257 FXUS64 KTSA 312234 AFDTSA Area Forecast Discussion National Weather Service Tulsa OK 434 PM CST Sun Jan 31 2021 ...UPDATE... .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. The main aviation concern is timing how quickly the ongoing MVFR ceilings at all terminals except MLC will improve. FYV/XNA/ROG will be the last to see the improvement, with ceilings persisting through at least mid morning tomorrow. BVO/TUL/RVS/FSM have the greatest uncertainty at this point, as these terminals are on the edge of the eroding deck. Expect that some of this will fill in once again with sunset, but the satellite loop also shows a non- trivial eastward progression of the clearing line even upstream in Central Kansas. Will keep the MVFR ceilings at TUL/RVS through mid evening, at BVO through late evening, and at FSM into tomorrow morning. Wind-wise, directions will remain from the north to northwest through the period, with gustiness dropping off this evening. && .PREV DISCUSSION... /Issued 256 PM CST Sun Jan 31 2021/ DISCUSSION... The backside of a mid/upper level low pressure currently centered near the Ohio River Valley continued to push low level cloud cover within northwesterly flow across most of Eastern Oklahoma and Northwest Arkansas this afternoon. These clouds are expected to continue to be slow to erode overnight with far Eastern Oklahoma and Northwest Arkansas forecast to remain cloudy overnight. Further west over Eastern Oklahoma...there is potential that parts of the area could clear out overnight...especially west of a Bartlesville to Eufaula to Talihina line . In response...cloud cover should keep lows from bottoming out with low temps tonight falling into the mid 20s to lower 30s across the CWA. The cloud cover is forecast to erode from southwest to northeast during the day Monday and should hopefully exit far Northwest Arkansas by late afternoon as the low pressure system and associated upper trof axis nears the East Coast. Lighter winds and more sunshine forecast Monday afternoon will aid in warmer temps for the CWA with highs in the 40s/low 50s forecast. A warming trend continues through mid week with the return of southerly flow and a ridge of high pressure setting up over the Plains. Wednesday looks to be the warmest day for much of the CWA with southerly winds becoming gusty in the 20-30+ mph range ahead of the next cold front forecast to move into the region Thursday. These winds look to continue Wednesday night as the front approaches...which combined with increasing low level moisture...temps Wednesday night do not look to fall all that much and even could rise slightly overnight. During the day Wednesday...a wave is progged to drop southeast out of Western Canada while at the same time a second shortwave is forecast to push onto the West Coast. The longwave trof axis and associated cold front are forecast to drops southeast across the CWA during the day Thursday with the second shortwave looking to move across the Southern Plains Thursday night/Friday. Rain chances become possible during the day Thursday as the front moves through the CWA. There continues to be some differences within the details for moisture as the GFS continues to hold precip over the CWA Thursday night while the deterministic run of the ECMWF had Thursday night dry. Ensemble runs indicate that there maybe some pops holding on Thursday night. Thus...have continued small pops overnight. Colder air behind the front could allow for some wintry weather for parts of Northeast Oklahoma and far Northwest Arkansas late Thursday night into early Friday morning. Over the weekend...the upper level longwave trof remains across the Plains with another disturbance pushing across the region Saturday into Sunday. Behind the weekend system...arctic high pressure is progged to drop southward through the Plains with the coldest temps of the season thus far possible Sunday. Wintry weather will again be possible Saturday/Saturday night before the majority of the moisture pushes eastward with the departing system. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && $$ AVIATION.....22