917
FXUS64 KFWD 280102
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
802 PM CDT Mon May 27 2024

...New Short Term, Aviation...

.SHORT TERM... /NEW/
/Tonight through Tuesday Night/

Thunderstorms continue across parts of North and Central TX this
evening in an extremely unstable airmass posing mainly a very
large hail and damaging wind threat. The convection has developed
along a retreating theta-e boundary which is easily seen in
regional dewpoint temperatures draped generally along I-20. To the
south of this boundary, mixed layer CAPE has exceeded 5000 J/kg
but low level winds are notably weak which will limit any tornado
threat into the late evening hours. Convection should decrease in
coverage through the late evening, however, an uptick in
thunderstorms is expected later tonight as an area of warm
advection develops coinciding with a strengthening low level jet.
This activity should primarily be elevated, but ample instability
will support a large hail threat well into the overnight and early
morning hours on Tuesday. This focused area of isentropic ascent
should generally extend from the Metroplex northward into southern
Oklahoma, but coverage of storms is a little uncertain. We`ll keep
PoPs at 20% through the remainder of the evening and raise them to
30-50% after 3 am across far North Texas and parts of Texoma.

The extent of the morning convection will likely impact late
afternoon/evening activity on Tuesday, but it appears that we`ll
see at least some lull across the region Tuesday afternoon. That
being said, afternoon heating will again result in a strongly
unstable airmass across North Texas. Thunderstorms will develop
across West Texas by late afternoon aided by weak ascent from a
passing shortwave embedded in the northwest flow aloft. These
storms should eventually grow upscale into a fairly large MCS that
is currently forecast to move through North Texas Tuesday
evening/night. Damaging winds would be the primary threat with
this activity.

Dunn

&&

.LONG TERM... /Issued 312 PM CDT Mon May 27 2024/
Update:

The forecast trends discussed below generally remain on track,
therefore no significant changes were made to the previous
forecast. The first in a series of weak shortwaves/perturbations
embedded in the W/NW flow aloft will shift over a High Plains
dryline on Tuesday. The resulting thunderstorm complex will carry
primarily a damaging wind threat as these storms progress
east/southeast into our area during the late afternoon and evening
hours on Tuesday. There will also be a threat for isolated
instances of large hail, particularly south I-20 and west of I-35.
This repetitive pattern of passing disturbances and daily storm
chances will continue through the end of the week. Multiple rounds
of heavy rainfall will likely lead to an increasing flood threat,
especially given vulnerable soils due to recent rainfall. This
unsettled pattern is likely to continue through the upcoming
weekend as the weakening upper ridge shifts to the east late week.
In its wake, a series of shortwave troughs riding around the
upper low over the Gulf of Alaska will eject across the northern
Rockies keeping our pattern somewhat amplified.

12

Previous Discussion:
/Tuesday Evening and Beyond/

An active northwest flow pattern will set up over North and
Central Texas by midweek as the region becomes sandwiched between
a developing ridge over portions of the Desert Southwest/northern
Mexico and troughing over the Great Lakes region. An initial
shortwave perturbation looks to shift over a sharpening dryline
late Tuesday afternoon/evening, initiating isolated to scattered
convection over portions of West Texas and the Big Country. This
activity will likely develop initially as supercells before
growing upscale into a cluster of cells or possibly an MCS. With a
northwesterly mean cloud-layer wind and a 25-35 southeasterly
LLJ, this complex of thunderstorms will rapidly shift southeast
toward our forecast area late Tuesday evening into the overnight.
Where the initial convection occurs will play a large part in
determining where this complex tracks Tuesday evening/night.
However, there are several signals that our western Central Texas
counties could witness the brunt of this complex`s impact.

These convective systems tend to track along instability
gradients, and most guidance right now places that SBCAPE
gradient/weak, stalled frontal boundary generally along/south of
the I-20 corridor Tuesday night. This track over western Central
Texas and the Hill Country may also be reinforced by outflow from
thunderstorms near the Red River Valley earlier in the day. Damaging
wind gusts along the leading edge of this complex and isolated
hail will be the primary hazards. Latest high-resolution guidance
currently places an area along/southwest of a Breckenridge-
Hillsboro line in the track of this potentially severe line of
storms. The portion of this complex north of the instability
gradient will likely be sub-severe with a lack of surface-based
instability present. PWATs approaching 1.9-2.1" and warm cloud
depths greater than 15,000ft will make these thunderstorms very
efficient rainfall producers and several locations beneath these
storms could pick up a quick 2-3" of rain. Continue to monitor the
forecast over the next couple of days as we further refine
location and timing details.

This active pattern will continue through the rest of the work
week with daily chances for thunderstorms over portions of North
and Central Texas through at least Saturday. Coverage Wednesday
may be more isolated, but the next chance for more widespread
rainfall looks to arrive late Thursday into Friday as another
compact shortwave progresses overhead through the northwesterly
flow aloft and the aforementioned stalled frontal boundary lifts
north toward the Red River enveloping most of the region in
moderate surface-based instability. Severe weather will be
possible at times. Additionally, multiple rounds of heavy rainfall
will increase the flooding threat, especially over already
saturated areas. Otherwise, temperatures will be slightly tempered
by clouds and precipitation with widespread afternoon highs in the
80s and low 90s and overnight lows in the mid-60s to low 70s.

Langfeld

&&

.AVIATION... /NEW/
/00Z TAFs/

Outside of isolated convection which has surely resulted in
significant disruptions to DFW air traffic operations, VFR
prevails and will likely continue through much of the night. Some
lower clouds will be possible south of the major airports and will
include some MVFR at Waco during the early morning hours. The main
concern over the next 24 hours will be potential for additional
convection. Thunderstorms will likely increase in coverage again
late tonight mainly north of DFW but will include VCTS from
10-15Z. Better storm chances will arrive late Tuesday evening and
night as a complex of storms approaches from the west.

Dunn

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    72  89  70  83  70 /  30  50  60  60  30
Waco                72  89  70  82  69 /  20  50  60  60  30
Paris               67  84  66  79  64 /  30  40  50  50  30
Denton              70  86  67  81  67 /  30  50  60  60  30
McKinney            69  86  68  81  67 /  30  50  60  50  30
Dallas              71  89  71  83  69 /  30  50  60  60  30
Terrell             69  88  68  82  67 /  30  50  50  50  30
Corsicana           72  89  71  83  69 /  20  50  50  60  30
Temple              73  90  70  83  69 /  20  40  60  60  30
Mineral Wells       70  89  68  81  69 /  20  60  70  60  30

&&

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

&&

$$