FXUS64 KSJT 181945 AFDSJT Area Forecast Discussion National Weather Service San Angelo TX 245 PM CDT Sun Apr 18 2021 ...New SHORT TERM... .SHORT TERM... (This evening through Monday) Issued at 230 PM CDT Sun Apr 18 2021 Surface high pressure will be directly over West Central Texas this evening. North winds of 5 to 15 mph this afternoon will become light, and eventually shift south by morning as the high pressure moves east. It will be cooler tonight with lows in the lower 40s. Valley and low lying areas may fall into the mid/upper 30s. Isolated weak reflectivity's on radar early this afternoon were indicating a few sprinkles aloft in the mid level clouds, mainly over the I-10 corridor and northwest Hill Country. Models indicate more mid level clouds redevelop back north into the Concho Valley after midnight and Monday. Kept in a slight chance of light showers Monday...for Crockett County, the I-10 corridor and NW Hill Country region...as an upper disturbance moves across. Most of rain from the mid clouds will evaporate before hitting the ground, however. It will be warmer Monday, mainly in he lower 70s, except mid/upper 60s across Crockett, Sutton and Schleicher counties. && .LONG TERM... (Monday night through next Sunday) Issued at 220 PM CDT Sun Apr 18 2021 Monday night, an upper level trough will start to dig south out of the Central Rockies and into the Southern Plains. This will bring a cold front and a surface trough with a tight pressure gradient in tow. This is expected to begin moving through the area early in the day on Tuesday. Due to the tight pressure gradient, winds behind the front are expected to be strong out of the north between 20-25 mph with gusts approaching 35-40 mph at times. Highs on Tuesday will vary greatly across the area. The Big Country, where the front will move through first, will see highs in the upper 50s compared to mid 70s down south where daytime heating ahead of the front will be more promising. A high pressure system will build into north central Texas Tuesday night and lows will be downright cold in the low to mid 30s. Aside from the modest winds on Tuesday night, the ingredients for radiational cooling are there: clear skies and dry, post-frontal air. Even so, some places could very well see temperatures at or below the freeing mark. It should be noted that this is well past our average last freeze of spring which normally occurs in mid-March. The high pressure lingers into Wednesday but starts to trek eastward allowing for our low-level flow to turn more to the southeast which will help our temperatures recover into the 60s. This will also aid in moisture return, bringing in the warmer and wetter gulf air. Thursday will see more warming with highs in the mid to upper 60s, knocking on 70 degrees. Winds could be gusty on Thursday as the high pressure moves out of the area and a rockies low begins to form, tightening the pressure gradient. Long-range models pose some diverging solutions for Friday and Saturday. Both indicate precipitation but how much and for how long are the questions. GFS creates a cutoff low in the Four Corners region and digs an upper level trough into the area by Friday. The upper low then lingers over our area into Saturday. With plenty of low level moisture, lift, and instability, GFS has higher precip chances across our whole area Friday into Saturday. The ECMWF, on the other hand, brings an upper level trough through the area Friday along with a surface low in the Panhandle region. It also produces a dryline which limits the precip potential to our eastern counties. This dryline interaction with the ample instability in place could create potential for thunderstorms, the strength of which is still undetermined. Because of the lack of agreement at this time, have kept the blend for the present forecast. Something to pay attention to as it gets closer. A cold front moves through Friday night, cooling temperatures a bit but not by much. Looking ahead into next weekend, models are indicating an 850mb thermal ridge building into our area and sticking around for a little bit. This would mean the return of more late spring/early summer temperatures. If the cold is your cup of tea, enjoy Tuesday and Wednesday because summer may be coming... && .AVIATION... (18Z TAFS) Issued at 1201 PM CDT Sun Apr 18 2021 VFR next 24 hours. An isolated shower possible at KSJT, KSOA, KJCT this afternoon, but potential is too low to mention. North winds 5 to 10 KTS this afternoon become light this evening and shift south overnight. && .PRELIMINARY POINT TEMPS/POPS... Abilene 41 71 45 58 / 0 0 0 0 San Angelo 42 71 46 67 / 0 10 0 0 Junction 43 71 44 77 / 0 20 0 0 Brownwood 40 71 44 64 / 0 0 0 0 Sweetwater 43 71 43 57 / 0 0 0 0 Ozona 45 67 46 71 / 5 20 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...04 LONG TERM....50 AVIATION...04