Area Forecast Discussion
Issued by NWS
Issued by NWS
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970 FXUS64 KLUB 300538 AFDLUB Area Forecast Discussion National Weather Service Lubbock TX 1238 AM CDT Tue Apr 30 2024 ...New AVIATION... .SHORT TERM... (This evening through Tuesday) Issued at 246 PM CDT Mon Apr 29 2024 Zonal flow aloft will continue over the forecast area tonight while at the surface a low will develop in eastern Colorado. This will allow a return of southerly and southeasterly surface winds which will bring moisture back into the forecast area with surface dewpoints climbing into the 50s and 60s east of the Caprock escarpment. This will keep temperatures warmer across the Rolling Plains and far southeastern Texas Panhandle in the mid 50s to lower 60s while on the Caprock overnight temperatures will drop into the upper 40s to mid 50s. The surface low will slide southeast during the day tomorrow into the Oklahoma Panhandle which will tighten the surface pressure gradient across our forecast area and continue to drag a plume of surface moisture northward. As mixing increases, drier air aloft will mix down to the surface causing a diffuse dryline to setup near the edge of the Caprock. Forcing along the dryline will be weak and large scale lift won`t be strong as a weak disturbance moves overhead in the nearly zonal flow. However, with temperatures warming into the lower 90s for much of the area this will be sufficient for thunderstorm development as it will be nearly uncapped with convective temperatures around 90 degrees. Based on the uncapped nature of the atmosphere scattered thunderstorms seem likely during peak heating wherever the strongest thermals occur and where surface dewpoints remain in the mid and upper 50s. If mixing manages to lower dewpoints into the 40s across our area by the afternoon, which some guidance shows, then thunderstorm development will be less likely within our area. Assuming the higher dewpoints remain, the environment will be characterized by around 2000 J/Kg of MLCAPE along with around 30 kts of bulk shear hence supercells would be the favored storm mode with large hail and damaging winds the primary threat assuming that destructive storm interference doesn`t occur. With relatively weak steering flow, any right moving supercell will move fairly slow to the east hence locally heavy rainfall may also be possible. Thunderstorm activity will come to an end a few hours after sunset. /WI && .LONG TERM... (Tuesday night through next Sunday) Issued at 246 PM CDT Mon Apr 29 2024 Dryline convection will be possible once again Wednesday afternoon and evening. As of current, models are in decent agreement with having isolated convective initiation near/just east of the I27/US 87 corridor. Severe potential will still exist with this activity as bulk shear will be in the realm of 30 kt with CAPE over 2500 J/kg. Large hail over 2 inches in diameter and winds up to 70 mph will be the main concerns with storms that develop. Chances for severe convection will be extremely limited Thursday as a cold front pushes into the region Thursday morning. This will help cool temps from the 80s/90s Wednesday to the 70s Friday. Models disagree with precip/convective chances late Friday afternoon and evening. The ECMWF is relatively dry and has the surface cold front in eastern New Mexico 00Z Saturday. The GFS has the frontal boundary/dry line across our western zones by the same time with convection developing along the boundary by 00Z. There is better agreement, however, with precip chances late Saturday into Sunday morning. Surface flow is progged to remain mostly out of the east to southeast as a disturbance develops in the over head southwesterly upper flow providing the region with elevated convection. && .AVIATION... (06Z TAFS) Issued at 1226 AM CDT Tue Apr 30 2024 VFR conditions are expected to prevail through the period at all three TAF sites. Low level wind shear out of the southwest at 40 knots around 800 feet is expected at all three sites this morning as the low level jet ramps up. Southwesterly surface winds will increase through the afternoon hours to around 15 to 20 knots with higher gusts up to 30 knots possible. Winds will turn southerly this evening and diminish to around 10 to 15 knots. Scattered thunderstorms are possible this afternoon and evening, but are expected to remain south and east of all TAF sites. && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...58 LONG TERM....51 AVIATION...11