754 
ACUS03 KWNS 030731
SWODY3
SPC AC 030730

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0230 AM CDT Thu Apr 03 2025

Valid 051200Z - 061200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
THE SABINE AND LOWER MISSISSIPPI VALLEY...

...SUMMARY...
Severe storms producing damaging winds and a few tornadoes are
forecast Saturday from the Sabine Valley to the Tennessee Valley.

...Synopsis...
On Saturday, an upper trough with a meridional leading speed max
will move across the southern Plains, with the wave ejecting into
the mid MS Valley into Sunday morning. As the trough approaches,
winds aloft will increase through the period, with 50-60 kt midlevel
winds common into the lower MS and TN Valleys.

At the surface, a front will stretch roughly from eastern TX into
central AR, with the TX portion surging east as a cold front. The
northeastward extension of this boundary may remain quasi-stationary
through much of the day and evening prior to the surface wave
developing. A very moist air mass will remain ahead of this front,
with the 68 to 70 F dewpoints across eastern TX, LA, MS and southern
AR. A broad fetch of 50+ kt southerly winds around 850 mb will help
maintain the unstable warm sector, while also providing low-level
shear for a tornado risk.

...Texas northeastward toward the Tennessee Valley...
Widespread rain and storms will be ongoing from the Red River to the
OH Valley, primarily north of the surface boundary and aided by
low-level warm advection. With lengthy hodographs and over 1000 J/kg
MUCAPE from TX into AR, some of those storms may produce hail.

Depending on how much early day convection occurs, the effective
AR/TN portion of the front may be farther south than forecast.
However, the opposing southerly low-level jet and upstream pockets
of heating should keep the front over AR and perhaps western
TN/northern MS. 

Forecast soundings show moist and unstable profiles, though midlevel
lapse rates will be a bit weaker than on the previous few days.
However, shear will remain strong and favorable for both supercells
and tornadoes. Storms will develop both along the cold front as it
surges eastward, and along the boundary extending east/northeast
into TN/KY, with highest tornado potential across the Enhanced Risk
area, the bounds of which will likely be adjusted in later outlooks.

..Jewell.. 04/03/2025

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS03/20250403T0731.txt



756 
ACUS03 KWNS 021928
SWODY3
SPC AC 021927

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0227 PM CDT Wed Apr 02 2025

Valid 041200Z - 051200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE
ARKLATEX TO THE MO BOOTHEEL...

...SUMMARY...
Several clusters of strong to severe storms are possible from the
Rio Grande and Red River Valleys, through the ArkLaTex and into the
lower Ohio Valley Friday and Friday night. The greatest threat for
large hail, damaging wind gusts, and tornadoes will be from the
ArkLaTex to the Missouri Bootheel.

...Synopsis...
Broad upper troughing over the western US will continue to deepen
Friday into the weekend, as an upper low forms over northern Mexico.
Flow aloft will become increasingly southerly over the southern
Plains while it curves anticyclonically over the Mid South and
eastern US. A rich pool of deep moisture will continue to reside
along a quasi stationary frontal zone from the Red River to the OH
Valley. Several clusters of strong to severe storms appear possible
within the broadly favorable zone of weak ascent and large
buoyancy/shear.

...ArkLaTex to the MO Bootheel...
An unseasonably warm/moist airmass will be in place across East
Texas and Louisiana Friday morning with mean mixing ratios of 15 to
16 g/kg forecast. During the morning, the front will move north
across Arkansas as a warm front with strong instability developing
across much of the state by mid day. During the afternoon ascent
will increase as height falls overspread the region, the low-level
jet strengthens, and the influence of the left entrance region of
the upper-level jet streak is realized. This should result in
scattered thunderstorm development during the afternoon in an
environment featuring 2500-3500 J/kg MLCAPE (per ECMWF forecast
soundings). Storms will likely develop along the surface front
during the early afternoon with greater uncertainty whether forcing
will be sufficient enough for discrete development ahead of the
front. Either way, the instability and 45-55 knots of effective
shear should be sufficient for supercells capable of all hazards
with eventual upscale growth and an increasing wind threat along the
front. The strong tornado/very large hail threat will be more
closely tied to the potential for maintenance of discrete supercells
and due to these uncertainties, no hatched area has been added at
this time.

...Ohio Valley...
Additional severe thunderstorms are possible farther northeast in
the Ohio Valley both during the day and into the overnight hours.
Weaker instability and mid-level lapse rates, in addition to ongoing
convection and cloud cover from Friday morning convection, casts
uncertainties on a greater threat. However, sufficient instability
and shear along the frontal zone should support at least some threat
for isolated to scattered severe storms. 

...Central Texas to northern and northeast Texas...
Between 00Z and 06Z a mid-level jet streak is forecast to eject from
northern Mexico into south-central Texas. As this occurs, a
low-level jet will strengthen across south Texas into central Texas.
Amid 3000+ J/kg MUCAPE, initially elevated supercells are expected
to develop. As ascent continues to increase across the southern
Plains, expect additional thunderstorm development Friday night with
some severe threat persisting into Saturday morning. Eventually,
these storms will likely become surface based given the rich
moisture in place across East Texas. Moderate instability and strong
low-level shear will support a threat for all severe hazards, but
some relatively warm temperatures in the 850-700mb layer may limit a
greater severe weather threat in the absence of diurnal
destabilization.

..Bentley.. 04/02/2025

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS03/20250402T1928.txt