063
ACUS02 KWNS 050538
SWODY2
SPC AC 050536

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1236 AM CDT Fri Jun 05 2026

Valid 061200Z - 071200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER
OHIO VALLEY INTO SOUTHERN NEW ENGLAND...AND OVER PORTIONS OF THE
NORTHERN HIGH PLAINS...

...SUMMARY...
Scattered severe storms capable of large hail and damaging winds are
possible from portions of the Great Lakes and Ohio Valley into the
Northeast, and over the northern High Plains. More isolated
occurrences of large hail and damaging winds are possible across
parts of the southern Plains and the lower Missouri Valley into Mid
Mississippi Valley.

...Synopsis...

A short-wave trough initially from James Bay into the Great Lakes
Saturday morning is forecast to amplify while translating through
southern Quebec and the Northeast. Associated mid/upper-level jet
streaks within the base of the strengthening trough are forecast to
overspread the upper OH Valley through southern New England,
enhancing vertical shear and forcing for ascent in those areas.
Elsewhere, a jet streak will round the base of a deep trough over
the Canadian Rockies into Pacific Northwest, with the trough axis
pivoting east through the Columbia Basin toward the northern
Rockies. Meanwhile, a lower-latitude trough will move through the
southern and central Plains, with a belt of enhanced mid/upper-level
flow extending from southwest TX through the ArkLaTex into Ozark
Plateau during the peak of the diurnal heating cycle.

At the surface, an initially diffuse cold front associated with the
Great Lakes/Northeast short-wave trough will slowly advance through
the Great Lakes, northern OH Valley, and St. Lawrence Valley into
northern New England. Over the northern High Plains, a surface low
is forecast to deepen along a cold front emerging from the northern
Rockies.


...Great Lakes and OH Valley into the Northeast...

Areas of showers and thunderstorms are expected to be ongoing
Saturday morning within a broad zone of warm advection and moisture
flux occurring along a westerly low-level jet. A subset of those
thunderstorms are likely to persist and gradually intensify from
late morning into afternoon. Additional, diurnally enhanced storms
are expected to develop within preferred zones of confluence within
the weakly capped warm sector, which will destabilize from
west-to-east over the course of the day.

The 00z HREF indicates a corridor of mean SBCAPE of 1000-1500+ J/kg
developing by afternoon from the OH Valley into southern New
England, which will coincide with steadily strengthening deep-layer
shear. As such, the potential exists for organized storm modes,
including bowing line segments and supercells capable of swaths of
wind damage and large hail during the afternoon and evening hours.
The greatest supercell potential is expected to evolve across the
upper OH Valley, where the large hail is most probable, along with
the threat for a brief tornado or two.


...Northern High Plains...

Late-arriving forcing for ascent and more robust boundary-layer
moisture content are expected to delay thunderstorm development
until late afternoon or evening in the vicinity of the surface low
and front situated along the MT-ND Border. The presence of a
moderately unstable air mass and steadily strengthening vertical
shear are expected to support supercell storm modes with an
attendant threat for large hail and damaging wind gusts. The
severe-weather threat may continue into the overnight hours,
centered along the low-level jet axis.


...Red River Valley into southwest Texas...

As mentioned in the synopsis, a belt of enhanced mid-level flow is
forecast within the southern/southeastern periphery of the upper
low, which will enhance vertical shear to some extent. Slightly
cooler temperatures aloft coupled with a warm and moist boundary
layer will support a moderately unstable air mass in areas
unaffected by early storms and lingering cloud cover. Forecast
soundings indicate relatively weak capping, which should permit
increasing storm coverage by afternoon along any pre-existing
boundaries. The overall environment appears supportive of multicell
storms capable of isolated occurrences of large hail and locally
strong wind gusts during the afternoon and evening hours.


...Lower Missouri and Mid Mississippi Valleys...

Moderate to strong afternoon instability is forecast to develop
along and south of the trailing surface front or convective outflow
boundary remnant from Friday night thunderstorms. Weak low-level
warm advection coupled with the growing influence of a mid-level
trough approaching from the southwest are expected to support widely
scattered thunderstorm development during the afternoon. While
vertical shear is expected to remain relatively weak, the degree of
instability will support vigorous up/downdrafts capable of
marginally severe hail and/or locally damaging wind gusts.

..Mead.. 06/05/2026

$$