110 
FXUS64 KFWD 101137
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
637 AM CDT Sun Mar 10 2019


.AVIATION...
/12z TAFs/

A weak cold front has moved southward through the TAF sites over 
the past few hours, and winds are now prevailing out of the NNE 
around 8-10 kts. Southerly winds are in place just above the 
frontal inversion, which are contributing to ascent via isentropic
upglide. This has resulted in showers and isolated storms across 
parts of West Texas this morning, and this activity will spread 
into parts of North Texas over the next 6-12 hours. I haven't 
indicated any precip at the TAF sites through today as strongest 
lift should remain just north of the immediate DFW area, but a 
VCSH mention may be necessary depending on trends later this 
morning. Meanwhile, an area of low-level moisture is contributing 
to fog and low cigs across parts of Central and southeastern 
Texas, some of which have spread into Waco in the past hour. Have
introduced Tempo groups for IFR and MVFR cigs at Waco through 
midday to handle these conditions which will likely be
intermittent. Otherwise, an increase in VFR cigs should occur 
through the afternoon and early evening hours as top-down 
saturation occurs and additional low-level moisture arrives.

Later tonight, warm advection will increase over much of the area
which will aid in the development of scattered showers heading 
into Monday morning. Have handled this activity with VCSH for now,
but a TS mention may be necessary in future TAFs. In addition, 
low-level moisture will surge northward and become trapped beneath
the frontal inversion. The resultant low-level saturation should 
become sufficient for MVFR/IFR cigs around the end of the TAF 
period, and have introduced worsening conditions in the extended 
DFW TAF.

-Stalley

&&


.SHORT TERM... /Issued 345 AM CDT Sun Mar 10 2019/
/Through Tonight/

A weak cold front is making its way through the forecast area this
morning, and is located roughly along I-20 as of 330 AM. Behind
this front, a light northeast breeze will aid in brining in
slightly lower dewpoints as well as cooler air today. To the 
south, dewpoints remain mostly in the 40s or even low 50s. Later 
this morning, this front will decelerate and stall across parts 
of Central Texas, causing a 30F spread in both dewpoint and 
temperature across the CWA throughout the remainder of the day. At
this point, the NAM has the best handle on the post-frontal 
airmass, and have trended heavily towards its solution through 
the short-term.

Later this morning, warm advection will ramp up across the Concho
Valley in advance of a deepening upper trough over the western 
US. Ascent atop the cold frontal inversion should result in a 
rapid expanse of low/mid clouds and the development of a swath of
light rain. Initially, much of this activity may be in the form 
of virga due to dry air beneath the cloud layer, but the low- 
levels should saturate rather rapidly later this afternoon as top-
down saturation occurs with aid from moisture return within 
southerly flow in the 850-700mb layer. Most of this activity 
should consist of rather light stratiform rain as it spreads into
our western and northern zones throughout the day. However, a 
slight steepening of mid-level lapse rates later in the afternoon 
may allow for precipitation to become more showery in nature. 
Elevated instability appears a bit too low for a mention of 
thunder in the forecast, though slightly more robust convection
supportive of a lightning strike may be possible across the far 
western and southwestern portion of the CWA around midday. PoPs 
will be highest over our northwest and decrease to the southeast,
but just about any location within the forecast area has a shot 
at seeing some light rain throughout the course of this afternoon 
or evening. 

Otherwise, the vast expanse of cloud cover should keep 
temperatures on the cooler side of guidance, especially across 
North Texas where the post-frontal airmass and occasional rain 
will be located throughout the day. Locations that remain on the 
southern side of the stalling front may still manage to reach the 
upper 70s or low 80s, mostly across our far southeastern zones. 
The shallow frontal inversion will remain in place across the 
area into tonight with deep southerly flow beginning to strengthen
just above. The increased warm advection should support an 
increase in sporadic rain showers, and also an increase in low 
stratus and some fog/mist heading into Monday morning. 

-Stalley

&&

.LONG TERM... /Issued 345 AM CDT Sun Mar 10 2019/
/Monday through Next Weekend/

A frontal boundary will be draped across South-Central Texas and 
the northern Gulf at the start of the forecast period, placing 
North and Central Texas in a cool continental airmass as a deep 
upper low approaches from the west. The resulting overrunning 
pattern will bring cloudy conditions and increasing rain chances
while temperatures remain in the 50s on Monday. The stronger
isentropic lift may initially be located across the Hill Country
associated with a lead shortwave to the southwest, with the 
higher POPs subsequently located across the southern half of the 
region Monday morning. This zone of relatively stronger lift will 
spread north as the disturbance moves northeast, shifting the
higher POPs to the northern half of the forecast area Monday
afternoon and evening. Precipitation will be primarily in the 
form of stratiform rain, but there should be enough elevated 
instability to generate isolated thunderstorms embedded within 
the broad precipitation shield. 

A lull in activity may occur Monday night as the disturbance 
continues off to the northeast, but showers should redevelop
Tuesday morning associated with a similar upper level impulse. By
this time, the boundary should begin to retreat northward as a
warm front. The better chances of showers and storms will likely
occur along and just north of the front, shifting from the 
southern counties northward across the rest of the area during the
day. Warmer air will accompany the front as it moves northward, 
resulting in a continued damp but warmer day compared to Monday. 
High temperatures will range from the lower 70s across the south 
to near 60 along the Red River where the front will not reach 
until late afternoon or early evening.

The upper low to the west will open up and acquire a negative 
tilt as it encroaches on West-Central Texas Tuesday evening. An 
area of strong forcing for ascent will allow for rapid convective 
development to the west of the forecast area during the late 
afternoon and evening hours. Showers and thunderstorms will likely
evolve fairly quickly into a quasi-linear system as activity 
becomes organized along a Pacific front while approaching the 
western counties of North Texas late Tuesday evening. Instability 
still looks to be fairly marginal with most unstable CAPE values 
between 500 and 1000 J/KG. However, deep layer shear values 
exceeding 60kt will support the potential for a few severe storms 
with damaging wind gusts. This potential will accompany the line 
of storms as it pushes east across all of North and Central Texas 
during the overnight hours into early Wednesday morning. 

There will also be a chance of localized flash flooding where 
heavier rain occurs, particularly since we expect a couple more 
days of rain chances prior to the arrival of the main trough. 
Storm total precip values between now and Wednesday are generally 
in the 2 to 2.5 inch range, and areas which receive isolated 
higher totals will need to keep a close eye on local creeks and 
rivers, particularly since the heaver precipitation will occur at 
night.

Showers and storms will exit to the east Wednesday morning, 
giving way to a dry and windy Wednesday afternoon across the 
board. The strongest winds will be across the northwest counties,
which will be closest to the surface cyclone moving east and then
northeast along with the upper level system. Winds generally 
north of I-20 and west of I-35 will be westerly in the 25 to 35 
MPH range with higher gusts. A gradual decrease in velocities can 
be expected the farther southeast you go. 

We will then enter what at this time looks to be a dry period
Thursday through next weekend, as northwest flow dominates the 
Central part of the CONUS. Seasonal temperatures and 
precipitation-free weather can be expected Thursday through next
Sunday. Longer range models then show the potential for more 
unsettled weather just beyond this forecast period as we enter the
second half of March.


30

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    58  50  58  53  66 /  30  40  60  50  70 
Waco                68  53  60  56  71 /  20  30  60  50  60 
Paris               57  50  58  49  61 /  40  40  50  50  60 
Denton              54  49  57  52  65 /  50  40  60  50  70 
McKinney            56  49  58  52  64 /  40  40  60  50  70 
Dallas              59  51  59  54  67 /  30  40  60  50  70 
Terrell             65  52  59  52  67 /  20  40  60  40  60 
Corsicana           69  54  58  54  69 /  10  30  60  50  50 
Temple              69  54  62  57  71 /  20  40  50  50  50 
Mineral Wells       55  49  57  51  67 /  40  40  60  50  70 

&&

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

$$

26/30