WW 562 SEVERE TSTM SD 110045Z - 110800Z

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 562
NWS Storm Prediction Center Norman OK
645 PM MDT Mon Aug 10 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Western into Central South Dakota
* Effective this Monday night and Tuesday morning from 645 PM
until 200 AM MDT.
* Primary threats include...
Scattered damaging winds and isolated significant gusts to 75
mph likely
Scattered large hail and isolated very large hail events to 2
inches in diameter likely
A tornado or two possible
SUMMARY...Ongoing supercells across far southwest North Dakota are
expected to progress southeastward into northwest South Dakota soon.
The airmass across South Dakota is very unstable and strongly
sheared, suggesting these supercells will maintain their intensity.
Upscale growth of these storms is possible, with the resulting
convective line then tracking southeastward into more of central
South Dakota. If this convective line is realized, environmental
conditional support the potential for strong to severe gust (i.e.
75+ mph). Additionally, strong low-level shear will develop across
central South Dakota so there is risk for a line-embedded tornado or
two, if a mature convective line materializes.
The severe thunderstorm watch area is approximately along and 95
statute miles north and south of a line from 55 miles southwest of
Lemmon SD to 40 miles east of Pierre SD. For a complete depiction of
the watch see the associated watch outline update (WOUS64 KWNS
WOU2).
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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 558...WW 559...WW
560...WW 561...
AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 65 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
30035.
...Mosier
WW 561 SEVERE TSTM AZ 102350Z - 110700Z

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 561
NWS Storm Prediction Center Norman OK
450 PM MST Mon Aug 10 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Southern Arizona
* Effective this Monday afternoon from 450 PM until Midnight MST.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1 inch in diameter possible
SUMMARY...Thunderstorms are ongoing across the higher terrain of
central and east-central Arizona, as well as across far
south-central and southeast Arizona. Much of this activity is
forecast to progress westward, where a very warm and deeply mixed
airmass is in place. High-based storms moving into this airmass
could produce strong downbursts capable of damaging gusts. Some cold
pool amalgamation is possible, which would result in more widespread
damaging gusts. Isolated instances of hail are possible as well,
primarily within the areas of greater buoyancy over far southeastern
Arizona.
The severe thunderstorm watch area is approximately along and 70
statute miles north and south of a line from 35 miles west of Gila
Bend AZ to 75 miles northeast of Tucson AZ. For a complete depiction
of the watch see the associated watch outline update (WOUS64 KWNS
WOU1).
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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 555...WW 556...WW
558...WW 559...WW 560...
AVIATION...A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few
cumulonimbi with maximum tops to 500. Mean storm motion vector
09020.
...Mosier
WW 560 SEVERE TSTM IL IN MI OH LE LM 102320Z - 110600Z

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 560
NWS Storm Prediction Center Norman OK
720 PM EDT Mon Aug 10 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Northeast Illinois
Northern Indiana
Far Southern Lower Michigan
Western Ohio
Lake Erie
Lake Michigan
* Effective this Monday night and Tuesday morning from 720 PM
until 200 AM EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1.5 inches in diameter possible
SUMMARY...Thunderstorm coverage and intensity is expected to
increase over the next few hours within the warm, moist, and very
unstable airmass in place across much of the Ohio Valley. Moderate
deep-layer vertical shear extends across the region as well. These
environmental conditions will support robust updrafts, with some
degree of updraft organization possible. Damaging gusts and/or large
hail are possible with any of the more organized storms.
The severe thunderstorm watch area is approximately along and 55
statute miles north and south of a line from 65 miles west southwest
of Valparaiso IN to 30 miles northeast of Columbus OH. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU0).
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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 554...WW 555...WW
556...WW 558...WW 559...
AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
28025.
...Mosier
WW 0562 Status Updates

STATUS REPORT ON WW 562
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 5 E 2WX TO
35 WNW ABR.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1914
..MOORE..08/11/26
ATTN...WFO...ABR...UNR...
STATUS REPORT FOR WS 562
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
SDC041-055-065-075-085-093-105-107-117-119-129-137-110340-
SD
. SOUTH DAKOTA COUNTIES INCLUDED ARE
DEWEY HAAKON HUGHES
JONES LYMAN MEADE
PERKINS POTTER STANLEY
SULLY WALWORTH ZIEBACH
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
WW 0561 Status Updates

STATUS REPORT ON WW 561
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1913
..GLEASON..08/11/26
ATTN...WFO...PSR...TWC...
STATUS REPORT FOR WS 561
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
AZC007-013-019-021-023-110440-
AZ
. ARIZONA COUNTIES INCLUDED ARE
GILA MARICOPA PIMA
PINAL SANTA CRUZ
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
WW 0560 Status Updates

STATUS REPORT ON WW 560
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 SSW DAY
TO 30 WNW TOL.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1915
..GLEASON..08/11/26
ATTN...WFO...LOT...IWX...IND...ILN...CLE...
STATUS REPORT FOR WS 560
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
OHC003-011-021-023-033-041-043-045-047-049-051-057-063-065-069-
073-077-083-089-091-095-097-101-109-113-117-123-129-137-139-143-
147-149-159-173-175-110440-
OH
. OHIO COUNTIES INCLUDED ARE
ALLEN AUGLAIZE CHAMPAIGN
CLARK CRAWFORD DELAWARE
ERIE FAIRFIELD FAYETTE
FRANKLIN FULTON GREENE
HANCOCK HARDIN HENRY
HOCKING HURON KNOX
LICKING LOGAN LUCAS
MADISON MARION MIAMI
MONTGOMERY MORROW OTTAWA
PICKAWAY PUTNAM RICHLAND
SANDUSKY SENECA SHELBY
UNION WOOD WYANDOT
LEZ142-143-144-162-163-164-110440-
WW 0559 Status Updates

STATUS REPORT ON WW 559
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 ESE LBF
TO 40 WNW LBF TO 20 WNW MHN TO 10 SSE ANW.
..MOORE..08/11/26
ATTN...WFO...GLD...BOU...LBF...CYS...
STATUS REPORT FOR WS 559
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
COC017-110340-
CO
. COLORADO COUNTIES INCLUDED ARE
CHEYENNE
KSC109-199-110340-
KS
. KANSAS COUNTIES INCLUDED ARE
LOGAN WALLACE
NEC091-113-117-171-110340-
NE
. NEBRASKA COUNTIES INCLUDED ARE
HOOKER LOGAN MCPHERSON
THOMAS
WW 0558 Status Updates

STATUS REPORT ON WW 558
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 E RZZ TO
15 N ORF TO 25 NE WAL TO 50 E SBY.
..GLEASON..08/11/26
ATTN...WFO...AKQ...
STATUS REPORT FOR WS 558
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
VAC131-550-710-740-800-810-110140-
VA
. VIRGINIA COUNTIES INCLUDED ARE
NORTHAMPTON
VIRGINIA INDEPENDENT CITIES INCLUDED ARE
CHESAPEAKE NORFOLK PORTSMOUTH
SUFFOLK VIRGINIA BEACH
ANZ632-634-639-650-652-654-656-110140-
CW
. ADJACENT COASTAL WATERS INCLUDED ARE
CHESAPEAKE BAY FROM NEW POINT COMFORT TO LITTLE CREEK VA
CHESAPEAKE BAY FROM LITTLE CREEK VA TO CAPE HENRY VA INCLUDING
THE CHESAPEAKE BAY BRIDGE TUNNEL
WW 0557 Status Updates

STATUS REPORT ON WW 557
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 W DAN TO
45 NNW AVC.
..GLEASON..08/10/26
ATTN...WFO...RNK...
STATUS REPORT FOR WS 557
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
VAC037-083-143-590-102340-
VA
. VIRGINIA COUNTIES INCLUDED ARE
CHARLOTTE HALIFAX PITTSYLVANIA
VIRGINIA INDEPENDENT CITIES INCLUDED ARE
DANVILLE
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
WW 0556 Status Updates

STATUS REPORT ON WW 556
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 NE NHK TO
15 SE DOV TO 25 E DOV TO 25 SSE ACY.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1906
..GLEASON..08/10/26
ATTN...WFO...PHI...OKX...
STATUS REPORT FOR WS 556
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
DEC005-102340-
DE
. DELAWARE COUNTIES INCLUDED ARE
SUSSEX
NJC009-102340-
NJ
. NEW JERSEY COUNTIES INCLUDED ARE
CAPE MAY
ANZ431-453-454-455-102340-
CW
. ADJACENT COASTAL WATERS INCLUDED ARE
DELAWARE BAY WATERS SOUTH OF EAST POINT NJ TO SLAUGHTER BEACH DE
WW 0555 Status Updates

STATUS REPORT ON WW 555
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 WSW NHK
TO 35 SW DOV.
..GLEASON..08/10/26
ATTN...WFO...LWX...
STATUS REPORT FOR WS 555
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
MDC037-102340-
MD
. MARYLAND COUNTIES INCLUDED ARE
ST. MARYS
ANZ534-537-543-102340-
CW
. ADJACENT COASTAL WATERS INCLUDED ARE
CHESAPEAKE BAY FROM DRUM POINT MD TO SMITH POINT VA
TIDAL POTOMAC FROM COBB ISLAND MD TO SMITH POINT VA
TANGIER SOUND AND THE INLAND WATERS SURROUNDING BLOODSWORTH
ISLAND
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
WW 0554 Status Updates

STATUS REPORT ON WW 554
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 SSE HTS
TO 25 NNW HTS TO 20 SSE UNI TO 35 N CRW TO 15 NW BKW.
..GLEASON..08/10/26
ATTN...WFO...RLX...ILN...PBZ...
STATUS REPORT FOR WS 554
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
OHC053-087-102340-
OH
. OHIO COUNTIES INCLUDED ARE
GALLIA LAWRENCE
WVC005-011-035-039-043-053-079-099-102340-
WV
. WEST VIRGINIA COUNTIES INCLUDED ARE
BOONE CABELL JACKSON
KANAWHA LINCOLN MASON
PUTNAM WAYNE
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
MD 1916 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR SOUTHWEST NORTH DAKOTA INTO NORTHERN SOUTH DAKOTA

Mesoscale Discussion 1916
NWS Storm Prediction Center Norman OK
1030 PM CDT Mon Aug 10 2026
Areas affected...Southwest North Dakota into northern South Dakota
Concerning...Severe potential...Watch possible
Valid 110330Z - 110530Z
Probability of Watch Issuance...40 percent
SUMMARY...Elevated convection developing across southwest North
Dakota may continue to intensify and pose a severe threat over the
next few hours, though confidence in exact evolution is uncertain.
DISCUSSION...Convection has been gradually intensifying to the west
of Bismarck, ND over the past 45 minutes, and a few additional
updrafts are noted to the southwest of this cell per GOES IR
imagery. This activity appears to be driven by weak ascent within a
diffuse low-level baroclinic zone draped from southwest ND
southeastward into SD based on recent upper-air analyses. Although
this activity is somewhat displaced to the north of the axis of
greater buoyancy (and is upstream of the cold pool associated with a
leading supercell in SD), the 00 UTC BIS RAOB and recent forecast
soundings suggest buoyancy should be adequate for sustained deep
convection downstream into south-central ND. Additionally, strong
deep-layer shear remains in place across the region and can support
intense supercell development (as evident by the aforementioned
supercell in SD, which matured in a similar kinematic environment).
Despite the favorable convective environment, it remains unclear
whether this emerging cell will remain isolated or if additional
convection will emerge within this zone and foster upscale growth
along the baroclinic zone into SD later tonight. Convective trends
will continue to be monitored, and watch issuance may be needed as
dictated by storm evolution and intensity.
..Moore/Mosier.. 08/11/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...ABR...BIS...UNR...
LAT...LON 45570379 46380319 46770250 46329853 46049819 45599830
45289877 45059933 44999957 45570379
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN
MD 1915 CONCERNING SEVERE THUNDERSTORM WATCH 560... FOR PARTS OF OH

Mesoscale Discussion 1915
NWS Storm Prediction Center Norman OK
0952 PM CDT Mon Aug 10 2026
Areas affected...Parts of OH
Concerning...Severe Thunderstorm Watch 560...
Valid 110252Z - 110415Z
The severe weather threat for Severe Thunderstorm Watch 560
continues.
SUMMARY...A severe hail/wind threat continues this evening across
parts of Ohio, but the need for a downstream watch remains
uncertain.
DISCUSSION...Two slow-moving clusters have become the primary severe
risk this evening across western OH. While a very unstable airmass
remains in place ahead of this activity (MLCAPE up to 3000-3500+
J/kg per recent mesoanalysis), a lack of recent wind reports
suggests that these thunderstorms may be slightly elevated. Even so,
modest low-level southwesterlies veering to west-northwesterly and
gradually strengthening with height through mid levels will continue
to foster around 30-35 kt of deep-layer shear (reference the 00Z ILN
observed sounding). This should be sufficient for continued updraft
organization, with occasional severe/damaging winds the primary
threat given the ongoing cluster mode. Isolated hail also appears
possible with embedded stronger cores. These clusters will spread
east-southeastward this evening across central OH, and will
eventually encounter a less unstable airmass into far eastern OH and
WV, where prior convective overturning occurred earlier today.
Therefore, the potential for organized severe convection persisting
east of Severe Thunderstorm Watch 560 remains uncertain, as does the
need for a downstream watch.
..Gleason.. 08/11/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PBZ...RLX...CLE...ILN...IWX...
LAT...LON 40578471 41368423 40398171 40078152 39498176 39488224
40038453 40578471
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
MD 1914 CONCERNING SEVERE THUNDERSTORM WATCH 562... FOR WESTERN SOUTH DAKOTA

Mesoscale Discussion 1914
NWS Storm Prediction Center Norman OK
0936 PM CDT Mon Aug 10 2026
Areas affected...Western South Dakota
Concerning...Severe Thunderstorm Watch 562...
Valid 110236Z - 110430Z
The severe weather threat for Severe Thunderstorm Watch 562
continues.
SUMMARY...The threat for very large hail and severe winds will
continue as a robust supercell migrates southeast across western
South Dakota.
DISCUSSION...Over the past hour, a lone, but intense, supercell has
exhibited persistent three-body scatter spikes consistent with very
large hail, and has also produced wind gusts of at least 61 mph per
recent reports. More recently, the reflectivity core has diminished
slightly, and the storm motion has shifted from due south to
southeasterly, suggesting a slight weakening of the storm's internal
pressure perturbations and overall intensity. However, this cell
will continue to reside within an environment very favorable for
intense convection (MLCAPE near 4000 J/kg and nearly 50 knots of
effective bulk shear as sampled by the 00 UTC UNR and ABR
soundings), so some degree of re-intensification appears possible.
Additionally, new updraft development is noted on the western flank
of the cell, which may also intensify and pose a threat for very
large (2 inch) hail and severe gusts. Given the elongated/straight
nature of regional wind profiles, the emergence of this new cell
hints that cell interactions and cold pool amalgamation may increase
over the next couple of hours as the new cell begins to split. This
may result in a very gradual transition from a supercellular to a
clustered/linear storm mode with an attendant increase in severe
wind potential as storms move further south/southeast. A few recent
high-res solutions hint at this transition, but confidence in this
scenario is somewhat limited at this point due to the isolated
nature of the convection.
..Moore.. 08/11/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...ABR...UNR...
LAT...LON 45330296 45560261 45620219 44519963 44069982 43780028
43730096 43780180 43870244 45330296
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN
MD 1912 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR EASTERN IOWA INTO NORTHERN ILLINOIS

Mesoscale Discussion 1912
NWS Storm Prediction Center Norman OK
0907 PM CDT Mon Aug 10 2026
Areas affected...Eastern Iowa into northern Illinois
Concerning...Severe potential...Watch possible
Valid 110207Z - 110400Z
Probability of Watch Issuance...60 percent
SUMMARY...Convection developing in eastern Iowa will likely
intensify in the coming hours and could pose some severe threat for
portions of eastern Iowa into northern Illinois. Confidence in exact
evolution is limited, but watch issuance may need to be considered.
DISCUSSION...Latest regional reflectivity and GOES IR imagery shows
steady deepening of nascent convection across eastern IA along a
diffuse warm frontal zone. A recent 00 UTC DVN RAOB sampled weak
mixed-layer inhibition that is evidently being overcome by ascent
within the frontal zone as a nocturnal jet slowly strengthens. This
sounding also sampled extreme buoyancy and adequate deep-layer wind
shear for organized convection. Consequently, it seems likely that
further intensification will occur over the next 1-2 hours.
Moderate veering through the lowest 3 km is also noted in the
observed hodograph, which should support the potential for a
supercell or two capable of producing large hail and perhaps brief
tornadoes. The primary uncertainty regarding this potential is the
possibility of destructive storm interactions and clustering given
forecast storm motions largely along the zone of initiation. This
potential is hinted by recent solutions of the HRRR and RRFS, which
show initially semi-discrete cells growing upscale into northern IL
later this evening. Convective trends will continue to be monitored,
and watch issuance may be needed if robust supercells become more
imminent.
..Moore/Mosier.. 08/11/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LOT...MKX...DVN...ARX...DMX...
LAT...LON 41879229 41999275 42309288 42609273 42789230 42508890
42228873 41928879 41718893 41568910 41408941 41879229
MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
SPC 0100Z Day 1 Outlook

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0753 PM CDT Mon Aug 10 2026
Valid 110100Z - 111200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
SOUTH DAKOTA...SOUTHWEST MINNESOTA...AND NORTHWEST IOWA...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE
NORTHERN/CENTRAL PLAINS TO THE OHIO VALLEY...AND ACROSS PART OF
AZ...
...SUMMARY...
A severe wind swath, with a few 75+ mph gusts is possible across
portions of the northern Plains into the Midwest tonight. A few
severe gusts may also occur over central and southern Arizona.
...South Dakota into Iowa vicinity...
A small cluster of storms near the western ND/SD border may be the
start of what is expected to be a severe MCS through the overnight
hours. These storms are developing within a corridor of strong
instability and favorable deep layer shear. The 00z ABR RAOB shows a
very favorable thermodynamic and kinematic parameter space for
initial supercells growing upscale into a bowing MCS as a low-level
jet increases tonight. This environment is characterized by an
elongated/straight hodograph, steep lapse rates and strong
instability with a layer of drier air around 700 mb atop a very
moist boundary layer. This profile suggests sufficient cold pool
generation is possible, aiding in development of a forward
propagating bowing MCS capable of severe gusts (some 75+ mph)
tonight into early Tuesday. Initial supercells also may pose a risk
for large hail up to 2.5 inches. Reference MCD 1908 for more short
term details.
...Central High Plains...
Scattered strong to severe storms will continue to pose a risk of
damaging winds and hail for a few more hours this evening,
particularly across parts of western NE. With loss of daytime
heating, this activity is expected to gradually wane in intensity.
Reference MCD 1910 for more short term information.
...AZ...
Widely scattered thunderstorms moving westward off higher terrain
will pose a risk for severe wind gusts over the next few hours.
...Northern IL into the Ohio Valley...
Convection ongoing across northern IN will persist into the evening
hours as it track east/southeast into OH. This activity may persist
through the overnight hours moving across much of the Ohio Valley
toward western PA and WV. Damaging winds will remain the primary
hazard, but isolated large hail may also occur.
...Mid-Atlantic/Northeast...
Strong wind gusts will remain possible with storms along the
southern Mid-Atlantic coast until they push completely offshore over
the next hour. Otherwise, severe potential has largely diminished
along the I-95 corridor and vicinity and severe probabilities have
been trimmed and/or removed. The exception will be across parts of
the northern NY into VT/NH area where a band of strong/severe storms
is ongoing along a surface boundary. Damaging gusts may continue
with this activity for a few more hours. Reference MCD 1909 for more
details.
..Leitman.. 08/11/2026
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