WW 474 SEVERE TSTM DC DE MD NJ VA WV CW 091830Z - 100200Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 474
NWS Storm Prediction Center Norman OK
230 PM EDT Thu Jul 9 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
District Of Columbia
Delaware
Central and Eastern Maryland
Southern New Jersey
Northern Virginia
Eastern Panhandle of West Virginia
Coastal Waters
* Effective this Thursday afternoon and evening from 230 PM until
1000 PM EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
SUMMARY...Thunderstorms will continue to intensify over the watch
area and spread toward the coast this evening. The strongest storms
will pose a risk of damaging wind gusts.
The severe thunderstorm watch area is approximately along and 60
statute miles north and south of a line from 20 miles north
northwest of Staunton VA to 30 miles east southeast of Dover DE. 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.
&&
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
27025.
...Hart
WW 0474 Status Updates
STATUS FOR WATCH 0474 HAS NOT BEEN ISSUED YET
MD 1557 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF WESTERN NEW YORK
Mesoscale Discussion 1557
NWS Storm Prediction Center Norman OK
0215 PM CDT Thu Jul 09 2026
Areas affected...Portions of western New York
Concerning...Severe potential...Watch unlikely
Valid 091915Z - 092115Z
Probability of Watch Issuance...20 percent
SUMMARY...Strong to marginally severe wind gusts are possible along
and near the southern Lake Ontario shoreline. A watch is not
expected given the limited spatial extent of the threat.
DISCUSSION...A organized linear segment is ongoing near Toronto
driven by ascent from a shortwave trough. While the airmass near the
Lake Ontario shore is slightly cooler than surrounding areas, the
organization of the linear segment will likely allow it to propagate
some distance along the shoreline with aid from the lake breeze
boundary. The spatial extent of the threat is not expected to reach
farther inland than a county or two. Strong to marginally severe
wind gusts, particularly along the more exposed lake shore, are
possible.
..Wendt/Hart.. 07/09/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BGM...BUF...
LAT...LON 42877729 42907891 42878019 43677928 43707631 43527607
43167630 42877729
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MD 1556 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF THE BLACK HILLS AND SOUTHWESTERN SOUTH DAKOTA
Mesoscale Discussion 1556
NWS Storm Prediction Center Norman OK
0201 PM CDT Thu Jul 09 2026
Areas affected...portions of the Black Hills and southwestern South
Dakota
Concerning...Severe potential...Watch unlikely
Valid 091901Z - 092030Z
Probability of Watch Issuance...20 percent
SUMMARY...Isolated thunderstorms may move off the Black Hills in
southwestern South Dakota and promote an isolated severe threat this
afternoon. A further increase in strong to severe thunderstorm
potential is expected late this afternoon and into the evening.
DISCUSSION...An isolated thunderstorm has recently developed across
the Black Hills in southwestern South Dakota. While latest objective
analysis suggests that capping remains in place to the east of the
Black Hills, modifying the nearby UNR 18z observed sounding for
current surface observations suggests that inhibition is quickly
eroding amid continued insolation. This may allow isolated
convection to evolve eastward off of the Black Hills this afternoon.
Should this scenario occur, storms would encounter increasing
instability across central South Dakota, with modest effective shear
(25-30 kts), well-mixed boundary layer profiles, and steep mid-level
lapse rates (as sampled by the aforementioned UNR observed sounding)
promoting a risk for isolated damaging/severe wind gusts and large
hail. Given that this risk remains conditional on a storm persisting
eastward off of the Black Hills, watch issuance is uncertain at this
time. An increase in severe potential and convective coverage is
then expected later this evening across portions of western South
Dakota.
..Chalmers/Hart.. 07/09/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...UNR...
LAT...LON 43410276 43380317 43430356 43580388 43830402 44130404
44500399 44700393 44790377 44790318 44750266 44550228
44200203 43840207 43580234 43410276
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
MD 1555 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR PARTS OF CENTRAL CENTRAL/NORTHERN VIRGINIA INTO SOUTHERN MARYLAND
Mesoscale Discussion 1555
NWS Storm Prediction Center Norman OK
0105 PM CDT Thu Jul 09 2026
Areas affected...Parts of central central/northern Virginia into
southern Maryland
Concerning...Severe potential...Watch likely
Valid 091805Z - 092000Z
Probability of Watch Issuance...80 percent
SUMMARY...Damaging wind gusts are possible as convection continues
to intensify and move eastward this afternoon. A watch is likely.
DISCUSSION...Convection along a stationary boundary has shown modest
intensification over the last hour near the MD/PA border. Additional
convection is developing along the Blue Ridge. Sufficiently strong
westerly winds across the Ridge will eventually move convection to
the east. Furthermore, around 30 kt of effective shear will be
present allowing for stronger storm cells and linear structures.
Low-level lapse rates will continue to steepen this afternoon,
though cloud cover has been greater in the vicinity of the
Chesapeake Bay. Given the potential for one or more clusters to
evolve this afternoon, a watch is likely to address the threat for
damaging wind gusts.
..Wendt/Hart.. 07/09/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PHI...AKQ...LWX...RNK...
LAT...LON 37517807 37697831 38537820 39337755 39597685 39657547
39157505 38637508 37837554 37697569 37457634 37537764
37517807
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MD 1554 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR LOWER OHIO VALLEY
Mesoscale Discussion 1554
NWS Storm Prediction Center Norman OK
1242 PM CDT Thu Jul 09 2026
Areas affected...Lower Ohio Valley
Concerning...Severe potential...Watch possible
Valid 091742Z - 091945Z
Probability of Watch Issuance...40 percent
SUMMARY...A risk for damaging winds will evolve from eastward moving
outflow in the lower Ohio Valley. The coverage of strong/severe
storms is not clear, but a watch is possible this afternoon. Trends
will be monitored.
DISCUSSION...Outflow from convection associated with an MCV
northwest of St. Louis is moving eastward into the lower Ohio
Valley. As this boundary moves into an increasingly unstable airmass
with strong heating and mid/upper 70s F dewpoints, some
intensification is possible. The main risk for damaging winds will
likely occur south of the cirrus plume from the MCV. With the MCV
displaced to the northwest, shear/forcing enhancement will be
minimal. The degree of damaging wind threat will be tied to how
organized convection along the outflow boundary becomes. A watch is
possible if convective trends warrant.
..Wendt/Hart.. 07/09/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LMK...OHX...PAH...MEG...
LAT...LON 36408908 36718904 37188902 37788916 38238836 38388777
38178731 37468677 37038649 36508682 36398764 36378829
36408908
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1116 AM CDT Thu Jul 09 2026
Valid 091630Z - 101200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE NORTHERN AND CENTRAL PLAINS...FROM THE LOWER MISSOURI VALLEY
INTO THE LOWER OHIO VALLEY...AND PORTIONS OF THE MID-ATLANTIC INTO
THE SOUTHEAST...
...SUMMARY...
Thunderstorms with severe wind gusts and hail will be possible this
afternoon and evening across parts of the central and northern
Plains. Severe wind gusts may also occur in parts of the Ozarks, mid
Mississippi Valley, lower Ohio Valley, Mid-Atlantic, Southeast, and
Arizona.
...Mid Atlantic...
Hot and humid condition are present once again today over parts of
the Mid Atlantic region, with dewpoints in the mid 70s and
temperatures rising through the 80s. A weak shortwave trough
passing across the central Appalachians will aid in the development
of scattered afternoon thunderstorms over eastern WV/western VA
southern PA, with storms tracking eastward through early evening.
Sufficient westerly flow aloft and moderate CAPE values will result
in scattered damaging winds over this area. Cloud cover in
southeast PA/NY/DE lends some uncertainty to severe threat that far
east, but storms are not expected to arrive in that area for several
hours, allowing time for the clouds to erode somewhat.
...Central High Plains...
Similar to yesterday, scattered high-based thunderstorms will form
over the mountains/foothills of CO/WY and spread eastward through
the afternoon/evening. Forecast soundings suggest parameters
favorable of locally damaging wind gusts with this activity, with an
increasing risk as storms build eastward into greater low-level
moisture. Several 12z CAMS suggest a linear MCS maintaining strong
intensity into the night into western KS, with a continuing risk of
damaging winds.
...ND/SD...
A convectively aided shortwave trough is moving eastward across
ND/southern Manitoba. Thunderstorms are expected to intensify by
late afternoon ahead of this feature from eastern ND into western
SD. Forecast soundings show steep mid-level lapse rates and ample
CAPE, along with favorable deep-layer shear for supercells. Large
hail and damaging winds will be possible.
...MO/IL/KY/IN...
The remnants of an overnight MCS over MO will continue tracking
eastward today into a very moist and moderately unstable air mass
over parts of IL/IN/KY. This feature is weakening with time, but
some mesoscale organization persists with a weak MCV noted over
east-central MO. This may be sufficient to promote re-development
of storms later today. If this occurs, the strongest cells could
pose a damaging wind threat.
Low-level warm advection on the western flank of this system will
result in the development of thunderstorms over western/central MO
by late afternoon or early evening. Forecast soundings in this
corridor show CAPE and shear profiles that would be favorable for
supercell structures capable of damaging winds and perhaps hail. An
isolated tornado cannot be ruled out.
..Hart/Chalmers.. 07/09/2026
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1224 PM CDT Thu Jul 09 2026
Valid 101200Z - 111200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ...
...SUMMARY...
Widely scattered severe thunderstorms capable of large hail and
severe wind gusts appear possible over the central and southern High
Plains and eastern Kansas into Missouri Friday afternoon and
evening. More sporadic occurrences of damaging winds and large hail
are possible from the lower Ohio and Tennessee Valleys into the
Southeast, the Mid-Atlantic, the western Florida Peninsula, and
parts of Minnesota and eastern South Dakota.
...Synopsis...
Considerable amplification of a mid/upper-level ridge is forecast
from the lower CO Valley into central Canada on Friday into Friday
night. To the immediate east of the building heights, the 12Z models
indicate multiple perturbations (some of convective origin)
progressing through the central Plains into the mid MS, lower OH,
and TN Valleys. At the surface, the primary front, the position of
which may be modified by convective outflow, is expected to stretch
from the southern High Plains through the mid MS Valley into the OH
Valley and Mid-Atlantic Friday afternoon.
...Central and Southern High Plains...
Widely scattered thunderstorm development is expected along the CO
Front Range and Raton Mesa, where moist upslope flow will coincide
with an EML to yield moderate instability with MLCAPE of 1000-1500
J/kg. Despite only modest westerly flow in the mid levels, an
easterly low-level wind component will augment deep-layer shear,
allowing for some supercell structures with a risk for isolated
large hail. 12Z CAM guidance is in relatively good agreement in
depicting the upscale growth of the initial storms into a bowing,
linear mode with an associated severe wind risk spreading east into
far southwest KS and the OK and TX Panhandles.
...Eastern KS into the mid MS Valley...
The eastern extension of the EML will overlie a moist boundary layer
with dewpoints in the upper 60s to mid 70s to yield moderate to
strong instability by afternoon with MLCAPE as high as 2500-3500+
J/kg. Convergence along the synoptic front and/or residual outflow
boundaries will be aided by forcing for ascent attendant to a
remnant MCV to support scattered afternoon storms. Some enhancement
of the mid-level wind field is forecast in the vicinity of the
MCV/shortwave trough, which will locally augment vertical shear,
supporting organized storm modes with an attendant risk for large
hail and severe wind gusts.
...Lower Ohio and Tennessee Valleys into the Southeast...
An area of thunderstorms is expected to be ongoing at 12Z Friday
near the confluence of the MS and OH Rivers. That activity may
weaken or dissipate by mid morning over the TN Valley; however, a
remnant MCV may support a reinvigoration of storms by afternoon from
the TN Valley through the southern Appalachians toward Carolina
coast. The presence of a moist and moderately unstable air mass,
featuring steep low-level lapse rates, will support sporadic
damaging wind occurrences, especially with any storm clusters.
...Mid-Atlantic...
Some mid-level flow enhancement is forecast Friday afternoon in
association with a shortwave trough moving through the region. That
feature, coupled with the synoptic front in the area, will support
scattered afternoon storms amidst a moist and at least modestly
unstable environment. Deep-layer shear is forecast to strengthen to
30-35 kt, which may contribute to some storm organization with the
primary hazard being isolated damaging wind gusts.
...Western Florida Peninsula...
A number of the 12Z CAMs suggest some degree of cold pool
organization with afternoon thunderstorms moving west/northwest
through the area. The presence of moderate to strong instability
will aid in the water loading of downdrafts with an associated risk
for locally damaging wind gusts.
...MN and Eastern SD...
Despite building mid-level heights, there is a fairly consistent
model signal for at least isolated thunderstorm development along a
front during the afternoon. The combination of moderate to strong
instability and a vertically veering wind profile with around 30 kt
of deep-layer shear will favor some storm organization with the
potential for a few large hail occurrences.
..Mead.. 07/09/2026
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1132 AM CDT Thu Jul 09 2026
Valid 091700Z - 101200Z
Very minor adjustments were made to the Elevated risk area in
eastern AZ where appreciable rainfall has fallen in the last 24-36
hours. Otherwise, the forecast remains on track, see the previous
discussion for more information.
..Elizalde-Garcia.. 07/09/2026
.PREV DISCUSSION... /ISSUED 1241 AM CDT Thu Jul 09 2026/
...Synopsis...
Another upper low will move into southwest Canada as the upper high
continues near the southern California coast. West-southwest flow
aloft will spread over much of the West, with the strongest
mid-level flow across central/southern California into northern
Arizona. A weak, Pacific cold front will stall out and weaken
further across the northern Great Basin and northern Rockies after
passing through the Inland Northwest.
West-southwest sustained winds of 12-20 mph with gusts of 20-40 mph
amid minimum RH of 5-15% are expected across inland southern
California and stretching across the southern Great Basin into the
Four Corners. The strongest gusts will be along/east the southern
Sierra/vicinity during the late afternoon and evening. Additionally,
elevated conditions are possible on portions of the Snake River
Plain near the weakening Pacific cold front. Given the recent
lightning, active large wildfires, and near to record dry fuels,
holdovers and growth on existing large fires are a concern for
portions of Nevada, Utah, and western Colorado.
Isolated dry thunderstorms are likely from northeast Nevada into
western Colorado. Enough residual mid-level moisture along with a
deep well mixed boundary layer and terrain circulations should
combine to produce isolated to possibly scattered mostly dry
thunderstorms. Deep pyroconvection on active large wildfires
in/around the IsoDryT area remain a concern.
Elevated conditions are possible in portions of the Carolinas and
eastern Georgia as west-southwest sustained winds of 8-15 mph and
minimum RH of 30-40% develop during the afternoon. ERCs are above
the 90th percentile across these areas. However, the potential for
showers and thunderstorms in the afternoon/evening and low
confidence in more than locally elevated conditions developing
precludes an Elevated area at this time.
...Please see www.spc.noaa.gov/fire for graphic product...
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0213 PM CDT Thu Jul 09 2026
Valid 101200Z - 111200Z
...Afternoon Update...
The Elevated risk area was expanded into far south-central WA where
recent guidance depicts an overlap of 10-20% RH and sustained
westerly winds of up to 20 mph. Strong wind gusts of 25-30 mph are
likely in terrain-favored areas along the Cascades and Sierra
Nevada. In addition, locally critical conditions are possible across
northwest NV/northeast CA. As daytime mixing ensues, and a 700 mb
25-35 kt jet emerges aloft, occasional wind gusts of up to 35 mph
may mix down to the surface. The rest of the forecast remains on
track, see the previous discussion for more information.
..Elizalde-Garcia.. 07/09/2026
.PREV DISCUSSION... /ISSUED 1243 AM CDT Thu Jul 09 2026/
...Synopsis...
An upper-level trough will move towards and deepen offshore from the
Pacific Northwest, while the upper high will shift eastward over
southern California. Stronger mid-level winds will begin to
overspread the Northwest with the onshore pressure gradient
strengthening again as a Pacific cold front moves into the
Northwest. Mid-level moisture that has been present across the Great
Basin and Four Corners will continue to push east of the Front Range
and suppressed southward to southern Arizona/New Mexico.
Dry and breezy conditions are expected to develop across much of the
Great Basin into the Four Corners. West-southwest sustained winds of
12-20 mph amid minimum RH of 8-20% are likely to develop from
central/eastern Oregon to the Four Corners. The strongest winds are
likely across the Sierra Front and northwest Nevada into portions of
southeast Oregon and southwest Idaho. While winds will not be as
strong across portions of central/northern Utah into western
Colorado, locally elevated conditions are expected. Locally elevated
conditions may extend into portions of southeast/eastern Idaho as
well.
Isolated high-based showers and thunderstorms are possible across
portions of southeast Idaho, northern Utah, and northwest Colorado.
While building to towering Cu are likely over the higher terrain,
thunderstorm chances are less than 10%, with high-based convective
showers with little to no rainfall reaching the ground more likely.
...Please see www.spc.noaa.gov/fire for graphic product...
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