RSS Mesoscale Discussions from Storm Prediction Center
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
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WW 0474 Status Updates
STATUS REPORT ON WW 474
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
..WENDT..07/09/26
ATTN...WFO...LWX...PHI...AKQ...
STATUS REPORT FOR WS 474
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
DEC001-003-005-092140-
DE
. DELAWARE COUNTIES INCLUDED ARE
KENT NEW CASTLE SUSSEX
DCC001-092140-
DC
. DISTRICT OF COLUMBIA COUNTIES INCLUDED ARE
DISTRICT OF COLUMBIA
MDC003-005-009-011-013-015-017-019-021-025-027-029-031-033-035-
037-039-041-043-045-047-510-092140-
MD
. MARYLAND COUNTIES INCLUDED ARE
ANNE ARUNDEL BALTIMORE CALVERT
CAROLINE CARROLL CECIL
CHARLES DORCHESTER FREDERICK
HARFORD HOWARD KENT
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MD 1561 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF WESTERN SOUTH DAKOTA INTO CENTRAL/NORTHEASTERN NORTH DAKOTA
Mesoscale Discussion 1561
NWS Storm Prediction Center Norman OK
0358 PM CDT Thu Jul 09 2026
Areas affected...portions of western South Dakota into
central/northeastern North Dakota
Concerning...Severe potential...Watch possible
Valid 092058Z - 092300Z
Probability of Watch Issuance...40 percent
SUMMARY...Isolated to widely scattered thunderstorms will bring a
risk for large hail and damaging/severe wind gusts through this
evening.
DISCUSSION...Latest observations depict ongoing thunderstorms in
close proximity to a convectively augmented shortwave trough noted
over far southern Manitoba with developing, agitated cumulus also
noted farther southwest over northwestern South Dakota. Aided by
ascent ahead of this shortwave and weak convergence along a surface
pre-frontal trough/weak wind shift, expectation is for ongoing
thunderstorm activity to persist southeastward into North Dakota and
for additional isolated to widely scattered thunderstorms to develop
southwestward into western South Dakota. Moderate to strong buoyancy
(up to 2500-3000 J/kg MLCAPE noted via latest mesoanalysis) and
effective shear of 30-40 kts (as sampled by the 18z BIS observed
sounding) will support supercells and a risk for large hail
(including perhaps an isolated instance to around 2" in diameter)
and damaging/severe wind gusts. Uncertainty remains regarding
eventual thunderstorm and severe coverage, but a Severe Thunderstorm
Watch may be needed for a portion of the discussion area to cover
these threats should a corridor of greater severe potential become
evident, such as across portions of central/eastern North Dakota
where effective shear is modestly greater and where latest guidance
suggests convective coverage may be greater.
..Chalmers/Thompson.. 07/09/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FGF...ABR...BIS...UNR...
LAT...LON 44300060 43880080 43300099 43150108 43080123 43050180
43070271 43210331 43410363 43760396 44230404 45070381
45750329 46980165 47980060 49029970 49199950 49209808
49199769 49049754 48479753 47879764 47419786 45759966
44300060
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
Read more
MD 1560 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR SOUTHEAST KANSAS INTO SOUTH-CENTRAL MISSOURI AND NORTHERN ARKANSAS
Mesoscale Discussion 1560
NWS Storm Prediction Center Norman OK
0353 PM CDT Thu Jul 09 2026
Areas affected...Southeast Kansas into south-central Missouri and
northern Arkansas
Concerning...Severe potential...Watch possible
Valid 092053Z - 092300Z
Probability of Watch Issuance...60 percent
SUMMARY...A watch is possible late this afternoon as storms form
along an outflow/differential heating boundary. Shear is sufficient
for marginal supercells capable of all hazards.
DISCUSSION...Airmass recovery continues in the wake of an MCV that
moved through Missouri earlier today. Temperatures to the southwest
of the outflow/differential heating boundary have risen in the upper
80s to low 90s F. Warm advection within this zone as well as near a
weak surface low in southeast Kansas will eventually initiate a few
thunderstorms. CAM guidance has generally suggested this will occur
by 5 PM CDT or thereabouts. Enhanced shear from the MCV (30-35 kt
effective shear) will promote marginal supercell structures. The
primary hazards will be isolated large hail and damaging winds.
Low-level flow is strong enough (see the KSGF VAD) to support
rotating storms. Should supercells maintain intensity, a risk for a
tornado could develop near the surface boundary.
..Wendt/Thompson.. 07/09/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PAH...LZK...SGF...EAX...TOP...ICT...
LAT...LON 35929168 36789335 37309414 38079561 38119567 38319563
38519485 38449350 37409164 36299095 35919162 35929168
MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
Read more
MD 1559 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF SOUTHEASTERN ARIZONA INTO SOUTHWESTERN NEW MEXICO
Mesoscale Discussion 1559
NWS Storm Prediction Center Norman OK
0345 PM CDT Thu Jul 09 2026
Areas affected...portions of southeastern Arizona into southwestern
New Mexico
Concerning...Severe potential...Watch unlikely
Valid 092045Z - 092245Z
Probability of Watch Issuance...5 percent
SUMMARY...Thunderstorms developing along the White Mountains will
progress southwestward through this evening with a threat for
isolated damaging wind gusts.
DISCUSSION...Latest visible satellite imagery depicts ongoing
thunderstorm development across the White Mountains of southeastern
Arizona and southwestern New Mexico amid a plume of enhanced
mid-level moisture along the eastern periphery of upper-level
ridging. Expectation is for these storms to gradually evolve
south-southwestward off of the high terrain through this evening. As
this evolution occurs, weak buoyancy (200-500 J/kg MLCAPE) based
atop a deep, well-mixed boundary layer (LCLs of 3.0-3.5 km AGL) will
support a risk for isolated damaging wind gusts. Weak effective
shear (less than 20 kts) and deep-layer flow (less than 15-20 kts
sampled by the EMX VWP) will largely limit storm organization and
preclude a more widespread severe risk. Thus, watch issuance is not
expected.
..Chalmers/Thompson.. 07/09/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...ABQ...EPZ...TWC...FGZ...PSR...
LAT...LON 31180890 31190823 31320813 32010813 32590816 32910825
33230844 33430872 33590908 33650923 33660951 33500999
33231056 32651117 31851179 31521201 31441197 31191111
31151093 31180890
MOST PROBABLE PEAK WIND GUST...55-70 MPH
Read more
MD 1558 CONCERNING SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY FOR PORTIONS OF THE CENTRAL HIGH PLAINS
Mesoscale Discussion 1558
NWS Storm Prediction Center Norman OK
0239 PM CDT Thu Jul 09 2026
Areas affected...portions of the central High Plains
Concerning...Severe potential...Severe Thunderstorm Watch likely
Valid 091939Z - 092145Z
Probability of Watch Issuance...80 percent
SUMMARY...Developing thunderstorms will evolve eastward off of the
high-terrain of southeastern Wyoming and central Colorado this
afternoon and evening, bringing a risk for damaging/severe wind
gusts and large hail.
DISCUSSION...Aided by forcing for ascent ahead of a subtle mid-level
perturbation and southeasterly upslope flow, ongoing thunderstorm
development across the central Rockies and Laramie Range is expected
to increase in coverage through the afternoon, with deep-layer
westerly flow aloft yielding an eastward progression of developing
convection. Steepening low-level lapse rates and dry, well-mixed
boundary layer profiles will favor efficient evaporative cooling and
an amalgamation of cold pools, with gradual upscale growth into one
or more linear clusters/segments and an increase in the threat for
damaging/severe wind gusts expected into this evening. Given the
presence of a surface moisture gradient (dewpoints in the 40s to low
50s F near the Foothills increasing into the low-to-mid 60s in
western Kansas/Nebraska) and only modest effective shear of 25-30
kts, storm organization/intensification may occur relatively slowly
as storms progress eastward. Thus, while one or more Severe
Thunderstorm Watches will likely be needed later this
afternoon/evening, the timing of watch issuance remains uncertain
pending the increase in storm organization and the attendant severe
risk.
..Chalmers/Hart.. 07/09/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LBF...DDC...GLD...PUB...BOU...CYS...
LAT...LON 39180410 40700425 42160414 42730402 42910373 42930311
42750250 42290224 41400200 39880187 38730188 37970200
37450216 37210240 37140266 37260304 38080374 39180410
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
Read more
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0300 PM CDT Thu Jul 09 2026
Valid 092000Z - 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.
...20Z Update...
The forecast remains on track, and only minor changes were made with
this update. Most noteworthy, the MRGL/SLGT risks in the Mid-South
were expanded slightly southward. A gradually strengthening
low-level jet should support the maintenance of ongoing thunderstorm
clusters and potentially new development into this evening/tonight.
Given strong buoyancy and increasing low-level flow, damaging winds
will be possible.
..Weinman.. 07/09/2026
.PREV DISCUSSION... /ISSUED 1116 AM CDT Thu Jul 09 2026/
...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.
Read more
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
Read more
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0227 PM CDT Thu Jul 09 2026
Valid 111200Z - 121200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE
SOUTHERN HIGH PLAINS THROUGH THE TENNESSEE VALLEY TO THE
MID-ATLANTIC AND CAROLINAS...
...SUMMARY...
Strong to severe storms capable of sporadic occurrences of damaging
wind and large hail are possible from the southern High Plains
through the Tennessee Valley to the Mid-Atlantic and Carolinas
Saturday afternoon and evening. Isolated severe storms are also
possible in southern Arizona.
...Synopsis...
A mid/upper-level high is forecast to strengthen while shifting from
the lower CO Valley and Four Corners into the central Rockies. A
belt of strong mid-level winds will develop across the Pacific
Northwest into northern Rockies, between the high and an upper low
along the British Columbia coast. Downstream from those
developments, a shortwave trough is forecast to move through New
England and the Mid-Atlantic with a mid-level wind shift/shear axis
stretching from the central Plains into the TN Valley.
At the surface, a front is expected to move through the Mid-Atlantic
with the trailing extension of the boundary stretching through the
Mid South/TN Valley into the southern High Plains.
...Central and Southern Plains...
Widely scattered thunderstorm development is expected by afternoon
along the surface front from southern KS and OK into the OK and TX
Panhandles. The steepest mid-level lapse rates will remain confined
to the High Plains with increasing boundary-layer moisture content
with eastward extent, both of which are expected to yield a
moderately unstable environment. The 12Z models indicate a channel
of stronger mid-level winds within the eastern periphery of the
upper high across the High Plains, which may enhance vertical shear
across that segment of the frontal zone. As such, the potential for
some storm organization appears to exist with an attendant risk for
large hail and severe wind gusts.
...Ozark Plateau to Tennessee Valley...
The potential for early-day storms introduces forecast uncertainty
due to the possibility for lingering clouds and precipitation to
limit the destabilization process in some areas. Where stronger
heating can occur, the presence of a moist boundary layer will
contribute to moderate to strong instability by the peak of the
diurnal heating cycle. The synoptic front and residual outflow
boundaries will likely focus the most intense storms with the
mid-level shear axis potentially enhancing background forcing for
ascent. Generally weak vertical shear will limit the potential for
storm organization with the primary hazard being damaging wind
gusts.
...Southern Mid-Atlantic into the Carolinas...
The glancing influence of the shortwave trough moving through the
Northeast will combine with convergence along the front and
preceding lee trough to foster scattered afternoon storms. The
strongest vertical shear is expected to remain to the north of the
area; however, the presence of a moist and moderately unstable air
mass will be supportive of a few strong storms capable of damaging
downburst winds.
...Southern Arizona...
Some enhancement of mid-level winds is forecast south of the upper
high, yielding a corridor of stronger deep-layer shear, which will
coincide with a moist and moderately unstable air mass. That
environment will be supportive of a few strong to briefly severe
storms with a risk for locally damaging wind gusts.
..Mead.. 07/09/2026
Read more
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...
Read more
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