776 FXUS64 KLUB 281743 AFDLUB Area Forecast Discussion National Weather Service Lubbock TX 1243 PM CDT Sun Jul 28 2019 .AVIATION... VFR will continue to prevail this period, complete with plenty of mid-high clouds and even a batch of afternoon boundary layer cumulus. Thunder chances will increase modestly at the terminals late this evening/tonight, but limited storm coverage/duration make confidence in any direct impacts too low for a mention in the TAFs. Breezy southerly winds this afternoon will become light and variable overnight as a weak front sags into the area. && .PREV DISCUSSION... /issued 1008 AM CDT Sun Jul 28 2019/ UPDATE... A few elevated showers, along with a solid deck of mid-upper level cloudiness, were making their way out of eastern New Mexico into the southwest Texas Panhandle and western South Plains. Much of the rain sampled by radar is likely drying up before reaching the ground, but at least small pockets of sprinkles and light showers are surfacing. Clovis recently reported light rainfall, though only trace amounts, and no WTM has reported measurable rain to this point. That said, did increase cloud cover in the sky grids over roughly the western half of the CWA through mid-afternoon. Also, added an isolated shower mention across the west through the the remainder of the morning, while maintaining a slim thunderstorm mention over the northwestern most zones later this afternoon. More robust thunderstorm activity is still expected to evolve late this afternoon into this evening. The initial storm development will occur over the higher terrain of New Mexico as well as along a weak cold front that will sag into northeast New Mexico and the northwest Texas Panhandle by peak heating. This activity will propagate southeastward, and should begin to affect our far northwestern counties by around 00Z. Both deep layer shear and instability will be up from recent days, but that isn't really saying much as they will still both be on the meager side. Still, they may be sufficient to support a couple of stronger storms capable of producing gusty downburst winds, small hail and locally heavy rainfall into the evening hours. The overall coverage and intensity of convection should decrease by late evening, but at least a few showers could linger well into the night. The ongoing forecast has a good handle on this and no adjustments have been made to the grids beyond this afternoon. PREV DISCUSSION... /issued 318 AM CDT Sun Jul 28 2019/ DISCUSSION... Once again seeing mid-level returns on radar this morning associated with a band of mid-level moisture across the region. Hard to tell if anything is reaching the ground as the returns are doing quite nicely missing regional observation and West Texas Mesonet stations. Trend so far has been for this activity to remain north of this forecast area and have opted to keep mention of any precipitation out of the forecast for early this morning. Attention then turns to the shortwave moving out over Colorado which will continue to slide southeast while a weak front pushes south into the northern Texas Panhandle and northeast New Mexico through the day. The front should provide a focus for storms development and northwesterly flow aloft, thanks to the center of the ridge continuing to slide east through they day, should steer any storms into our forecast area late tonight into early Monday morning. Biggest question remains coverage of storms; models have backed off quite a bit on the aerial extent and the 00Z ECMWF has removed PoPs completely for tonight into tomorrow morning. Higher resolution TTU-WRF and NSSL CAMs are showing lesser extent of coverage as well and those that do have convection keep it across the western South Plains. Various flavors of CAPE measurements keep the best instability across the western third of the forecast area still between 500-1000 J/kg but generally on the lower end of that range. Forecast soundings show that the biggest problem is a lack of boundary layer moisture and a deeply mixed layer up to between 8-10kft. Out west, this looks to actually help as parcels lifted out of the mixed layer should be able to tap into mid-level moisture to produce convection while the eastern two- thirds of the forecast area see parcels with not enough moisture to work with remain capped. All that to say that we kept PoPs pretty much unchanged from previous forecasts and this is under what the model blends have especially out west (40s vs 65-70 percent). High cloud bases and limited moisture make it appear that damaging wind from microbursts could be the main issue to deal with any storms that form. Storms may linger into Monday morning before dissipating after sunrise as the shortwave pushes south of the region. After that, the ridge will rebuild so that the center is generally somewhere over northeast New Mexico into southwest Kansas. This is close enough to help bump up high temperatures above normal but not directly overhead so that the heat becomes oppressive. Expect readings near the century mark for the Rolling Plains with mid to upper 90s for the Caprock through Friday. Uncertainty increases after that for how things will unfold with the ECMWF continuing to bring an easterly wave across South Texas but a bit further south this run compared to yesterday's 00Z run. The GFS remains weaker with this feature with the only similarities between the two being slightly lower thickness values so temperatures may drop back down to normal for the upcoming weekend. Jordan && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ 23