519
FXUS64 KFWD 151048
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
548 AM CDT Wed May 15 2024

...New Aviation, Short Term...

.SHORT TERM... /NEW/
Update:
No meaningful changes were necessary with this morning`s short
term forecast update. The bulk of shower and thunderstorm activity
looks to hold off until after daybreak Thursday morning, with only
isolated/scattered elevated convection during the overnight hours.
Otherwise, a swath of high cloud cover should be insufficient at
preventing afternoon high temperatures from climbing into the
upper 80s and lower 90s today. But, some relief from the above
normal mid-May warmth will come in the form of seasonably low
dewpoints and a decent southerly breeze of 10-20 mph.

-Stalley

Previous Discussion:
/Through Tonight/

Our brief break in shower and thunderstorm activity continues
today as we remain positioned in between shortwave disturbances.
Modest shortwave ridging aloft with strengthening low-level
southerly flow and warm advection will result in a seasonably warm
afternoon with highs in the upper 80s to lower 90s. Expect
southerly winds of 10-20 mph with a few higher gusts present
during the afternoon hours. High cloud cover will also be on the
increase late in the day, ushered eastward by a belt of
strengthening upper level westerlies.

By this evening, our next upper trough will begin sharpening to
our west, while a surface front and dryline become convectively
active across portions of West Texas and the Panhandle. Height
falls should allow for elevated showers and isolated storms
rooted above 10 kft to eventually drift eastward into parts of
North Texas, especially after midnight. Strong or severe storms
would be unlikely during the predawn hours though, as this
activity will remain high-based above a rather dry mid-level
layer. Meaningful low-level moisture necessary to produce more
robust convection will be slower to return despite a 40-50 kt low-
level jet, and a richer theta-e airmass will not be present until
after daybreak Thursday morning.

-Stalley

&&

.LONG TERM... /Issued 418 AM CDT Wed May 15 2024/
/Thursday Through the Middle of Next Week/

The potential is increasing for a significant rain event Thursday
into Thursday night, particularly from Central Texas into East
Texas. Guidance continues to be in good agreement with respect to
the main synoptic features, but the placement and amounts of the
heaviest rainfall still need to be fine-tuned.

As the upper system approaches from the west, forcing for ascent
may initiate some elevated convection early Thursday morning,
primarily across western portions of North Texas. These warm
advection showers (and perhaps a few isolated storms) may be
ongoing at daybreak Thursday morning, but with the low levels
still scoured of moisture, these convective elements will remain
elevated. The main event will develop later in the day.

As the system induces low-level cyclogenesis across West Texas,
moist advection will intensify across the eastern half of the
state. This will also serve to sharpen a warm frontal boundary
that will be forced northward through Central Texas. This may be
the initial focus for deeper convection rooted in the boundary
layer. Although cloud cover and rainfall may temper the heat
content within the boundary layer, strong warm/moist advection
should still allow for considerable instability as these more
deeply rooted cells develop during the daylight hours. The
boundary will also serve to back the surface flow, enhancing the
sub-cloud layer shear and the tornadic potential. A storm mode
favoring supercells will also pose a threat for very large hail
and damaging winds. However, the window for these isolated storms
may be small as the radar scope becomes cluttered. The transition
to multi-cell clusters will not end the severe potential but will
enhance the training/backbuilding that will lead to considerable
rainfall amounts.

Median event totals are 1 to 3 inches from the Big Country into
Central and East Central Texas. It still appears that there will
be a sharp gradient in amounts, with lesser totals across
Northeast Texas where the moisture and frontal boundary will
take the longest to arrive. Our worst-case scenario amounts (90th
percentile values) would put 1- to 3-inch values north of the I-20
corridor with 3- to 5-inch totals in areas that are both east of
I-35 and south of I-20. As is typical with convective activity,
locally higher amounts can occur. A Flood Watch will likely be
needed with subsequent forecast packages, the area matching the
Moderate risk for excessive rainfall, which overlaps those areas
that have seen considerable rainfall so far this month. As the
event is soon captured by short-range guidance and additional
CAMs, there will be greater precision with placement and amounts.

The event will continue into Thursday night, one area of
convection gradually exiting to our southeast and another
accompanying the frontal boundary into Northeast Texas. Renewed
convection on Friday may be within our CWA, but the primary
activity will be focused within those two departing areas (1) to
our southeast and (2) to our northeast. However, since much of the
event will be governed by convective evolution on the mesoscale,
this will need to be re-evaluated as the event unfolds Thursday
into Thursday night.

North and Central Texas should finally be safely on the backside
of the departing system Friday night into Saturday morning,
setting the stage for a sunny and unseasonably warm weekend as
ridging aloft transits the region. Afternoon temperatures in the
90s will be widespread early next week, with the potential for
triple digits across the Big Country. By Spring 2024 standards,
this will be a protracted rain-free period, with rain chances
potentially holding off until the middle of the upcoming week.

25

&&

.AVIATION... /NEW/
/12z TAFs/

VFR will prevail through the period. Light SE winds near 5 kts
will increase to 10-20 kts by midday with some higher afternoon
gusts possible. A cirrus canopy will spill into the area from the
west during the day, with increasing mid clouds around 10 kft
arriving later tonight. High-based showers and isolated
thunderstorms may also arrive from the west between 06-12z
Thursday morning. However, much more widespread shower and
thunderstorm activity is expected to develop and overspread the
region towards midday Thursday; TS has been introduced into the
extended DFW TAF accordingly.

-Stalley

&&


.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    89  68  79  67  83 /   0  30  70  60  20
Waco                90  66  78  66  83 /   0  20  90  50  10
Paris               87  66  81  65  81 /   0  10  40  70  30
Denton              88  66  78  64  81 /   0  30  70  60  20
McKinney            88  67  78  65  81 /   0  20  60  60  20
Dallas              91  69  80  67  84 /   0  20  70  60  20
Terrell             87  66  79  66  81 /   0  20  70  60  20
Corsicana           89  67  80  68  83 /   0  20  80  60  20
Temple              89  65  78  67  83 /   0  20  90  40  20
Mineral Wells       90  65  77  63  82 /   0  40  80  50  20

&&

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

$$