736 FXUS64 KLUB 221125 AFDLUB Area Forecast Discussion National Weather Service Lubbock TX 625 AM CDT Fri Apr 22 2022 .AVIATION... MVFR conditions are expected to continue at LBB & PVW through much the morning, with CDS falling below below VFR CIGs around sunrise. Windy conditions are expected to remain through the TAF period. There will be a chance of showers and thunderstorms this evening, mainly near LBB & PVW; however, confidence remains too low to include in this TAF cycle. && .PREV DISCUSSION... /issued 353 AM CDT Fri Apr 22 2022/ SHORT TERM... Early morning upper-level water vapor imagery shows a shortwave trough moving across the western CONUS. At the surface, analysis of West Texas Mesonet surface observation show generally strong southerly flow across the region, with slightly more backed flow over the southeastern Rolling Plains. Winds across much of our region will back some as a surface trough moves south across the Texas Panhandle. These southeasterly winds will continue to advect moist air across the CWA, with low-60s dewpoints already noted over the Rolling Plains and southern South Plains and mid-60s dewpoints starting to edge into the southeastern Rolling Plains. This moist upslope flow will result in low clouds through the morning and maybe early afternoon hours. With the surface trough dropping south, the surface gradient will tighten across the region and result in winds of 25-35 mph gusting up to 50 mph. Thus, a Wind Advisory has been issued for the entire area from 1 PM today through 1 AM tonight. Low clouds should mix out during the early afternoon hours, allowing for significant daytime heating across the area. With generally clear skies over eastern New Mexico and the western South Plains, the dryline will sharpen over near the NM/TX state-line and is expected to remain near the state-line through much of today. SBCAPE values of 1500-2000 J/kg are expected this afternoon across the area; however, storms will struggle to fire during the afternoon hours, as a strong CAP will exist. As the aforementioned upper trough moves closer to the region this afternoon, cooling aloft will result in increased lapse rates. Additionally, lift from an approaching shortwave embedded in the main trough and an increasing low-level jet will help to lift the lower levels, resulting in additional reduction of the CAP and an increase in SBCAPE and low- level shear. As lift increases near the vicinity of the dryline and the dryline bulge some due to the low-level jet, storms should start to fire over the southwestern Texas Panhandle and northern South Plains. With SBCAPE values of 2500-3000 J/kg, cloud layer shear around 50 kt, and a supportive hodograph, supercells will be possible, and all hazards are on the table. However, the main concern will be large hail, possibly greater than 2 inches, and wind gusts of 60-70 mph. Even though the sub-cloud layer is relatively dry, with precipitable water values nearing the daily maximum, a right mover could result in localized flooding. Storms are expected to move into a more stable environment as they move into the Rolling Plains after dark, which should result in them weakening some. Even with storms weakening as they move east of the Caprock escarpment, there will still remain a low possibility of locally heavy rain, large hail, and wind gusts of 60 mph. With all that said, today is not a slam dunk as the CAP may hold. A cold front will move into the area early tonight, bringing additional chances of precipitation to the southern Texas Panhandle and Rolling Plains; however, chances of rain remain low behind this boundary. GKendrick LONG TERM... Dry, confluent mid level southwest flow will be across the Texas South Plains region Saturday behind the upper closed low moving northeast into the northern plains. An upper 990s millibar Surface low pressure center is expected to move east across the Oklahoma panhandle Saturday while a Pacific cold front will cross the area early in the day, shoving majority of low level moisture and instability just south and east of our area during the afternoon and evening. The drier atmosphere should mix to around 650 millibars tapping into stronger mid level flow. Saturday will be modestly windy, mostly in the 20 to 30 mph range, though cannot rule out some areas having sustained 30 plus mph requiring Wind Advisory again. Thunderstorm chances will remain mostly east and south, but we will retain small chance in our southeast corner of eastern Stonewall County. A surface high pressure ridge will settle southward into the area Saturday night behind a continental cold front, and will help hold the frontal boundary just south and east of the area into Sunday morning. But another upper trough is expected to carve out over the southern and central Rockies Sunday with backing upper flow again across the South Plains region. This should pull moisture and instability back northwest with increasing thunder chances favoring the Rolling Plains although a capping inversion near 750 millibars appears may again limit thunderstorm potential. But instability and shear again will be favorable for hail growth should the cap weaken, making this another conditional event. This upper trough will pull east Monday and drier mid level northwest flow will follow later in the day. Relatively cool temperatures will continue Monday and Tuesday before an upper ridge lifts overhead Wednesday and then east Thursday and Friday with increasing southwest flow and warmer temperatures later in the week. Another upper low will move into the intermountain west late next week - trends thus far indicate this low will remain a bit further north and west as it approaches through the Rockies. RMcQueen FIRE WEATHER... Drying west to southwest winds will move across the area Saturday with deep enough mixing to tap into stronger flow in the 850 to 700 millibar level. Solutions in fair agreement indicating a trifurcated wind pattern across the area (three separate parallel strong wind corridors) which is typical for moderately strong west-southwest flow. Anyway, wind speeds should be at least 20 to 25 mph and humidity will again drop into single digits while this area is unlikely to receive enough rainfall later today and tonight to diminish wildfire concerns. A Fire Weather Watch is in effect late morning through mid evening Saturday for the entire area. RMcQueen && .LUB WATCHES/WARNINGS/ADVISORIES... Fire Weather Watch from Saturday morning through Saturday evening for TXZ021>044. Wind Advisory from 1 PM this afternoon to 1 AM CDT Saturday for TXZ021>044. && $$ 10/05/10