547
ACUS02 KWNS 021703
SWODY2
SPC AC 021701

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1201 PM CDT Tue Jul 02 2024

Valid 031200Z - 041200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE NORTHERN AND CENTRAL PLAINS...AND FROM THE OZARKS TO THE LOWER
OHIO VALLEY...

...SUMMARY...
Severe thunderstorms are expected on Wednesday, particularly across
parts of the Ozarks and Ohio Valley, and portions of the northern
and central Plains.

...Ozarks to the Lower Ohio Valley...

A modest shortwave impulse is forecast to develop northeast across
the Midwest and Great Lakes vicinity on Wednesday. The bulk of
strong mid/upper level southwesterly flow will remain over the Great
Lakes vicinity, somewhat displaced from richer boundary-layer
moisture and instability further south across the Mid-MS/OH Valley
region. At the surface, a cold front will sag south/southeast across
the Upper MS Valley/Great Lakes, perhaps stalling from northern
MO/IL into Lower MI. The effective front will be augmented by early
day clouds and perhaps showers over northern MO into northern IL. To
the south, rich boundary-layer moisture with dewpoints in the 70s F
and stronger heating across southern MO/IL into southwest OH, will
foster a corridor of moderate to strong instability amid 25-35 kt
effective shear magnitudes. Clusters/bands of strong to severe
thunderstorms will mainly pose a risk for damaging wind gusts during
the afternoon and early evening.

...Northern/Central Plains Vicinity...

Modest height falls and strengthening midlevel westerlies are
expected ahead of a deepening upper trough over the northern
Rockies. As this occurs, a surface trough will sharpen over the High
Plains. The western fringes of the Midwest cold front will be draped
west to east near the NE/SD border. To the south of this boundary,
south/southeasterly low-level flow will support low to mid 60s F
dewpoints across much of KS/far southern NE westward into eastern
CO, as well as across the adjacent southern Plains. Lower dewpoints
are expected across the northern High Plains in the post-frontal
airmass. Strong heating and steepening midlevel lapse rates will
support moderate to strong destabilization.

Vertically veering wind profiles with effective shear magnitudes
greater than 40 kt will support initial supercell development near
the surface trough from southwest SD/western NE southward into CO.
This initial activity will pose a severe/damaging wind risk in
additional to large to very large hail. Additionally, curved
low-level hodographs and increasing SRH by late afternoon/early
evening may support a few tornadoes near the surface trough. With
time, consolidation of convection via outflow interactions and a
modestly increasing low-level jet by early evening should result in
more linear storm modes. Some potential exists for MCS development,
shifting east across parts of far eastern CO into parts of southwest
NE/northwest KS. If confidence increases in a bowing MCS developing,
higher severe probabilities may be needed in subsequent outlooks.

Convection will be more sparse with southward extent into NM and OK
where large-scale ascent will be weaker and vertical shear overall
more marginal. Nevertheless, a moist and unstable airmass will be
present and any storms that develop could produce strong gusts.

..Leitman.. 07/02/2024

$$