Area Forecast Discussion
Issued by NWS Tulsa, OK

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
332
FXUS64 KTSA 101124
AFDTSA

Area Forecast Discussion
National Weather Service Tulsa OK
524 AM CST Sat Dec 10 2016

.DISCUSSION...
VFR cigs will prevail for the first half of the TAF period...
with mixing aiding is eroding cigs later this afternoon. Low level
wind fields increase overnight...and have carried a WS at KFSM
after 06z. MVFR cigs expected to overspread the region overnight
from south to north as well after 06Z.

&&

.PREV DISCUSSION... /Issued 237 AM CST Sat Dec 10 2016/

DISCUSSION...

Temperatures will be the main forecast problem thru the bulk of
the forecast. The forecast gets more complicated toward the end of
next week, however.

We are in the process of eroding out the arctic air that has been
in place for a few days. Part of that process is reflected in the
deck of persistent cloud cover at around 850mb. It`s not exactly
clear as to what this deck of clouds will do today. There`s some
indication that they will eventually erode over toward Western AR
by this afternoon, while continued warm/moist advection on the
back side of the retreating arctic high may maintain cloud cover
thru much of the day across Eastern OK. Will stay conservative for
highs today given uncertainties with cloud cover.

Southerly winds will increase today and tonight ahead of an
approaching shortwave trough. Warm/moist advection will continue
ahead of the associated surface low/cold front Sunday and Sunday
night to warrant a mention of light rain or drizzle across Eastern
OK. The best chance for showers will be across Western AR ahead of
the surging front Sunday evening. After highs in the 30s the past
couple days, highs could reach around 60 on Sunday as we change
airmasses, albeit briefly. Expect cooler temps to return for
Monday, but certainly not arctic cold like we saw this week.

The highly amplified flow in the high latitudes will set the stage
for the next significant arctic intrusion into the CONUS next
week. The cold air will ooze down the Plains in different pieces,
with the initial front pushing into our area Tuesday and the more
significant push arriving Wednesday. In between the first and
second fronts, models break out very light qpf over mainly eastern
portions of the forecast area. So it`s not out of the question we
could see some patchy drizzle or possibly some freezing drizzle
depending on surface temps. I have elected however to keep the
forecast dry for the time being and continue to monitor the
trends. Expect another couple of cold days and nights Wednesday
and Thursday, but at this time it should remain dry given
unfavorable upper pattern for lift over the cold dome.

Indications are that there will be some retreat to the arctic air
toward the end of the week as a deep positive tilt upper trough
develops over the Western CONUS, but the cold air will not be far
away. As the upper trough lifts out into the Plains next weekend,
low pressure will likely track along the sharp baroclinic zone and
could bring some wintry precipitation. We will also likely get
the most significant dose of arctic air yet in the wake of this
system. Looks like next weekend could be downright frigid. Stay
tuned.

Lacy

&&

.TSA WATCHES/WARNINGS/ADVISORIES...
OK...None.
AR...None.
&&

$$

AVIATION...23



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.