Area Forecast Discussion
Issued by NWS Oklahoma City, OK

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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

934
FXUS64 KOUN 132052
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
252 PM CST Wed Dec 13 2017

.DISCUSSION...
Impactful weather over the next several days is centered around
fire weather. Although, the weather/fuel environment does not
currently seem to support significant fire weather concern (see
details in fire weather section below). Otherwise, temperatures
will be normal to occasionally above normal for mid-December. One
low-medium probability precipitation opportunity will occur for
mainly eastern portions of the area Saturday night into Sunday
morning. Changes to the previous forecast were minimal.

Within northwesterly flow across the middle part of the country, a
weak shortwave is passing through. A band of cirrus across northern
Oklahoma early this afternoon is coincident with weak ascent
associated with this shortwave. This wave has sent a cold front into
the area today resulting in an increase in gusty northerly winds as
it passes.

There have been a few reports from northwest Oklahoma of some smoke
and this doesn`t appear to be due to any local wildfire activity,
rather MODIS satellite suggests it is probably from the Legion Lake
fire in the Black Hills of South Dakota.

A more intense shortwave trough will move through tomorrow forcing a
more significant cold surge into the area early in the day. High
temperatures are expected to be around 15 degrees colder.

Latest model runs show a persistent trough in the east and
diminishing Rex Block pattern with slowly deamplifying ridge in the
west through the end of the week. This will support a continuation
of dry northwesterly flow aloft across our region. Notable changes
on the synoptic scale occur by Saturday. A closed low, now over
northern Baja California, will open up and eject northeastward in
response to deepening longwave trough in the west. Despite PWAT
values being significantly below normal now across Texas into the
western Gulf, modest moisture return will occur quickly in
response to this lead shortwave and should be enough for some
showers across roughly the eastern two-thirds of the area Saturday
night through early Sunday. Instability will be very weak at
best, possibly supporting a few weak thunderstorms as well.

Eastward progression of this longwave is where uncertainties arise.
Deterministic guidance is as much as 24 hours out of phase.
Generally, ECMWF and its ensemble mean are much quicker than the GFS
and most of its ensembles. If the GFS/GEFS is right, this could
offer another low probability precipitation event for the eastern
portions of the area sometime around Monday, but we have kept the
forecast dry for now given significant uncertainty.

BRB

&&

.FIRE WEATHER...
Some fire activity will remain possible through this afternoon.
Latest Oklahoma mesonet observations show relative humidity
values around or below 20 percent for most of the area, and around
10-15 mph northerly winds behind the southward moving cold front.
This is resulting in elevated to near critical fire weather
conditions.

As mentioned above, a smoke smell may occur behind the cold front
moving through the state now. This smoke seems to be originating
from the Legion Lake fire in the Black Hills.

Latest shortwave band satellite imagery reveals one hotspot and
probable fire in western Love County. Local media reports and KTLX
radar indicate a minor fire in south OKC. No other ongoing
activity is known at this time, but additional initial attack
activity is certainly possible through the afternoon.

Cooler temperatures and comparatively higher relative humidity
should limit fire concerns tomorrow, and although humidity will be
lower Friday, winds should remain fairly light. The next fire
weather day is expected to be Saturday when gusty southerly winds
begin before a surge of low level moisture arrives. Elevated fire
weather conditions may result. Latest ERC-G values in western
Oklahoma where near or slightly above the 90th percentile which
would tend to enhance fire activity even if only marginal
meteorological conditions are realized.

BRB

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  65  35  47  30 /   0   0   0   0
Hobart OK         67  33  50  27 /   0   0   0   0
Wichita Falls TX  68  34  53  31 /   0   0   0   0
Gage OK           64  29  49  23 /   0   0   0   0
Ponca City OK     63  32  47  28 /   0   0   0  10
Durant OK         69  36  53  34 /   0   0   0   0

&&

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

$$

26/12



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