477
ACUS01 KWNS 040600
SWODY1
SPC AC 040558

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1258 AM CDT Tue Jun 04 2024

Valid 041200Z - 051200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE MID
MISSOURI RIVER VALLEY TO NORTHERN MINNESOTA AND FROM SOUTHERN
OKLAHOMA TO CENTRAL MISSISSIPPI....

...SUMMARY...
A large area of strong to severe storms are possible today from the
mid-Missouri River Valley to northern Minnesota with large hail and
severe wind gusts. Additional strong to severe storms are possible
from southern Oklahoma to southern Mississippi where damaging wind
gusts will be the primary threat.

...Synopsis...
An upper-level trough across the northern Rockies will amplify and
sharpen as it moves across the northern/central Plains today.
Additional mid-level shortwave troughs will move along the OK/TX
Panhandle and through the Midwest. A well-defined cold front will
move through the Upper Midwest with a secondary surface low
somewhere in the OK Panhandle vicinity.

...Northern Minnesota to Northeast Kansas...
Temperatures will warm into the 80s ahead of a cold front in the
Upper Midwest this afternoon where low to mid 60s will also be
present. This will result MLCAPE around 2000 to 2500 J/kg. Strong
thunderstorms are expected to develop by mid-afternoon as
convergence strengthens along the cold front and ascent increases
from the approaching mid-level shortwave trough. Modest,
unidirectional southwesterly flow across the region will support
multicell clusters/transient supercells with a threat for large hail
and damaging wind gusts.

...Southern Oklahoma to central Mississippi...
00Z CAM guidance had a consistent signal for extensive convection
(ongoing at 06Z) to congeal into a forward propagating MCS somewhere
near southeast Oklahoma at 12Z. Ahead of this MCS, a moist airmass
is present and with some heating, expect an uncapped and very
unstable environment by late morning to early afternoon. Therefore,
this MCS will likely continue through the day and intensify by early
afternoon as inhibition erodes. The primary threat from this
activity will be damaging wind gusts as the MCS moves southeast
along the instability gradient.

Similar to the last few days across the Texas Panhandle, an outflow
boundary will likely extend westward from the morning MCS with
warming/recovery in its wake as the EML advects across the region.
This will likely lead to a complicated surface pattern across
southwest Oklahoma as a surface low is forecast to develop and
strengthen amid mid to upper 70s dewpoints and a potential outflow
boundary from morning convection. A few supercells are possible with
extreme instability (6000+ MLCAPE) and effective shear around 35
knots (forecast by the 04Z RAP). Any supercells which develop will
pose the threat for large to very large hail and perhaps a tornado,
with eventual upscale growth into a MCS with a damaging wind threat
across north Texas the most likely evolution.

...Missouri into Illinois and Wisconsin...
Scattered storms may develop in the vicinity of a northeastward
moving upper-level trough as it moves from Kansas to Wisconsin
during the day. Moderate instability (1500 to 2000 J/kg MLCAPE) will
support strong updrafts with a threat for isolated large hail and
severe wind gusts. However, weak shear should limit a more organized
threat.

..Bentley/Lyons.. 06/04/2024

$$