866 FXUS64 KLUB 181123 AFDLUB Area Forecast Discussion National Weather Service Lubbock TX 623 AM CDT Sat Sep 18 2021 .AVIATION... VFR conditions will prevail through this TAF period. Isolated showers and thunderstorms may develop this afternoon and evening across the Caprock. Although, confidence in activity directly impacting KLBB/KPVW remains too low to include in the TAF at this time. Winds will remain relatively light and primarily out of the southeast today. /WCI && .PREV DISCUSSION... /issued 302 AM CDT Sat Sep 18 2021/ SHORT TERM... Surface cold front has become diffuse this morning across the forecast area. As of 2:30 am, an area of showers and thunderstorms has been slowly decaying across the eastern Rolling Plains however isolated showers and thunderstorms continue to develop along an outflow boundary that is moving to the south. This activity should come to an end closer to daybreak this morning. It also appears to be responsible for the development of a weak MCV which, as of 2:30 am, was located over Motley County and is expected to slowly drift to the south this morning. Upper level ridge will remain overhead today which will lead to a continuation of the warm temperatures with most locations in the upper 80's to low 90's. Low level flow will slowly transition to the east/southeast today which will help to advect some low level moisture into the Caprock today. This moist upslope flow combined with afternoon temperatures near the convective temperatures should allow for isolated shower and thunderstorm development for locations on the Caprock. If the MCV remains in the area it too may enhance convergence near the edge of the Caprock which may lead to a more preferential zone for thunderstorm development this afternoon hence this feature will have to be tracked. If development can occur, MUCAPEs of around 1000 J/Kg along with a deeply mixed boundary layer could support a few strong downburst wind gusts. With the loss of daytime heating shower and thunderstorm activity should come to an end this evening leading to a quiet night with overnight lows in the 60's. /WCI LONG TERM... A couple of new twists in the forecast guidance this morning, most of which will likely not be noticable, but there nonetheless. A trough coming ashore the Pacific northwest, BC coast, will phase with a remnant trough that developed out of a disturbance off the coast of California. To our east, a closed low will continue its trek through the ArkLaTex while we remain under the influence of weak ridging between these two features. The remnant California trough will evolve to not much more than a subtle kink in the overall flow and the feature will move north of the area on Sunday. This will be followed by the more vigorous Pac NW shortwave tending to dig/sharpen/become more neutrally tilted as it makes its time of closest approach early Tuesday morning. From mid week, NW flow aloft returns ahead of mid-level ridging. Another trough could approach by late week though guidance diverges rapidly after Wednesday. Sunday will be dry with southwesterly surface flow (though not particularly strong) continuing into Sunday night. By Monday, a surface trough/dryline will develop, initially over eastern NM, and swing into the CWFA. This will occur ahead of a southward moving cold front which is due in by late Monday afternoon. Compressional heating south of the frontal boundary, which will be stuck in the Panhandle during much of the afternoon, suggests Monday will be the warmest of the next week. A low risk of convection, firing along a triple point in our northeastern counties, will exist Monday evening. That said, most of the area will remain dry but the noticable drop in humidity will make it feel a lot more fall like for Tuesday. High temps have trended up a bit since last night, but still quite pleasant. As a surface high builds into Oklahoma and light winds start, we'll see refreshing overnight lows on Wednesday morning down in the 40s and 50s area-wide. Could prove to be a great morning to open the windows and enjoy the fresh air of fall. Quiet weather looks to be in store for Wednesday and Thursday. The GFS is picking up on storms for Thursday night into Friday as opposed to the ECM which develops a cut off low across the desert southwest and keeps us dry. && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ 58/58/26