631
FXUS64 KFWD 210610
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
110 AM CDT Sun Jul 21 2024

...New Short Term, Aviation...

.SHORT TERM... /NEW/
/Through Monday/

Scattered and disorganized convection will be the story through
the short term period as broad modest ascent prevails in the
presence of upper troughing while a diffuse frontal zone sags
towards North Texas later today. Synoptic scale ascent is aiding
in ongoing high-based activity across western North Texas, but
much more widespread showers and thunderstorms are forecast this
afternoon as surface-based diurnal destabilization is achieved.
The moderate CAPE but low shear environment typical of late July
will allow for some degree of microburst potential, but organized
severe weather is not expected. While peak coverage will occur
through the late afternoon and evening period, much more isolated
convective activity may linger through the overnight hours into
Monday morning, not dissimilar from tonight`s radar presentation.

There remains quite a bit of uncertainty for Monday`s convective
placement/coverage as recent CAM guidance has become more
aggressive with shunting the frontal zone farther south into
Central Texas, limiting any source of focused ascent through much
of our CWA. Have cautiously lowered PoPs with this scenario in
mind as coverage may only be in the 20-40% range for most of the
forecast area during the daytime on Monday. Even if a drier
solution were to come to fruition, the combination of slightly
cooler post-frontal air and increased cloud cover should still
hold high temperatures below normal, with most locations
struggling to approach 90 degrees.

-Stalley

&&

.LONG TERM... /Issued 236 PM CDT Sat Jul 20 2024/
Update:
No major changes were made to the previous forecast, with daily
rain chances and below normal temperatures continuing through the
period. The best potential for rain areawide will be on Monday,
but the highest rain chances will remain across Central Texas
throughout the week. Efficient rainfall rates will result in an
increased potential for flooding. The highest rainfall totals are
expected on Monday, with a low threat for flash flooding for areas
south of the I-20 corridor where 1-3" of rain are expected on
average. Persistent rain chances across Central Texas may renew
flooding concerns on a daily basis. Rainfall totals through the
end of the week are currently expected to be between 2-5" south of
I-20. It`ll be hit-or-miss across North Texas, with average
rainfall totals between 1/4" to 1" though a few locations may miss
out entirely.

Barnes

Previous Discussion:
/Monday Through Friday/

Texas will spend the upcoming week sandwiched between a strongly
amplified ridge in the West and a remarkably persistent Bermuda
high to the east. Early in the week, our northwest flow regime
will give way to troughing that will nose into the Lone Star
State from the northeast. Both of the aforementioned subtropical
ridges will strengthen through midweek, and while our mid-level
heights won`t significantly change, this will induce/enhance the
troughing overhead. A comparatively deepening saddle will maintain
minimal inhibition and daily rain chances. The persistent
convective activity should serve to reinforce the relative
depression aloft with some guidance suggesting a closed upper low
may develop by midweek. Unseasonably cloudy conditions will
prevail with below normal temperatures during what is
climatologically the hottest part of the year. The National Blend
of Models (NBM) has likely PoPs (at least 55 percent) within our
area each day from Monday through Thursday. This is far above
climatology, which is generally 15 to 25 percent across the region
in late July.

Aided by both a pronounced shortwave embedded in northerly flow
aloft and convective outflow at the surface, a cold front will
invade the region on Monday. While the bulk of the morning
convection may be coincident with the boundary, the activity will
steadily expand in areal coverage during the daylight hours as a
destabilizing uncapped boundary layer couples with increasing
forcing for ascent. Widespread showers and storms ahead of the
boundary will feed off of precipitable water values soaring above
2 inches. The precipitation efficiency, combined with the slow
motion of individual cells, will enhance rainfall amounts. Some
locations will experience multiple storms Monday afternoon, the
cumulative effect of which may result in flooding. The areas of
greatest concern will be across Central and East Texas, which will
have the longest duration south of the boundary. The rain and
extensive cloud cover will cap temperatures in the 80s, with the
NBM keeping parts of the Big Country in the 70s.

A similar but somewhat less rainy day will follow on Tuesday when
the frontal boundary will begin to lose its resolution. Sunshine
and fewer showers and storms will allow portions of North Texas to
reach or exceed 90F, a scenario that will repeat itself through
Friday. By midweek, the main heavy rain threat will shift into
South and Southeast Texas where the richest moisture influx will
be. However, further rounds of rainfall are expected Wednesday and
Thursday, particularly across Central and East Texas. Any
additional rainfall could initiate or reaggravate flooding
concerns. With persistent cloud cover and rainfall, some locations
across Central and East Texas may remain below 90F throughout the
upcoming workweek.

25

&&

.AVIATION... /NEW/
/06z TAFs/

Scattered convection exists on the western periphery of D10 as of
06z, and the eastward extend of this activity towards the TAF
sites remains uncertain through the rest of the overnight period.
Based on recent trends, it is likely that most of these cells
remain west of the terminals themselves, but signs of any new
development further to the east may warrant a brief inclusion of
VCSH/VCTS prior to 12z. Greater convective chances are forecast
from midday through late afternoon, coinciding with peak heating
and the arrival of a weak surface front. A window of VCTS will be
maintained at all airports during this time period, with
increasing cloud cover in the 5-10 kft layer accompanying
afternoon thunderstorm activity. Outside of convective outflow
boundaries, a southeast wind will prevail today before winds take
on a more easterly or perhaps even northeasterly direction by
Monday morning in the presence of the diffuse frontal zone.

-Stalley

&&

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

&&

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

$$