Winter Weather in Oklahoma, February 6, 2018

Area Forecast Discussion
National Weather Service Norman OK
528 PM CST Tue Feb 6 2018

.DISCUSSION...
The 00Z aviation discussion follows....

&&

.AVIATION...
Radar continues to show bands of -FZDZ/-FZRA roughly southeast of
a line from F05-KLAW-KOUN-KTUL. The main precipitation area is
affecting the southeast and eastern parts of Oklahoma. The
precipitation should clear this evening from west to east, along
with increasing ceiling heights and (where they're currently
restricted) visibilities. Expect generally light north winds after
0800Z at all our TAF sites, along with VFR conditions, as high
pressure moves into the southern Plains from the north-northwest.

CmS
&&

.PREV DISCUSSION... /issued 401 PM CST Tue Feb 6 2018/

DISCUSSION...
Primary forecast issue is the ongoing freezing rain/drizzle
event.

For this afternoon/evening, isentropic ascent has resulted in
scattered showers across south central and southeast Oklahoma.
Temperatures will remain below freezing with a warm (>0C) layer
aloft, so freezing rain will be the dominant precipitation type.
Elevated instability suggests even isolated thunderstorms will be
possible near the Red River as well. Precipitation will continue
through this evening. Therefore, the current Winter Weather
Advisory will continue through midnight.

Farther northwest, closer to I-44, some freezing drizzle or light
freezing rain can't be ruled out--especially across the southeast
parts of the Oklahoma City metro (i.e., parts of McClain and
Cleveland counties). Forecast soundings for this evening indicate
there might be a tight gradient of low-level saturation with
soundings in Purcell indicating the potential for freezing drizzle
while soundings in OKC suggesting a low chance for freezing
drizzle. Even a few sleet pellets might be possible farther
northwest (if larger drops are able to develop) with a rather cold
and deeper low- level boundary layer. Observation trends will
have to be monitored this evening.

For tomorrow, another cold day is expected with northerly winds
continuing across the area. High temperatures will be ~10F below
average.

By Thursday, winds will shift to the south as the surface ridge
moves eastward. Southerly winds may become breezy across western
Oklahoma as the pressure gradient increases. Even warmer, above-
average temperatures are expected for Friday as downslope winds
across the west result in a warm air mass that will advect
eastward into the Southern Plains.

As a  shortwave trough passes by the northern Plains, a cold front
is expected to enter northwest Oklahoma late Friday. The GFS and
ECMWF have come into slightly better agreement with timing of the
frontal passage; however, the GFS is still slower than the ECMWF.
For example, the 06/12Z GFS has a high temperature of 58F on
Saturday at Oklahoma City while the ECMWF has a high of 32F.
However, the GEFS ensemble mean is 44F. Therefore, opted to trend
the forecast toward the faster ECMWF/GEFS ensemble mean. There
could be quite the north-to-south temperature gradient on Saturday
across the area.

In addition, both the GFS and ECMWF indicate ascent associated
with subtle shortwave(s) Friday night into Saturday. Some
precipitation (including post-frontal) will be possible. BUFKIT
soundings indicate a variety of precipitation types from freezing
rain to snow are all be possible. For now, went with broad
transition zones that gradually shift southward with time.
Precipitation amounts are currently expected to be light.

Any precipitation is expected to end by Sunday morning, but Sunday
will still be a rather cold day with temperatures around 20F below-
average. Warmer weather is expected by Monday as southerly winds
increase across the area.

Mahale

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  20  41  25  56 /  20   0   0   0
Hobart OK         19  46  25  57 /   0   0   0   0
Wichita Falls TX  23  46  25  59 /  20   0   0   0
Gage OK           13  43  29  62 /   0   0   0   0
Ponca City OK     15  39  24  57 /  10   0   0   0
Durant OK         25  43  27  55 /  70   0   0   0

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Winter Weather Advisory until midnight CST tonight for OKZ031-
     032-039>048-050>052.

TX...Winter Weather Advisory until midnight CST tonight for TXZ090.

&&

09/23/23

Hazardous Weather Outlook...UPDATED
National Weather Service Norman OK
444 PM CST Tue Feb 6 2018

OKZ004>048-050>052-TXZ083>090-071100-
Harper-Woods-Alfalfa-Grant-Kay-Ellis-Woodward-Major-Garfield-
Noble-Roger Mills-Dewey-Custer-Blaine-Kingfisher-Logan-Payne-
Beckham-Washita-Caddo-Canadian-Oklahoma-Lincoln-Grady-McClain-
Cleveland-Pottawatomie-Seminole-Hughes-Harmon-Greer-Kiowa-Jackson-
Tillman-Comanche-Stephens-Garvin-Murray-Pontotoc-Coal-Cotton-
Jefferson-Carter-Johnston-Atoka-Love-Marshall-Bryan-Hardeman-
Foard-Wilbarger-Wichita-Knox-Baylor-Archer-Clay-
444 PM CST Tue Feb 6 2018

This hazardous weather outlook is for portions of northern...
western...central...and southern Oklahoma...and western north
Texas.

.DAY ONE...Through Tonight...

.Winter Weather...
Freezing drizzle and freezing rain will be seen across south
central and southeast Oklahoma, and parts of western north Texas
through this evening. Patchy and brief freezing drizzle will be
possible across central Oklahoma, just south and east of the OKC
metro.

A winter weather advisory is in effect through midnight for
across south central and southeast Oklahoma, and a small part of
western north Texas. A widespread glaze to a few hundreths of a
inch of ice accumulation may occur, with around one-tenth of an
inch of ice possible across far southeast Oklahoma. Slick and
hazardous travel conditions are expected.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday...

.Winter Weather...
A wintry mix is expected over the weekend. Even though any
precipitation amounts are expected to be light, some travel
impacts appear possible.

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