222
ACUS01 KWNS 071253
SWODY1
SPC AC 071251

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0751 AM CDT Sun Jul 07 2024

Valid 071300Z - 081200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN GREAT PLAINS...AND FROM THE MIDDLE TEXAS COAST INTO FAR
SOUTHWEST LOUISIANA...

...SUMMARY...
A few tornadoes will be possible along the middle to upper Texas
Coast into southwest Louisiana as Tropical Cyclone Beryl approaches
the coast and makes landfall later tonight.  Scattered severe
thunderstorms are possible across parts of Oklahoma into northern
and northwestern portions of Texas.

...Central and Southern Plains...
An extensive cluster of showers and thunderstorms early this morning
and related stabilizing effects have pushed southward into central
OK.  Outflow associated with this early day convection will likely
serve as a focus for additional storm development later today.
Water-vapor imagery shows broad, cyclonic mid-level flow with a
trough moving southeast from the Dakotas/northern High Plains.  This
mid-level trough will move into the central High Plains late in the
period as the northern part of the trough shifts east into the Upper
Midwest.  Along the periphery of the residual outflow, appreciable
destabilization is expected with mid 60s to lower 70s surface
dewpoints contributing to moderate to strong instability over the
southern Great Plains.  At the surface, a cold front will advance
southward across the central Plains.  Scattered to numerous
thunderstorms are forecast to develop during the afternoon into the
evening.  Severe gusts and large hail will be the primary hazards
with the stronger storms as this activity likely grows upscale into
one or two linear clusters this evening.

...Middle to Upper Texas Coast...
Tropical Cyclone Beryl and its outer envelope of strong low-level
flow, will continue to approach the TX coast through much of the
period before making landfall tonight. The outer convective bands
within the northern and northeast portions of the larger system will
overspread the TX coast beginning by late morning and eventually
into southwest LA.  Coincident with the strengthening lower
tropospheric flow, low-level shear (i.e., enlarging hodographs) will
increase across the middle to upper Texas Coast into southwest LA.
Embedded supercells within the convective bands and transient
rotating updrafts will pose an isolated risk for tornadoes perhaps
beginning as early as this afternoon.  This tornado risk will likely
increase into the evening and tonight as Beryl moves over the shelf
waters and approaches the coast tonight.

...IA into northern WI...
An ill-defined surface pattern will feature a weak front/surface
trough moving east from the eastern Dakotas and the NE Sandhills
into the IA/MN vicinity later today.  East of this wind shift, a
relatively moist airmass will destabilize in proximity to a
positively tilted mid-level trough over the Upper Midwest into the
central High Plains.  A belt of moderate mid-level flow will move
through the base of the trough over portions of NE eastward into IA.
With no expected appreciable moisture advection through peak
heating, surface dewpoints will likely remain in the upper 50s to
lower 60s north, to the lower to mid 60s south.  Model forecast
soundings show generally moderate buoyancy (1000-2500 J/kg MLCAPE).
Despite the diurnal destabilization, the modest large-scale forcing
for ascent will likely limit storm coverage/intensity.  A localized
risk for a strong storm or two may materialize, but uncertainty
remains high precluding the introduction of low-severe probabilities
this outlook update.

..Smith/Bentley.. 07/07/2024

$$