Area Forecast Discussion
Issued by NWS San Angelo, TX
Issued by NWS San Angelo, TX
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622 FXUS64 KSJT 301141 AFDSJT Area Forecast Discussion National Weather Service San Angelo TX 641 AM 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... (12Z TAFS) Issued at 640 AM CDT Tue Apr 30 2024 Low clouds can be seen on satellite imagery quickly moving northward into the area. However, there are many breaks in the clouds, so our southern sites are transitioning quickly from MVFR to VFR at times. Expect the ceilings to fill in and become more continuous over the next hour or so, and will start our southern sites at MVFR heights at 12Z or within the the next hour or two. These low clouds should scatter out of the area by late morning, with VFR conditions through the afternoon and evening hours. Although isolated to scattered TSRA are possible this evening, confidence is still too low in enough coverage for a mention at any one location. Otherwise, another round of low clouds can be expected Wednesday morning. && .PRELIMINARY POINT TEMPS/POPS... Abilene 91 67 87 65 / 10 20 30 60 San Angelo 93 68 89 66 / 0 10 30 50 Junction 92 69 88 67 / 0 0 30 60 Brownwood 87 68 84 66 / 0 10 30 70 Sweetwater 91 67 87 66 / 20 20 30 50 Ozona 89 68 84 66 / 0 10 30 40 Brady 88 69 85 67 / 0 10 30 70 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...20 LONG TERM....50 AVIATION...20