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