069 FXUS64 KSJT 091800 AFDSJT Area Forecast Discussion National Weather Service San Angelo TX 1200 PM CST Sat Jan 9 2021 ...New AVIATION... .SHORT TERM... (Today) Issued at 439 AM CST Sat Jan 9 2021 Temperatures have dropped below freezing across all of West Central Texas early this morning, with readings in the middle 20s across the Concho Valley. Shallow moisture trapped near the surface has allowed areas of freezing fog and mist to develop mainly across the western and southern half of the area. Expect the fog to dissipate by the late morning hours. Otherwise, surface high pressure will nudge east of the region today, with continued cool and moist easterly flow similar to yesterday. Have again hedged temperatures this afternoon closer to the cooler NAM, with the shallow cold airmass in place and cloud cover persisting for most of the day. Expect highs in the lower to mid 40s across the Big Country down into the western Concho Valley and northern Edwards Plateau. Temperatures may be slightly warmer across the Hill Country, with highs near 50. && .LONG TERM... (Tonight through Friday) Issued at 439 AM CST Sat Jan 9 2021 ...Heavy snow is still a good possibility over the Big Country Sunday... The upper level storm system currently over northern Nevada will drop southward to the Four Corners area today, then southeastward across west Texas late tonight through Sunday. Expect precipitation to begin as light rain this evening before transitioning to snow by Sunday morning as colder air moves in with the upper low. Latest models edge the track of the upper low a little more southward than previous runs. Appears the best accumulations of snow in the 4-6 inch range will still occur across the western Big Country. However, with the more southward track of the storm system, we could see increased snow amounts of 2-3 with areas of 4 inches across parts of the Concho Valley and Heartland. Decided to include another group of counties into the Winter Storm Watch. The watch will likely be upgraded to warnings/advisories later today as we get a better handle on the track and timing of the upper low. Expect a cold rain across the I-10 corridor on Sunday where temperatures are not expected to be quite as cold. The precipitation will end late Sunday as the system moves quickly to the east. However, with overnight lows in the 20s, roads will remain icy and slushy for Monday morning. Temperatures will warm above freezing Monday afternoon, allowing the snow to quickly melt. A warming trend expected through the week, with no additional precipitation expected. && .AVIATION... (18Z TAFS) Issued at 1139 AM CST Sat Jan 9 2021 Most of the fog from earlier this morning will continue to clear out over the first part of the TAF period. We will see all of the terminals return to IFR and LIFR conditions overnight tonight. An approaching disturbance will bring snow across much of the area. However, there may be a quick period of rain across KSOA and KJCT prior to transitioning to snow. Look for reduced visibility across the terminals overnight. && .PRELIMINARY POINT TEMPS/POPS... Abilene 31 32 25 41 / 80 100 10 0 San Angelo 31 34 24 44 / 80 90 0 0 Junction 31 35 25 46 / 80 100 0 0 Brownwood 29 33 25 42 / 50 100 10 0 Sweetwater 32 32 24 40 / 90 100 5 0 Ozona 34 35 26 46 / 80 80 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... Winter Storm Watch from 6 PM CST this evening through Sunday afternoon for Fisher-Haskell-Jones-Nolan-Shackelford-Taylor- Throckmorton. Winter Storm Watch from late tonight through Sunday afternoon for Brown-Callahan-Coke-Coleman-Concho-McCulloch-Runnels-San Saba-Sterling-Tom Green. && $$ SHORT TERM...42 LONG TERM....08 AVIATION...41