RSS Mesoscale Discussions from Storm Prediction Center
WW 480 SEVERE TSTM IL IN KY MO 102340Z - 110500Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 480
NWS Storm Prediction Center Norman OK
640 PM CDT Fri Jul 10 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Southern Illinois
Southwest Indiana
Western Kentucky
Southeast Missouri
* Effective this Friday night from 640 PM until Midnight CDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1 inch in diameter possible
SUMMARY...Multiple clusters of storms are expected to spread
eastward across the watch area with the potential for occasional
wind damage (60-70 mph gusts) and isolated large hail (near 1 inch
diameter) into early tonight.
The severe thunderstorm watch area is approximately along and 65
statute miles north and south of a line from 40 miles south of Vichy
MO to 50 miles northeast of Paducah KY. 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 479...
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 550. Mean storm motion vector
28020.
...Thompson
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WW 0480 Status Updates
STATUS REPORT ON WW 480
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1582
..DEAN..07/11/26
ATTN...WFO...PAH...LSX...SGF...
STATUS REPORT FOR WS 480
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
ILC003-047-055-059-065-069-077-081-087-127-133-145-151-153-157-
163-165-181-185-189-191-193-199-110140-
IL
. ILLINOIS COUNTIES INCLUDED ARE
ALEXANDER EDWARDS FRANKLIN
GALLATIN HAMILTON HARDIN
JACKSON JEFFERSON JOHNSON
MASSAC MONROE PERRY
POPE PULASKI RANDOLPH
ST. CLAIR SALINE UNION
WABASH WASHINGTON WAYNE
WHITE WILLIAMSON
INC051-129-163-110140-
IN
. INDIANA COUNTIES INCLUDED ARE
GIBSON POSEY VANDERBURGH
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WW 0479 Status Updates
STATUS REPORT ON WW 479
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 ESE SZL
TO 45 SSW UIN TO 40 SSE UIN.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1582
..DEAN..07/11/26
ATTN...WFO...LSX...EAX...
STATUS REPORT FOR WS 479
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
MOC027-051-135-110140-
MO
. MISSOURI COUNTIES INCLUDED ARE
CALLAWAY COLE MONITEAU
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.
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MD 1582 CONCERNING SEVERE THUNDERSTORM WATCH 479...480... FOR PARTS OF CENTRAL/EASTERN MO INTO SOUTHERN IL AND FAR WESTERN KY
Mesoscale Discussion 1582
NWS Storm Prediction Center Norman OK
0726 PM CDT Fri Jul 10 2026
Areas affected...Parts of central/eastern MO into southern IL and
far western KY
Concerning...Severe Thunderstorm Watch 479...480...
Valid 110026Z - 110200Z
The severe weather threat for Severe Thunderstorm Watch 479, 480
continues.
SUMMARY...Small storm clusters capable of producing wind damage may
continue through the evening.
DISCUSSION...At 0015 UTC, a small but long-lived storm cluster is
moving along I-70 between Columbia and St. Louis. Some wind damage
was reported in the Columbia area, and strong inbound velocities are
currently observed from the KLSX radar. This cluster may continue
propagating along a surface theta-e gradient, with rich moisture
(dewpoints in the 70s F and PW above 2 inches), moderate buoyancy,
and sufficient low-level flow and deep-layer shear supporting a
continued damaging wind threat as this cluster approaches the
Mississippi River.
To the east, another storm cluster across southwest IL may also
continue to propagate along the theta-e/buoyancy gradient, posing a
threat of wind damage into a larger portion of southern IL through
the evening.
Farther south, a measured severe gust was recently observed near
West Plains in south-central MO, near another developing storm
cluster. Deep-layer shear is weaker in this area, but strong
downstream buoyancy may allow for modest upscale growth and a
continued wind damage threat this evening into southeast MO (as
depicted by some recent HRRR runs).
..Dean.. 07/11/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PAH...MEG...LSX...SGF...
LAT...LON 36589224 38869203 39239186 39009000 38398832 37538806
36818845 36568898 36509012 36549165 36589224
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
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SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0758 PM CDT Fri Jul 10 2026
Valid 110100Z - 111200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN AND CENTRAL HIGH PLAINS AND MID MISSISSIPPI VALLEY...
...SUMMARY...
Thunderstorms with severe wind gusts and hail will be possible this
evening across parts of the southern and central High Plains. Storms
with severe wind gusts will also be possible in parts of the mid
Mississippi Valley. A few severe gusts may also occur in parts of
the Ohio Valley and in far southeast Arizona.
...Southern and Central High Plains...
A mid-level shortwave trough is evident on water vapor imagery over
the central Plains. At the surface, upslope flow is present over
much of Kansas, eastern Colorado and southwestern Nebraska.
Low-level convergence is maximized over eastern Colorado to the east
of the higher terrain, where scattered thunderstorms are ongoing.
Surface dewpoints over eastern Colorado are in the 50s F and the RAP
shows moderate instability with very steep low to mid-level lapse
rates. In addition, the WSR-88D VWP at Pueblo has 0-6 km near 45
knots, and veering winds with height in the low to mid-levels. This
environment will continue to support severe storm development this
evening. Supercells and short muticell line segments will be capable
of severe wind gusts and hail. The severe threat will gradually move
eastward into western Kansas, and the Oklahoma/Texas Panhandles
later this evening.
...Mid Mississippi and Ohio Valleys...
A very moist airmass is currently located over the mid Mississippi
Valley, where surface dewpoints range from the mid 70s to mid 80s F.
Along the axis of highest surface dewpoints, the RAP has a pocket of
strong instability over southeast Missouri with MLCAPE in the 3000
to 4000 J/kg range. Low-level convergence is maximized across parts
of eastern Missouri, where thunderstorms are ongoing. The WSR-88D
VWP at St. Louis has 0-6 km shear around 25 knots with
unidirectional west-southwesterly flow. This, along with the
instability and steep low-level lapse rates, could support a
potential for severe wind gusts with the stronger cores this
evening...see MCD 1582.
Further east into parts of the Ohio Valley, surface dewpoints are in
the 70s F. The RAP shows an axis of moderate instability with MLCAPE
in the 1500 to 2000 J/kg range, which is coincident with a zone of
low-level convergence. Near this zone, scattered thunderstorms are
ongoing from north-central Illinois into central Indiana and
southern Ohio. The instability and steep low-level lapse rates may
support a threat for isolated severe gusts over the next couple of
hours.
...Far Southeast Arizona...
Scattered thunderstorms are currently ongoing in far southeast
Arizona along an axis of low-level convergence. Near this axis, the
RAP has SBCAPE near 1000 J/kg with 0-3 km lapse rates exceeding 9
C/km. This environment will support a potential for isolated severe
gusts early this evening.
..Broyles.. 07/11/2026
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SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0512 PM CDT Fri Jul 10 2026
Valid 121200Z - 181200Z
...Synopsis...
Strong upper troughing will persist over the Pacific Northwest
through early next week, meanwhile amplifying ridging and southerly
flow aloft will encourage monsoonal moisture to slowly translate
northward. Ensembles indicate the potential for thunderstorms on
Days 3-5/Sunday-Tuesday across portions of the Intermountain West,
where preceding hot and dry conditions may increase fuel
receptivity. PWATs are forecast to increase quickly while
instability becomes more widespread by Day 5/Tuesday, indicating
deeper moisture could promote areas of heavy rainfall. Initial
thunderstorm development and lightning on the periphery of
appreciable precipitation will present a concern for potential
ignitions where receptive fuels exist. Farther east, warm weekend
temperatures and minimal recent rainfall has led to a dry fuelscape
across parts of the Upper Great Lakes. As ridging flattens over the
northern CONUS late next week, stronger flow aloft may allow broader
fire weather concerns to emerge in the Upper Midwest.
...Days 3-4/Sunday-Monday...
High pressure will expand across the central CONUS this weekend and
early next week, yielding near-record high temperatures and very dry
conditions in Idaho, Montana, Wyoming, and the Dakotas. Beneath
upper-level troughing and strong southwesterly flow, tight surface
pressure gradients will promote gusty winds and critically low RH to
overspread portions of the Northwest, northern Great Basin, and the
northern Plains. While some uncertainty remains regarding fuel
receptivity across the Northern Rockies and adjacent Plains, 40%
Critical probabilities have been expanded on Day 3/Sunday (and
introduced on Day 4/Monday) where guidance depicts dry and breezy
conditions amid forecast ERCs approaching the 80-90th percentile.
...Dry Thunderstorm Potential...
As the ridge strengthens and high pressure centers over the Greater
Four Corners region, the upper pattern will favor the advection of
monsoonal moisture northward where hot and dry antecedent conditions
have led to receptive fuels across portions of the Interior West.
There remains significant forecast uncertainty in where sufficient
instability will support dry thunderstorm development on the fringes
of monsoonal moisture. Some guidance does indicate meager convective
potential on Day 4/Monday along the Sierra Nevada into south-central
Oregon if instability can accommodate, but spread is still too high.
As a result, 10% probabilities for dry thunderstorms have been
withheld for Day 4/Monday and beyond; however, trends will be
monitored in future outlook cycles.
..Elizalde-Garcia.. 07/10/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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