279
ACUS01 KWNS 061631
SWODY1
SPC AC 061629

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1129 AM CDT Sat Jun 06 2026

Valid 061630Z - 071200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON/EVENING FROM OHIO TO THE NORTHERN MID-ATLANTIC/SOUTHERN
NEW ENGLAND...AND ACROSS THE NORTHERN HIGH PLAINS...

...SUMMARY...
Thunderstorms with damaging wind gusts and isolated large hail are
expected this afternoon/evening from the Ohio Valley to the northern
Mid-Atlantic and southern New England. Large hail and severe wind
gusts are also expected in the northern High Plains late this
afternoon/evening.

...OH Valley into New England through late evening...
A surface cyclone will move eastward across southern QC this
afternoon and into northern New England tonight, in advance of a
midlevel shortwave trough over the Great Lakes.  An associated
surface cold front will progress southward into the OH Valley and
southeastward to near the southern New England and northern
Mid-Atlantic coasts by early Sunday.  A convective cluster is
ongoing as of midday in OH to the south of the cold front, and it
appears likely that these storms will be maintained through the
afternoon as surface temperatures continue to warm and MLCAPE
increases into the 1000-1500 J/kg range.  Sufficient buoyancy, along
with steepening low-level lapse rates and gradually strengthening
midlevel flow, will result in the potential for downward momentum
transfer and wind damage from eastern OH across PA through the
afternoon (potentially reaching Philadelphia-New York City by this
evening).  Otherwise, additional storm development will be possible
later this afternoon along the cold front from the OH Valley into
NY, where a mix of supercells and multicell clusters will be capable
of producing damaging winds, isolated large hail, and a tornado or
two.

...Northern High Plains late this afternoon through late evening...
A midlevel trough will continue eastward from WA/OR to the northern
Rockies, with downstream lee cyclogenesis expected across southeast
MT.  Forecast soundings suggest surface temperatures will need to
reach ~90 F to weaken convective inhibition and support thunderstorm
development along the stalled front across northeast MT/northwest ND
late this afternoon/evening.  Forecast wind profiles support both
multicell clusters and supercells, and steep lapse rates through
most of the column will favor both severe outflow gusts (up to 75
mph) and large hail (up to 2 inches in diameter) with a mix of
high-based supercells and multicell clusters.

...TX/OK this afternoon...
Pockets of surface heating from central/northwest TX into southern
OK, near and south of a weak surface low and MCV, will support
additional thunderstorm development through the afternoon.  Isolated
wind damage and marginally severe hail will be the main concerns
this afternoon.

..Thompson/Chalmers.. 06/06/2026

$$