WW 556 SEVERE TSTM DE MD NJ NY PA CW 101810Z - 110100Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 556
NWS Storm Prediction Center Norman OK
210 PM EDT Mon Aug 10 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Delaware
Eastern Maryland
New Jersey
Southeast New York
Eastern Pennsylvania
Coastal Waters
* Effective this Monday afternoon and evening from 210 PM until
900 PM EDT.
* Primary threats include...
Scattered damaging winds likely with isolated significant gusts
to 75 mph possible
Isolated large hail events to 1 inch in diameter possible
SUMMARY...Lines and clusters of thunderstorms over central
Pennsylvania will track eastward across the watch area this
afternoon and early evening. Damaging winds may accompany the
stronger storms.
The severe thunderstorm watch area is approximately along and 40
statute miles east and west of a line from 55 miles north northwest
of Newark NJ to 40 miles south of Dover DE. For a complete depiction
of the watch see the associated watch outline update (WOUS64 KWNS
WOU6).
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 552...WW 553...WW
554...WW 555...
AVIATION...A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 65 knots. A few
cumulonimbi with maximum tops to 500. Mean storm motion vector
27030.
...Hart
WW 555 SEVERE TSTM DC MD VA WV CW 101715Z - 110100Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 555
NWS Storm Prediction Center Norman OK
115 PM EDT Mon Aug 10 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
District Of Columbia
Maryland
Northern Virginia
Eastern Panhandle of West Virginia
Coastal Waters
* Effective this Monday afternoon and evening from 115 PM until
900 PM EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph likely
Isolated large hail events to 1 inch in diameter possible
SUMMARY...Thunderstorms will spread southeastward across the watch
area through the afternoon and early evening. Hot and humid
conditions will combine with favorable winds aloft for a risk of
damaging wind gusts in the stronger storms.
The severe thunderstorm watch area is approximately along and 45
statute miles north and south of a line from 85 miles west southwest
of Martinsburg WV to 40 miles east northeast of Baltimore MD. 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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 552...WW 553...WW 554...
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
29030.
...Hart
WW 554 SEVERE TSTM KY OH WV 101645Z - 110000Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 554
NWS Storm Prediction Center Norman OK
1245 PM EDT Mon Aug 10 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Northeast Kentucky
Southeast Ohio
Central West Virginia
* Effective this Monday afternoon and evening from 1245 PM until
800 PM EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph likely
Isolated large hail events to 1.5 inches in diameter possible
SUMMARY...Thunderstorms over southeast Ohio are expected to persist
through the afternoon and spread across the watch area. Locally
damaging winds are possible with the strongest storms.
The severe thunderstorm watch area is approximately along and 45
statute miles north and south of a line from 60 miles west northwest
of Huntington WV to 10 miles south of Elkins WV. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU4).
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 552...WW 553...
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
29030.
...Hart
WW 553 SEVERE TSTM NY PA 101625Z - 102300Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 553
NWS Storm Prediction Center Norman OK
1225 PM EDT Mon Aug 10 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Southern New York
Eastern Pennsylvania
* Effective this Monday afternoon and evening from 1225 PM until
700 PM EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph likely
Isolated large hail events to 1 inch in diameter possible
SUMMARY...Thunderstorms continue to spread eastward across
Pennsylvania and southern New York. Locally damaging wind gusts
will be the main concern.
The severe thunderstorm watch area is approximately along and 75
statute miles north and south of a line from 40 miles west southwest
of Williamsport PA to 15 miles south southeast of Wilkesbarre PA.
For a complete depiction of the watch see the associated watch
outline update (WOUS64 KWNS WOU3).
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 552...
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
27030.
...Hart
WW 552 SEVERE TSTM OH PA WV LE 101330Z - 101900Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 552
NWS Storm Prediction Center Norman OK
930 AM EDT Mon Aug 10 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Eastern Ohio
Western and Central Pennsylvania
Northern Panhandle of West Virginia
Lake Erie
* Effective this Monday morning and afternoon from 930 AM until
300 PM EDT.
* Primary threats include...
Scattered damaging winds likely with isolated significant gusts
to 75 mph possible
Isolated large hail events to 1.5 inches in diameter possible
SUMMARY...Intense thunderstorms over eastern Ohio will track
eastward across the watch area, posing risks of damaging wind gusts
and hail.
The severe thunderstorm watch area is approximately along and 70
statute miles north and south of a line from 20 miles southwest of
Akron OH to 10 miles east of State College PA. 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.
&&
AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
28030.
...Hart
WW 0556 Status Updates
STATUS FOR WATCH 0556 HAS NOT BEEN ISSUED YET
WW 0555 Status Updates
STATUS REPORT ON WW 555
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 NNE EKN
TO 50 NE EKN TO 25 S AOO.
..WEINMAN..08/10/26
ATTN...WFO...LWX...
STATUS REPORT FOR WS 555
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
DCC001-101940-
DC
. DISTRICT OF COLUMBIA COUNTIES INCLUDED ARE
DISTRICT OF COLUMBIA
MDC001-003-005-009-013-015-017-021-025-027-031-033-043-510-
101940-
MD
. MARYLAND COUNTIES INCLUDED ARE
ALLEGANY ANNE ARUNDEL BALTIMORE
CALVERT CARROLL CECIL
CHARLES FREDERICK HARFORD
HOWARD MONTGOMERY PRINCE GEORGES
WASHINGTON
MARYLAND INDEPENDENT CITIES INCLUDED ARE
BALTIMORE CITY
WW 0554 Status Updates
STATUS REPORT ON WW 554
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
..MEAD..08/10/26
ATTN...WFO...RLX...ILN...PBZ...
STATUS REPORT FOR WS 554
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
KYC019-043-089-127-135-101840-
KY
. KENTUCKY COUNTIES INCLUDED ARE
BOYD CARTER GREENUP
LAWRENCE LEWIS
OHC001-009-053-071-079-087-105-131-141-145-163-167-101840-
OH
. OHIO COUNTIES INCLUDED ARE
ADAMS ATHENS GALLIA
HIGHLAND JACKSON LAWRENCE
MEIGS PIKE ROSS
SCIOTO VINTON WASHINGTON
WVC001-005-007-011-013-015-017-019-021-033-035-039-041-043-053-
067-073-075-079-083-085-087-091-093-095-097-099-101-105-107-
101840-
WV
. WEST VIRGINIA COUNTIES INCLUDED ARE
WW 0553 Status Updates
STATUS REPORT ON WW 553
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1897
..MEAD..08/10/26
ATTN...WFO...BGM...CTP...
STATUS REPORT FOR WS 553
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
NYC007-015-097-101-107-109-101840-
NY
. NEW YORK COUNTIES INCLUDED ARE
BROOME CHEMUNG SCHUYLER
STEUBEN TIOGA TOMPKINS
PAC001-015-037-041-043-055-067-069-071-075-079-093-097-099-107-
109-115-119-127-131-133-101840-
PA
. PENNSYLVANIA COUNTIES INCLUDED ARE
ADAMS BRADFORD COLUMBIA
CUMBERLAND DAUPHIN FRANKLIN
JUNIATA LACKAWANNA LANCASTER
LEBANON LUZERNE MONTOUR
NORTHUMBERLAND PERRY SCHUYLKILL
SNYDER SUSQUEHANNA UNION
WAYNE WYOMING YORK
WW 0552 Status Updates
STATUS REPORT ON WW 552
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 ENE MGW
TO 35 SSE DUJ TO 40 SE BFD TO 35 E BFD.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1897
..MEAD..08/10/26
ATTN...WFO...CLE...PBZ...CTP...
STATUS REPORT FOR WS 552
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
PAC009-013-021-027-035-057-061-081-087-105-111-113-117-101840-
PA
. PENNSYLVANIA COUNTIES INCLUDED ARE
BEDFORD BLAIR CAMBRIA
CENTRE CLINTON FULTON
HUNTINGDON LYCOMING MIFFLIN
POTTER SOMERSET SULLIVAN
TIOGA
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 1899 CONCERNING SEVERE THUNDERSTORM WATCH 554... FOR PORTIONS OF WESTERN OHIO
Mesoscale Discussion 1899
NWS Storm Prediction Center Norman OK
0129 PM CDT Mon Aug 10 2026
Areas affected...Portions of western Ohio
Concerning...Severe Thunderstorm Watch 554...
Valid 101829Z - 102000Z
The severe weather threat for Severe Thunderstorm Watch 554
continues.
SUMMARY...The risk of severe storms may be increasing in parts of
western Ohio, and an extension of Severe Thunderstorm Watch #554 may
be warranted.
DISCUSSION...The latest visible satellite imagery shows deepening
boundary-layer cumulus evolving in the vicinity of a N/S-oriented
outflow boundary along the western flank of earlier convection that
moved through central OH. Here, steep midlevel lapse rates atop a
warm/moist PBL are contributing to a strongly unstable air mass.
This, combined with around 30-40 kt of effective shear, may support
intensification of thunderstorms along this corridor over the next
few hours. There may be some tendency for storms to track eastward
into the stabilized air mass, though any sustained storms that track
southeastward along the boundary will be capable of producing
damaging wind gusts and severe hail. An extension of Severe
Thunderstorm Watch #554 may be warranted in parts of western OH to
cover this risk.
..Weinman.. 08/10/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...RLX...ILN...IWX...
LAT...LON 38588358 39108406 39798434 40418446 40668431 40728406
40678379 40518355 40228333 39828320 39248291 38798272
38488311 38588358
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 1898 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR FAR EAST-CENTRAL IA AND NORTHERN IL
Mesoscale Discussion 1898
NWS Storm Prediction Center Norman OK
1247 PM CDT Mon Aug 10 2026
Areas affected...Far east-central IA and northern IL
Concerning...Severe potential...Watch possible
Valid 101747Z - 102015Z
Probability of Watch Issuance...40 percent
SUMMARY...Portions of far east-central Iowa into northern Illinois
are being monitored for some increase in severe-thunderstorm
potential this afternoon. If sustained storms can evolve, severe
wind gusts and large hail will both be possible.
DISCUSSION...The latest surface analysis and visible satellite
imagery indicate a W/E-oriented stationary boundary extending from
east-central IA across northern IL. The earlier 12Z ILX sounding
sampled robust capping at the base of the EML, though temperatures
are warming into the lower/middle 80s amid upper 70s dewpoints, and
continued heating should further erode inhibition. Steep midlevel
lapse rates accompanying the EML atop the rich PBL moisture is
yielding strong to locally extreme surface-based buoyancy along the
boundary. Isolated thunderstorms are evolving along the boundary in
far east-central IA, where surface convergence is maximized. While
remaining inhibition and generally weak large-scale forcing for
ascent cast uncertainty on the longevity of this activity and the
development of additional storms this afternoon, the aforementioned
buoyancy and around 30-40 kt of effective shear will conditionally
support organized storms including supercells.
Any sustained storms will pose a risk of large hail and severe wind
gusts. Currently, confidence in sustained storms is highest over
eastern IA and vicinity, where some influence of large-scale forcing
for ascent preceding an approaching midlevel wave is evident. The
need for a watch is uncertain, though convective and environmental
trends are being monitored.
..Weinman/Hart.. 08/10/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LOT...ILX...DVN...
LAT...LON 41148980 41199035 41359106 41569136 41939136 42289095
42419004 42388864 42238813 41778774 41178801 41118859
41148980
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
MD 1897 CONCERNING SEVERE THUNDERSTORM WATCH 552...553... FOR SOUTH-CENTRAL NEW YORK INTO PORTIONS OF CENTRAL AND EASTERN PENNSYLVANIA
Mesoscale Discussion 1897
NWS Storm Prediction Center Norman OK
1238 PM CDT Mon Aug 10 2026
Areas affected...south-central New York into portions of central and
eastern Pennsylvania
Concerning...Severe Thunderstorm Watch 552...553...
Valid 101738Z - 101945Z
The severe weather threat for Severe Thunderstorm Watch 552, 553
continues.
SUMMARY...The threat for mainly damaging winds is expected to
increase from central into eastern Pennsylvania and locations
farther east. An additional downstream watch will likely be
required.
DISCUSSION...A transition from a line into more cellular convection
has occurred over the past 1-2 hours from the vicinity of an MCV
over north-central PA into central PA. Storm mode and poor low-level
lapse rates have limited damaging wind potential thus far with the
cellular convection. With time, coalescing storm-scale cold pools,
40 kt of westerly deep-layer shear, and continued heating/
destabilization of the inflow air mass should support increasing
damaging wind potential from central into eastern PA, and eventually
NJ and the lower Hudson Valley. As such, a downstream severe
thunderstorm watch will likely be required.
..Mead/Hart.. 08/10/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...OKX...ALY...PHI...BGM...CTP...
LAT...LON 40227896 40827812 41417794 41947767 42317747 42437681
42257593 41537363 40957343 39857422 39777597 39747716
39757827 39767896 39837912 40227896
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
MD 1896 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR THE MARYLAND AND WEST VIRGINIA PANHANDLES INTO THE DELMARVA
Mesoscale Discussion 1896
NWS Storm Prediction Center Norman OK
1159 AM CDT Mon Aug 10 2026
Areas affected...the Maryland and West Virginia Panhandles into the
Delmarva
Concerning...Severe potential...Watch likely
Valid 101659Z - 101900Z
Probability of Watch Issuance...80 percent
SUMMARY...The threat for locally damaging winds is expected to
increase this afternoon, likely requiring a severe thunderstorm
watch issuance.
DISCUSSION...Daytime heating combined with boundary-layer dewpoints
in the upper 60s to lower 70s has contributed to a moderately
unstable air mass as of early afternoon with steepening low-level
lapse rates and MLCAPE of 1500-2500 J/kg. Upstream convection over
southwest PA is gradually developing a tighter leading-edge
reflectivity gradient and more robust trailing stratiform region,
suggestive of an organizing cold pool.
Current thinking is that the evolving convective system will further
intensify as it continues east-southeast and encounters an
increasingly unstable environment across the discussion area. The
current KPBZ VWP is sampling strengthening west-northwest flow above
2 km AGL, which will likely aid in further cold pool organization.
These factors will lead to an increasing threat for damaging wind
gusts across the area this afternoon, likely requiring the issuance
of a severe thunderstorm watch.
..Mead/Hart.. 08/10/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PHI...AKQ...LWX...
LAT...LON 39117919 39457922 39687831 39607644 39657577 39167542
38627575 38367675 38547793 38717879 38877919 39117919
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1100 AM CDT Mon Aug 10 2026
Valid 101630Z - 111200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
ILLINOIS TO THE MID-ATLANTIC COAST...OVER PARTS OF THE NORTHERN AND
CENTRAL PLAINS...AND OVER SOUTHERN ARIZONA...
...SUMMARY...
Thunderstorms with severe wind gusts will be possible this afternoon
and evening from northern Illinois eastward into Pennsylvania.
Severe gusts and hail will also be possible from parts of the
central and northern Plains into the Midwest, with scattered severe
storms over southern Arizona.
...PA/NY/NJ...
Multiple clusters and lines of thunderstorms are ongoing this
morning from western PA. So far, this activity has produced limited
severe wind gusts due to weak low-level lapse rates. However,
continued heating over central/eastern PA will eventually allow the
storms to be more efficient wind-producers with locally damaging
gusts expected. See MD #1894 for further details.
...OH/WV...
A secondary cluster of storms over central OH is tracking
southeastward in a moderately sheared environment. Rapid heating is
occurring to the southwest of this cluster, which should result in
intensification by mid afternoon. Storms will likely spread into
northern WV with a risk of damaging wind gusts and perhaps hail.
...SD/MN/IA...
A large reservoir of unstable air will reside across much of SD
today, with MLCAPE values over 3000 J/kg, steep lapse rates, and
dewpoints in the upper 60s. A capping inversion should preclude
sustained convection until after 00z when strengthening southerly
low-level flow and warm advection will aid initiation. Supercells
capable of large hail and damaging winds are expected, with eventual
upscale organization into a bowing MCS possible through the
evening/night.
...CO/KS...
Most model guidance shows the likelihood of scattered high-based
thunderstorm development late this afternoon over northeast CO,
spreading into northwest KS and southwest NE this evening. Cloud
cover is somewhat limiting heating, but sufficient CAPE and winds
aloft may promote a period of damaging wind potential later today.
...AZ...
Another round of evening thunderstorms is expected to initiate off
the higher terrain of east-central AZ and spread westward toward the
TUS/PHX metro areas. Parameters remain conditionally favorable for
damaging winds in any sustained/organized clusters of storms that
may develop.
..Hart/Weinman.. 08/10/2026
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1231 PM CDT Mon Aug 10 2026
Valid 111200Z - 121200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM FAR
EASTERN IOWA AND NORTHERN ILLINOIS INTO INDIANA AND SOUTHWEST
OHIO...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN IOWA
TO THE CENTRAL APPALACHIANS...AND OVER THE DAKOTAS...
...SUMMARY...
Severe thunderstorms with damaging wind gusts will be possible
Tuesday from the eastern Iowa/northern Illinois vicinity into parts
of the Ohio Valley and central Appalachians. Areas of severe wind
gusts and hail will also be possible from parts of the northern
Plains.
...From eastern IA into IL...IN...OH...Northern KY...WV...
Moderate northwest flow aloft will persist over the region on
Tuesday, while a large area of moisture and instability remain in
place. Several rounds of thunderstorms will be possible throughout
the region, with some uncertainty regarding timing and placement.
However, the corridor of highest wind damage probability appears to
be tied to early day storms which will be moving across IA. Several
models suggest an organized MCS early on Tuesday, which would then
proceed east/southeast during the day. This scenario seems plausible
as instability will be strong with MUCAPE over 3000 J/kg, steep
midlevel lapse rates, and moderate deep-layer mean wind speeds. A
few significant wind gusts over 75 mph may occur, depending on MCS
organization. Additional late day cells may redevelop along any
trailing outflow, affecting areas from northern KY into WV and
western VA with damaging gusts potential.
...Dakotas into MN and IA...
A surface trough will develop during the afternoon as strong heating
occurs, beneath moderate northwest flow aloft. Storms are expected
to form after 21Z from the Black Hills into western ND, proceeding
east/southeast into the central Dakotas and northern NE through the
evening. Deep-layer shear around 40 kt and substantial instability
will favor cells capable of large hail.
There is significant uncertainly in whether storms will aggregate
into an MCS, which could potentially spread into more of southern MN
and IA Wednesday morning. If this occurs, damaging winds would be
possible.
..Jewell.. 08/10/2026
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1129 AM CDT Mon Aug 10 2026
Valid 101700Z - 111200Z
The ongoing forecast remains on track for elevated fire weather
conditions across the California Central Valley and portions of the
Intermountain West, and isolated dry thunderstorms in the Great
Basin, northwestern Colorado, and the Wyoming higher terrain.
Surface observations depict more improved overnight recoveries
occurred across southern Utah and eastern Nevada, resulting from
surging monsoonal moisture and greater coverage of observed 0.1-0.4"
rainfall in the last 24 hours. Farther north/east, a mix of dry
thunderstorms remain likely where a dry boundary layer will favor
evaporation and less precipitation efficiency. Wildfires and any new
starts may be exacerbated by meteorological conditions, especially
in areas where breezy winds/low RH and the isolated dry thunderstorm
risk overlap. Deep pyroconvection is also possible on active large
wildfires due to the favorable dry thunderstorm environment, as
shown by the Rocky Canyon fire producing a pyroCb yesterday
afternoon. Please see the previous discussion for more information.
..Elizalde-Garcia.. 08/10/2026
.PREV DISCUSSION... /ISSUED 0134 AM CDT Mon Aug 10 2026/
...Synopsis...
Fire weather concerns will persist today across parts of the western
CONUS. Early morning water-vapor imagery continues to depict a broad
upper ridge over the Southwest, and this feature is expected to
remain in place through at least the next 48 hours. As a result,
low-level mass responses will be muted with generally weak gradient
winds for most locations west of the Rockies. Nonetheless, some
areas will still experience terrain-driven wind speeds reaching or
exceeding Elevated thresholds with a very dry air mass.
Additionally, monsoonal moisture continues to spread northward
through the Great Basin and Four Corners region, and will support
another day of isolated dry thunderstorms.
...Great Basin...
Breezy conditions (sustained winds around 15 mph) with RH minimums
in the teens and low 20s are expected across a broad swath of the
northern Great Basin again today, largely heating and deep mixing of
a dry low-level air mass in place across the region. A few regions
will likely see more prolonged and somewhat widespread elevated
conditions with sustained winds closer to 20 mph where topographic
influences will locally augment low-level flow (namely in the lee of
the northern Sierra Nevada in northwest NV and through the Snake
River Valley in eastern ID). Fuels across the broader region remain
receptive to fire starts (as evident by scattered new starts over
the past 24 hours), and will support another day of fire weather
concerns.
...California Central Valley...
An onshore flow regime will persist for today along the CA coast,
which should favor downslope flow into western portions of the
Central Valley. Dry conditions should prevail again today with
afternoon RH values in the teens to low 20s. Elevated fire weather
conditions are possible where breezy downslope winds can overlap
with dry conditions.
...Southern High Plains...
Modest lee troughing will remain in place along the High Plains for
today, which will maintain south to southwesterly low-level winds
across the OK/TX Panhandles and adjacent portions of southwest KS
and northwest OK. Based on recent ensemble guidance and observed
winds yesterday (which featured a similar synoptic regime),
sustained winds between 15-20 mph are likely with gusts up to 30-40
mph possible. Additionally, forecast high temperatures are expected
to once again exceed 100 F with afternoon RH values in the teens to
low 20s. These hot, dry, and windy conditions should support a swath
of elevated to locally critical fire weather conditions.
...Dry Thunderstorms...
00 UTC RAOBs from across the Great Basin and Four Corners region
sampled very steep mid-level lapse rates within a plume of rich
monsoonal moisture. PWAT values of 0.8 to 1.0 inch were noted across
much of the region and will promote a mix of wet and dry
thunderstorms for most of AZ, UT, and NV. However, drier conditions
are noted on the northern fringe of the moisture plume and should
support a higher probability for predominantly dry thunderstorms
this afternoon and evening - mainly across northern NV into portions
of ID and WY. Given a receptive fuel landscape already in place,
lightning ignitions will be a concern.
...Please see www.spc.noaa.gov/fire for graphic product...
| 
