Area Forecast Discussion
Issued by NWS
Issued by NWS
475 FXUS64 KLUB 211104 AFDLUB Area Forecast Discussion National Weather Service Lubbock TX 604 AM CDT Thu Aug 21 2025 ...New AVIATION... .KEY MESSAGES... Issued at 1220 AM CDT Tue Aug 19 2025 - Dry and hot weather is expected through the weekend. - A strong cold front is forecast to arrive early next week, along with chances for showers and thunderstorms. && .SHORT TERM... (Today and tonight) Issued at 1229 AM CDT Thu Aug 21 2025 The subtropical ridge continues to amplify and stack over the Four Corners region. A wide swath of subsidence is advecting across the central U.S. and into W TX, with dry and hot conditions expected area-wide Thursday. A much cooler night will follow, as a crystal clear sky maximizes the effects of radiational cooling. Sincavage && .LONG TERM... (Friday through Wednesday) Issued at 1229 AM CDT Thu Aug 21 2025 A persistence forecasting technique has been applied through the weekend. In the mid/upper-levels, the subtropical ridge centered over the Four Corners region will have peaked in amplitude, as the phasing of 250 mb jetlets occurs over the northern Rocky Mountains and induces geopotential height falls over the northern half of the U.S., causing the ridge to begin to dampen. High temperatures are forecast to remain near seasonal norms (e.g., middle 90s) area-wide through the weekend, with light, easterly winds Friday becoming variable in direction by Saturday due to the surface high settling into the southern Great Plains. Global NWP guidance is in agreement of a cyclonically-breaking wave event occurring over the northern U.S. by Sunday. Several wavelets associated with a high-latitude extension of a Pacific jet streak will translate over far northern Canada and drive negative momentum fluxes that will force the phased jet stream southward over the Rust Belt, with an expectation for it to evolve into a longwave trough. Farther west, the subtropical ridge will deamplify in response to the cyclonically-breaking wave event, with the ridge potentially collapsing altogether or its center shifting southeast of the CWA. Cyclonic wave breaks are notorious for generating intense surface lows, and while this will occur over 1,000 miles away from W TX (i.e., Ontario), it will have a substantial effect on the forecast for next week. The all-time record high sea-level-corrected pressure values are in the 1032-1034 mb range across the northern Great Plains and into southern Canada for 12Z Monday, but global NWP guidance indicates that the surface high will be a few millibars short (e.g., between 1024-1028 mb). NAEFS/ENS also indicate that the normalized pressure anomalies are nearly three standard deviations above the climatological mean across those regions, which has statistical significance for August. A synoptic-scale cold front is forecast to dive southward across the entire Great Plains early next week as the surface high rotates south of the 49th parallel, but global NWP guidance remains bifurcated on the timing of the cold front (on the order of a day). Regardless, there is increasing confidence in a much cooler pattern to encompass the CWA, especially by the middle of next week. Following the demise of the subtropical ridge, the upstream effects of the cyclonic wave break should allow a split-flow regime to evolve over the western U.S., with the potential for a southern-stream shortwave trough to emerge over the Desert Southwest and into the High Plains. Therefore, chances for showers and thunderstorms remain forecast area-wide throughout the early and middle part of next week. Sincavage && .AVIATION... (12Z TAFS) Issued at 545 AM CDT Thu Aug 21 2025 VFR conditions will prevail. && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...09 LONG TERM....09 AVIATION...51