Mesoscale Discussion 1107
NWS Storm Prediction Center Norman OK
1257 PM CDT Fri Jun 12 2026

Areas affected...much of Virginia...parts of West
Virginia...Maryland...northern North Carolina

Concerning...Severe potential...Watch likely 

Valid 121757Z - 121900Z

Probability of Watch Issuance...80 percent

SUMMARY...Scattered storms capable of damaging wind gusts are
expected to develop through the afternoon.

DISCUSSION...A surface trough is gradually deepening across MD/VA/NC
with strong heating resulting in very steep low-level lapse rates.
Modest northwest flow aloft exists into the area, which may aid in
steering storms in a southeastward direction. Visible imagery shows
a moist air mass across the entire area and extending west across
the higher terrain as well, suggesting minimal drying/downslope
effects. 

In the next couple hours, storms may form in the agitated CU area
currently seen over northern into northwest VA. Several models
depict a possible cluster of storms moving southeastward later
today, with a corridor of damaging winds possible.

Other storms are likely to develop over WV and southward across the
Appalachians. Given the weak northwest winds aloft, any such
activity may move into the lower terrain late in the day. Several
models suggest any such convection and/or outflows may instigate new
development during the later afternoon into much of central VA and
perhaps northern NC.

..Jewell/Thompson.. 06/12/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...AKQ...LWX...RAH...RNK...RLX...GSP...MRX...

LAT...LON   37258177 37808116 38787980 38987924 39137802 39027702
            38927678 38377634 37847641 37517710 36987785 36397880
            36018174 36018182 36368227 36798229 37258177 

MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN

Mesoscale Discussion 1106
NWS Storm Prediction Center Norman OK
1248 PM CDT Fri Jun 12 2026

Areas affected...portions of the Mid-Atlantic and Northeast

Concerning...Severe potential...Watch possible 

Valid 121748Z - 121945Z

Probability of Watch Issuance...40 percent

SUMMARY...Widely scattered thunderstorms and a risk of occasional
damaging wind gusts are expected across portions of the Mid-Atlantic
and Northeast this afternoon/evening.

DISCUSSION...Latest regional radar imagery depicts ongoing
thunderstorm development across portions of the Mid-Atlantic and
Northeast along a surface cold front and prefrontal trough. This
activity is occurring as weak mid-level height falls begin to
overspread the region ahead of a mid-level shortwave trough
progressing across the Great Lakes region. While mid-level lapse
rates will remain weak, strong surface heating and dewpoints around
70 F will support 1000 to locally 2000+ J/kg MLCAPE by peak heating
this afternoon as convection evolves eastward. While stronger
deep-layer flow will remain displaced to the north, modest mid-level
westerlies of 25-35 kts and steepening low-level lapse rates will
promote the potential for multicell clusters capable of occasional
damaging wind gusts. Currently, the greatest potential appears
likely to manifest across southeastern New York and adjacent areas
where the best overlap of modestly stronger mid-level flow and
greater buoyancy may develop.

A Severe Thunderstorm Watch may be needed for portions of the
discussion area within the next 1-2 hours to cover these threats.
More uncertainty exists regarding watch issuance farther south into
southeastern Pennsylvania and southern New Jersey where latest
guidance indicates a relative minimum in convective coverage could
occur.

..Chalmers/Thompson.. 06/12/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...GYX...BOX...BTV...OKX...ALY...PHI...BGM...CTP...

LAT...LON   40857626 41097631 41407632 41697625 42197594 42587567
            43237521 43677461 43787433 43837408 43807371 43757340
            43567300 43327268 43107249 42797235 42377244 41577291
            40757347 40357380 40207409 40157449 40177490 40257543
            40417580 40647607 40857626 

MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1130 AM CDT Fri Jun 12 2026

Valid 121630Z - 131200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON/EVENING ACROSS THE APPALACHIANS...MID-ATLANTIC AND
NORTHEAST...AND THIS EVENING ACROSS THE SOUTHERN HIGH PLAINS...

...SUMMARY...
Strong to severe storms capable of damaging winds are expected
across parts of the Appalachians, Mid-Atlantic, and Northeast,
mainly this afternoon and evening. Severe storms with a threat of
large hail and severe wind gusts will also be possible across parts
of the south-central High Plains.

...Mid-Atlantic into New England this afternoon/evening...
Within the northern stream, a shortwave trough will progress
east-northeastward over the lower Great Lakes this
afternoon/evening, while an associated surface cold front moves
eastward into New England and southeastward into the Mid-Atlantic. 
Forcing for ascent will not be particularly strong and the stronger
midlevel flow/deep-layer vertical shear will remain displaced to the
cool side of the front.  Still, 25-30 kt midlevel flow will overlap
the warm sector this afternoon from northern Chesapeake Bay
northward into eastern NY.  Strong surface heating is ongoing from
the Piedmont into VA/southern PA, with a few more cloud patches from
northeast PA into central NY.  The net result will be moderate
buoyancy (MLCAPE of 1000-2000 J/kg) in an environment with steep
low-level lapse rates and weak upper flow, favoring multicell
clusters with occasional wind damage.  The weak forcing for ascent
suggests that widely scattered, loosely organized clusters will be
possible this afternoon, with some gaps in the wind threat.

...Southern High Plains late this afternoon into early tonight...
Lee cyclogenesis across southeast CO will draw low-level moisture
northwestward into the southern High Plains as a stalled front
begins to lift northward across the TX Panhandle.  Thunderstorm
development is expected this afternoon/evening with upslope flow
into the higher terrain of NM, and along the Raton Mesa.  Deep-layer
vertical shear/hodograph length will be sufficient for supercells
initially off Raton Mesa, with large hail the primary threat.  Some
upscale growth and an increase in the potential for severe outflow
gusts is expected late this evening as storms spread eastward toward
southwest KS and the northern Panhandles in association with a
nocturnal low-level jet and strengthened warm advection/moisture
transport.

...Eastern KS/western MO early Saturday...
In response to low-level warm advection and returning moisture,
elevated convection is probable late in the period across eastern
KS/western MO.  This area will be near the east edge of the steep
midlevel lapse rates, where isolated large hail will be possible. 
There will also be some potential for evolution into a cluster or
two with isolated damaging gusts.  Farther north into eastern NE
(very near the end of the period) there will be a chance for
elevated storms with some hail.  This area will be re-evaluated this
afternoon in the 20z update.

..Thompson/Chalmers.. 06/12/2026

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1228 PM CDT Fri Jun 12 2026

Valid 131200Z - 141200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SATURDAY
AFTERNOON INTO SATURDAY NIGHT ACROSS EASTERN KANSAS...ADJACENT
PORTIONS OF SOUTHEASTERN NEBRASKA AND NORTHEASTERN OKLAHOMA...AND
MUCH OF WESTERN THROUGH CENTRAL MISSOURI...

...SUMMARY...
One or two evolving thunderstorm clusters appear possible across
parts of the central Great Plains and lower Missouri Valley vicinity
Saturday afternoon through Saturday night.  Some of this activity
will pose a risk for producing large hail and swaths of strong,
potentially damaging wind gusts.

...Discussion...
Downstream of amplified mid-level ridging, offshore of the U.S.
Pacific coast through British Columbia, it appears that flow will
begin to veer to an increasing northwesterly component across and
east of the Rockies through this period.  Within this regime,
substantive mid-level troughing is forecast to dig across the Upper
Midwest, to the southwest of a lingering mid-level low centered
across northwestern Ontario.  Spread within model output remains
larger concerning short wave perturbations digging through initially
weaker flow across the Missouri through lower Ohio Valleys, and the
extent to which they may begin to suppress the northern periphery of
subtropical ridging centered over the northern Gulf Basin.

In lower levels, an initial, convective outflow enhanced, surface
front overspreading much of the Mid Atlantic through Mid South
vicinity will likely already be in the process of weakening at the
outset of the period.  However, surges of cooler/drier air will
continue to develop southward into and through the interior of the
U.S., with the general leading edge reaching the lower Great Lakes
through Ohio Valley, Ozarks Plateau and Texas South Plains by 12Z
Sunday.  This may be preceded across the Ohio Valley through western
slopes of the Appalachians by outflow from extensive prior
convective development.

...Central Great Plains into Missouri Valley...
The potential for increasing thunderstorm development at the outset
of the period across eastern Nebraska into western Iowa (near the
nose of an east-northeastward advecting plume of elevated
mixed-layer air) coupled with potential for substantive, but
weakening, remnant convection from overnight overspreading the Ozark
Plateau, contribute to continuing uncertainty concerning subsequent
convective development Saturday through Saturday night.
The evolution of convective outflows, and their impact on
boundary-layer destabilization, coupled with uncertain short wave
developments, will substantially impact the timing, location and
potential upscale growth of potentially stronger thunderstorm
development.

However, beneath the plume of elevated mixed-layer air, a corridor
of stronger boundary-layer heating and deeper mixing across Kansas
during the day seems to provide the highest certainty for moderate
to strong destabilization.  Near the nose of this regime, somewhere
across eastern Kansas into western Missouri, based on a consensus of
model output, low-level warm advection in the presence of weaker
inhibition may provide the focus for intensifying thunderstorm
development by late afternoon.  And there appears a general signal
in the model output that a modifying outflow boundary/zone of
differential heating may provide a focus for the southeastward
development of upscale growing convection toward the Mid South
through Saturday night.  As this occurs, increasing thunderstorm
development also appears probable ahead of the southward advancing
cold front across Kansas through Oklahoma and the Texas Panhandle
vicinity.

Although deep-layer shear may be initially modest, it may still be
sufficient to support the evolution of a few supercells capable of
producing large hail and potential for a couple tornadoes, before
evolving swaths of strong to severe wind gusts become the more
prominent threat with organizing clusters into late Saturday
evening.

..Kerr.. 06/12/2026