Area Forecast Discussion
Issued by NWS
Issued by NWS
122 FXUS64 KLUB 170517 AFDLUB Area Forecast Discussion National Weather Service Lubbock TX 1217 AM CDT Sun Aug 17 2025 ...New SHORT TERM, LONG TERM, AVIATION... .KEY MESSAGES... Issued at 1217 AM CDT Sun Aug 17 2025 - Scattered thunderstorms are forecast across the Caprock and Rolling Plains Sunday, with localized flash flooding possible. - Daily chances for storms will continue through the middle of this week, along with near-normal temperatures. && .SHORT TERM... (Today and tonight) Issued at 1217 AM CDT Sun Aug 17 2025 02Z upper air analysis depicts a retrograding subtropical ridge, with the 250 mb circulation remaining misaligned from its 500 mb center, the latter of which is broad yet well-defined over the ARKLATEX and Mississippi Alluvial Plain. Farther west, broadly cyclonic flow continued to expand over the Great Basin and into the western U.S. interior, ultimately repositioning the monsoon into a southwest-to-northeast-oriented manner. This is evident in recent trends in water-vapor imagery and the 17/00Z objectively analyzed UA charts compared to last evening. The 00Z balloons from WFOs AMA and MAF also observed warm mid-levels (i.e., subsidence) which increases substantially in magnitude farther east, and has resulted in the suppression of any thunderstorm development across the CWA, with the exception of the weakening storms along the NM state line. The intensification of the 250 mb jet streak along the downstream tranche of the shortwave troughing over the western U.S. interior will continue to advect several series of shortwave perturbations into the southern High Plains throughout the short-term period and induce lift in the mid/upper-levels, with improved chances for storms set to occur Sunday, especially across the Caprock, while remaining more-isolated in the Rolling Plains. However, elevated, WAA-induced rain showers, and perhaps an isolated storm or two, are forecast to evolve during the pre-dawn hours Sunday given the presence of a backed, low-level jet and saturation of the low-level isentropes. Coverage will be limited, as moist, isentropic ascent is solely driven by the nocturnal wind maximum beneath the moderate subsidence layer aloft. At the surface, winds were backed to the southeast in response to lee cyclogenesis in southeastern CO. The attendant surface trough branched southward from the OK/TX PH, and essentially along the longitude of the NM state line into the TX Big Bend. Winds will veer towards the south-southwest prior to sunrise Sunday before backing southward in response to the diurnal trends in lee cyclogenesis across southeastern CO, and the near-cardinal southerly direction of the winds will aid in boosting temperatures a degree or two warmer compared to Saturday when winds were backed to the southeast as the ridge moves overhead. An altocu castellanus field will already be present Sunday morning, and with the airmass becoming uncapped by the early afternoon hours, the bubbling cu field will evolve into widely-scattered-to-scattered showers and storms after 17Z/noon CDT Sunday, particularly on the Caprock. The severe weather risk will be tempered by warm mid-level temperatures; however, a few strong wind gusts near 50 mph will be possible with cells that can temporarily organize. Otherwise, heavy rainfall will be the primary hazard with storms Sunday. Storms are forecast to last into the early morning hours Monday, as the monsoon continues to deflect into W TX. Sincavage && .LONG TERM... (Monday through Saturday) Issued at 1217 AM CDT Sun Aug 17 2025 Isolated-to-widely-scattered showers and storms may be ongoing across portions of the CWA through the post-dawn hours Monday, as the decaying, monsoonal fetch will eventually become centered over the region. By this time, the mid/upper-level circulations of the subtropical ridge will begin to align over the southern Rocky Mountains. As mentioned in the previous discussions, this will terminate the continuum of monsoonal advection into the region, resulting in slightly lesser storm chances area-wide by Monday night. An intense shortwave trough is forecast to dig into the Pacific Northwest during the overnight hours into Tuesday, with a strong, ageostrophic response resulting in the strengthening of the southern-stream 250 mb jet streak. This jet streak will eventually phase with the aforementioned shortwave trough, with its leading edge arcing around the apex of the ridge and diving southward towards the southern Great Plains by mid-week. A train of vorticity lobes will rotate through the intensifying flow arcing around the amplifying subtropical ridge, with geopotential heights rising to 598 dam at its center. However, a net-neutral response in geopotential heights will occur over W TX, as the ridge will have retrograded into the central Rocky Mountains, giving way to near-seasonably hot temperatures. The impingement of the vorticity lobes embedded within the belt of strengthening northerly flow will cause storm chances to peak Tuesday into Wednesday. Meanwhile, the mid/upper-levels will also remain semi-progressive over the 49th parallel, with a shortwave trough forecast to dig into the Upper Midwest by early Wednesday morning. Its attendant cold front is forecast to move into the CWA during this time, albeit weakening, which will knock temperatures down a couple of degrees before a drying trend follows to close out the week. NBM PoPs are similar to the prior prognostications, reflecting the continuity in the global NWP guidance, with the highest PoPs forecast Wednesday. Mesoscale details will become more clear over the next 48-72 hours. Sincavage && .AVIATION... (06Z TAFS) Issued at 1217 AM CDT Sun Aug 17 2025 Continued VFR. TS chances increase by this afternoon and evening from LBB-PVW, but potential is not enough to warrant mention in the TAFs at this time. && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...09 LONG TERM....09 AVIATION...93