649
FXUS64 KFWD 252019
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
319 PM CDT Sat May 25 2024

...New Long Term...

.SHORT TERM... /Issued 144 PM CDT Sat May 25 2024/
/This Weekend/

There is a chance for isolated instances of severe weather late
this afternoon and evening across North Texas. Hot and humid
weather is also expected this weekend across the region.


Heat...
Our attention has largely been on the severe weather, but a much
more widespread impact the next few days will be the heat. We have
issued a Heat Advisory for parts of Eastern Central Texas for this
afternoon. We will collaborate with neighboring offices and assess
new data over the next few hours to decide if we will extend the
advisory through tomorrow or Monday afternoon. As a reminder, our
Heat Advisory criteria is a heat index value >= 105 F (or ambient
temperature >= 103 F) for two consecutive days. Most locations
will hit this value either today or tomorrow, and most outside of
the advisory will not hit it both days.

Today`s main concern will be heat index values between 103-109
for most of the area. It will be hot, humid, and mostly sunny for
a good part of the afternoon. A dryline will move into our area
tomorrow, resulting in temperatures soaring into the upper 90s to
near 100 degrees for most locations along and west of I-35. Areas
east of the dryline will contend with another day of 105+ degree
heat index values. If you plan to spend extended periods of time
outdoors this weekend, please remember to have a plan to beat the
heat: Drink plenty of water, limit time spent outdoors in direct
sunlight, wear light- colored and breathable clothing, and be able
to recognize the symptoms of heat illness.


Severe Weather...
Yesterday`s remnant boundaries are in the process of washing out
as a low pressure center deepens to our northwest. A vigorous
shortwave trough will eject out of the Rockies this afternoon,
helping strengthen pressure falls and provide a source of large
scale ascent later today. A dryline is becoming better defined
well to our west (currently west of Childress and near Big Spring)
that will advance east this afternoon.

We`re still not 100% sure exactly where or when the first storms
of the day will take place as the CAM guidance has had modest to
poor run-to-run consistency regarding this aspect. Mesoanalysis
satellite data has already started to indicate a few modest
updraft towers going up within a shallow cumulus field between
Sterling City and Spur...or about 50 miles ahead of the dryline.
If these updrafts are able to mature into mature thunderstorms,
they would approach our forecast area between ~5-6PM this
afternoon. There is a 30% chance of this occurring. We are not
expecting any thunderstorms in our area earlier than 5PM due to a
very strong cap residing over our forecast area. Surface heating
alone should not be sufficient to break the cap without the help
of forced ascent by either the dryline or the supercell itself.

We are mainly concerned about *isolated* supercells developing
along the dryline late this afternoon to our northwest. CI is most
likely to take place where a moisture/theta-e ridge extends into
the dryline west of Wichita Falls/Abilene. Storms will develop in
a highly buoyant and well-sheared atmosphere, more than capable
of supporting supercells. Both left and right splitting storms
will also be likely this afternoon and evening. As is usually the
case...right moving supercells will have a higher potential of
large hail, damaging winds, and perhaps a tornado, while left
moving supercells will primarily have a large hail threat.

As the storms move off the boundary this evening, the storms
should remain isolated as they continue east into our forecast
area after about 7PM. The nocturnal low-level jet will strengthen
and provide sufficient inflow to maintain the storm`s intensity
several hours after sunset (particularly any right-moving storms).
Most CAM guidance only has 1 or 2 storms moving across North Texas
this evening, so while the coverage of severe weather will be
low...any storm that lives into the evening should pack a punch.
The storms should gradually weaken as they ingest more CIN
overnight, this is particularly true for areas along and east of
I-35. While an isolated storm can`t be ruled out after midnight,
most storms will end before this time.

Tomorrow morning will start precip-free, but there is a 10% chance
of isolated storms developing along a dryline over east/northeast
Texas late in the day. Near parallel flow to the boundary will
limit moisture convergence, and therefore the convective
potential. However, similar to today...any storm that develops
should be capable of producing large hail and damaging wind gusts.

Bonnette

&&

.LONG TERM... /NEW/
/Memorial Day and Beyond/

By 00Z Monday (Sunday night), the cold front associated with the
shortwave moving across the Central Plains will still be lagging
well behind the associated surface low located near the Great
Lakes. This front, extending from the Upper Midwest into North
Texas, is projected to push south of the Red River early Monday
morning. With mid-level ascent mostly displaced well to the
northeast, forcing for ascent will generally be limited to the
surface boundary(ies). 12Z guidance continues to favor a
precipitation-free Memorial Day holiday (NBM PoPs < 10%), at least
until after dark. By the Monday evening, isentropic lift over the
shallow front in addition to ongoing warm air advection may lead
to some chances for showers and a few elevated thunderstorms. We
will also need to monitor any convection developing along the
dryline, which will likely have retreated west towards the Edwards
Plateau as moisture advection continues ahead of the boundary. We
have maintained the low (20% or less) chance for showers and
thunderstorms across Central Texas (generally south of I-20) after
midnight.

Consolidation of an expanding mid-level ridge over the
Intermountain West and the subtropical high over Mexico combined
with troughing over the Great Lakes and Appalachians will result
in northwest flow aloft across the Plains. Ridge-topping
perturbations/shortwaves embedded in the flow aloft in conjunction
with the sharpening dryline to the west and lingering frontal
boundary across Central Texas should provide sufficient forcing
for daily rain/storm chances. This pattern will support rounds of
thunderstorms developing initially over the higher terrain to our
west and northwest during the afternoon and evening tracking south
and east into North and Central Texas overnight and into the
daytime hours. The first shortwave is currently progged to arrive
Tuesday night into Wednesday with additional waves arriving
nightly through the end of the week. Forecast soundings indicate
the environment may support severe weather though the finer
details including location and specific impacts will be difficult
to define at this stage especially for later periods as the
forecast will become increasingly affected by any remnant
boundaries/outflows from previous convection.

Given recent locally heavy rainfall and the potential for
multiple additional rounds of showers and storms next week
isolated flash and urban flooding impacts are also likely,
especially over areas that recently received heavy rainfall. With
regard to the recent bout of heat, as post-frontal dewpoints drop
slightly (upper 50s/60s across North TX and low/mid 70s across
Central TX) and temperatures peak in the low to mid 90s, heat
indices on Monday should be well below Heat Advisory criteria for
all but our southern row of counties. By Wednesday, with the aid
of precipitation and increasingly cloudy skies, highs will
generally be in the 80s region wide. The active pattern looks to
keep this "cool down" in place through the end of the month.

12

&&

.AVIATION... /Issued 144 PM CDT Sat May 25 2024/
/18Z TAFs/

MVFR stratus over North Texas will gradually lift/scatter over the
next 1-2 hours. Similar to yesterday, the skies will be hazy all
day with 6-9 SM visibility expected through the afternoon. We have
omitted this detail from the TAF due to its low operational impact.

Our main concern will be another round of thunderstorms moving
toward the area late in the day. A few storms are starting to go
up well to the west of D10 at this time. These storms will move
east, with only a 10% chance they live long enough to move into
D10 or ACT airspace around/after 00Z. Additional storms should
develop near the Bowie feeder routes between 21-23Z that will move
east/southeast late in the day/*this evening. These should encroach
on the D10 terminals after 00-01Z and move east after a couple
hours. The storms will be isolated, so there is only a 30% chance
of storms directly impacting the terminals at this time.

After the storms move east, VFR and south flow should prevail
before another round of MVFR stratus moves in early Sunday
morning. The stratus should clear by mid-late morning with breezy
south-southwest flow expected tomorrow afternoon.

Bonnette

&&


.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    74  97  71  94  71 /  30  10   0   5  20
Waco                74  95  71  93  71 /  10   5   0   5  20
Paris               72  91  68  90  65 /  30  10   5   5  10
Denton              73  96  66  92  68 /  30  10   0   5  20
McKinney            74  94  69  91  68 /  30  10   0   5  20
Dallas              74  97  72  94  71 /  20  10   0   5  20
Terrell             73  91  71  91  69 /  20  10   0   5  20
Corsicana           75  93  74  93  73 /  10   5   0   5  10
Temple              74  95  72  94  71 /   5   5   0  10  20
Mineral Wells       72 100  66  94  69 /  20   0   0   0  10

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM CDT Sunday for TXZ147-148-158>162-174-
175.

&&

$$