Mesoscale Discussion 0998
NWS Storm Prediction Center Norman OK
1007 AM CDT Sat Jun 06 2026

Areas affected...eastern Ohio...western Pennsylvania...northern West
Virginia...and northern Maryland

Concerning...Severe potential...Severe Thunderstorm Watch likely 

Valid 061507Z - 061730Z

Probability of Watch Issuance...80 percent

SUMMARY...Thunderstorm activity to increase in coverage and
intensity through the late morning/afternoon with an increase in
damaging wind potential.

DISCUSSION...A line of storms continues south and east across
portions of eastern Indiana into Ohio, with occasional strong to
isolated severe gusts (50-60 mph). It is uncertain how this will
evolve downstream, with guidance showing potential for maintenance
and intensification along the remaining outflow later in the
afternoon. Gradual increase in forcing for ascent will occur this
afternoon as strengthening mid-level flow overspreads the area with
the trough across the Great Lakes. Filtered heating is expected
through broken mid-level cloud cover. This in combination with dew
points in the low to mid 60s will yield around 1000-1500 J/kg
MLCAPE. Additionally, steepening low-level lapse rates are expected,
supporting downward transport of higher momentum flow aloft to the
surface. Additional downstream development is likely with potential
for several clusters of storms capable of damaging wind through the
afternoon. While exact timing of this threat remains uncertain, a
watch will likely be needed to cover this potential by the
afternoon.

..Thornton/Thompson.. 06/06/2026

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

ATTN...WFO...CTP...LWX...PBZ...RLX...CLE...ILN...IWX...

LAT...LON   39388094 39598308 39778367 40128449 40428451 40718435
            41138399 41408307 41498278 41707930 41127867 40497870
            39977880 39517912 39388094 

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0700 AM CDT Sat Jun 06 2026

Valid 061300Z - 071200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING FROM INDIANA INTO THE UPPER OHIO VALLEY AND SOUTHERN NEW
ENGLAND...AND OVER PARTS OF EASTERN MONTANA AND WESTERN NORTH
DAKOTA...

...SUMMARY...
Thunderstorms with damaging wind gusts and isolated large hail are
expected to develop later today from parts of the lower Great Lakes
and Ohio Valley into southern New England. Large hail and severe
wind gusts are also expected in the northern High Plains and
southern Plains.

...Indiana to Southern New England...
Morning water vapor loop shows a deepening upper trough over the
Great Lakes region.  This trough and an associated mid-level speed
max will spread across the upper Ohio Valley into New England this
afternoon and tonight.  Strengthening large-scale ascent ahead of
the trough has led to multiple clusters of ongoing thunderstorms
from eastern IL into parts of OH/PA/NY.  One or more of these
clusters, along with new development by early afternoon, is expected
to intensify and spread across the SLGT risk region.  Forecast
soundings suggest sufficient CAPE and low-level lapse rates to
support a risk of damaging wind gusts with this activity.  Overnight
CAM solutions continue to vary on the likely corridor of greatest
concern.  However, there is the potential for a rather widespread
damaging wind event across parts of PA/NY/NJ this afternoon/evening
if sufficient heating and mesoscale organization of the clusters
occur.

...Northern High Plains...
A large upper ridge is in place today over the High Plains region. 
A southerly low-level jet is expected to intensify by early evening
as an upper trough approaches and low-level cyclogenesis occurs over
southeast MT.  This should encourage the development of evening
thunderstorms across eastern MT tracking into western ND overnight. 
It is unclear whether the bulk of these storms will be just west of
the warm sector and elevated, or will be surface-based.  Regardless,
large hail is the primary concern.

...Southern Plains...
A weak upper low is tracking northeastward from west TX into
Oklahoma this morning. A band of stronger winds aloft to the east of
the low, coupled with pockets of daytime heating and ample moisture,
will promote damaging wind gusts and hail in the strongest storms.

..Hart/Wendt.. 06/06/2026