996 
FXUS64 KFWD 110542
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
1142 PM CST Sun Feb 10 2019


.AVIATION...
/06 TAFs/

A fairly challenging near-term aviation forecast continues to be
the main theme. CIGs have generally held within the LIFR/IFR 
range this evening, but VSBYs have risen at most sites to MVFR/VFR
levels. Although dew points have slowly risen across the area, 
veering surface flow, emanating from a ridge axis to our 
southeast, has coincided with enough near-surface subsidence to 
maintain higher VSBYs. Confidence has decreased regarding a 
prolonged period of VSBYs below 1SM at Metroplex sites tonight; 
therefore, while brief periods (generally through 11Z) could 
feature VSBYs this low, adjusted forecast trends to show only 2SM 
through the morning. KACT should be a little closer to more 
vigorous low-level warming/moistening so have continued to 
advertise TEMPO 1/2SM there overnight. Still, confidence has 
decreased some regarding this outcome.

Categories gradually improve to IFR/MVFR Monday morning into the 
afternoon, given more notable veering of flow from the surface 
through 700mb. Occasional periods of rain are still to be expected
into the afternoon, and a non-zero chance for a thunderstorm 
exists around 18-22Z. Confidence in thunder at any site is far too
low for inclusion in TAFs, though.

Winds increase from the southwest towards 12/00Z with the passage
of a surface trough. Related drying should bring all sites to VFR
by this point as well. A cold front then pushes across the
Metroplex after 06Z, such that northwesterly flow is advertised at
the end of the KDFW 30-hour TAF. Occasional gusts around 5-7 kt 
higher than the TAF forecast will be possible.

Picca

&&


.UPDATE... /Issued 935 PM CST Sun Feb 10 2019/
/Tonight/

Only notable change with this update is the increasing of PoPs 
over parts of western North Texas, where another subtle shortwave 
impulse is yielding a band of generally light rain this evening. 
The expectation is for this band to slowly shift northeast, while 
a low-level warm conveyor gradually matures along/east of the I-35
corridor after midnight. Rain chances will accordingly increase 
here as well.

Visibilities have been slow to fall with any consistency across
the region, perhaps due to some veered low-level flow in the wake
of a subtle mid/upper trough departing to our north over 
Oklahoma. As such, no plans to hoist a dense fog advisory anywhere
at this time. However, in tandem with the aforementioned
maturation of a warm-advection corridor, hi-res/probabilistic
guidance still suggest visibilities may fall close to advisory
criteria across parts of East Texas and perhaps near the Red
River after midnight. These trends will be monitored accordingly.

Picca

&&

.SHORT TERM... /Issued 309 PM CST Sun Feb 10 2019/
/Tonight/

The main concerns through the overnight hours will be periods of
drizzle, light rain and fog. 

Surface analysis revealed that southerly flow was beginning to
envelop much of the area this afternoon in response to lee-side 
surface pressure falls to the north. Rich low level moisture 
remains confined to the upper TX coast at this time, but as 
surface flow continues to veer, some of this moisture should make 
a run northward into parts of North and Central Texas. The warm 
and moist advection should result in near steady or rising 
temperatures. With isentropic upglide expected to continue, there 
will be a a continued risk for light measurable rainfall along 
with drizzle and some fog. Increased surface moisture, per RAP 
soundings, into this airmass signals more of an advection fog type
setup tonight. A consensus of hi-resolution guidance supports 
reduced visibility down to 1/2 a mile and I wouldn't be surprised 
to see some areas of dense fog...especially near and east of I-35.
For now, we'll hold off on any advisories, but one may be needed 
late tonight into early Monday. 

Otherwise, temperatures should remain in the 40s areawide. 

Bain

&&

.LONG TERM... /Issued 309 PM CST Sun Feb 10 2019/
/Monday Onward/

Areas of fog are likely to continue into Monday morning as 
south winds usher ample moisture northward into a cooler airmass 
already in place. Some warming will occur throughout the day via 
warm advection as strong low-level southerly flow prevails. While 
one wave of precipitation will be exiting the area around 
daybreak, another will develop off to the west later in the day as
an approaching shortwave trough swings through the Plains while 
becoming negatively tilted. This will cause mid-level lapse rates 
to steepen via cooling during the afternoon and evening hours, 
which may result in a few thunderstorms near or east of I-35. 
Instability is expected to be very limited, which should confine 
hazards to occasional lightning or at most some small hail across 
our eastern zones. As the upper trough's associated surface low 
accompanies it eastward late Monday, a cold front will be pulled 
through the region, scouring moisture while bringing rain chances 
to an end from west to east. 

In wake of Monday's front, cooler and dry conditions are expected
to prevail through the middle portion of the week. Temperatures
will generally be within a few degrees of seasonal normals as a
slow warming trend occurs through Wednesday. Zonal flow aloft will
prevail throughout the time period, and moisture will largely
remain scoured from the forecast area.

By Thursday, a dynamic storm system is expected to dive into the
Plains, prompting strong lee cyclogenesis. A deep surface low will
develop through southeastern Colorado and drift eastward through 
Kansas and Oklahoma. This surface pattern will result in veered 
low-level winds across our forecast area, which should make for a 
warm and breezy day as the pressure gradient tightens. With west 
winds and increased downsloping, 70s are likely area-wide and 
some of our western zones may flirt with 80 degrees. Moisture 
return will be fairly limited with this setup, so despite the 
dynamic storm system, precipitation may be confined to some warm 
advection showers east of I-35 Thursday afternoon. At this point,
it appears most areas will remain rain-free. The strong and 
rather deep southwesterly flow should keep a stout lid on any 
surface- based convective attempts with what meager moisture will 
be available in the first place. Given the windy and warm 
conditions with low RH values along with limited rainfall in 
recent weeks, there may end up being some elevated fire conditions
Thursday afternoon west of I-35.

Thursday night and Friday morning, this system's strong cold front
will push through the forecast area turning winds abruptly to the
north at 20-30 mph. At this stage, it appears moisture will be 
too meager to support any precipitation along the front. Strong 
cold advection and post-frontal stratus should keep temperatures 
20 or more degrees cooler than Thursday with highs likely only in
the 40s or lower 50s. The cool weather will continue heading into
next weekend, with temperatures expected to be around 10 degrees 
below normal on Saturday. 

-Stalley

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    43  65  40  58  35 /  60  40  20   0   0 
Waco                45  66  43  59  35 /  40  60  20   0   0 
Paris               41  62  40  54  32 /  90  90  40   0   0 
Denton              42  64  38  58  33 /  60  40  20   0   0 
McKinney            43  64  40  56  33 /  70  60  20   0   0 
Dallas              43  65  41  58  36 /  60  50  20   0   0 
Terrell             43  64  40  57  33 /  80  70  30   0   0 
Corsicana           43  65  42  57  34 /  70  60  30   5   0 
Temple              45  66  43  60  35 /  40  60  20   0   0 
Mineral Wells       43  65  36  58  33 /  60  30  10   0   0 

&&

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

$$

11/30