620
ACUS01 KWNS 201614
SWODY1
SPC AC 201612

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1112 AM CDT Thu Jun 20 2024

Valid 201630Z - 211200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
NORTH-CENTRAL HIGH PLAINS AND NORTHEAST/NEW ENGLAND...

...SUMMARY...
Storms may produce scattered damaging wind gusts over parts of the
Northeast and New England mainly this afternoon. Scattered severe
storms are also expected over parts of the north-central High
Plains.

...Eastern NY and New England...
Visible satellite imagery shows strong daytime heating occurring
across all of New England and parts of NY/PA.  A well-defined MCV
currently over eastern Lake Ontario will track eastward into this
warm and very humid air mass (dewpoints in the low 70s), where
afternoon MLCAPE values will exceed 2000 J/kg.  Scattered to
numerous thunderstorms are expected, with storms spreading eastward
through the afternoon towards the coast of southern ME/NH/MA.  Winds
aloft are not particularly strong, suggest early activity may be
rather disorganized.  However, eventual congealing of outflow will
likely result in locally damaging wind gusts.  Hail will also be
possible in the strongest cells.  Please refer to MCD #1340 for
further details.

...Central High Plains...
Latest surface analysis shows south-southeasterly low-level winds
across the NE Panhandle and southeast WY, where dewpoints are in the
50s and lower 60s.  This will help maintain a moist/unstable air
mass in the area, yielding afternoon MLCAPE values of around 1500
J/kg.  Scattered thunderstorms are expected to form over southeast
WY by 20z, where sufficient deep-layer shear and steep lapse rates
will favor supercell structures capable of very large hail and
perhaps a tornado.  Storms will track eastward into the NE Panhandle
and southern SD through the evening, with an increasing risk of
damaging winds (possibly exceeding 65kt).

...Western CO...
Moderately strong southwesterly low/mid-level flow is present today
across western CO, where full heating and diurnal destabilization
will occur.  Morning models continue to show scattered or greater
thunderstorms coverage this afternoon, in a deeply mixed
environment.  Several fast-moving high-based thunderstorms are
expected, with a risk of locally severe winds in the stronger cores.

..Hart/Lyons/Halbert.. 06/20/2024

$$