653
ACUS01 KWNS 231615
SWODY1
SPC AC 231613

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1113 AM CDT Sun Jun 23 2024

Valid 231630Z - 241200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
ACROSS PORTIONS OF EASTERN NEW YORK...VERMONT...NEW
HAMPSHIRE...MASSACHUSETTS...AND WESTERN MAINE....

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING OVER
PARTS OF NORTHEAST MONTANA AND NORTHWEST NORTH DAKOTA...

...SUMMARY...
Scattered damaging winds and a few tornadoes are likely across parts
of the Northeast and New England, with additional severe storms
expected across the Ohio Valley, Mid-Atlantic region, as well as the
Northern High Plains.

...New England...
Visible satellite imagery shows broken clouds across central/eastern
NY and parts of southern/western New England, where dewpoints are in
the upper 60s to lower 70s.  This is resulting in rapid
destabilization of the air mass, with a corridor of ~2000 J/kg and
little inhibition.  This should lead to scattered thunderstorm
development early this afternoon over central/eastern NY, tracking
rapidly eastward into VT/NH and northern MA.  Forecast soundings
show substantial vertical shear in this region, as storms develop
beneath the mid-level jet axis.  A remnant surface boundary
currently extends from northeast VT into northeast MA.  As storms
interact with this boundary, locally enhanced low-level shear may
result in a more focused risk for a few tornadoes.  Otherwise,
damaging wind gusts and some hail are the main threats.

...Upper OH Valley...
An axis of warm/humid conditions is present today from KY
northeastward into western PA, where temperatures will warm through
the 80s with dewpoints in the lower 70s.  Model guidance suggests at
least widely scattered afternoon thunderstorms will form.
Relatively steep low level lapse rates, significant water-loaded
downdrafts, and favorably strong low/mid level wind fields will pose
a risk of locally damaging wind gusts in the stronger cells through
the afternoon and early evening.

...MT/ND...
Model guidance continues to show the potential for a supercell storm
or two to form over southern Manitoba and track near/across the
international border, affecting parts of northeast MT and northwest
ND tonight - mainly after dark.  Sufficient CAPE/shear parameters
would support a risk of large hail in these storms.

..Hart/Weinman.. 06/23/2024

$$