460 FXUS64 KLUB 050557 AFDLUB Area Forecast Discussion National Weather Service Lubbock TX 1257 AM CDT Mon Jul 5 2021 .AVIATION... A line of thunderstorms are moving south out of the Texas Panhandle this morning capable of producing strong straight line winds. These thunderstorms will remain west of KLBB and KPVW through the morning. Additional shower and thunderstorm development will be possible area wide closer to sunrise this morning however confidence in exact timing/location remains too low to include in the TAFs at this time. Low ceilings are possible at KLBB/KPVW this morning with MVFR to IFR conditions possible by sunrise. These low clouds will gradually dissipate by mid to late morning leading to mainly VFR conditions for the rest of this TAF period. Additional thunderstorms will be possible this afternoon and evening but again timing/location is too uncertain to mention in the TAFs. /WCI && PREV DISCUSSION... /issued 155 PM CDT Sun Jul 4 2021/ SHORT TERM... Northwest flow storms will be the main story over the next 24 hours with a potential for severe weather associated with this activity. An upper level ridge will be centered over the four-corners region today through tomorrow. We may see some upper level support with convection this evening and overnight. A short wave was diving southward on the east side of the upper ridge. A weak speed max at 250mb was also over Colorado following this short wave trough. The latest RAP analyzes this speed max around 45kt and will shift farther to the southeast into the Texas Panhandle this evening. This feature was already initiating thunderstorms in the eastern Texas Panhandle this afternoon. A surface pressure trough has formed in eastern New Mexico in response to this upper level shortwave over the Central Plains. A north-south oriented frontal boundary extends farther north from northeastern New Mexico. Initial development of widespread convection will be favored along this boundary and will not likely reach the extreme southwestern Texas Panhandle until after 00Z. Storms that do maintain their strength as they move out of the Panhandle will be met by very rich low level theta-e air. However, given how moist the atmospheric column has been over the past few weeks, lapse rates will not be too impressive over the South Plains. Much stronger mid level lapse rates will exist farther north which will allow progged CAPE values to taper off the farther south you travel. Despite the weak lapse rates, very moist low levels of the atmosphere will allow for 0-1.5km mixed layer CAPEs peaking around 1500-2000 J/kg. The 0-1.5km layer looks to be the most representative average mixed layer today across the entire South Plains region. Increasing CIN over the South Plains during the late evening hours and overnight will likely limit the southern extent of convection. Deep layer shear will further increase this afternoon and evening ahead of an expected convective complex. This should be able to garner some organization to the convection into the South Plains. Although storms will be fairly quick moving, heavy rainfall and flooding will still be possible. Precipitable water values are still abnormally high for this time of year which will be able to generate heavy rainfall. LONG TERM... Isolated-to-widely scattered rain showers and thunderstorms are forecast to develop Tuesday afternoon and evening, especially across the western portions of the CWA where low-level convergence is greatest in vicinity of the surface trough. A multi-cellular storm characteristic is expected once again, and it is uncertain just how far south the cold front will move late Tuesday into Wednesday, which may have implications on mean convective movement (i.e. advection vs. propagation). Regardless, a localized risk for flash flooding given saturated soils as per recent West Texas Mesonet data will be possible as little drying of the ground is forecast through mid-week. If the cold front is able to cross into the Texas Panhandle region, an isolated wind-damage risk may also develop within the best-organized cold pools as multi-cells would attempt to transition into loosely-organized line segments. The front is then forecast to move northeastward on Wednesday as a weakly baroclinic trough pivots across the northern Great Plains and into the Upper Midwest, with the mid/upper-level ridge centered over the Desert Southwest expanding eastward Wednesday into Thursday. Precipitation chances will decrease accordingly with warm-to-hot temperatures forecast given the gradual build in geopotential heights by the end of next week. Sincavage && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ 58/99/99