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

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000
FXUS64 KFWD 101812
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
1212 PM CST Sat Dec 10 2016

.AVIATION...
Concerns: Deteriorating cigs this evening and overnight, drizzle
Sunday morning followed by gusty south/southwest winds.

A low/mid-level cloud deck overspreads much of the region this
afternoon with VFR cigs prevailing at the area TAF sites. Just to
the west, an area of MVFR cigs continues to gradually expand
eastward, although they remain more scattered as they approach the
I-35 corridor. This cloud deck should continue lowering over the
next few hours resulting in MVFR cigs at all TAF sites by early
evening.

Later tonight, a stout low-level jet of 40-50 kts will
overspread the region ushering in copious moisture though the
lowest 5 kft. IFR cigs will develop across much of the Hill
Country and Central Texas and will be spread northeastward by
strong south/southwest flow through this layer. IFR cigs seem like
a safe bet at Waco but it is more uncertain at DFW Metroplex
sites. A few fingers of IFR stratus may work northward along I-35
but should be shunted northeastward with the low-level flow,
therefore have included a tempo only at DFW and DAL at this time
and expect western DFW Metroplex sites to be primarily MVFR.
Drizzle will be possible overnight through Sunday morning as the
highest moisture content surges into the area resulting in a deep
saturated layer. In addition, the very shallow boundary layer will
not decouple overnight and some gusty south/southwest winds should
easily mix down to the surface.

Conditions should begin improving by mid to late morning with cigs
lifting to around 2 kft. As vertical mixing increases around
midday, so should momentum transfer from the ~50 kt low-level jet
that will remain in place. Southwest winds of 20-30 kts with some
higher gusts will be possible beginning late Sunday morning and
lasting into the afternoon hours. Remaining MVFR cigs should
scatter as slightly drier air filters into the region Sunday
afternoon and have included this in the extended DFW TAF. A cold
front will move through the area Sunday evening/night causing a
wind shift to the north; this will have to be addressed in the
upcoming TAF issuances.

-Stalley

&&

.UPDATE...
No major changes to the previous forecast other than some tweaks
to sky cover through the remainder of the day. Visible satellite
imagery shows a swath of mid level clouds that extend across
almost all of North Texas. This cloud cover is associated with
increasing warm advection ahead of a fast moving shortwave that
will swing through the Plains tomorrow. As low level flow
increases through the day...warm moist advection will continue and
cloud ceilings will continue to lower. While there may be some
west to east erosion of the cloud deck through afternoon...think
most areas will stay cloudy through the day. Otherwise no other
changes are necessary at this time.

Dunn

&&

.PREV DISCUSSION... /ISSUED 357 AM CST Sat Dec 10 2016/
With high pressure continuing to depart to our east, southerly and
southeasterly low-level flow has returned to the region. The
atmosphere`s visual demarcation of the return flow and associated
northward moisture transport is provided in the form of low
clouds streaming through the Hill Country early this morning. This
cloud cover will muck up our skies today, but we may see some
thinning of the cloud deck later today. Temperatures will respond
as well by increasing today into the upper 40s and 50s as a bit of
a southerly breeze kicks up this afternoon.

Impressive warm advection will commence tonight ahead of a
developing area of low pressure across the Texas and Oklahoma
Panhandles. Additional cloud cover will subsequently stream
into the region, carried northward on a potent low-level jet. As
the lower-levels rapidly moisten to near saturation, areas of very
light precipitation or drizzle are expected to develop, primarily
near and east of the I-35 corridor overnight Saturday. Chances for
measurable precipitation do not appear overly impressive, so we`ll
simply continue to indicate low (20-30%) PoPs during the overnight
period. Additionally, the threat for widespread dense fog appears
low at this time given the strength of the flow (40 kt+) just off
the surface.

On Sunday, temperatures will rocket into the upper 60s and 70s.
CIPS analog guidance and statistical MOS products even suggests
the potential for some middle 70s readings out west--certainly an
impressive warmup considering we`ve been in the 20s and 30s the
past few days! In addition, winds may briefly approach wind
advisory criteria along and east of I-35/35W as the aforementioned
very strong winds aloft begin to mix down to the surface. A cold
front will sweep through the region Sunday night and into Monday,
ushering in drier air and ending any low precipitation chances.

A nice and seasonable start to the workweek is in store, with
temperatures in the 50s and 60s, although some cloud cover may
linger around behind the front.

On Wednesday, yet another cold front should be approaching North
and Central Texas. It`s becoming more evident that the truly
Continental Polar airmass will stay held up across the Central and
Northern Great Plains, a symptom of the continuing fast zonal flow
aloft. As a result, we`ve started nudging temperatures up just a
bit on Wednesday and Thursday. That said, colder air should still
manage to trickle into our region on Thursday with breezy
northerly winds. In addition, there may be a potential for some
very light showers or drizzle with the frontal passage on
Wednesday into Wednesday night. For now, I`ve just maintained some
silent 10% PoPs during this time frame. At this point, it appears
cold air will lag sufficiently behind any potential light precip
to significantly limit the potential for wintry weather.

On Friday, stout warm advection will ensue once again as southerly
winds return, bringing moderating temperatures and another low
potential for showers across our eastern counties. The pertinent
details for the Friday/Saturday period, however, remain in
considerable doubt as significant timing differences exist among
the global models regarding the potential intrusion of yet another
arctic front.

Carlaw



&&


.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    51  49  73  45  62 /   0  20  10   0   0
Waco                52  51  71  48  65 /   5  20  10   5   0
Paris               48  42  67  45  58 /   0  20  30  10   5
Denton              50  47  72  40  60 /   0  10  10   0   0
McKinney            49  46  71  43  59 /   0  20  10   0   0
Dallas              51  50  73  46  62 /   0  20  10   0   0
Terrell             50  47  70  47  61 /   5  20  20   5   0
Corsicana           51  49  71  51  64 /   5  20  20   5   5
Temple              51  49  70  49  66 /   5  20  10   5   0
Mineral Wells       52  47  73  39  61 /   0  10   5   0   0

&&

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

$$

26/91



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