760 FXUS64 KLUB 201226 AAA AFDLUB Area Forecast Discussion...UPDATED National Weather Service Lubbock TX 626 AM CST Sun Dec 20 2020 .AVIATION... VFR will prevail for the next 24 hours. Winds will start out from the north and then slowly shift to the west this afternoon, but will remain light. && .PREV DISCUSSION... /issued 330 AM CST Sun Dec 20 2020/ SHORT TERM... Dry northwest flow aloft will dominate our weather pattern today creating another nice December day with light winds and sunny skies. Thanks to the continued northerly flow aloft and southwesterly flow at the surface todays high temperatures won't be too dissimilar from yesterday. Optimal radiational cooling tonight mean lows could be a few degrees cooler than last night, but still in the upper 20s to mid 30s. Upper level ridging begins to build in during the late afternoon from the west as surface winds turn southwesterly. LONG TERM... A dry progressive flow pattern will remain in place for the week ahead. A low amplitude upper ridge currently crossing the southwest coast will move across the southern Rockies and high plains Monday and early Tuesday. A weak shallow frontal boundary arriving early Monday from the Texas Panhandle will wash out and we will see highs Monday in the 60s about 10 degrees warmer than normal, then about 5 additional degrees of warmth Tuesday. Surface pressures expected to fall late Tuesday will lead to breezy or low-end windy conditions that may continue into early Wednesday. The pattern upstream will be undergoing buckling mid week as a strong upper jet crosses the Pacific and the next upper trough will arrive out of the Rockies amplified though still positively tilted. Solutions now indicate more energy and flow dipping into the southern part of the upper trough as it pulls through the Texas High Plains late Wednesday, though best energy and moisture will remain north and east of our area. The amplification appears will slow the cold front a bit and allow some warming Wednesday, but as is typical our area will be in the temperature transition zone during the day; the extreme southwest Panhandle may struggle getting into the 40s Wednesday while the southern Rolling Plains could climb even into the 60s before cold air settles in during the afternoon. Some potential for brief mid level saturation late Wednesday leading to virga but even prospects for a flurry are quite low and not mentioned in this forecast. Either way, cooler air will invade Wednesday night and Thursday with temperatures dropping several degrees below normal. Then, building upper heights Friday, Christmas Day, should allow warming close to normal. There is some potential for increasing mid or upper level moisture with an approaching weak low latitude upper trough cruising the US/Mexico border on Friday that could taper warming to some extent. This upper trough appears will pass through the area sometime next Saturday. Lacking significant moisture and energy, we expect a few additional degrees of warming Saturday. RMcQueen FIRE WEATHER... Approach of an upper level low pressure trough late Tuesday is expected to deepen surface low pressure across the high plains and lead to breezy or low-end windy conditions. The airmass is expected to remain dry and temperatures Tuesday will be nearly 15 degrees warmer than normal. Elevated or low-end Critical Fire Weather conditions are possible late Tuesday, mainly on the Caprock. Breezy and dry northwest winds may continue Wednesday though with cooler temperatures. RMcQueen && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ 99/99/28