Area Forecast Discussion
Issued by NWS San Angelo, TX
Issued by NWS San Angelo, TX
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797 FXUS64 KSJT 301719 AFDSJT Area Forecast Discussion National Weather Service San Angelo TX 1219 PM CDT Tue Apr 30 2024 ...New AVIATION... .SHORT TERM... (Today and tonight) Issued at 335 AM CDT Tue Apr 30 2024 The main concern for today and tonight will be the potential for isolated strong to severe storms in our western and northern counties. We will have some low clouds this morning across much of the area, especially south of Interstate 20. These low clouds will scatter out of area by around noon. Later this afternoon, as temperatures warm, CAPE values will climb into the 2000 J/kg range by mid afternoon, while convergence increases along the dryline to our west. Coverage is expected to be fairly isolated as we will have very limited upper level support underneath broad low amplitude ridging. With the amount of instability combined with deep layer shear values in the 30 to 40 knot range, any storms that can develop will have the potential to become strong to severe, with the main hazards being large hail and damaging winds. If any storms can get going, expect them to develop during the late afternoon hours, and last through late evening. Otherwise, highs today will be in the mid 80s to lower 90s. Winds will be southerly and gusty, and lows tonight should be in the mid 60s to around 70. && .LONG TERM... (Wednesday through Monday) Issued at 335 AM CDT Tue Apr 30 2024 An active pattern is setting up for the long-term duration of the forecast. A strong upper low well to our north will put us in relatively weak southwest flow aloft for the rest of the work week with our area on the northern fringe of the southern stream jet. Wednesday afternoon and evening looks to be our best chance of seeing some potentially strong to severe storms. A surface low is expected to deepen in the southeastern Colorado region with a dryline extending south into West Texas. Ample daytime heating in the warm sector (highs in the mid 80s to low 90s) and continued modest southerly flow bringing increased moisture into the area will yield significant instability on the order of 2000+ J/kg of MLCAPE across our CWA. The main limiting factor will be weak shear (20-30 kts) across the area. A weak upper level shortwave is progged to eject northeastward out of Mexico during the late afternoon which would likely kick-start development along the dryline. Initial development off of the dryline is expected to be supercellular and will pose the greatest threat for all hazards, especially large hail. With pWats right around 1 inch, the storms will also likely be efficient rainfall producers leading to a potential for flash flooding concerns, primarily in areas that have already seen ample rainfall over the last week or so. The lack of shear should allow storms to grow upscale rather quickly into a more linear feature as noted by most of the 00Z HREF members. This line would make its way through the area overnight with the significant severe threat likely decreasing as one moves east. Though it should be noted that the threat for damaging winds and marginally severe hail will remain through the duration of the line. We`ll see chances for storms yet again on Thursday. As a cold front starts to sag south into the Red River region, we could see some warm sector development again, though the dryline should be much further east, nearly bisecting our CWA north to south. Instability will be weaker from the previous day and shear will still be hard to come by. The most likely area for development will be across our eastern counties where the much better moisture will reside. As we will still be under weak southwest flow aloft, another weak shortwave may pass overhead aiding in some more development though this aspect remains more uncertain. Temperatures will be slightly warmer across western portions of the area where southwesterly flow and a strengthening 850 mb thermal ridge to our west will allow highs to climb into the low to mid 90s. Further east, more ample moisture will hold highs in the mid to upper 80s. The cold front will make its way into our area early on Friday, helping to cool temperatures areawide into the 80s. However, there continues to be significant uncertainty regarding the placement of this front. The general consensus is that it is expected to stall out but the location of that remains rather nebulous at this time. It is expected to stick around the central Texas region for much of the weekend. This combined with the continued weak southwest flow aloft will keep rain chances in play through Sunday. Specifics are hard to come by at this point but a wetter and "cooler" pattern is expected for the weekend with temperatures generally in the low to mid 80s. Conditions look to dry out by Monday but for how long remains uncertain given the significant differences in the upper level pattern with the long-range models. What we do know is that temperatures will return to well above normal with highs in the 90s. Temperatures in the upper 90s will even be possible for areas south of the Big Country by Tuesday. && .AVIATION... (18Z TAFS) Issued at 1213 PM CDT Tue Apr 30 2024 The MVFR cigs of the morning have largely lifted and are starting to break up some, with most areas likely to see VFR conditions for the remainder of the afternoon and evening. More low clouds are likely to return overnight and VFR conditions will prevail again by sunrise Wednesday morning. Latest CAMs continue to show some support for some convection this evening, although they vary widely in coverage. Right now it looks like the best chances may be near KABI for a few hours around sunset, with much more isolated activity farther south. Will include a tstm mention up at KABI for a few hours but hold off elsewhere until the chances look better. && .PRELIMINARY POINT TEMPS/POPS... Abilene 91 67 86 65 / 20 30 30 70 San Angelo 93 69 89 67 / 10 20 40 60 Junction 92 70 87 69 / 0 0 30 60 Brownwood 87 67 84 67 / 0 20 30 80 Sweetwater 91 68 87 65 / 20 20 40 50 Ozona 89 68 82 67 / 10 10 30 40 Brady 88 69 84 67 / 0 10 30 80 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...20 LONG TERM....50 AVIATION...07