979
FXUS64 KFWD 231100
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
600 AM CDT Thu May 23 2024

...New Aviation, Short Term...

.SHORT TERM... /NEW/
Update:

A cluster of thunderstorms may impact northern Lamar County over
the next couple of hours before exiting to the east. Thunderstorms
have also began developing near San Angelo and will shift into
our western Central Texas counties later this morning. Expect
additional scattered thunderstorm development throughout the day
across North Texas and portions of Central Texas. Not everyone
will see storms, but the locations that do could be impacted by
large hail and damaging wind gusts. An increasing LLJ and backing
surface flow may increase the threat for an isolated tornado later
this afternoon into this evening. Locally heavy rainfall leading
to additional isolated rainfall amounts of 2-3" may reinvigorate
flooding issues across portions of the region. Much of North and
Central Texas remains in a Flood Watch through this evening.

Langfeld

Previous Discussion:
/Through Thursday Night/

Increasing warm advection associated with a strengthening
nocturnal low-level jet will continue to support isolated
thunderstorm activity across portions of North and Central Texas
overnight with a marginally severe hail threat. This activity
should become primarily focused across our northeast zones during
the pre-dawn hours which will be in closest proximity to the nose
of the low-level jet. Despite widespread convection over the past
12 hours, the environment is not terribly worked over, and pockets
of steep lapse rates remain with MUCAPE values exceeding 2000
J/kg across much of the region.

After daybreak, additional convective development is expected
across western Central Texas in response to lift from a subtle
shortwave acting upon robust instability. This should send a
round of loosely organized convection east/northeastward through
the daytime, likely affecting much of Central Texas and perhaps
areas as far north as the I-20 corridor by mid afternoon.
Additional development is possible through peak heating to our
west/northwest along the dryline, and some of these storms could
impact North Texas late in the afternoon and evening. Due to a
volatile parameter space, all severe hazards will be possible,
with large hail being the primary threat. Additional flooding is
likely even with modest rainfall totals as grounds remain
saturated from recent exceptional rainfall. With some uncertainty
in both coverage and placement of storms, no adjustments were made
to the existing Flood Watch, but overall the threat for flooding
should be more isolated than Wednesday`s. High-end localized rain
amounts tomorrow could be around 2-3", but most areas will see
much less than that, and some locations will miss out on rainfall
entirely. Most thunderstorm activity should be winding down and
exiting the area to the east during the evening with a quieter
overnight period to follow.

-Stalley

&&

.LONG TERM... /Issued 307 AM CDT Thu May 23 2024/
/Friday Onward/

Zonal flow aloft will be in place on Friday while a shortwave in
the Central and Northern Pains helps advance the dryline east into
western portions of North and Central Texas. Conditions will be
exceptionally humid east of the dryline as dewpoints climb well
into the 70s. The resulting heat indices will be around 100
degrees by Friday afternoon as ambient temperatures climb into the
upper 80s and lower 90s.

Strong flow aloft (around 90kt at 250mb), 50+ knots of effective
shear, the presence of the dryline, and a highly unstable airmass
will result in isolated to scattered thunderstorm development
late Friday afternoon and Friday evening. There will be a decent
cap in place, but it is likely that a few cells will overcome it
and quickly become severe. Wind profiles support supercell
development with large hail the primary concern. Damaging winds
and heavy rain/flooding may also occur, while high surface
dewpoints and low LCLs could very well support a tornado or two.
As far as timing and location: recent CAMs have focused on
convective initiation near or just west of the I-35 corridor
beginning around peak heating (~4 PM). Storms would then spread
east through and east of the I-35 corridor during the late
afternoon and early evening hours, eventually dissipating around
midnight Friday night.

Another oppressive day is in store for Saturday, with the dryline
having shifted farther west in response to a shortwave trough
lifting northeast through the Four Corners region. More
thunderstorm development is expected in the vicinity of the
dryline Saturday afternoon, with convective initiation likely
somewhere across the Big Country. A stronger cap will be in place
on Saturday, which will work against convective development, but a
few storms will likely break through and become severe late
afternoon into Saturday evening. The best storm chances will be
north of the I-20 corridor where the cap will be weakest. The
highest severe threat may end up along the Red River area, where
the better forcing will occur as the shortwave continues northeast
through the Central and Southern Plains.

A reprieve from the active weather can be expected on Sunday as
subsidence takes over in the wake of the departing shortwave. The
highest temperatures of the period will also occur Sunday
afternoon as highs range from the lower 90s near Paris to the
upper 90s in the western-most zones. SLightly lower dewpoints
should help offset the higher temperatures, hopefully keeping heat
index values just below 100.

A stronger shortwave trough will then swing through the Plains
Sunday night, pushing a cold front south through all of the region
in time for Memorial Day. Convection will be difficult to attain
due to the overnight passage of the front and the cap being
exceptionally strong. Will still include some low POPs across the
east where a few isolated storms may still occur. The front will
otherwise bring some relief in the form of drier air and more
seasonable temperatures for the first half of next week. The
dryline will eventually come into play again around Wednesday of
next week, when more thunderstorms will be possible as the next
upper level disturbance passes through. This will begin what
appears to be another active period for the second half of next
week and the final days of May.

30

&&

.AVIATION... /NEW/
/12Z TAFs/

MVFR cigs have overspread much of North and Central Texas as of
1030Z. Intermittent IFR cigs around 800-900ft have been observed
as well. Cig heights should start to lift later this morning
becoming VFR by 16Z-17Z.

Thunderstorms have developed near the San Angelo area and will
push into our western Central Texas counties later this morning.
We will bring VCTS into the D10 TAFs and the KACT TAF starting at
16Z-17Z. It is entirely possible that much of this activity
remains scattered enough to limit impacts to the terminals.
However, the greatest potential for TSRA impacts at KACT will be
this afternoon, and for the D10 terminals, later this afternoon
into this evening. Some storms may be severe with primarily a hail
and damaging wind threat. The bulk of this activity should exit to
the east and southeast by 00Z-01Z.

Langfeld

&&


.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    87  74  93  73  92 /  50  30  20  20  20
Waco                87  73  91  73  92 /  50  20  20  30   5
Paris               84  69  88  69  88 /  50  50  20  30  10
Denton              85  72  93  71  90 /  50  30  20  20  20
McKinney            85  72  90  72  89 /  50  40  20  30  20
Dallas              88  73  93  73  91 /  50  30  20  30  10
Terrell             86  72  90  72  89 /  40  40  20  30   5
Corsicana           88  74  92  74  92 /  50  30  20  30   5
Temple              89  74  92  73  93 /  40  10  20  30   5
Mineral Wells       86  73  93  70  93 /  50  10  10  10  20

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
Flood Watch through late tonight for TXZ092>095-102>107-117>123-
130>135-141>148-156>161.

&&

$$