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000
FXUS64 KOUN 210450
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
1050 PM CST Sun Jan 20 2019

.DISCUSSION...


&&

.AVIATION...
VFR conditions are expected. Light south winds will become gusty
on Monday, gusting around 35 kts in western Oklahoma.


&&

.PREV DISCUSSION... /issued 846 PM CST Sun Jan 20 2019/

DISCUSSION...
High clouds will continue to increase across the rest of
the area tonight, while a south to southeast wind prevails and
increases slightly. Overall the forecast looks OK.

PREV DISCUSSION... /issued 616 PM CST Sun Jan 20 2019/

DISCUSSION...

AVIATION...
VFR conditions are expected. Light south winds will become gusty
on Monday, gusting around 35 kts in western Oklahoma.

PREV DISCUSSION... /issued 236 PM CST Sun Jan 20 2019/

DISCUSSION...
By far, the most significant challenge the next several days will
be temperatures. Confidence in the temperature forecast the next
seven days continues to be below average, particularly from mid-
week onward when the upper flow pattern amplifies further. High
level moisture traversing the northern edge of mean ridge that is
centered west of us will bring increasing cirrus late this
afternoon and into the night. We adjusted sky cover upward to
account for this, and this may impact viewing of the lunar
eclipse. Only one precipitation event is expected through next
week, and that will come in the form of a few locations across
eastern portions of our area seeing light amounts (a few hundreths
of an inch or less) Monday night into Tuesday. Meteorological
details and uncertainties are discussed below.

An upper trough will become elongated and increasingly positively
tilted as it moves through our region Tuesday/Tuesday night.
Signaling its approach, in addition to an increase in cirrus, will
be the mass response to deepening lee surface trough. South winds
tomorrow will be 20-30 mph with gusts up to around 40 at some
locations. Orientation and position of trough suggest a less
significant wind event than the preceding system, especially with
respect to post-frontal winds.

Deeper saturation and best coverage of precipitation will be east
of the area, although modest surface moisture return within
confluent flow pattern may be enough for drizzle late Monday night
and early Tuesday across our eastern counties. Ascent as the
trough approaches won`t be enough to lift out stout capping warm
layer aloft, and so our precipitation process should be limited to
either the aforementioned drizzle and/or some light shallow
convective showers as moist boundary layer deepens before the
trough axis passes. Sometimes in these scenarios sloping front and
enhanced mid-level frontogenesis can result in a band of light
precip roughly near or just ahead of with 500-mb vort max, but
moisture profiles look insufficient for this until its east of
our area. The cold front forced southeast will bring strong enough
cold advection for falling temperatures across much of the area
Tuesday.

I could list off current depictions of synoptic features
from medium-range guidance (including the intense gulf coast
cyclone depicted by the ECMWF) but doing so would be quite
meaningless given run-to-run consistency issues. The general
signal has been for some sort of a very anomalous trough across
the eastern portion of the country which could force an impactful
weather event to our east. Details on how broad/strong longwave
trough is, and timing/amplitude of shortwaves embedded within will
determine our sensible weather. There is potential for major
temperature busts here, but for now we didn`t feel comfortable
straying from a blend of guidance. Significantly colder or
significantly warmer temperatures may occur. These highly
amplified and highly anomalous ridge->trough scenarios with belt
of mean northwesterly flow over our region can be the most
difficult temperature forecasts.

BRB

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  45  31  57  47 /   0   0   0  10
Hobart OK         47  32  59  45 /   0   0   0   0
Wichita Falls TX  50  36  64  51 /   0   0   0  10
Gage OK           54  31  64  35 /   0   0   0   0
Ponca City OK     42  27  52  45 /   0   0   0  10
Durant OK         44  31  58  47 /   0   0   0  20

&&

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

$$

06/09/09