608 FXUS64 KLUB 070525 AFDLUB Area Forecast Discussion National Weather Service Lubbock TX 1225 AM CDT Fri Sep 7 2018 .AVIATION... Not a straight forward TAF forecast this early morning with a tropical airmass in place. Expect cigs to bounce around, mainly between MVFR and IFR as the morning progresses. Spotty shower activity during this TAF period is expected to give way to more expansive showers across all three TAF sites during the day Friday. Expect amendments. && .PREV DISCUSSION... /issued 719 PM CDT Thu Sep 6 2018/ DISCUSSION... Quick update to reduce precip to slight chance this evening on the Caprock where a low-level theta-e minimum persists. We still expect an uptick in precip later tonight as an axis of deeper moisture drifts southwestward from western Oklahoma and NW Texas on northeasterly winds. Some indication of this is already underway in the form of scattered storms in the southeast Panhandle, although the westward progress of this activity will likely be stunted more than the NAM and GFS suggest given stubborn theta-e deficits downstream. The threat for some flooding overnight is greatest off the Caprock where training cell motions coincide with very rich PWATs already nearing 2 inches. MCZ AFTERNOON FORECAST DISCUSSION... /issued 335 PM CDT Thu Sep 6 2018/ DISCUSSION... So far this afternoon, convection has been limited to the Rolling Plains with a pocket of relatively stable air across the South Plains as indicated by the lack of developing cumulus. Models seem to have picked up on this a bit but still have varying amounts of coverage this afternoon through tonight. Will continue chance PoPs across the forecast area as there could be additional development overnight tonight. Cool weather will also continue through Saturday ahead of and with the trough axis passing overhead with highs remaining in the upper 70s to near 80. Main uncertainty will be the coverage and timing on precipitation chances which the models have had a poor handle on. In general, the best precipitation chances will remain over the Rolling Plains which will have a longer amount of time east of the trough axis with decreasing PoPs as you head northwest across the forecast area. Trough axis will swing east of the area during the day Saturday which should finally remove the widespread rain chances we have seen the past several days. However, northwest flow develops behind the departing trough as the ridge starts to develop west of the forecast area. Both the GFS and ECMWF bring a weak shortwave down towards the area Saturday and Sunday evenings which could result in some isolated storms making it into the northwestern South Plains and far southwestern Texas Panhandle. Will keep slight chance PoPs in the forecast for this. After Sunday, we should see the ridge start to build and move over the region by Thursday of next week. Warmer temperatures, but still near normal, and dry conditions are expected. Models are still trying to figure out how the flow pattern will evolve so this may change as we head into next week. Jordan && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ 99/99/74