357
FXUS64 KFWD 270548
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
1248 AM CDT Mon May 27 2024

...New Short Term, Aviation...

.SHORT TERM... /NEW/
/Memorial Day Into Tuesday/

...More Severe Weather Returns Late Today Into This Evening...
...More Numerous Showers/Storms Tuesday With Locally Heavy
Rainfall...

After a much-needed quiet period yesterday and through much of
Memorial Day, things unfortunately become quite unstable and
volatile by this evening with unsettled weather continuing off
and on Tuesday. The highest likelihood for isolated to scattered
severe storms will be very late this afternoon and through
midnight, with lesser chances overnight. Locally heavy rain and
flooding gets added to the mix by later on Tuesday, as a very
energized northwest flow aloft regime evolves across the area.

A weak frontal boundary has stalled this evening along the I-20/30
corridors with tropical-like moisture and very light winds both
ahead and behind this feature. I expect some fog to develop
across especially eastern Central Texas where surface dew points
are pushing around 80 degrees in spots. That`s unheard of this
time of year across our region. It`s possible dense fog could
develop across the far southeast counties enough for a brief
advisory this morning, but will await development to occur. Our
weak stalled front will mix readily north across possibly all but
our northeast counties, as a strong shortwave induces pressure
falls well west of the area. Peak heating will see temperatures
soaring into the 90s with heat index values right to around 105
degrees across particularly eastern Central Texas where a Heat
Advisory remains in effect through mid evening. In addition, the
heat and rich moisture will help surface-based instability to soar
up to 5000-6000 J/KG as additional mid level energy lifts
northeast from Mexico. Combined with very steep lapse rates =>
than 8 Deg C/km, the atmosphere as noted beforehand becomes very
volatile. This should help ignite isolated to scattered severe
storms with all modes of severe weather possible, including
tornadoes by this evening with discrete storms that can develop.
The only thing missing is a surface focus, or coverage would be
higher than the 20%-40% advertised. Still, most CAMs are showing
the potential with the strong mid level impulse arriving late
today. With this still being the end of the holiday weekend, those
planning to be outdoors in this oppressive heat will need to keep
a close eye on forecast updates and radar if possible.

Though a few storms will linger near the stalled boundary across
our northeast counties just past midnight, a downward trend in
coverage and intensity of storms will occur as temperatures cool
and subsidence briefly takes over overnight and Tuesday morning.
Morning conditions will remain very humid and warm with lows in
the 70s. After the reprieve Tuesday morning, the aforementioned
evolving and energetic northwest flow regime sets up across the
Southern Plains as the shortwave ridge to our immediate west
dampens. Though more expansive cloud cover will hold high
temperatures Tuesday to the mid-80s to the lower 90s, plenty of
strong deep layer shear >40 kts, large-scale ascent, and steep
lapse rates will again result in some severe weather with the
added addition of flooding late in the day as localized heavy
rainfall from more widespread convection evolves late in the day.
Details are more murky on Tuesday regarding coverage and timing of
impacts as models struggle with these scenarios of high moisture,
instability, and energy aloft, so my advice is too stay abreast
of the forecasts early this week. It looks like May is definitely
going out like a lion versus a lamb. Wish I had better news.

05/Marty

&&

.LONG TERM... /Issued 322 PM CDT Sun May 26 2024/
/Monday Night into the weekend/

With a mid/upper-level ridge building over the western U.S. and
consolidating lows/troughs over the Great Lakes, North and Central
Texas will be on the southern fringe of a northwest flow pattern
by late Monday. Regional models and high-resolution CAMs show rain
chances may return as early as Monday evening as a cold front
continues to slowly move across the region. This will kick-off
the next multi-day period of unsettled weather across North and
Central Texas. Daily thunderstorm complexes are expected to
develop across the High Plains in response to a series of subtle
shortwaves/perturbations embedded along the northern periphery of
the larger scale ridge. Convection will spread eastward nightly,
bringing periodic rain and storm chances to the region through the
end of the week.

The pattern will become increasingly messy as the week wears on
as mesoscale features evolve. This lowered predictability has
resulted in some broad-brushing of PoPs, especially mid/late
week. The main change with this forecast update will be the
introduction of slight chance (20% of less) PoPs after 00Z Tuesday
(7 PM Monday) generally near and west of the I-35 corridor. As
the backdoor front temporarily stalls over the region late Monday,
the moist/unstable and briefly uncapped airmass south of the
front will be primed for storm development with the potential for
severe weather given the 50 kts of available effective shear. A
strengthening low level jet during the evening will also enhance
moisture advection and isentropic ascent through the overnight
period. If storms develop, all severe hazards will be possible.

By Thursday into Friday, the front should lift back northward as
a warm front, repositioning the warm/moist airmass more directly
overhead and fueling thunderstorm development through the end of
the week and into the weekend. With PWATs approaching 1.75 to 2
inches at times, periods of locally heavy rainfall are likely. Due
to lingering moist soils, localized flooding issues may also
emerge, especially wherever higher convective rain rates occur.
Temperatures will be fairly steady throughout the week though
tempered slightly by the expected cloud cover and precipitation.
Highs will generally be in the 80s to lower 90s with lows in the
mid 60s to lower 70s.

12

&&

.AVIATION... /NEW/
/06Z TAFs/

A weak FROPA made it to about I-20(I-30 out E), but has since lost
any upper support with AFW/FTW/DFW seeing light NE around 5-7 kts
with light S or VRB winds at DAL/GKY 5 kts or less.

Moisture to the south of this boundary is very tropical-like and
high and with only light S or calm winds, I can`t rule out spotty
5-6sm BR near GKY and possible DAL/FTW by 12z, but the better bet
for MVFR/IFR and possibly LIFR conditions will be at ACT between
10z-14z. Once the old boundary and ESE/SE winds pick up to between
10-15 kts, then all sites will see VFR with SCT Cu and high
clouds.

With the old surface front out of the area, scattered TSRA are
expected over the DFW D10 area by 00z Tuesday and have an added a
VCTS until almost 03z per latest CAMs. The only driver will be mid
level energy arriving at peak heating. However, with a very
unstable airmass, look for TS+ and GS/GR to occur with TSRA.

05/Marty

&&


.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    74  95  72  87  69 /   0  10  40  50  60
Waco                75  93  72  89  69 /   0  20  20  40  60
Paris               69  92  67  85  66 /  10   5  20  40  50
Denton              68  93  69  84  67 /   0   5  40  50  60
McKinney            70  93  69  83  68 /   0  10  30  50  60
Dallas              75  95  73  88  69 /   0  20  30  50  60
Terrell             73  91  70  86  68 /   5  20  30  50  50
Corsicana           75  91  71  90  70 /   5  20  20  40  50
Temple              75  92  72  89  68 /   0  30  20  40  50
Mineral Wells       68  95  70  88  67 /   0  10  40  50  70

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM CDT Monday for TXZ135-145>148-158>162-
174-175.

&&

$$