380
FXUS64 KFWD 221917
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
217 PM CDT Wed May 22 2024

...New Long Term...

.SHORT TERM... /Issued 1109 AM CDT Wed May 22 2024/
/This afternoon through Tonight/

Active weather is expected over the next 48 hours, but we will
highlight the fist 18 to 24 hours in this portion of the
discussion. Very humid air is currently in place across the
entire region this morning with middle and upper 70s dew points.
The 12Z sounding showed a very unstable and largely uncapped
environment which will support thunderstorms. The other two
ingredients necessary for strong to severe storms are lift and
shear and we already have enough deep layer shear to support
long-lived updrafts. Large scale lift will be provided by subtle
shortwave energy moving through southwest flow aloft. However, the
more important and much stronger forcing for ascent will accompany
a southward moving cold front. The front is currently sliding
through the northwest zones and will continue its southward
progression through the afternoon. Storms will develop along the
front with most CAMs showing initiation across North Texas around
noon and based on the current radar, that may be a bit slow. Once
the first storms develop, the interaction of outflow boundaries
with the favorable storm environment will result in a combination
of storm modes with a potential for discrete supercells as well as
storm clusters. All modes of severe weather will be possible this
afternoon with large hail being the primary hazard. However, any
mesoscale induced, backed, low level flow could result in a brief
tornado or two. Storms may become more organized into a complex
late this afternoon and evening with mergers from storm moving off
of the dryline west of the forecast area. Our Central Texas
counties will be the most likely place for this to occur and
should it happen, the damaging wind threat will increase. Storm
chances will decrease overnight with the exiting shortwave, but
the front and multiple outflows will linger across the region,
becoming a focus for additional storms on Thursday (as highlighted
in the long term discussion).

Since moisture will not be confined to just the boundary layer,
many storms will be heavy rain producers. The good news is that
steering flow should keep storms moving, but there will be
potential for brief but heavy downpours and storm training.
Therefore, flooding will be possible and with more storms expected
Thursday, we will keep a Flood Watch in effect for much of the
forecast area.

Clouds and rain-cooled air will keep afternoon highs generally in
the 80s, except for some lower 90s across Central Texas. High
humidity will keep overnight lows mainly in the 70s, except for
near the Red River where the post-frontal air will be slightly
drier and cooler.

79

&&

.LONG TERM... /NEW/
Update:
The long term portion of the forecast, as described below, has not
changed much with additional storms expected Thursday associated
with a lifting front and passing shortwave. It does appear the
atmosphere will need to recover from overnight convection before
additional storms get going, and that the front will have moved
well to the north before large scale lift associated with the
shortwave arrives. The best storm chances will be across North
Texas during the afternoon with storms exiting to the northeast
late Thursday evening. Plenty of moisture and instability will
remain in place and there should be adequate deep layer shear to
sustain updrafts. The difficult part will be determining just
where convection will initiate Thursday since there will be no
well-defined sources of low level convergence. Therefore, we will
keep chance PoPs in the forecast for now. Some storms will be
strong to severe with large hail being the primary threat. The
threat for localized flooding will also remain through the
afternoon.

The remainder of the week through the weekend will be hot and
humid with only some low afternoon/evening storm chances. It still
appears that another cold front will enter the region Sunday
night/Monday, resulting in drier and slightly cooler weather for
Memorial Day.

79

Previous Discussion:
/Thursday Onward/

A meandering surface front and a dryline will provide focus for
thunderstorm development again on Thursday as a modest shortwave
trough passes overhead. Recent CAM guidance has indicated that
showers and storms may begin developing Thursday morning across
Central Texas as forcing for ascent strengthens in advance of the
disturbance, likely on the nose of a strong theta-e ridge. Morning
showers and storms would likely be elevated in nature, making hail
the main concern in any strong or severe storm. Convection would
then develop farther north in the vicinity of the aforementioned
surface boundaries as the atmosphere destabilizes Thursday
afternoon.

Models have been less aggressive with the Thursday convection
compared to previous suites, perhaps a result of the atmosphere
being worked over from Wednesday night storms or cloud cover
associated with the Thursday morning activity. In addition, a
persistent capping inversion around 850mb may also be a mitigating
factor. Will keep POPs in the chance to slight chance category
for now, with the best chances across Central Texas in the morning
and North Texas in the afternoon. Any storm which forms
(particularly in the afternoon and evening) could become severe
with large hail and damaging winds; and locally heavy rain may
also occur.

Precipitation will come to an end Thursday night, followed by hot
and humid weather on Friday as the front lifts well north of the
region. A strong shortwave in the Plains will drag the dryline
east to near the I-35 corridor, which may serve as a focus for
isolated thunderstorms Friday afternoon and evening. Storm
coverage would likely remain low, but a highly unstable airmass
and strong flow aloft would allow any storm which forms to once
again become severe. The dryline will remain the main focus for
development on Saturday afternoon and evening as a stronger
shortwave crosses the Southern Plains. A strong cap will be in
place, but a few cells will likely break through it and quickly
become severe. The best chances for storms on Saturday appears at
this time to be along and north of I-20, and in the afternoon and
evening hours.

A lull in storm chances is then expected on Sunday as subsidence
briefly dominates in the wake of the Saturday system. It will
remain quite warm with highs ranging from the low 90s in the
northeast to the upper 90s across the west. Sunday may end up
being the warmest day temperature-wise, but lower dewpoints will
be in place compared to Friday and Saturday (when heat indices
will reach 100+ across most of the CWA).

The next upper level system will drop southeast from
Nebraska into
Arkansas/Missouri Sunday night and Monday, dragging a cold front
south through the entire region. Weak forcing will keep storm
chances fairly low and limited to the eastern half of the region.
Otherwise, cooler air will arrive on Memorial Day with the cold
front, bringing near-normal temperatures to North and Central
Texas Monday night through the midweek period of next week.

30

&&

.AVIATION... /Issued 112 PM CDT Wed May 22 2024/
/18Z TAFs/

Thunderstorms will temporarily impact all TAF sites this afternoon
with the best window of time for storms at the Metroplex
terminals between 18Z and 23Z. Thunderstorms could linger in the
vicinity beyond 23Z, especially in Waco. All storms should exit to
the east or northeast with a passing shortwave overnight, but
additional storms will be possible Thursday afternoon.

MVFR to low end VFR ceilings are expected through the afternoon
with improvements to VFR during the evening. MVFR/IFR ceilings
will return overnight and prevail through much of the morning
Thursday along with reduced visibility in mist.

A south wind to start the TAF cycle will temporarily turn to the
northeast/east behind a cold front at the Metroplex TAF sites.
The wind will turn back to the south/southeast this evening.
Sustained wind speeds will stay in the 7 to 13 knot range overall.
However, much stronger, gusty, and erratic winds are likely in and
near any thunderstorm.

79

&&


.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    71  87  73  93  73 /  50  40  20   5  20
Waco                72  88  73  91  72 /  50  20  10  10  20
Paris               67  83  68  89  68 /  60  40  50   5  30
Denton              68  85  71  91  69 /  50  40  10   5  10
McKinney            68  85  71  91  70 /  50  50  20   5  20
Dallas              70  87  73  93  72 /  50  40  20   5  20
Terrell             69  85  72  91  71 /  50  30  20   5  20
Corsicana           73  89  75  92  73 /  50  20  20   5  20
Temple              73  89  73  92  72 /  40  20   5  10  10
Mineral Wells       69  86  71  93  69 /  40  40   5   5  10

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
Flood Watch through late Thursday night for TXZ092>095-102>107-
117>123-130>135-141>148-156>161.

&&

$$