increased large scale ascent along with veering low level flow and backing mid level flow looks to strengthen forcing/focus across southern Colorado. This will help set the stage for thunderstorm development initially over the mountains and plains interface by mid to late afternoon, and then over the remaining plains later in the day into the evening. The strong to severe risk will be higher on this day given the forcing/focus, but more importantly the increased moisture and instability as far west as the mountains and plains interface. This will be something to monitor as guidance continues to vary to the placement of the axis of highest moisture and instability, which could easily vary from north to south. Given this setup, thunderstorm development will have a higher chance to quickly strengthen as it pulls off the higher terrain, as some moisture pooling is possible up against the mountains and along the Palmer Divide. Forecast soundings do indicate a cap in place, though you can see this cap mechanically erode along the I-25 corridor during the afternoon with the arrival of the forcing. Further to the east, the cap is even stronger and will have to see how this factors with additional thunderstorm development later in the day and evening. I don`t think it will limit thunderstorm development especially given the increased instability and dew points possibly in the low 60s, but I think it will help to keep storms more limited and discrete. This will be something else to closely monitor, especially given the instability and abundance of shear that will support the risk of all hazards on Saturday. By Sunday, will see rising heights and weakening flow, but will see moisture and instability remain in place. It does look as if the moisture/instability axis shifts further west, with increased chances for showers and thunderstorms over the mountains and mountain valleys. With weakening flow, the risk for more widespread organized development lowers. That being said, still think there will be a risk for at least isolated strong to severe storms on Sunday. Large hail is possible, but think damaging winds would be more of the threat on this day. What will be more concerning on this day and even again on Monday given a persistent pattern, is the risk for heavy rainfall and flash flooding. The highest risk looks to be situated right along the southeast mountains into the I-25 corridor. Once again, the risk of heavy rainfall and flash flooding continues Monday, but will need to see how guidance evolves over the next couple of days, as more recent runs are showing a closed low developing across the region. It does appear that by Tuesday, we`ll see coverage of precip chances lower that continues on Wednesday as upper ridging is the trend. This will return building heat to the area though, with well above normal temperatures in the 80s and 90s, and quite possibly 100 degrees, returning to southern Colorado by mid week. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1108 PM MDT Fri Jun 7 2024 VFR conditions are expected to prevail for all TAF sites (KALS, KCOS, and KPUB) throughout the forecast period. Winds will be mostly influenced by synoptic forcing, due to an approaching system. They will begin to increase out of the SW at KALS, and SE-SSE at KPUB and KCOS, by later in the day with gusts around 25 to 30 kts at all terminals. SHRA and TSRA are expected to be in and around the vicinity of KCOS and KPUB by later in the afternoon and through the evening tomorrow, mainly between 20 and 23z, and only a slight chance of occurrence at KALS (which is why VCSH/VCTS has been left out of the KALS TAF at this time). If SHRA/TSRA does develop, it could temporarily reduce CIGs and VIS to MVFR/IFR criteria. It could also result in periodic windshifts and increased wind speeds for all terminals. High res models also suggest that a windshift will occur at KCOS around 23Z to become more NE`ly, due to a frontal boundary and outflow from convection, and may occur sooner than this depending on timing of convective initiation. This boundary will likely make it through KPUB around 02Z with winds becoming more NE`ly as well and then remaining out of this direction at both KCOS and KPUB throughout the rest of the forecast period. Winds as KALS will also come around to a more NE`y direction and then weaken to L&V right at the end of the forecast period. && .HYDROLOGY... Issued at 348 PM MDT Fri Jun 7 2024 Rapid snow melt will continue across the mountains leading to elevated flows along the Arkansas River from Leadville to Canon City through the weekend as well as on smaller creeks and streams in and near the mountains. Flows are expected to remain within banks for most locations along the Arkansas River but fast flows can still be dangerous. Slightly cooler temperatures may decrease the snow melt this weekend into early next week, however the potential for heavy rainfall will increase Saturday through Monday for the southeast mountains and plains. This could cause localized flash flooding and push flows above the projected bank full forecast for localized areas depending on where the rain falls. Confidence in this scenario unfolding is low for the major river stems for now. Continue to monitor weather forecasts closely. && .PUB WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...PETERSEN SHORT TERM...EHR LONG TERM...RODRIGUEZ AVIATION...STEWARD HYDROLOGY...MOZLEY