836
ACUS02 KWNS 030558
SWODY2
SPC AC 030556

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1256 AM CDT Wed Jul 03 2024

Valid 041200Z - 051200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS EASTERN
KANSAS...NORTHEAST OKLAHOMA...PORTIONS OF MISSOURI...

...SUMMARY...
Severe thunderstorms will be possible on Independence Day, mainly
across the Lower Missouri Valley, Ozarks, and south-central Plains.

...Synopsis...
A strong upper-level trough for this time of year will dig into the
central Rockies/Plains by early Thursday morning. This trough will
slow and intensify across portions of the mid Missouri/Mississippi
Valleys by the afternoon. As this occurs, an upper low will deepen
in the upper Midwest. At the surface, a remnant boundary will be
positioned roughly from the southern Plains into the upper Ohio
Valley/Mid-Atlantic. 70s F dewpoints will reside south of this
boundary. Through the day, a modest surface low is forecast to
develop in the Iowa/Minnesota border vicinity. This will draw at
least mid 60s F dewpoints northward into the region. Ongoing
convection early Thursday will have an impact on where the most
favorable areas for severe weather will be by the afternoon.
Convection from Missouri into much of the Ohio Valley will slow the
northward return of moisture and leave outflow boundaries.
Additional activity seems likely closely tied to the shortwave
trough/developing upper low into portions of the Missouri Valley.

...Eastern Kansas...northeast Oklahoma...Missouri...
Early convection is expected to move out of the region by the
afternoon. Strong heating ahead of the cold front that will
eventually push into eastern Kansas/Missouri and near whatever
composite front/outflow is left from the earlier storms will yield
2500-3000 J/kg MLCAPE. Effective shear will be weaker with southern
extent, but 40-45 kts is possible in central/southeastern Missouri
into southeast Kansas. Mid-level ascent will be quite modest, but
storms are expected to develop along the cold front and potentially
along the outflow farther east. Initial storms would be supercells
capable of large hail and damaging winds. While low-level shear will
be weak, a tornado could occur with discrete storms favorably
interacting with the outflow boundary in particular. Upscale growth
will likely occur fairly quickly given the boundary-parallel
deep-layer shear along the cold front. Wind damage would become more
common as a potential MCS would move into large buoyancy.

...Upper Midwest...
Uncertainty in the degree of destabilization remains rather high as
there will be potential for cloud cover from activity to the west
and south. Storm development is most likely to occur along the cold
front moving through Iowa given the greater forcing for ascent. Less
certain is development into western/central Wisconsin along a weak
warm front. Temperatures aloft will support some potential for
marginally severe hail. Isolated damaging winds will be possible as
well, but this, again, will largely depend on how steep low-level
lapse rates can become. Though the threat is low and uncertain, a
tornado would be possible if sufficient destabilization can occur in
Iowa. Low-level shear would be maximized near the surface low, and
deep-layer shear across the initiating boundary would mean discrete
storms for at least a short duration.

...Southern Plains...
Strong heating south of the boundary (mid 90s to potentially low
100s F) will promote 1500-2500 J/kg MLCAPE by the afternoon. Heating
plus convergence along the front give reasonable confidence in
widely scattered to scattered storms. Storms will only be modestly
organized given the area will be on the extreme southern periphery
of stronger mid-level winds. Activity will likely grow upscale and
push southward until MLCIN increases. Severe/damaging winds will be
the primary concern.

...Ohio Valley into Mid-Atlantic...
Convection appears likely to be ongoing along the surface boundary
due to modest mid-level ascent and low-level warm advection. South
of the boundary, a very moist airmass will be in place. Additional
stronger activity will be possible either along the boundary itself
or along outflow from earlier storms. Deep-layer shear will be weak
except right along/north of the boundary, but a few damaging
microbursts will be possible due to the moderate to strong buoyancy
and steep low-level lapse rates in cloud-free areas.

..Wendt.. 07/03/2024

$$