967
ACUS01 KWNS 221631
SWODY1
SPC AC 221629

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1129 AM CDT Sat Jun 22 2024

Valid 221630Z - 231200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
THE UPPER MIDWEST INTO LOWER MICHIGAN...AND ACROSS PARTS OF SOUTHERN
NEW ENGLAND...

...SUMMARY...
Severe thunderstorms are possible this afternoon and evening across
parts of the Midwest and Great Lakes region, mainly posing a risk of
damaging winds.

...Midwest into Lower MI...
A moderately strong mid-level shortwave trough over the eastern
Dakotas will track into the upper MS valley this afternoon.  The
main synoptic surface boundary extends from northern IA into
southern WI, with strong heating and ample low-level moisture
present to the south.  Present indications are that scattered
thunderstorms will develop along the boundary by mid-afternoon and
sag southward across eastern IA and northern MO/IL through the
evening.  Forecast soundings show moderate CAPE values and favorable
deep-layer shear for convective organization and a few supercells,
capable of damaging winds, hail, and a few tornadoes.  The main
limiting factors for a more significant severe weather event appear
to be the warm temperatures aloft and resulting weak lapse rates,
and CAM solutions indicating a rather quick evolution into more
linear storm-modes.

...Southern New England...
A cluster of thunderstorms currently over eastern NY is expected to
intensify and track southeastward along a surface boundary into
southern New England this afternoon.  This may result in a corridor
of locally damaging wind gusts.  Have therefore added a small SLGT
risk area.  Please refer to MCD #1371 for further details.

...Western FL Peninsula...
Strong heating is resulting in a hot/humid airmass over the western
FL peninsula today, with temperatures in the mid 90s.  Combined with
dewpoints in the mid-upper 70s, steep low-level lapse rates, and
high PWAT values, the environment appears favorable for a few wet
microbursts later today.  Several morning CAM solutions suggest
organized outflow from early storms over eastern FL may further
increase the risk of strong wind gusts.

..Hart/Weinman.. 06/22/2024

$$