Area Forecast Discussion
Issued by NWS
Issued by NWS
983 FXUS64 KLUB 220525 AFDLUB Area Forecast Discussion National Weather Service Lubbock TX 1225 AM CDT Fri Aug 22 2025 ...New SHORT TERM, LONG TERM, 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 Tuesday, and will be accompanied by much cooler temperatures. - Thunderstorm chances return to the forecast area through most of next week. && .SHORT TERM... (Today and tonight) Issued at 1218 AM CDT Fri Aug 22 2025 Strong subsidence associated with the subtropical ridge over the Four Corners region will continue to advect into W TX throughout the next 24 hours. SIGWX NIL. Sincavage && .LONG TERM... (Saturday through Thursday) Issued at 1218 AM CDT Fri Aug 22 2025 In the mid/upper-levels, the subtropical ridge centered over the Four Corners region will begin to deamplify Saturday, as a pair of 250 mb jet streaks will phase over the 49th parallel and begin to dig southeastward into the Upper Midwest in congruence with the development of a high-amplitude, longwave trough. A persistence forecasting technique was once again applied to most elements for Saturday and Sunday, with the exception of weak return flow becoming established Sunday in response to leeward pressure falls associated with lee cyclogenesis in eastern CO beneath the southwestern edge of the aforementioned jet streak. Global NWP guidance continues to converge on a cyclonic wave break event occurring over the northern U.S. by Sunday. Cyclonically-breaking wave events occur in a realm of higher frequencies relative to the anticyclonically-breaking waves (i.e., several wavelets are forecast to emanate out of the high-latitude extension of a Pacific jet streak). The southeastward translation of these shortwave troughs will result in a significant enhancement in the budget of negative momentum flux and cause the phased jet streak to dig southward into the Ohio River Valley/Rust Belt region, eventually evolving into a high-amplitude, longwave trough. Farther west, the subtropical ridge will shift southward while deamplifying in response to the development of the longwave trough, and it is possible that the ridge collapses entirely by the early part of next week. Cyclonic wave breaks are notorious for generating intense surface lows that ultimately drive very large isallobaric responses, and global NWP guidance continues to indicate the potential development of an upstream surface ridge between 1022-1028 mb across the Canadian Prairies and into the northern Great Plains from Sunday into Monday. 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. NAEFS/ENS continue indicate that the normalized pressure anomalies are nearly three standard deviations above the climatological mean across those regions, which has statistical significance for August. Intense frontogenesis will occur at the surface through the mid-levels as this longwave trough amplifies, and global NWP guidance has come into slightly better agreement with the timing of the cold front (i.e., sometime Tuesday compared to a difference of a day from 24 hours ago) that will have a heavily modifying cP airmass advecting southward in its wake. The strength of the respective surface ridge in the Canadian Prairies and northern Great Plains will correspond to the magnitude of baroclinity associated with the cold front. Prior to the arrival of the polar cold front, high temperatures will remain near seasonal norms, with substantially cooler temperatures forecast by the middle of next week. The upstream effect of the cyclonic wave break is forecast to cause a split-flow pattern to develop over the far northeastern Pacific Ocean and into the western U.S., allowing for shortwave perturbations to translate around and/or through the dampened, subtropical ridge over the southern Rocky Mountains. Prospects for showers and thunderstorms remain intact and continue to be forecast throughout most of next week as the cold front moves into the region and large-scale, moist, isentropic ascent cements its return from persistent, northwesterly flow aloft. Adjustments to the temperature forecast for next week will be necessary as the synoptic-scale evolution occurs over the next several days and NWP guidance becomes convergent. Sincavage && .AVIATION... (06Z TAFS) Issued at 1218 AM CDT Fri Aug 22 2025 VFR conditions will prevail. && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...09 LONG TERM....09 AVIATION...51