Area Forecast Discussion
Issued by NWS San Angelo, TX
Issued by NWS San Angelo, TX
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210 FXUS64 KSJT 281809 AFDSJT Area Forecast Discussion National Weather Service San Angelo TX 109 PM CDT Tue May 28 2024 ...New MESOSCALE UPDATE... .MESOSCALE UPDATE FOR SEVERE THUNDERSTORM POTENTIAL... Issued at 108 PM CDT Tue May 28 2024 Satellite imagery shows some cumulus forming along a weak dry- line that stretches from the TX/NM border south through around the Ft Stocktion area. Meanwhile, a strong outflow boundary from earlier convection continues to push west and southwest across West-Central Texas, with a position at 12:45pm stretching from Big Spring southeast through Sonora. Latest hi-res model guidance indicates that storms will initiate around 3-4pm along that outflow boundary as it intersects with the weak-dry line to the west. The amount of instability east of this boundary intersection will be questionable, as the outflow boundary has cooled the air mass in that region, with temperatures currently in the upper 70s/low80s east of the boundary, and upper 90s/low 100s west of the boundary. The expectation is that there will still be enough instability and shear (50+ KT of effective shear and 100-200 m2/s2 of effective SRH) east of the dry-line/outflow boundary intersection for storms to maintain themselves at least into the Concho Valley, Northern Edwards Plateau and western Big Country. When severe storms do develop today/tonight, the main hazards look to be damaging winds of 70-80 mph (with the highest wind risk being later this evening/overnight when a potential strong outflow boundary to our west helps develop a line of thunderstorms that moves across the region), large to very large hail (highest risk this afternoon and early evening), and possible flash flooding (with the highest flooding risk being over locations that have gotten plenty of rainfall over the last few weeks). Tornado potential looks low, as the low level shear isnt too favorable. SJH && .SHORT TERM... (Today and tonight) Issued at 229 AM CDT Tue May 28 2024 ....Another Round of Severe Weather for West Central Texas Today... The seemingly never-ending severe weather this spring across West Central Texas looks to continue this afternoon and evening. Trying to pin down the where and how bad is more difficult this time around because the convection ongoing this morning across the Red River Valley will play a significant role, helping determine where the surface boundaries tend up today. 00Z NAMNEST was very aggressive with the convection this morning, eventually developing a coherent outflow boundary that pushes all the way south into or even through the Concho Valley and Heartland to near I-10 by early afternoon. This would produce a little less unstable air mass for the area and a little less widespread severe weather. Other CAMs are not as aggressive and keep the boundary to the north, leaving most of West Central Texas with a potent severe weather potential. Decent amount of convection is ongoing across the Red River so the NAMNEST scenario is possible, although first thought is that it may be a little too aggressive with the speed of the boundary and how far south it can make it. For now, will aim for something in the middle with convection developing to the west along the dryline and perhaps directly across West Central Texas with the outflow boundary. Given the air mass (CAPE values in excess of 3500 and perhaps much higher) and shear, storms may quickly become severe. Initially, very large hail possible, but an overall trend toward a strengthening MCS looks possible with very strong winds as well. SPC has bumped the risk category up to Enhanced across the area, and see zero reason to disagree. Given the high theta-e air mass that may pool along the outflow boundary as well, there is a risk of very efficient rainfall production as well and thus, flash flooding. After a quick coordination with WPC, have bumped the risk of excessive rainfall up as well. All in all, looks to be a busy afternoon and evening that people will need to keep a very close eye on. && .LONG TERM... (Wednesday through Monday) Issued at 341 AM CDT Tue May 28 2024 Unsettled weather pattern will continue through much of the long term. How much thunderstorm development we see on Wednesday is uncertain. Models build in shortwave ridging overhead in the wake of the Tuesday/Tuesday night convection. The dry line is forecast to hang back to the west for most of the day. Thunderstorms may develop ahead of the dry line across the higher terrain of the Davis Mountains and propagate eastward into the northern Edwards Plateau in the late afternoon/evening. Most of the CAMs however keep most of the area dry through the day on Wednesday. Have cut down PoPs a bit but kept them in the chance category for now. Shower and thunderstorm chances will continue on Thursday and Friday. The ridge weakens on Thursday as another shortwave trough dives down into the southern Plains. Models hint at another round of storms developing in the Panhandle Thursday afternoon, with this activity potentially developing into an MCS and and moving southeastward into the Big Country Thursday evening/night. SPC has introduced a slight risk for severe weather on Thursday mainly north of I-20 to account for this scenario. Large hail and damaging winds would be the primary hazards especially if an MCS does develop. Could see a lull in activity on Friday before yet another shortwave trough initiates another round of thunderstorms Saturday afternoon/night. Upper level ridge over northern Mexico builds back in Sunday and Monday resulting in only a slight chance of afternoon thunderstorms. Temperatures will be much cooler for the rest of the week- mainly in the 80s and 90s- before warming back up near the triple digits by the beginning of next week. && .AVIATION... (18Z TAFS) Issued at 1251 PM CDT Tue May 28 2024 Outflow boundary near KSOA, heading southwest, has left strong east winds gusting between 30 and 40 KTS across terminals. These will gradually weaken this afternoon, but should remain gusty until early evening. Thunderstorms developing out west, may affect KSJT and KSOA mainly after 00Z, and KBBD and KJCT later after 02Z. Storms may also affect KABI late evening. MVFR stratus otherwise returns late tonight and early Tuesday morning. && .PRELIMINARY POINT TEMPS/POPS... Abilene 65 83 67 85 / 70 40 30 40 San Angelo 66 88 70 93 / 60 40 20 30 Junction 68 91 72 94 / 70 30 20 10 Brownwood 65 83 68 84 / 60 40 40 30 Sweetwater 65 83 68 87 / 50 40 20 40 Ozona 67 91 72 92 / 60 30 10 10 Brady 66 83 69 86 / 70 40 30 30 && .SJT WATCHES/WARNINGS/ADVISORIES... High Wind Warning until 4 PM CDT this afternoon for Brown- Callahan-Coke-Coleman-Concho-Irion-Kimble-Mason-McCulloch-Menard- Nolan-Runnels-San Saba-Schleicher-Sterling-Sutton-Taylor-Tom Green. && $$ SHORT TERM...07 LONG TERM....42 AVIATION...07