841 FXUS64 KSJT 150857 AFDSJT Area Forecast Discussion National Weather Service San Angelo TX 357 AM CDT Sat Jun 15 2019 .SHORT TERM... (Today and Tonight) Warm morning so far across the region, as temperatures have only dropped into the upper 70s as of 2 am. Debris clouds from a dissipating mesoscale convective system near Del Rio is bringing overcast skies to the southern half of our forecast area. These clouds and any low stratus clouds that develop over our southeastern and southern areas, should clear out from west to east through mid morning. This morning, the dry-line will start out across the eastern New Mexico/West Texas border and down through the Trans-Pecos region before an upper level trough over New Mexico and associated developing surface low over southeast New Mexico pushes the dry-line east to our western forecast area border by late afternoon. Meanwhile, increased moisture from the southerly low level flow will bring dewpoints into the upper 60s to around 70 over West Central Texas by late morning/early afternoon. This moisture, in addition to day-time heating, will allow ML CAPEs to rise to 3500-5000 J/KG according to the NAM. Hi-res models indicate thunderstorms initiating along the dry-line around mid-to-late afternoon in our extreme western counties, and then the thunderstorms form into a line that moves through the Big Country during the evening hours and then mostly east of the forecast area after midnight. Wind shear looks weak, so supercells appear unlikely. However, with such high amounts of instability, there is a marginal severe weather threat as there is the possibility of large hail and collapsing cores bringing damaging downdraft winds. Today will also be quite hot and muggy due to strengthening of the 850 mb thermal ridge. Expecting highs in the mid to upper 90s, and with high dewpoints the heat index values will likely reach 100 in many locations. Expect another warm night as well tonight, with lows in the low 70s. SJH && .LONG TERM... (Sunday through Next Weekend) A rather messy, mesoscale-driven pattern is expected to continue through the middle of next week. Several 500mb shortwaves embedded in generally west-northwest flow will push eastward across the area. During this time, instability on the order of 3000-4000 J/kg will be a daily occurrence, which should allow for decent thunderstorm chances. However, the fly in the ointment is how much effect evening and nocturnal thunderstorms may have on when and where new convection will develop the following day. Old outflow boundaries, cloud cover, potential Mesoscale Convective Vortices (MCVs), and even dryline location will all come into play. At this point, models are in a general consensus that the best chances for rain will be across the Big Country, especially Sunday evening and overnight, with some activity lingering into Monday morning. By late Tuesday, the global models attempt to build in a 500mb ridge across much of West Central Texas. Heights easily rise to around 588-590dam, which looks likely to persist through the remainder of the week. Temperatures at 850mb will also increase to the upper 20s to near 30 at times, which is enough to support surface temperatures right around 100 degrees. Given the high dewpoints in place, conditions will be downright muggy and miserable during this time period. SK && .AVIATION... /06Z TAFS/ MVFR CIGs possibly developing across southeastern and southern counties between 09Z and 14Z, with KJCT likeliest to be impacted, followed by KBBD and KSOA. Also, thunderstorms possibly moving into mainly the Big Country and northern Concho Valley after 00Z Sun, with possible impacts at KABI. Although storms could develop south of there, confidence is too low to put TS in the other TAFs. Storms could result in local and brief LIFR conditions. Otherwise, expect VFR conditions to prevail across the terminals through 06Z Sun. Gusty winds from the south will continue, with strongest winds occurring during the 14Z today to 00Z Sun time-period (15-18 KT gusting 22-27 KT). SJH .PRELIMINARY POINT TEMPS/POPS... Abilene 95 72 93 70 / 10 50 20 40 San Angelo 95 72 94 70 / 10 10 10 20 Junction 93 73 93 71 / 5 10 10 20 Brownwood 94 73 91 70 / 10 20 20 40 Sweetwater 96 70 93 70 / 20 40 20 30 Ozona 90 70 92 70 / 10 10 5 20 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$