WW 665 SEVERE TSTM NY OH PA WV LE 091850Z - 100300Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 665
NWS Storm Prediction Center Norman OK
250 PM EDT Wed Sep 9 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Western New York
Northern Ohio
Northwest Pennsylvania
Northern Panhandle of West Virginia
Lake Erie
* Effective this Wednesday afternoon and evening from 250 PM
until 1100 PM EDT.
* Primary threats include...
Scattered damaging wind gusts to 65 mph possible
SUMMARY...Thunderstorms will increase in coverage through the
afternoon, in a relatively warm and humid air mass. A few of the
storms may become severe, with damaging wind gusts being the main
concern.
The severe thunderstorm watch area is approximately along and 35
statute miles north and south of a line from 35 miles west northwest
of Mansfield OH to 60 miles east northeast of Bradford PA. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU5).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
AVIATION...A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 55 knots. A few
cumulonimbi with maximum tops to 450. Mean storm motion vector
27025.
...Hart
WW 0665 Status Updates
STATUS REPORT ON WW 665
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 NW CMH TO
15 NW JHW TO 30 W ELM.
..THORNTON..09/09/26
ATTN...WFO...BUF...CLE...PBZ...CTP...
STATUS REPORT FOR WS 665
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
NYC013-100040-
NY
. NEW YORK COUNTIES INCLUDED ARE
CHAUTAUQUA
OHC019-029-031-067-075-081-083-099-103-117-133-151-153-155-157-
169-100040-
OH
. OHIO COUNTIES INCLUDED ARE
CARROLL COLUMBIANA COSHOCTON
HARRISON HOLMES JEFFERSON
KNOX MAHONING MEDINA
MORROW PORTAGE STARK
SUMMIT TRUMBULL TUSCARAWAS
WAYNE
PAC003-005-007-019-023-031-033-039-047-053-063-065-073-083-085-
105-121-123-125-129-100040-
MD 2275 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF THE SOUTHERN/CENTRAL GREAT PLAINS INTO THE LOWER MISSOURI VALLEY
Mesoscale Discussion 2275
NWS Storm Prediction Center Norman OK
0448 PM CDT Wed Sep 09 2026
Areas affected...portions of the southern/central Great Plains into
the Lower Missouri Valley
Concerning...Severe potential...Watch unlikely
Valid 092148Z - 092345Z
Probability of Watch Issuance...5 percent
SUMMARY...Isolated damaging/severe wind gusts will remain possible
through this evening.
DISCUSSION...Scattered showers and thunderstorms are ongoing along a
convectively reinforced surface cold front extending from just south
of Kansas City, MO, into the TX/OK Panhandles. The environment
along/ahead of this boundary is characterized by 500-1500 J/kg
MLCAPE and very steep low-level lapse rates (>9 C/km), with surface
temperatures commonly in the low 100s F. Deep-layer flow/shear
remains weak, with regional VWPs generally sampling 20-25 kts or
less through the column. This should continue to promote a
pulse-severe storm mode, with the potential for isolated
damaging/severe wind gusts to accompany stronger downdraft (as
evidenced by a recently measured 72 mph gust in the northern Texas
Panhandle).
The exception is across portions of west-central MO, where locally
greater convective coverage is noted in closer proximity to stronger
mid-level westerlies and in the vicinity of a weak surface low.
Stronger effective shear (30-40 kts) coupled with marginally greater
buoyancy (up to 2000 J/kg MLCAPE) may support a somewhat more
well-organized cluster that would evolve eastward into west-central
MO. Recent HRRR/RRFS explicit wind gust forecasts suggest some
potential exists for isolated gusts up to 55-65 mph.
The overall severe risk is expected to remain relatively isolated,
however, precluding the need for watch issuance.
..Chalmers/Smith.. 09/09/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...SGF...EAX...TSA...TOP...ICT...OUN...DDC...AMA...
LAT...LON 36779983 37009912 37379794 37749679 38029622 38269592
38559571 38669560 38879487 38899389 38789356 38619312
38409305 38179302 38019315 37909333 37749362 37679383
37639397 36929585 36209816 35909927 35839986 35870013
35990028 36190037 36450025 36670008 36779983
MOST PROBABLE PEAK WIND GUST...55-70 MPH
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook RESENT 1
NWS Storm Prediction Center Norman OK
0318 PM CDT Wed Sep 09 2026
Valid 092000Z - 101200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING FROM CENTRAL OHIO INTO NORTHWEST PENNSYLVANIA AND WESTERN
NEW YORK...
...SUMMARY...
Isolated strong to severe thunderstorms are possible across portions
of the central Plains to the Ohio Valley today.
...20Z Update...
Minor changes were made to the general thunderstorms forecast based
on observations and recent guidance. Severe probabilities remain
unchanged, however. See the previous discussion for additional
information.
..Wendt.. 09/09/2026
.PREV DISCUSSION... /ISSUED 1127 AM CDT Wed Sep 09 2026/
...OH/PA/NY...
A fast-moving shortwave trough now over WI/IL will track eastward
today across the Great Lakes region. At the surface, the primary
baroclinic currently extends from Lake Erie into OH/IN and will move
eastward and be the focus for scattered afternoon thunderstorms.
Strong heating and dewpoints in the 70s across much of OH and
western PA will result in moderate CAPE values and steep low-level
lapse rates. Sufficient deep-layer shear will promote organized
storms with some bowing structures expected, capable of locally
damaging wind gusts. This activity will spread into western
NY/northwest PA by early evening before weakening.
...IN/IL/MO...
The storms that form over OH will zipper southwestward along the
boundary into a pocket of ample CAPE/moisture over parts of southern
IN/IL into southern MO. Winds aloft in this area will be weaker,
with less overall organization of storms. Nevertheless, a few
storms may occasionally produce damaging wind gusts.
...TX/OK/KS...
Widely scattered slow-moving afternoon thunderstorms will pose a
risk of gusty/damaging winds in a hot/humid surface air mass.
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook RESENT 1
NWS Storm Prediction Center Norman OK
0320 PM CDT Wed Sep 09 2026
Valid 111200Z - 121200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN SOUTH
DAKOTA INTO MUCH OF WESTERN MINNESOTA...AND INTO CENTRAL NEBRASKA...
...SUMMARY...
Severe thunderstorms are possible across portions of the Upper
Midwest late Friday afternoon into Friday night.
...Discussion...
A leading shortwave trough will move into the Northern Plains on
Friday, as an upper low drops south along the Pacific Northwest. A
pre-frontal trough will develop into northern MN, extending into
eastern SD and central NE by late afternoon. Ahead of this trough,
strong heating will occur from NE into SD, with a cooler boundary
layer into central MN.
Temperatures aloft will cool with the upper wave, resulting in
moderately steep lapse rates aloft. Midlevel wind speeds of 20-40
kt, combined with low-level southerlies (including 40 kt at 850 mb
late in the day) will favor a few supercells initially before storms
become linear along the advancing cold front.
Forecast soundings indicate large hail will be likely with the
initial cellular activity, though shear in the mid to upper levels
will not be particularly strong. As such, will not add any sig
hatching for hail.
A brief tornado may occur with initial supercells, particularly from
eastern SD into western MN where low-level shear will be strongest.
Otherwise, damaging winds will be possible through the evening as
storms move northeast across MN.
..Jewell.. 09/09/2026
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0200 PM CDT Wed Sep 09 2026
Valid 101200Z - 111200Z
The forecast remains on track for expansive elevated fire weather
conditions across eastern ID/southwestern MT into the northern
Plains region on Day 2/Thursday; please see the previous discussion
for details.
..Elizalde-Garcia.. 09/09/2026
.PREV DISCUSSION... /ISSUED 1158 PM CDT Tue Sep 08 2026/
...Synopsis...
A mid/upper trough will push into the Northwest D2/Thursday while a
deepening surface trough and cold front evolve over the southern
Canadian prairies. Dry and breezy conditions developing in advance
of a cold front will enhance fire weather concerns across portions
of the northern Rockies and northern High Plains, where fuels remain
largely receptive.
...Eastern Idaho, southern Montana and portions of Wyoming...
West/northwest surface flow south of the mid-upper trough entering
the northwestern CONUS will expand and increase in magnitude across
much of the northern Great Basin into southern ID, southern MT and
parts of WY by Thursday afternoon. A very dry boundary layer across
much of the Intermountain West and Southwest will promote RH
reductions to below 10% in lower elevations by peak afternoon
heating. Broad west/northwest winds of around 15 mph coincident with
the low RH during the day will promote an elevated fire weather
threat primarily across eastern ID, southern MT and portions of WY
where fuels remain more receptive. Localized critical fire weather
conditions are most likely across south-central WY where 20 mph west
winds at times align with single digit RH. Thus, elevated fire
weather highlights were introduced with some expansions noted based
on latest model guidance.
...Please see www.spc.noaa.gov/fire for graphic product...
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0440 PM CDT Wed Sep 09 2026
Valid 111200Z - 171200Z
...Synopsis...
A decaying mid-level trough will enhance zonal flow over the
northern U.S. as a strong cold front navigates the north-central
states, promoting fire weather concerns where fuels remain receptive
on Day 3/Friday. An upper-level low will enter the Pacific Northwest
and Northern Rockies this weekend with an accompanying 60-70 kt jet
over the Great Basin. This pattern may provide broader precipitation
chances and much cooler temperatures to the northwestern CONUS, thus
subduing fire weather concerns; however, strong southwesterly winds
amid critically low RH values may support a broader fire weather
threat in the Great Basin. As troughing departs and enters the Upper
Midwest and Great Lakes region early next week, a very dry and much
cooler airmass will reside over the western CONUS. Simultaneously,
ridging is forecast to build across the Southeast favoring drier
conditions and above-normal temperatures.
...Day 3/Friday - Northern High Plains...
Poor overnight humidity recoveries are expected across eastern WY,
western SD, and the NE Panhandle leading into Day 3/Friday. As a
result, RH values will quickly decline to 10-20% as winds accelerate
ahead of an advancing cold front. Sustained westerly winds may
approach 25 mph across the terrain-favored plains, then shift to
northerly as the front passes. Notably, guidance indicates a 50-80%
probability of wind gusts exceeding 35 mph through the afternoon.
40% Critical probabilities have been maintained across southeastern
WY, northwestern NE Panhandle, and southwestern SD to account for
this threat.
...Day 4/Saturday - Northeastern California and Great Basin...
A robust upper low will impinge upon the northwestern U.S. on Day
4/Saturday, amplifying west-southwesterly flow over northern CA and
the western Great Basin. Ensemble guidance depicts expansive 75-90%
probabilities of wind speeds exceeding 25 mph (50-80% chance of
sustained winds exceeding 30 mph) amid critically low RH in
northeastern CA and northern NV. Despite modest ERCs,
drought-stressed fuels could support new ignitions given the
severity of meteorological conditions. As a result, 40% Critical
probabilities were introduced across the region.
..Elizalde-Garcia.. 09/09/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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