National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS64 KFWD 151036
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
536 AM CDT Mon Apr 15 2024

...New Short Term, Aviation...

.SHORT TERM... 
-- Changed Discussion --
/NEW/
Update:
Complex forecast and have no confidence for any wholesale changes
from the thinking below. Time will tell to see how the elevated
mixed layer/EML (cap aloft) plays a role in coverage and severity.

05/Marty

Previous Discussion:
/Early Week Period/

The evolution of the approaching system later today and through
Tuesday has changed very little, as strong mid level height falls
associated with a lead shortwave lifting northeast from West TX
and the South Plains toward Northwest TX, the Big Country, and
into Southwest OK helps to gradually lift and weaken the existing
EML (capping inversion) over the surface dryline west of the
area. Isolated, strong to marginally severe semi-elevated storms
may impact our Big Country areas west of US-281 later this
afternoon. After the morning surge of stratus, this area will see
little if any stratus this morning and if they were to see some,
it would be only a few hours before seeing partial sunshine and
strong afternoon heating well into the 80s for an increase in
ML/MUCAPE, but also mid level lapse rates steepening to between
7-8 deg C/km with impressive CAPE within the hail growth zone (-10
to -30 degC) during the first few hours of their life cycle which
would strongly suggest at minimum some large to very large hail
across our far northwest counties. If the NSSL WRF/3km NAM were
to be believed, it would be a bit more multicellular or more messy
environment due to the increasing large scale ascent and strong
low level WAA ongoing just above the surface and near the bottom
layer of the cap (which the 00z FWD sounding has shown to
strengthen in the past 24-36 hours). The HRRR is the one model
that does show more discrete, isolated coverage and considering
the EML strength, I may be inclined to lean toward that solution.
Either way, the kinematic environment of 50 kt+ SW effective deep
layer shear and impressive southerly 15-20 kt 0-1 km shear would
insinuate storm maintenance and a hail and wind threat. If storms,
even briefly, were to become completely rooted at the surface,
then a tornado would be possible, but elevated versus non-elevated
mode is where confidence gets murky due to the uncertainty of the
EML completely eroding. As discrete storms over the South
Plains/Big Country migrate ENE/NE toward the Red River Valley and
western North TX through nightfall, they will encounter increasing
low level WAA in conjunction with an impressive 55-65 kt
(possibly as strong as 70 kts) LLJ developing across this region.
This and point forecast sounding hodographs would suggest storm
mode evolving more into a linear, or even possibly a LEWP (line
echo wave pattern) segment containing both large hail and damaging
winds as storms move from our northern Big Country area, ENE
toward I-35 and primarily along and north of the Hwy 380 corridor
to the Red River Valley.

As they do move further east after nightfall and toward/past the
I-35 corridor mid to late this coming evening, it`s likely they`ll
begin to encounter increasing CINH and weakening 925mb-850mb
southerly flow. This would likely signal a weakening trend with
time and likely storms becoming just sub-severe as they move into
eastern North TX after midnight. With gusty southerly winds 15 to
30 mph likely continuing through daybreak Tuesday along with more
late night/morning stratus, low temperatures Tuesday morning will
remain well up into the 60s. Despite a brief lull in weather
after midnight, the threat for storms doesn`t end just yet. The
exiting of the main mid level disturbance eastward out over the
Central/Southern Plains just before 12z Tuesday will support a Pacific
cold front arriving into the far western counties. Additional,
scattered showers and thunderstorms are likely to develop along
the feature initially along and just west of I-35 post daybreak,
before progressively moving east along and ahead of the front
into Central and East TX by/after midday Tuesday. Again, these
storms may remain potentially elevated as the best large-scale
ascent remains removed to the north over Nebraska, Kansas, and
Oklahoma. Nevertheless, strong storms with hail and very gusty
winds would remain in play. Another item to mention is that
progressive and scattered nature of activity will limit any heavy
rainfall or flooding throughout the entirety of this event
associated with this system/event. Little in the way of low level
cold advection is anticipated behind the front as it progresses
into E/SE Texas and Western Louisiana later Tuesday afternoon.
Instead, veering surface and low level wind fields, increasing
mid-April insolation, and much drier air will help to warm
temperatures well into the mid-upper 80s. A sign that as we
continue progressing through mid-Spring, that the likelihood of
dramatic temperature falls is waning by the day.

05/Marty
-- End Changed Discussion --

&&

.LONG TERM... 
-- Changed Discussion --
/Issued 323 AM CDT Mon Apr 15 2024/
/Wednesday Onward/

A brief warmer and rain-free period will encompass the middle of
the week following the eastward departure of the early week storm
system. Highs on Wednesday afternoon will be able to climb into
the mid 80s to lower 90s, while low-level moisture content
quickly climbs back northward. A subtle disturbance transiting
zonal flow aloft will result in strengthened low-level warm
advection, and this should allow for some shower and thunderstorm
activity heading into Thursday. This will be particularly true
later in the day as a surface frontal boundary digs southward
into the Southern Plains before eventually stalling through
portions of North Texas through the end of the week. The
parameter space ahead of this boundary will consist of very strong
instability due to pooled low-level moisture along it, and some
isolated severe storm activity is possible Thursday afternoon when
aided further by diurnal destabilization.

The stalled frontal zone will acquire a renewed southward push
heading into the upcoming weekend as a stronger mid-level
disturbance digs into the area from the northwest. This will
simultaneously drive the front southward into Southeast Texas,
while simultaneously establishing a strong isentropic lift regime
atop the frontal surface. An episode of widespread elevated
convection should be the result, some of which may be rather
robust with a hail threat given strong MUCAPE in place. However,
the main issue over the upcoming weekend could be additional heavy
rainfall and flooding, as this type of setup with a stalled or
slow-moving frontal zone could be conducive for training deep
convection in a west-to-east fashion somewhere across the eastern
half of the state. Any finer details in this regard won`t be known
for at least a few more days. Our temperatures during this time
period will be below normal as we spend a few days within the cool
sector, so highs in the 60s and lower 70s seem likely through
most of next weekend.

-Stalley
-- End Changed Discussion --

&&

.AVIATION... 
-- Changed Discussion --
/NEW/
Update:
/12z TAFs/

About the only change from the 06z discussion below was to move
up both the windows for VCSH and VCTS per latest CAMs, development
of a very strong 60 kt+ LLJ after nightfall, and uncertainty with
the approach of the Pacific FROPA towards or just after 12z
Tuesday. Otherwise, cig and wind trends remain relatively the same
regarding stratus today into tonight. Mainly MVFR.

05/Marty

Previous Discussion:
/06z TAFs/

Challenges through the first half of the D10 area forecast
through 00z Tuesday will be timing categorical trends and
adjustments of cigs, especially during the afternoon hours as
moisture depth of nearly  50mb will be way more than seen
yesterday, thus keeping stratus around through the 18z-21z period
today. Southerly winds Southerly winds will between 15-20 kts with
gusts to 30 kts+ at times will occur through tonight.

Scattered TSRA will impact the region, particularly North TX from
I-20 to the Red River Valley this evening. As 925mb flow cranks
up to at/above 55-60 kts after nightfall, the  warm advection
coupled with increasing ascent will bring some spotty -SHRA to the
airports after 01z, with a window for potential TSRA between
04z-06z or 07z.  For now, with exact coverage and timing in
question due to a capping inversion still present over the region,
I have elected to only introduce VCSH/VCTS at this time.  We`ll
continue to refine these convective trends, as well as this
morning`s IFR/MVFR  stratus in the 12z TAFs and beyond. 

05/Marty
-- End Changed Discussion --


&&


.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    80  69  88  68  86 /  10  40  20   0   0
Waco                79  67  86  68  85 /   0  30  30   0   5
Paris               77  66  83  67  84 /  10  40  40   5   0
Denton              80  67  86  62  84 /  20  50  10   0   0
McKinney            79  67  87  66  84 /  10  40  20   0   0
Dallas              79  69  87  68  87 /  10  40  20   0   0
Terrell             78  67  83  68  84 /  10  30  30   0   0
Corsicana           80  68  83  70  86 /   0  20  40   0   0
Temple              80  68  84  68  86 /   0  20  30   0   5
Mineral Wells       84  66  87  59  87 /  20  50   5   0   0

&&

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

$$