447
FXUS64 KFWD 231147
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
547 AM CST Mon Dec 23 2024

...New Aviation, Short Term...

.KEY MESSAGES...

- Many areas will see rain on Tuesday (Christmas Eve), with the
  best chances near and east of the I-35 corridor.

- Wednesday (Christmas Day) will be rain-free, but storm chances return
  on Thursday and will linger through the end of the week.

- There will be a low threat for isolated strong to severe storms
  in Central Texas on Tuesday (Christmas Eve). A severe weather
  threat may materialize again on Thursday, but its magnitude and
  areal extent remain uncertain at this time.

&&

.SHORT TERM... /NEW/
Update:
Minor adjustments have been made to account for the latest
analysis/observations. Otherwise, the current forecast seems to be
trending well at this time. Though forcing for ascent associated
with the approaching shortwave trough will initially be weak, the
potential for measurable rainfall is expected to begin increasing,
particularly across North Texas, late tonight/early Christmas Eve
as the saturated layer deepens. The better chances continue to be
after sunrise tomorrow.

12

Previous Discussion:
/Today and Tonight/

The evening sounding from Ft Worth showed that the existing
moisture remains confined to roughly the 925-800 mb layer
resulting in increasingly overcast skies across North and Central
Texas tonight. Strengthening southerly low level flow aided by a
35-45 kt southwesterly LLJ will continue to deepen this layer of
saturation over North and Central Texas through the morning. The
breezy southerly winds, increasing dewpoints, and thickening cloud
cover will keep tonight`s temperatures closer to the normal high
temperature for this time of the year (56F at DFW and 59F at Waco)
rather than the normal low temperature (37F at both DFW and Waco)
with morning lows in the mid 40s to mid 50s.

By this afternoon, the surface low currently analyzed over the
Panhandles will drift eastward towards the Red River Valley,
scouring out some of the moisture in the lowest levels and
decreasing the potential for drizzle/light rain and lowering cloud
decks through the mid to late afternoon. However, the widespread
cloud cover should still significantly limit insolation today.
Forecast high temperatures range from the lower 60s (eastern N TX)
to the lower 70s (western N TX and Central TX). Low level
warm/moist advection is still expected to become maximized across
North Texas around midnight as the surface low to our northwest
deepens and the low level jet strengthens. The net result will be
the development of drizzle and scattered showers, initially just
near/north of the Red River in the evening and expanding across
North Texas overnight and into the early morning hours on
Christmas Eve. Better rain chances are still expected to hold off
until after daybreak on Tuesday. See the forecast discussion below
for the complete Christmas holiday forecast. Despite returning
rain chances, WAA and thickening cloud cover will lead to another
warm night tonight with lows in the 50s regionwide.

12

&&

.LONG TERM... /Issued 230 AM CST Mon Dec 23 2024/
Update:
There have been no significant changes to the previous forecast
with the latest model data overnight. Multiple storm systems will
traverse the area throughout the week, some of which will be
accompanied by a low threat for strong to marginally severe
storms. This threat will exist for Central Texas and portions of
East Texas on Tuesday (Christmas Eve), with isolated damaging wind
gusts and marginally severe hail expected to be the primary
hazards. A slightly more favorable setup for severe weather may
materialize on Thursday, but there remain some uncertainties in
the magnitude and areal extent of the threat. Low rain/storm
chances will linger through the weekend, but another rain-free
period looks to begin on Sunday and continue into next week. See
the previous discussion below for additional details.

Barnes

Previous Discussion:
/Tuesday through Sunday/

The upcoming week will be notable for its sustained mild and
somewhat unsettled conditions across North Texas. Two separate
storm systems and attendant cold fronts will produce distinct
opportunities for rainfall - one on Christmas Eve, and the other
on the day following Christmas. Additional light rain is possible
in the eastern zones on Saturday.

A vigorous, fast moving shortwave trough will sweep eastward
across the region on Tuesday, with an attendant Pacific cold front
moving from west to east through the area. Patchy light rain with
embedded showers will begin forming across the northernmost
counties before noon, with additional convection building
southward into our eastern and southern counties by early to mid
afternoon. Surface and mixed-layer instability will be fairly
modest, but sufficient to induce some scattered thunderstorm
development during the afternoon. Overall coverage will be
greatest along and east of I-35, but in no areas will QPF be
particularly generous. MUCAPE will be a tad healthier generally
south of a Lampasas to Hillsboro to Athens line, possibly
approaching 1000 J/kg by afternoon. This may facilitate some
better organized thunderstorms capable of producing brief strong
wind gusts and marginally severe hail by late afternoon and
evening. All precipitation should move out of North Texas by
midnight Christmas Day.

Christmas Day itself will feature a reprieve from the rainfall,
with mostly cloudy, unseasonably mild conditions prevailing.
Another, stronger shortwave will approach the Southern Plains by
daybreak Thursday, with strong southerly low level pumping
additional moisture and warmer air northward into the region.
Ample low level isentropic ascent will couple with the forcing
provided by the shortwave to trigger another round of showers and
thunderstorms across most of North Central Texas. Modest
instability will again be present across the region, and this may
promote the development of some stronger storms capable of hail
and strong winds. The exact timing and areal extent of any
stronger storms remains somewhat uncertain at this point, however.
Much like the Christmas Eve system, the Thursday rainfall event
should conclude across the eastern counties by late evening.

Given historical events, there is understandable sensitivity
regarding the mention of strong or severe thunderstorms
immediately before and after Christmas Day. However, it needs to
be stressed that any thunderstorms occurring across North Texas
either Tuesday or Thursday at best will be capable of only
marginally severe impacts - primarily marginally severe hail or
brief wind gusts. No significant tornado threats are apparent at
this time.

The third and final opportunity for precipitation across North
Texas will materialize late Friday night through Saturday. The
third in our series of fast moving shortwave troughs will zip
through the Southern Plains during this time period. With decent
low level isentropic lift and moisture in place, scattered showers
will develop Friday night and continue through Saturday in areas
mainly east of I-35. Sunday should feature drier, rain-free
conditions.

High temperatures throughout the period will be not show a great
deal of variance from day to day - with 60s and lower 70s being
the rule. Overnight lows will remain well above freezing,
primarily in the 40s and 50s. Our next opportunity for
significantly cooler air appears a number of days farther off -
most likely around or shortly after New Years Day.

Bradshaw

&&

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

MVFR cigs are expanding from west (KFTW/KAFW) to east
(KDFW/KDAL/KGKY/KACT) across North and Central Texas this morning
as low level moisture continues to deepen amid gusty south winds.
Some brief improvement is likely this afternoon into the evening
as moisture in the lowest levels is temporarily scoured out. MVFR
cigs will return late this evening with widespread IFR cigs likely
by daybreak Christmas Eve.

Areas of patchy drizzle/light rain may begin developing after 00Z
initially north of the Metroplex near the Red River and gradually
expanding southward across North Texas overnight. Given low
confidence in how far south the drizzle or light showers will
spread (and limited coverage), opted not to include any mention
of SHRA or lowered vis in the extended TAF. Coverage of
precipitation will increase around daybreak Tuesday and continue
through the afternoon and evening.

12

&&


.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    68  58  66  49  62 /   0  20  70  20   0
Waco                70  60  70  51  65 /   0  10  60  30   5
Paris               62  54  64  49  60 /   5  60  90  40  10
Denton              67  55  65  44  61 /   5  20  60  10   0
McKinney            66  56  66  47  61 /   0  40  80  20   5
Dallas              67  59  68  50  63 /   0  20  70  20   0
Terrell             68  56  66  49  62 /   0  20  80  40   5
Corsicana           71  59  69  52  65 /   0  10  80  40   5
Temple              73  59  71  50  68 /   5  10  60  30   5
Mineral Wells       71  53  65  44  64 /   0  10  40  10   0

&&

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

$$