FXUS64 KTSA 211529

Area Forecast Discussion
National Weather Service Tulsa OK
929 AM CST Wed Feb 21 2018


There were no major changes to the forecast this morning. PoPs
have been nudged north a bit this morning across E OK, and
sleet/ice amounts have been tweaked during the day today. The
configuration of the current winter weather advisory has not been
changed. See discussion below.



An upper level wave ejecting north out of old Mexico this morning,
on the eastern side of broad western CONUS trough, will bring the
next round of precip to the region, while round 1 gradually comes
to an end down in far SE OK. The models are in agreement that
light precip will gradually spread northeast over the region
mainly this afternoon and tonight in association with the
ejecting wave. Thermal profiles from the 12Z NAM suggest a mix of
sleet and frz rain for precip types, where temps are expected to
remain at or below frz. The latest obs from MLC suggest that light
sleet may be falling there currently. The current winter weather
advisory covers areas that are expected to receive the wintry mix
either now or later today, and thus no changes are planned at this
time. Updated text products have been sent.



.PREV DISCUSSION... /Issued 531 AM CST Wed Feb 21 2018/

Overall flight conditions will remain in the IFR category through
this forecast cycle. Widespread rain has largely shifted
southeast of the area for the time being, however some additional
light rain or freezing rain will spread back north across
southeast OK and possibly west central AR later this morning, with
another round of ice accumulating expected to impact northeast OK
by around 00z.

PREV DISCUSSION... /Issued 349 AM CST Wed Feb 21 2018/


Cloud cover along with surface ridging to our west/persistent
northeasterly surface winds will keep the shallow cold air in
place today, with much of eastern OK and far northwest AR
remaining near or below freezing. Morning precipitation will be
mainly confined to areas near or a little above freezing (far
southeast OK/western AR), although precipitation is expected to
lift back north through western/central OK later this morning and
into portions of eastern OK during the afternoon and into the
evening hours. RAP/NAM soundings suggest a mix of freezing rain
and some sleet, with the greatest accumulations generally along
and west of a McAlester to Vinita line. The risk of wintry
precipitation across northwest AR may hold off until beyond 00Z,
with the better chances arriving later Wednesday night.

While there are obvious uncertainties with how quickly
precipitation redevelops and areal extent, feel its prudent to go
ahead with another winter weather advisory for a large portion of
eastern OK and into far northwest AR beginning this afternoon and
continue through Wednesday night. Precipitation looks to taper off
later tonight/early Thursday morning although later shifts will
need to monitor the ending of the advisory.

The active southwesterly flow will continue, with additional
periods of showers/isolated storms expected later Thursday
afternoon into early Saturday. Rainfall axis looks to set up
across southeast OK into northwest AR during this period, with
additional heavy rainfall expected across areas that have received
2-4 inches of rain over the past few days. We'll likely need flood
headlines, but will hold off for now.

A more pronounced trof axis will swing through the region later
Saturday, with a drying/warming trend expected going into next


TUL 31 30 47 38 / 40 60 60 60
FSM 41 39 53 47 / 60 50 50 90
MLC 34 32 50 41 / 60 50 60 80
BVO 32 30 43 34 / 40 70 60 50
FYV 36 34 53 43 / 40 40 50 80
BYV 33 32 53 45 / 40 40 40 80
MKO 34 32 50 41 / 40 50 60 70
MIO 32 31 49 39 / 20 50 50 60
F10 31 30 47 39 / 60 50 60 70
HHW 41 37 53 48 / 90 50 70 80


OK...Winter Weather Advisory until 6 AM CST Thursday for OKZ054>067-

AR...Winter Weather Advisory until 6 AM CST Thursday for ARZ001-002.



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