Expires:No;;433683 FXUS64 KLUB 291121 AFDLUB Area Forecast Discussion National Weather Service Lubbock TX 521 AM CST Mon Dec 29 2025 ...New AVIATION... .KEY MESSAGES... Issued at 520 AM CST Mon Dec 29 2025 - A light coating of snow, mainly on grassy surfaces, will be possible across the far southwestern South Plains today. - Cold and cloudy conditions are expected area-wide today. - Milder and dry from Tuesday through the first weekend of 2026. && .SHORT TERM... (Today and tonight) Issued at 1205 AM CST Mon Dec 29 2025 In the mid/upper-levels, a well-defined cyclone was rotating into the Corn Belt; and was embedded within a broad, large-scale trough pivoting over the central and northern Great Plains. Farther west, a splitting of the synoptic flow has occurred over the southwestern U.S. and the far northeastern Pacific Ocean, as the formation of a substantially tilted Rex Block is underway following the completion of a high-amplitude wave break. The superposition of the large-scale troughing over the central U.S. and the Rex Block relative to the CWA has resulted in a belt of intense, mid/upper-level divergence, with the right-entrance region to the 500 mb and 300 mb jet streaks located to the south of the CWA. A wide swath of mid- and high-level cirrus associated with the baroclinic generated by the cut-off low rotating offshore Baja Sur continues to advect northeastward over Mexico and into the TX Big Bend. This high-altitude cirrus deck is expected to advect over most of the CWA today, with its northern edge of clipping the far southern TX PH due to the deep-layer flow becoming increasingly convergent with northward extent. At the surface, the Arctic cold front that previously moved through the CWA early Sunday has now crossed into Mexico. Post-frontal winds have diminished and will become calm by sunrise, as a 1038 mb surface high rotates into W TX this morning. While there will be a cessation of CAA, the thick overcast will restrict the full effects of diabatic warming, and high temperatures for this afternoon were lowered from the NBM and aligned with the cooler side of the recent MOS guidance. As is typical with an Arctic airmass, the sub-cloud layer will be very dry this afternoon, with T/Td spreads of nearly 40 degrees expected. The 29/00Z RAOBs from WFOs ABQ, AMA, EPZ, and MAF sampled a large depth of dry air in the mid-levels, which will eventually saturate as the cirrus shield advects over the region, with the highly elevated, convective filaments slowly enhancing the wet-bulb cooling processes aloft. However, the sub-cloud layer is expected to remain very dry, and this more-narrow depth was observed particularly by the 29/00Z EPZ and MAF RAOBs above the well-mixed boundary-layer. This Arctic cold front was also well-defined on water-vapor imagery, and extended to a depth of about 800 mb, per the 29/00Z AMA RAOB, which will stifle the top-down moistening processes generated by the vigorous, mid-level, isentropic ascent over most of the CWA. The backside of the large-scale trough will emerge over the southern High Plains today, with an expectation for a sharpened deformation zone to form in congruence with intense frontogenesis at 700 mb over southern NM and into the northern Permian Basin. The tongue of warm, elevated theta-e advection will remain well to the south of the CWA, with the northern edge of the 700 mb FGEN bands forecast to clip the southern South Plains later this morning and into the late afternoon hours. Since the northern periphery of the band(s) will clip the southwestern zones, the columns will become less saturated with respect to water and deter the potential for supersaturation with respect to ice, which will eliminate any potential for dendritic growth. Forecast soundings continue to indicate the potential for the formation of small platelets, with the best chances for light snow situated across portions of Yoakum and Terry Counties. Due to the recent period of record-breaking warmth, a light coating of snow will be possible on grassy surfaces, as roadways should still be too warm for accumulations to occur, especially given the light snowfall rates. A Special Weather Statement will be issued for Yoakum and Terry Counties to handle this sub-advisory event. Otherwise, snow flurries will be possible along the HWY-114 and HWY-87 corridors, with the rest of the CWA remaining dry. The potential for snow of any kind will end altogether after dark, as the cloud-layer flow veers following the arrival of the base of the nearly inverted trough and related NVA. The thick overcast will gradually clear overnight, with temperatures cratering into the lower-middle 20s area-wide Tuesday morning. Lows were manually adjusted for the northwestern zones that are notoriously colder than surrounding areas due to the sandy soils and terrain-induced drainages. Sincavage && .LONG TERM... (Tuesday through Sunday) Issued at 1205 AM CST Mon Dec 29 2025 Tuesday morning opens with a chilly surface high departing to our south underneath rising heights in NW flow. Gentle SW breezes with full sun point to a quick recovery in temps - mildest off the Caprock where some low 60s appear in reach. Meanwhile in the Intermountain West, longwave ridging is forecast to deamplify through New Year's Day as a southern stream low off the coast of SOCAL speeds east and over the TX Panhandle by Friday. A thick plume of mid and upper Pacific moisture preceding this wave should make for a mostly cloudy New Year's Day while breezier west winds with a lee trough serve to keep temps on the mild side. The dry NBM during this wave's passage looks good as ensemble support for the ECMWF's QPF is poor. Following this trough, upper ridging rebounds to our west on Friday and then passes overhead by the weekend ensuring mild temps with continued SW breezes. && .AVIATION... (12Z TAFS) Issued at 520 AM CST Mon Dec 29 2025 VFR is expected through the TAF period. An upper level storm system will bring wintry precipitation to the south and west of the terminals but is not currently expected to affect any TAF site outside of light flurries. && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...09 LONG TERM....93 AVIATION...01