River Flood Advisory 2, NWS Norman, OK

Area Forecast Discussion
National Weather Service Norman OK
555 PM CST Sat Jan 2 2021

...New AVIATION...

.SHORT TERM...
(This evening through Sunday)
Issued at 341 PM CST Sat Jan 2 2021

Clearing skies and light wind this evening will lead to
temperatures dropping quickly, especially over/near the snowpack.
T/Td spreads will become minimal by midnight over the mentioned
areas an also over a larger area where soils are saturated. Fast
moving s/wv trough approaching from the central Rockies tonight
will result in surface cyclogenesis across the Red River Valley
region of southwest Oklahoma this evening, with the low progd to
progress eastward across southern Oklahoma on Sunday. Weak low
level warm air advection and convergence north and east of this
feature will combine with shallow moist layer previously mentioned
to yield fog and low cloud development overnight through Sunday
morning. Depending on timing of stratus development, some of the
fog could become dense across central and north-central Oklahoma.
With temperatures expected to be well below freezing at onset of
fog development, we could see freezing fog dense enough to result
in riming of elevated surfaces.

Although lower level flow will remain somewhat weak tomorrow,
erosion of fog/stratus expected through the afternoon hours,
mainly from west to east as slightly drier westerly winds spread
eastward. High temperatures across central into north-central
Oklahoma were lowered several degrees from guidance due to
residual snow cover and expected impact from cloud cover at least
first half of the day. If clouds persist through most of the
afternoon, some areas will struggle to get much above freezing.

&&

.LONG TERM...
(Sunday night through next Friday)
Issued at 341 PM CST Sat Jan 2 2021

A warming trend will commence for Monday and Tuesday as mid-level
heights rise with with the attendant development of a shortwave
ridge across the Plains. Remnant snow cover will likely temper the
magnitude of the warm-up slightly, so opted to lower temperatures
in areas where the heaviest snowfall fell for Monday afternoon.

Southerly winds will increase on Tuesday as a surface cyclone
develops in the lee of Rockies in response to an approaching
shortwave trough. Temperatures in the 50s and 60s deg F are
expected.

The aforementioned shortwave trough is forecast to dig into the
Plains on Wednesday. There is uncertainty on the evolution of the
trough, including the latitude of its track and its amplitude. The
National Blend of Models (NBM) probability of precipitation
values are below mentionable during this period. However, given
that the 02/12Z deterministic models and the several of members of
the ECMWF ensemble have a favorable track and QPF signal/pattern
(which would not be included in the current NBM run), opted to
increase the probability of precipitation Wednesday into early
Thursday. There is a chance rain may mix with or transition to
snow within the comma-head as center of the mid /upper-level low
passes by early Thursday morning--especially across northern
Oklahoma.

Seasonable (cool) temperatures are expected in the system's wake
for the end of the week.

Mahale

&&

.AVIATION...
(00Z TAFS)
Issued at 555 PM CST Sat Jan 2 2021

Light, generally southerly winds will shift to the west/northwest
late tonight into tomorrow morning.

IFR to LIFR stratus and/or freezing fog is expected to develop
across portions of central into north central Oklahoma late
tonight into tomorrow morning (KOKC/KOUN to KSWO/KPNC). Flight
restrictions should persist through the morning and perhaps even
the early afternoon. Confidence for flight restrictions is lower
at other terminals, but could briefly impact KLAW and KCSM.

Mahale

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  25  40  29  51 /   0   0   0   0
Hobart OK         26  52  29  58 /   0   0   0   0
Wichita Falls TX  29  49  29  59 /   0   0   0   0
Gage OK           25  54  29  57 /   0   0   0   0
Ponca City OK     23  40  26  48 /   0   0   0   0
Durant OK         31  55  32  61 /   0   0   0   0

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&

SHORT TERM...11
LONG TERM....10
AVIATION...10

Hazardous Weather Outlook
National Weather Service Norman OK
1239 PM CST Sat Jan 2 2021

OKZ004>048-050>052-TXZ083>090-031100-
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-
1239 PM CST Sat Jan 2 2021

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

.DAY ONE...Through Tonight...

.Freezing Fog...
Areas of freezing fog appear possible tonight, mainly across
central and northern Oklahoma, where the heaviest snow fell
yesterday. Some of the fog could be dense late tonight, resulting
in a thin layer of ice on elevated surfaces.

.DAYS TWO THROUGH SEVEN...Sunday through Friday...

.Freezing Fog...
Areas of fog freezing will be possible through Sunday morning,
primarily across central and northern parts of Oklahoma where
snowpack remains. Some of the fog could be dense early,
resulting in a thin layer of ice on elevated surfaces.

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