137
FXUS64 KFWD 281018
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
518 AM CDT Tue May 28 2024

...New Short Term, Aviation...

.SHORT TERM... /NEW/
/Moving Into Mid Week/

The unsettled weather with periodic showers and storms, some
strong to severe and flooding coming back into the picture late
tonight and Wednesday. A weak surface boundary continues to be
draped along or just north of the I-20 corridor as earlier storms
and associated outflows have only solidified this boundary
evening. However, this lull in weather will be short-lived, as a
25-35 kt southeasterly LLJ feeds into an elevated boundary up
through 850mb up across Northwest Texas and Southern OK through
the overnight hours. As the next shortwave round the dampened mid
level ridge to our west, another potential complex of storms will
develop to our north and west during the predawn hours. Models,
though at different magnitudes will bring this into North Texas
around sunrise and eventually Central Texas later in the morning
or afternoon. More severe weather will be possible as this storm
cluster ridges southeast along the instability gradient.
Initially, large hail will be the primary hazard with storms
potentially being semi-elevated, then as a cold pool evolves we
could see damaging winds as well. Just a few hour of removing one
severe storm watch, another severe tstorm watch will be
forthcoming and will go to around dawn/7 am, as elevated storms
are already going up over Southwest OK/Northwest TX. Easterly
winds will continue with a slightly cooler morning that previously
over the holiday weekend, with some upper 60s to lower 70s being
the rule.

As the storm complex weakens some this afternoon across Central
Texas, numerous surface boundaries and temperature/instability
gradients from cloudy to partly cloudy skies will only play new
roles to act as focal points for another round of storms,
potentially an MCS this coming evening and overnight into
Wednesday morning. Models, especially CAMs are struggling as to be
expected in these active northwest flow environments and no
knowledge said mesoscale surface boundaries. Though surface
instability won`t be as extreme as recent days, plenty of shear
and lift, along with very steep lapse rates. Severe weather
hazards of large hail and damaging winds will once again be
impacts again, though we can start adding localized flooding at
this point. Despite the increasing flood threat, the uncertainties
noted above gives me low confidence on where/when for any Flood
Watch issuance. Later today, that should be more clear from this
early morning`s storms to hopefully the CAMs getting a better
handle with the MCS track tonight.

The MCS should be ongoing Wednesday morning as well, just the
"where" of the main track and worse weather conditions is
uncertain once again. This system should become more of a damaging
wind threat around this time, though isolated large hail will
remain possible on Wednesday. This system will weaken before
midday laying more surface boundaries from outflow with more
scattered development late in the day. The only saving grace from
the very active severe weather and locally heavy rainfall will be
much cooler high temperatures mostly in the 80s with lows
Wednesday morning mainly in the 60s.

05/Marty

&&

.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/
/06z TAFs/

Earlier storms have cooled the BL enough for some high MVFR for a
few hours before environment S flow at 925mb breaks out to VFR
before the next round of storms arrives from the north from OK
around 10z-12z. I`ll will carry MVFR cigs with VCTS from 12z-15z
with a TEMPO group for MVFR cigs with IFR vsbys in TSRA.

Otherwise, kept similar trends beyond this time with prevailing
ESE winds around 10 kts and VFR returning by 18z, as we experience
a brief reprieve before tonight`s MCS. Speaking of, I removed the
TEMPO group beyond 00z Wed due to very low confidence on timing
and track of a nocturnal MCS expected Tues night on latest CAMs
and will just hold a VCTS/CB group from 02z onward.

05/Marty

&&


.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    74  86  69  83  70 /  40  70  60  50  30
Waco                75  90  70  82  69 /  20  30  70  60  30
Paris               67  81  67  81  64 /  30  60  50  60  30
Denton              69  84  67  82  67 /  40  70  60  50  30
McKinney            71  83  68  82  67 /  40  70  60  50  30
Dallas              74  87  69  83  69 /  40  70  60  50  30
Terrell             71  85  68  82  67 /  30  70  50  50  30
Corsicana           74  87  69  84  69 /  20  40  50  60  30
Temple              75  90  70  83  69 /  20  30  70  50  30
Mineral Wells       73  86  68  81  69 /  40  50  70  50  30

&&

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

$$