809
FXUS64 KFWD 011907
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
207 PM CDT Wed May 1 2024

...New Short Term, Aviation...

.SHORT TERM... /NEW/
/Through Thursday/

After our brief break, another period of unsettled weather begins
later today. The 70F isodrosotherm is already within our CWA, with
even richer boundary-layer moisture approaching Central Texas. It`s
within this deeper moisture that bubbles on visible satellite and
weak echoes on radar are foreshadowing the convective potential
later this afternoon. Just south of our southern boundary, MLCAPE
values exceed 2000 J/kg and MUCAPE values top 3000 J/kg owing to
steep mid-level lapse rates. Although these initial convective
attempts are separated from the boundary layer, effective erosion
of the remaining inhibition should allow for updrafts to be rooted
in the rich surface layer. Deep-layer shear and classically veered
profiles will favor supercells. These storms would have a tendency
to move north faster than the buoyant boundary layer can advect,
and they may weaken as they ingest the somewhat cooler, cloud-
stifled parcels within our CWA. Nonetheless, the more enduring
cells could still pose a wind/hail threat, and low LCLs and
adequate 0-1km shear will maintain a tornado threat. Some of these
storms may survive as far north as the Dallas/Fort Worth Metroplex
after dark.

A West Texas dryline will come alive late this afternoon. The
mid-level impulse responsible for the initiation will be further
enhanced by the convection as it approaches North and Central
Texas this evening. There may be little separation in space and
time between the activity mentioned in the paragraph above and the
subsequent round that will arrive later in the evening and
through the overnight hours. Discrete hail cores will eventually
give way to a more linear complex that will primarily pose a wind
threat. While wetting rainfall is anticipated for much if not all
of the region, our main focus for flooding remains within the
ongoing Flood Watch where positive soil moisture anomalies from
recent rainfall coincide with the greatest QPF from tonight`s
event. However, heavy rainfall outside of the watch area could
also reaggravate flooding issues elsewhere. Some showers or storms
may linger in its wake, but the main MCS should exit into East
Texas around daybreak Thursday morning.

A lull in convective activity should follow on Thursday, but the
atmosphere may be able to recharge by afternoon. Another round of
warm-advection showers and storms could spread north across the
region by late Thursday afternoon. While these cells would likely
be less organized and generally less robust than their
predecessors 24 hours earlier, they could still pose a wind/hail
threat. However, the more significant storm potential will
accompany a cold front that will approach our northwestern
frontier Thursday evening.

25

&&

.LONG TERM... /Issued 414 AM CDT Wed May 1 2024/
/Thursday Onward/

The overnight MCS will likely be ongoing across the eastern and
southern parts of our forecast area early Thursday morning, mainly
the trailing stratiform portion of the MCS. There is about a 10%
chance of backbuilding convection on the upshear flank of the
system continuing through the morning in Central Texas. This would
drastically increase and prolong the flood threat. There is a low
probability of this occurring, but the impact of it is high
enough that it is worth mentioning.

A lull in convective activity is expected in the early afternoon
Thursday as the MCS moves East before additional storms develop
along a cold front and dryline late in the day. Convective
initiation is expected near a triple point in western North
Texas...consensus in the guidance generally has this taking place
between Childress-Wichita Falls and as far south as Abilene. The
convective mode will start as supercells that transition to
outflow dominate clusters as they move into our forecast area
overnight into Friday morning. All modes of severe weather will be
possible with the supercells, but only a few strong to marginally
severe wind gusts or hail stones will be possible once the storms
become outflow dominant Thursday night.

The cold front will then flutter near the area Friday with
additional scattered storms developing along the boundary in the
afternoon. Guidance has started to latch on to a stronger cold
front moving down the Plains late Friday into Saturday, stalling
in or near North Texas Saturday. One again...scattered storms are
expected to develop along the boundary in the afternoon. The best
chance for storms will be Saturday night and Sunday as a shortwave
trough moves over the front. The front should then lift north and
wash out, leaving our area precip-free and under the influence of
a warm and humid airmass next week.

Ensemble trends are still indicating the development of a strong
mid-level ridge over the Gulf Coast in the middle and late parts
of next week. This would result in a warming trend with highs in
the 90s more likely than not (50-70% chance for most locations
south of I-20) from Tuesday onward. Since surface moisture will
not be significantly scoured, heat index values will become
important next week...especially across Central and East Texas
where heat index values in the upper 90s or even low 100s are
possible next Wednesday-Thursday.

Bonnette

&&

.AVIATION... /NEW/
/18Z TAFs/

Concerns include thunder potential and IFR ceilings Thursday.

MVFR ceilings will eventually climb above 3kft AGL this afternoon
though this process will be slower across Central Texas. These
clouds have slowed the warming of the surface layer, which is
still separated from the stronger momentum air within the cloud-
bearing layer. The 18Z TAF tempers wind speeds, but somewhat
stronger sustained speeds with higher gusts may still occur later
this afternoon.

Convective attempts continue to struggle across Central Texas, but
guidance maintains the potential for storms to impact the Waco
terminal late this afternoon. The introduction of VCTS is the same
warm-advection activity that may trek as far north as the Dallas/
Fort Worth for the initial TEMPO group in the Metroplex (02-04Z).
The main MCS with wind potential will be after midnight along the
I-35 corridor, thankfully during the nocturnal minimum for
aviation operations.

Some showers/storms may trail behind the MCS, but the TAFs
endeavor to limit the duration of TS. After the thunderstorm winds
subside, a period of low-level wind shear may follow (not
currently included). IFR ceilings will then follow and persist
throughout the daylight hours of Thursday morning. Reductions in
visibility are likely above the rain-soaked ground, but the
ceilings will determine the flight category.

25

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    83  68  81  69  82 /  20  70  70  50  20
Waco                83  67  80  70  82 /  40  80  70  40  20
Paris               84  66  76  66  80 /  10  60  90  70  40
Denton              83  66  81  65  80 /  20  70  60  50  20
McKinney            83  67  79  67  81 /  20  70  70  60  20
Dallas              86  68  81  69  83 /  20  70  70  50  20
Terrell             83  67  79  67  81 /  20  80  80  60  30
Corsicana           85  68  81  70  83 /  30  80  90  50  30
Temple              82  67  81  70  82 /  50  80  50  30  20
Mineral Wells       82  67  84  67  81 /  20  70  30  40  20

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
Flood Watch from 7 PM CDT this evening through Thursday
afternoon for TXZ121-122-134-135-142>148-156>162-174-175.

&&

$$