718 FXUS64 KLUB 091120 AFDLUBArea Forecast Discussion National Weather Service Lubbock TX 620 AM CDT Tue Sep 9 2025
...New AVIATION...
.KEY MESSAGES... Updated at 615 AM CDT Tue Sep 9 2025
- Isolated thunderstorms, some severe, will be possible across portions of the Caprock this afternoon and evening.
- Dry and hot weather is expected Wednesday through Friday.
- Low storm chances remain forecast this weekend.
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.SHORT TERM... (Today and tonight) Issued at 1223 AM CDT Tue Sep 9 2025
In the mid/upper-levels, a closed low embedded within an amplifying, neutrally-tilted trough was rotating over Cape Mendocino and into the Klamath Mountains. Farther east, the subtropical ridge continues to steadily amplify over the Intermountain West and is beginning to emerge into the High Plains, with predominately northwest flow advecting over the CWA. The 09/00Z objectively analyzed UA charts observed a negligible change to the geopotential heights despite the deep-layer flow veering northwestward, as the apex of the ridge is located over the central Rocky Mountains. The subtropical ridge will continue to shift eastward over the next 24 hours, as the shortwave troughing to the west begins to pivot into the Great Basin while becoming more sharply cyclonic. This will maintain the position of the leading edge of the southern-stream 250 mb jet streak over the CWA, resulting in a corridor of strong divergence beneath what will be an uncapped airmass by peak heating Tuesday afternoon.
At the surface, the CWA remains within a broad fetch of moist, southerly-to-southeasterly flow, with a diffuse trough located along the edge of the Mescalero Escarpment that connects to a lee cyclone near TCC. Little change to the state of the airmass is expected throughout the short-term period, as surface troughing will remain parked to the west of the NM state line due to the subtropical ridge shifting over W TX. The combination of increasing geopotential heights and full insolation will allow temperatures to breach 90 degrees area-wide Tuesday afternoon, with winds remaining backed to the south-to-south-southeast in response to cyclogenesis near the Raton Mesa. Deep mixing of the boundary-layer will occur, with mixing heights soaring into the mid-levels and LCL/LFCs rooted near 700 mb. (An inspection of the 09/00Z RAOB from WFO ABQ sampled the PBL top near 600 mb amidst west-northwesterly flow.)
Isolated-to-widely-scattered, high-based thunderstorms are forecast to form along the aforementioned surface trough, with storms crossing the NM state line after 21Z. The weak steering flow will govern propagation versus advection, with storms propagating along outflow(s), which may result in constructive interference during the late afternoon hours such that a loosely-organized cluster or two may develop. Inverted-V boundary-layer profiles beneath sufficient hydrometeor-loading of updrafts will maximize outflow-related theta deficits beneath cloud base, with the potential for a few storms to generate severe-caliber wind gusts up to 70 mph. Hail up to the size of quarters may accompany the best-organized cores, especially if a cell can develop a mid-level mesocyclone and attain a rightward propagation component to its movement. Heavy rainfall will remain localized, with a limited potential for flash flooding.
The orientation of the storm-relative winds at anvil-level will also cause anvils to advect southeastward in the path that cells will be propagating, which may result in some pre-stabilization of the airmass before nocturnal decoupling of the boundary-layer occurs after dark. This should keep storm chances confined solely to the Caprock through Tuesday evening, with storms diminishing entirely after dark due to the effects of diabatic stabilization and the subsidence aloft. Low PoPs (i.e., 20-percent/slight chance) introduced by the previous shift have been redrawn across most of the Caprock between 21Z-10/03Z. Fair weather will follow heading into Wednesday morning, with mild temperatures and light winds.
Sincavage
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.LONG TERM... (Wednesday through Monday) Issued at 1223 AM CDT Tue Sep 9 2025
The previous forecast assessments remain on track, with little change necessitated for this package. At the beginning of the period, the subtropical ridge will be centered over the Great Plains ahead of a sharply cyclonic, neutrally-tilted trough wobbling over the Sierra Nevada Mountains. Large-scale subsidence will preclude any potential for storms Wednesday through Friday, and a persistence forecasting technique has once again been applied for each of those days due to the slow, eastward progression of the subtropical ridge and near-neutral geopotential height tendencies. Above-normal high temperatures continue to be forecast Wednesday through Friday, with highs peaking in the lower-middle 90s area-wide, which is about 5-7 degrees above seasonal norms.
Global NWP guidance continues to converge on the timing of an anticyclonic wave break over the polar latitudes by the end of the week and into this weekend, with a well-defined PV anomaly propagating towards the Pacific coast. The sharply cyclonic trough previously meandering over the Great Basin should become open by the weekend and eject into the central Great Plains, and there appears to be an indication of a gyre-like behavior to the cyclonic flow to evolve over the Intermountain West as the aforementioned PV anomaly moves onshore. Ultimately, should a cyclonic gyre attempt to evolve or become established, its position will dictate PoPs for the weekend and into early next week. Therefore, low storm chances continue to be reflected for the tail-end of the forecast period, but adjustments will be made as the week progresses and global NWP guidance converges on the state of the upper air pattern.
Sincavage
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.AVIATION... (12Z TAFS) Issued at 615 AM CDT Tue Sep 9 2025
A deck of MVFR to IFR stratus was observed developing about 60 NM to the southwest of LBB at 11z, and is likely to continue spreading north-northeastward through the next couple of hours. As of time of issuance, it appears that this stratus should remain west of the terminals. Still, a period of MVFR or perhaps even IFR CIGs is possible at LBB should this stratus deck expand more than expected, but confidence in this occurring is low. VFR will then prevail area-wide from late morning through the rest of today. This afternoon, isolated to scattered TSRA are expected to develop near the TX/NM state line and shift eastward through the evening hours. Some convective impacts to the terminals are possible after 21z, but confidence in timing and coverage of convection is too low to add thunder mention to the TAFs at this time.
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.LUB WATCHES/WARNINGS/ADVISORIES... None. &&
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SHORT TERM...09 LONG TERM....09 AVIATION...30
NWS LUB Office Area Forecast Discussion