Area Forecast Discussion
Issued by NWS Dallas/Fort Worth, TX

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FXUS64 KFWD 150907
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
307 AM CST Wed Feb 15 2017

.DISCUSSION...
The shortwave trough that gave all the rain and thunderstorms on
Valentine`s Day was lifting readily east over the Tennessee Valley
early this morning. However, a broad positive-tilted long wave
trough was lingering back west- southwest across Oklahoma and into
Southern Arizona/New Mexico and northern Mexico. At the surface,
North and Central Texas remained under the influence of strong
surface ridge occurring over the High Plains, with NNW winds 5 to
15 mph and cold conditions. As more shortwave energy passes
southeast overhead this morning, scattered- broken mid and high
clouds will hang around. Low levels are dry, so not expecting any
measurable precipitation, though we couldn`t rule out a brief rain
drop or snow flurry. Mostly sunny, cool, and brisk conditions
will return for this afternoon with cold 925-850 mb temps 0-5
deg/C, so highs will warm slowly this afternoon into the 50s.

The broad positive-tilted trough will persist through tonight and
early Thursday, with continued, but seasonable mid February
temperatures under mostly clear skies. Mid level energy will cut
off over western Mexico Wednesday night. Temperatures will tank
back down into the 30s Thursday morning, as the High Plains
surface ridge slides east across much of the state. In addition,
we`ll keep the patchy fog wording going, as winds will be light
with continued, moist top soils from our rainfall yesterday. This
will need to be watched closely if dew pt depressions are lower
than expected, in which case at least patchy dense fog, especially
across our southeast half of the CWA where low level moisture is
a little more prevalent. Any patchy fog should dissipate quickly
by mid-late morning Thursday, as light west winds become
southwesterly at 10 to 15 mph. The cut off mid level low over
Mexico will begin translating northeast across the state on
Thursday, as a more potent storm system approaches Oregon/California.
The modest downslope component of the southwest wind direction
will combine with plentiful sunshine for highs to recover into the
60s Thursday afternoon...nipping at 70 degrees across the far
western counties.

The first disturbance will pass across us Thursday night and
Friday and should be mostly dry, as moisture fields and soundings
indicate relatively dry low levels. Meanwhile at the surface, lee
side cyclogenesis will develop in wake of the retreating surface
ridge shifting over the Southeast U.S. The return of breezy south
winds and southerly flow up through 850mb, we still will see
modified moisture return for a slight chance of light showers
across our far southeast counties. Otherwise, this first system
will do little to affect our area outside of some sporadic
cloudiness. Shortwave ridging will ensue Friday night into
Saturday, thus we will continue with our warming trend with highs
warming each day with mid to upper 70s by Saturday. In addition,
south winds will continue to be brisk. Despite the wake trough
over the area, the strength of low level WAA has me trending
warmer than MOS guidances on Friday, and even more so on Saturday,
as MOS guidance tends to trend toward climatology later in
forecast periods. Did collaborate this with neighbors and all
agree with a general consensus of warming temps more into the
weekend.

By this weekend, broad and deep mid level energy will be digging
southward along the California and western Mexico coastlines. This
will be our next weather maker for the end of the weekend into
first half of next week. However, out ahead of this system, steep
mid level ridging over the Southern Plains should continue
through at least Saturday night and Sunday morning, with likely
low cloud/stratus surges occurring each morning with the moisture
stream north from the Gulf of Mexico. Rain and convective chances
will increase Sunday afternoon into Sunday night and especially
Monday. As been the case with deep energy in the southern stream
of split flow aloft as of late, medium range models are already
slowing it down, but still may be too fast. We have leaned with
the slower GFS/ECMWF consensus over the more open, further north,
and progressive solution of the Canadian model. The usual
reasoning for poor model handling with such deep systems is the
lack of an upper-air network over Mexico and the Pacific, along
with no `kicker system` immediately upstream to move these slow-
moving, closed southern stream systems along. I have collaborated
this model dilemma with several NWS neighbors and the slower model
consensus has been agreed upon with the bulk of the weekend being
warm, breezy, and pleasant for the most part.

Sunday night-Monday night look wet as large-scale and isentropic
ascent increases within the broad WAA regime. Was more
conservative on rain/convective chances beyond that time frame,
being it`s wholly possible the system slows down a little more, as
it awaits the next system driving down the Western U.S. coastline
Tues/Wed. Just know that confidence on exact timing/track remain
uncertain. In addition, the potential for strong-severe
thunderstorms, heavy rains, and flooding remain even more
uncertain not knowing how our thermodynamic environment evolves.
Keep checking future forecasts with regard to the very late
weekend, early next week system when confidence should slowly
increase on all fronts.

05/

&&

.AVIATION...
/ISSUED 1108 PM CST Tue Feb 14 2017/
MVFR cigs continue to rapidly improve to VFR as an upper-low
continues to track steadily east of the region. Northwest winds,
which were previously gusty, will diminish into the 10-13 kt range
overnight. These speeds should be high enough to mitigate the
development of any fog tonight. Winds will remain out of the
northwest on Wednesday before backing to the west and southwest
Wednesday night as high pressure slides just to the south of the
area. With light winds and clear skies, there is a potential for
some shallow fog at area TAF sites Wednesday night. However,
forecast soundings reveal the moist-layer will be exceptionally
shallow, with rapid drying a few hundred feet off the surface,
which tends to work strongly against fog formation. As a result,
have forgone mention of visibility reductions in the DFW extended
TAF at this time, but we will continue to assess this potential
in future updates.

Carlaw


&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    58  38  68  47  71 /   0   0   0   0   5
Waco                59  36  66  46  71 /   0   0   0   0  10
Paris               57  35  63  43  68 /   0   0   0   0   0
Denton              57  35  67  45  71 /   0   0   0   0   0
McKinney            57  35  65  44  70 /   0   0   0   0   0
Dallas              59  39  68  47  71 /   0   0   0   0   5
Terrell             58  36  65  45  69 /   0   0   0   0   5
Corsicana           59  39  65  46  71 /   0   0   0   0  10
Temple              59  37  67  46  72 /   0   0   0   0  10
Mineral Wells       58  33  68  43  73 /   0   0   0   0   0

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

/05



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