305
FXUS64 KFWD 281045
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
545 AM CDT Sun Apr 28 2024

...New Short Term, Aviation...

.SHORT TERM... /NEW/
/This Morning through Monday/

A line of generally sub severe thunderstorms continues to move
through North Texas this morning. While this activity has
struggled to produce any severe weather, the threat for localized
flash flooding is increasing as multiple rain gauges have reported
2 to 2.5 inches of rain in an hour across the Metroplex. This line
of storms will continue to slowly move east through the morning,
but the upper support is pulling away and a tight theta-e gradient
will only slowly advance east of I-35 through late morning. This
means that strong low level inflow and moisture transport will
continue to feed into an axis of moderate instability through the
early morning hours supporting locally intense rainfall rates and
an increasing threat for flash flooding. One limiting factor for a
more substantial flash flood threat would be the ability for any
line segments to sustain a cold pool outflow (which may be
happening across Dallas/Ellis/Kaufman counties at this time)
thereby forcing the line eastward and reducing rain rates.
Nonetheless, flash flooding will remain the immediate threat
through the morning.

Concerning the Flood Watch...we`ll likely trim off some of our
northern and western counties this morning and leave the eastern
portions of the watch remaining.

As the morning upper support pulls away, the aforementioned
theta-e gradient will become nearly stationary along or just east
of I-35 by midday into the early afternoon. The environment will
become moderately unstable through the afternoon with MLCAPE >2000
J/kg and little inhibition as yet another upstream disturbance
approaches the area. This should support additional thunderstorm
development through the afternoon hours. While mid level lapse
rates will be relatively unimpressive, deep layer shear profiles
will continue to support a severe threat with a damaging wind and
isolated tornado threat through the late afternoon/early evening.
This threat will be highest across our southeast counties and
generally east of I-35. Additional thunderstorms that develop will
move out of our area by late evening.

Tonight and Monday should be fairly quiet with the active pattern
continuing into the middle part of the upcoming week.

Dunn

&&

.LONG TERM... /Issued 210 AM CDT Sun Apr 28 2024/
Update:
An active weather pattern will continue through much of the
upcoming workweek after a brief lull on Monday. Additional
opportunities for thunderstorms are forecast from Tuesday through
Friday, although the potential for organized severe weather on any
particular day is still uncertain at this time. Sufficient
shear/instability parameter space for at least an isolated strong
or severe storm will exist on a daily basis as we remain in an
open warm sector though Friday before the arrival of a cold front.
Aside from nominal adjustments to PoPs, minimal changes were
needed from the previous long term forecast.

-Stalley

Previous Discussion:
/Monday Onward/

A lull in the active weather will occur on Monday as the
multitude of upper level systems responsible for this weekend`s
thunderstorms shift to the east, and a weak ridge develops
overhead. Storm chances will return on Tuesday, however, as a
shortwave rounds the northern flank of the ridge. This will help
ignite thunderstorms along the dryline, which will be positioned
across the Big Country by Tuesday afternoon. These storms should
remain confined to the western half of the region, keeping the
severe weather potential largely west of the I-35 corridor. A
secondary batch of convection may also occur across the southeast
zones where an active seabreeze may infiltrate Tuesday afternoon.
The southeast storms will likely remain sub-severe, though a few
may produce gusty winds and heavy rain.

By Wednesday, a stronger shortwave will be dropping southeast
through the Rockies, weakening the ridge and generating another
round of dryline convection across the Big Country mid to late
afternoon. A warm and unstable environment along with 35+ knots
of effective shear will support more severe thunderstorm potential
as convection spreads east through the region Wednesday evening.
Storms will dissipate Wednesday night as instability wanes and a
capping inversion strengthens at the 850-700mb level.

A cold front will then approach on Thursday as the shortwave
trough traverses the Plains, providing another focus for showers
and storms along with the dryline Thursday afternoon and evening.
Widespread convection will be the result Thursday afternoon
through Thursday night, with activity pushing south of the region
along with the front on Friday.

A short reprieve in rain chances will occur Friday into Friday
evening before a shortwave embedded in the subtropical jet
generates another round of precipitation Friday night into next
Saturday. All of the forecast area should be in the cool sector
following the frontal passage, keeping any thunderstorms elevated
in nature and resulting from isentropic ascent. This should limit
the severe potential, but a strong storm or two would be capable
of producing hail. After a seasonably cool and damp (next)
weekend, a strengthening ridge aloft should lead to a warm-up and
a rain-free start to the following week.

30

&&

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

Thunderstorms are continuing through the D10 airspace at this time
and we should see a decrease in activity through the late morning
hours with generally VFR prevailing. While this initial line of
storms will steadily make eastward progress and weaken, additional
thunderstorms are expected to develop this afternoon generally
along and east of I-35. Right now, it looks like DAL may have the
best chance for additional TS activity this afternoon. VFR should
prevail outside of convective areas, but we`ll have to monitor for
some potential visibility reductions early Monday morning.

Dunn

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    80  66  86  67  84 /  80   5   5   5  20
Waco                79  64  84  64  83 / 100  10   5   5  20
Paris               76  62  81  60  81 / 100  50   5   5  20
Denton              79  61  83  64  83 /  70   0   5   0  10
McKinney            78  63  83  65  83 /  90   5   5   5  20
Dallas              80  65  86  65  85 /  90   5   5   5  20
Terrell             77  64  83  65  82 / 100  30   5   5  20
Corsicana           79  67  85  67  84 /  90  50   5   5  30
Temple              78  66  85  66  84 / 100  10   5   5  20
Mineral Wells       81  59  86  64  86 /  20   0   5   0  10

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
Flood Watch through this evening for TXZ091>095-100>107-117>123-
131>135-144>146-159.

Flood Watch through this evening for TXZ147-148-160>162-174-175.

&&

$$