134
FXUS64 KFWD 041114
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
614 AM CDT Sat May 4 2024

...New Aviation, Short Term...

.SHORT TERM... /NEW/
Update:

No significant changes to the forecast through tonight.
Thunderstorms should start to increase in coverage later this
morning and afternoon as a cold front approaches the area, but the
better storm chances will arrive later tonight as deep convection
from West Texas spreads across North and Central Texas. While
there will be a threat for severe weather, particularly west of
I-35, the threat for heavy rainfall is increasing across our
southwest counties. This area hasn`t seen as much rain the last
few days, but an expansion of the Flood Watch may be needed later
this morning.

Dunn

Previous Discussion:
/Overnight through Sunday/

Convection is waning across the region tonight as surface based
inhibition increases. A cluster of showers and a few storms
continue to the south of Waco at this hour, but this activity
should diminish over the next hour or so. The remainder of the
night should be quiet with light winds and humid conditions. Some
patchy fog may develop later tonight into the early morning hours
on Saturday.

The active weather pattern will continue with a cold front
currently across southwest Kansas expected to move through
Oklahoma overnight and approaching North Texas Saturday morning.
Synoptic scale forcing for ascent may be negligible during this
time, but forcing along the front itself may be sufficient for
scattered showers/storms to develop earlier than they did on
Friday. This activity is most likely to occur across our northwest
counties and generally north of I-20 into the early afternoon.
We`ll have some 30-40% PoPs to account for this activity while our
central TX counties will likely remain dry.

It`s a little unclear whether or not the front will actually make
it down into our area through midday with a consensus of the
guidance suggesting that it`ll get hung up to our north in
response to an approaching upstream shortwave. This shortwave is
evident on water vapor imagery approaching northern Baja
California at this hour. Meanwhile, either an outflow boundary or
just a general backing of the low level flow ahead of the front
will likely lead to increased low level moisture convergence
across the I-20 corridor through the afternoon. This will support
isolated/scattered storm development through late afternoon,
especially from the Metroplex westward. Meanwhile, thunderstorms
will increase in coverage across West Texas and become severe near
the intersection of the southward moving front and dryline late
this afternoon. This activity will likely evolve into one or more
clusters of thunderstorms and spread eastward into North Texas
late Saturday night as stronger forcing for ascent from the
aforementioned shortwave overspreads the Southern Plains. While
there will certainly be some potential for severe weather,
especially across our western counties, widespread heavy rainfall
may result in additional flooding issues across parts of the
region. Latest HREF guidance shows a large swath of 2-3 inches of
rain through late Saturday night across our southwest counties,
the majority of which falls in about 3 hours. This may necessitate
a westward expansion of the flood watch. We`ll coordinate this
over the next several hours.

Showers and thunderstorms will overspread much of the region late
Saturday night and continue to move eastward into early Sunday
morning, tapering off from west to east through the day.
Additional thunderstorm development may occur late Sunday
afternoon across our central and southeast counties as the front
stalls in wake of the departing shortwave.

Dunn

&&

.LONG TERM... /Issued 309 AM CDT Sat May 4 2024/
/Sunday Night Through Next Saturday Afternoon/

Thunderstorms may be ongoing at the start of the period, but
convection will be weakening and should completely dissipate late
Sunday evening. By early next week, the upper level low evident in
current mid-level water vapor satellite imagery near the coast of
the Pacific Northwest will eject across the central and northern
Plains as an increasingly negatively tilted upper trough. As
stronger height falls spread east toward the Rockies, surface low
pressure will be generated enhancing southerly low-level flow and
moisture advection across the southern Plains on Monday. While
large-scale ascent attendant to the upper trough will largely be
displaced to the north (OK/KS), favorable low-level
moisture/instability ahead of an eastward mixing dryline may be
sufficient for the development of isolated dryline-induced
convection Monday afternoon. Given that convective coverage is
likely to be low due to the presence of a capping inversion, PoPs
have been capped at 30% Monday afternoon and evening. Instability
in excess of 3000 J/kg MUCAPE and 35-50 kts of deep-layer shear
should sustain any updrafts that develop. Large hail, localized
severe gusts, and a tornado or two will be possible.

Tuesday into Wednesday, the upper-level trough/low will linger
over Montana and the Dakotas while upper-level ridging builds
eastward across the Gulf Coast states. Amid south to southwest
flow at the surface and quasi-zonal flow aloft, abnormal but sub-
record heat is expected each afternoon through Thursday with highs
in the mid 80s to lower 90s. This is near the 99th percentile of
the historical temperature distribution for early May (according
to NAEFS and ECMWF). A shortwave trough will begin working around
the base of the slowly evolving northern Plains upper trough/low
on Wednesday. The enhancement of mid-level flow along with strong
instability ahead of the lingering dryline is expected to bring
thunderstorm chances back into parts of North and Central Texas
Wednesday afternoon and evening. Any thunderstorms that develop
could become severe with all hazards possible. Storm chances will
likely increase again on Thursday afternoon as the stalled surface
cold front over Kansas finally begins pushing through Oklahoma
and North TX providing a focus for additional convective
development. In the wake of the departing trough/front, Mother`s
Day weekend is shaping up to be seasonably mild with highs in the
mid 70s.

12

&&

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

MVFR/IFR cigs are overspreading North Texas this morning and we`ll
prevail this through the rest of the morning at all airports. The
threat for TS will increase a little later this morning as a cold
front approaches the area, but coverage should generally be
scattered and peak around midday along the I-20 corridor. We`ll
continue with a VCTS from 17-21Z to account for this activity.
More widespread TSRA is expected later this evening and overnight
followed by a period of IFR cigs into early Sunday morning.

Dunn

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    79  67  79  69  83 /  40 100  40  20  30
Waco                79  66  78  68  82 /  30 100  40  20  20
Paris               80  65  75  65  81 /  30  70  90  20  30
Denton              78  65  77  66  82 /  30 100  40  10  30
McKinney            79  67  76  67  82 /  30  90  60  20  30
Dallas              80  67  79  68  83 /  30  90  40  20  30
Terrell             80  66  77  67  82 /  30  90  60  20  20
Corsicana           81  69  79  69  84 /  30  80  50  20  20
Temple              81  67  79  69  82 /  30  90  40  20  10
Mineral Wells       78  65  78  66  84 /  40 100  20  20  30

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
Flood Watch through Sunday afternoon for TXZ135-146>148-160>162-
174-175.

&&

$$