439
FXUS64 KFWD 170755
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
255 AM CDT Tue Sep 17 2024

...New Long Term...

.SHORT TERM... /Issued 111 AM CDT Tue Sep 17 2024/
/Today and Tonight/

Warm, tranquil weather will persist across North Central Texas
once again today, thanks to the presence of a stout shortwave
ridge draped across the region. An easterly low level flow regime
will advect slightly milder air westward into the area from
Arkansas and Louisiana through the day, mitigating this
afternoon`s temperature climb versus what would otherwise be
expected from the current degree of subsidence. Nevertheless,
readings across the western and southern counties should rise
into the mid 90s by late afternoon, which is several degrees above
seasonal norms.

The current low level flow is also bringing an expanse of low
clouds westward into the northeastern counties of the forecast
area. By daybreak, scattered to broken cloudiness should exist
generally east of a Gainesville to Rockwall to Canton line. Most
of these clouds will erode by later morning, yielding mostly sunny
conditions in all areas. Some of the CAM guidance is suggesting
the potential for isolated showers and thunderstorms across our
far west and southwest counties. However, the source of forcing
for this convection is hard to discern, and given the low
confidence, have opted to leave PoPs out of the current forecast
for this afternoon/evening.

Bradshaw

&&

.LONG TERM... /NEW/
/Wednesday and beyond/

As a persistent ridge of high pressure maintains unseasonably
warm temperatures across the Southern Plains on Wednesday, a
strong mid-level low/shortwave trough will lift across the
northern Rockies and northern Plains. Though the southern Plains
mid-level ridge will remain tethered to the state through the
forecast period, the expanding western U.S. trough will tilt the
ridge axis across North and Central Texas. The eastward shift of
the associated low level thermal ridge will inflate 850 mb
temperatures locally by an average of 4 to 7C according to model
projections. This is good for about the 90th percentile of the
historical temperature distribution in both the NAEFS and ECMWF
ensembles. Mixing to the surface during peak daytime heating,
this will translate to widespread highs in the mid to upper 90s
each afternoon. For this time of year, the average high at DFW and
Waco is 87F and 90F, respectively. Adjustments have been made to
account for the deep vertical mixing expected which should allow
dewpoints to mix out on these hot and dry afternoons, up to
several degrees below the current NBM guidance. The resulting heat
indices should peak below Heat Advisory criteria, however heat
safety precautions should still be considered if spending time
outdoors this week.

As the first shortwave ejects into the Canadian Prairies, another
upper level low pressure system will dive down the West Coast
reaching central California by Thursday morning. This feature is
progged to track across the Rockies and move into the Plains this
weekend. Unfortunately, any previously held hopes of returning
(low) rain chances and seasonally appropriate temperatures late
this weekend and into the following week have vanished as the
shortwave and associated frontal boundary look to remain on a
track north of the forecast area. This will keep the subtropical
ridge in control of our sensible weather through the end of the
period. Favoring a status quo forecast for day 6 (Sunday) and
beyond, temperatures have been raised above the MOS and NBM
guidance to near the NBM 50th percentile. As always, forecast
details for this time period will continue to change/update as we
go through the rest of the week.

12

&&

.AVIATION... /Issued 111 AM CDT Tue Sep 17 2024/
/06z TAFS/

VFR conditions should prevail at all TAF sites through 12z
Wednesday, as upper level high pressure continues to dominate. An
area of MVFR ceilings is slowly advancing westward out of Arkansas
and Northwest Louisiana early this morning. A few leading shreds
of stratus associated with this cloud mass may reach the eastern
portion of D10, particularly KDAL, by 12z. However, am skeptical
that enough cloudiness will arrive in order to justify a mention
of BKN/OVC conditions at any Metroplex TAF site, so have omitted
any mention of ceilings. The cloud mass northeast through east of
the D10 area should largely erode by midday, yielding VFR
conditions.

A light east-southeast flow regime should persist at all TAF sites through
midday, likely backing to a modest east-northeast direction after
17z.

Bradshaw

&&


.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    91  74  95  76  96 /   0   0   0   0   0
Waco                94  72  96  74  96 /   0   0   0   0   0
Paris               86  68  91  71  95 /   0   0   0   0   0
Denton              92  71  96  75  98 /   0   0   0   0   0
McKinney            91  71  96  74  98 /   0   0   0   0   0
Dallas              92  73  96  76  98 /   0   0   0   0   0
Terrell             90  71  95  73  96 /   0   0   0   0   0
Corsicana           93  73  96  74  98 /   0   0   0   0   0
Temple              95  72  97  73  97 /   0   0   0   0   0
Mineral Wells       93  70  96  73  98 /   0   0   0   0   0

&&

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

$$