RSS Mesoscale Discussions from Storm Prediction Center
WW 517 SEVERE TSTM TN 270110Z - 270600Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 517
NWS Storm Prediction Center Norman OK
810 PM CDT Sun Jul 26 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Western and Middle Tennessee
* Effective this Sunday night and Monday morning from 810 PM
until 100 AM CDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph likely
SUMMARY...A linear cluster of severe thunderstorms will move
southward into the Watch this evening. The primary hazard will be
severe gusts (60 to 70 mph) capable of wind damage with the stronger
downbursts.
The severe thunderstorm watch area is approximately along and 50
statute miles east and west of a line from 5 miles northwest of Fort
Campbell KY to 110 miles south of Clarksville TN. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU7).
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 516...
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
36035.
...Smith
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WW 516 SEVERE TSTM IL IN KY 262210Z - 270500Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 516
NWS Storm Prediction Center Norman OK
510 PM CDT Sun Jul 26 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Southern Illinois
Southwest Indiana
Western into Central Kentucky
* Effective this Sunday afternoon from 510 PM until Midnight CDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph likely
Isolated very large hail events to 2 inches in diameter possible
A tornado or two possible
SUMMARY...Widely scattered thunderstorms are forecast to continue to
develop and intensify through the early and mid evening. A couple
of the stronger storms will probably acquire supercell structure and
pose a risk for large hail, damaging gusts, and perhaps a tornado
through the early evening. As additional storms develop and outflow
becomes more prevalent, strong to severe gusts (55 to 70 mph)
capable of wind damage will become the primary severe hazard towards
the mid to late evening.
The severe thunderstorm watch area is approximately along and 60
statute miles east and west of a line from 50 miles northeast of
Salem IL to 30 miles southwest of Bowling Green KY. 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.
&&
AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 550. Mean storm motion vector
33025.
...Smith
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WW 0517 Status Updates
STATUS FOR WATCH 0517 HAS NOT BEEN ISSUED YET
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WW 0516 Status Updates
STATUS REPORT ON WW 516
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 ENE MDH
TO 35 WSW EVV TO 25 WSW OWB TO 5 S OWB TO 45 W SDF TO 35 W SDF.
..SQUITIERI..07/27/26
ATTN...WFO...ILX...PAH...LSX...IND...LMK...
STATUS REPORT FOR WS 516
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
ILC059-069-087-127-151-165-199-270140-
IL
. ILLINOIS COUNTIES INCLUDED ARE
GALLATIN HARDIN JOHNSON
MASSAC POPE SALINE
WILLIAMSON
KYC003-009-027-031-033-035-047-055-059-061-083-085-091-107-139-
141-143-145-149-157-171-177-183-213-219-221-225-227-233-
270140-
KY
. KENTUCKY COUNTIES INCLUDED ARE
ALLEN BARREN BRECKINRIDGE
BUTLER CALDWELL CALLOWAY
CHRISTIAN CRITTENDEN DAVIESS
EDMONSON GRAVES GRAYSON
HANCOCK HOPKINS LIVINGSTON
LOGAN LYON MCCRACKEN
MCLEAN MARSHALL MONROE
MUHLENBERG OHIO SIMPSON
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No Mesoscale Discussions are in effect as of Mon Jul 27 03:00:11 UTC 2026.
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0802 PM CDT Sun Jul 26 2026
Valid 270100Z - 271200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE
UPPER MIDWEST AND WESTERN GREAT LAKES...
...SUMMARY...
Severe thunderstorms capable of large to very large hail, damaging
winds (possibly 75+ mph), and tornado risk remain likely from the
upper Mississippi Valley and Great Lakes southwestward into
Nebraska, mainly late this evening and tonight.
...Upper Midwest...
A very unstable environment remains in place across the region, with
the MPX, GRB, and DVN 00Z soundings sampling MLCAPE from 3100, 2900,
and 2800 J/kg, respectively. Surface observations show mid to upper
70s dewpoints on the warm side of the warm front extending from
north-central MN through northeast WI/far western Upper MI. A
thunderstorm has matured upstream of this corridor, with the
expectation it will remain strong to severe as it continues
southeastward. Modest low-level warm advection into this boundary
will also contribute to additional thunderstorms this evening and
overnight. Environmental conditions are still expected to support
large to very large hail early in the convective cycle while a more
cellular mode is likely. Thereafter, a trend towards bowing segments
capable of severe wind gusts is anticipated. A singular MCS could
eventually develop, with severe gusts possible as it moves southward
as well. Some gusts, both within the line segments and early in the
MCS lifecycle, could be significant (i.e. over 75 mph).
...TN Valley...
A cold-pool-driven MCS continues to propagate south-southeast at
approximately 40 kts. The downstream airmass is very moist, with
numerous sites reporting dewpoints in the low 80s. This moisture is
contributing to extreme buoyancy, with the recent 00Z BNA sounding
sampling 4500 J/kg of SBCAPE. This MCS is also oriented
perpendicular to the deep-layer vertical shear. All of these factors
will contribute to continued southward progression, with an
attendant risk for strong gusts likely extending into Middle TN this
evening.
...South-Central into Southeast SD into central NE...
Numerous attempts at deep convection along the weak surface trough
extending from south-central SD through central NE have failed thus
far. The window of opportunity for deep convection will likely
remain open for the next hour or two before building inhibition
associated with nocturnal cooling precludes mature convection. Until
that occurs, there remains a conditional risk for severe
thunderstorms capable of strong downdrafts and isolated large hail.
...Elsewhere...
Increasing thunderstorm coverage is possible across the Mid-Atlantic
over the next few hours as a shortwave trough progresses
southeastward across the region. Moderate vertical shear could
support updraft organization with deeper, more persistent
convection. Isolated damaging gusts and hail are possible with the
more organized storms. Isolated damaging gusts remain possible
across northern Wyoming and far southwest South Dakota as high-based
thunderstorms track northeastward across the region this evening.
Jackson Hole Wyoming reported a gust of 50 kt at 2353Z.
..Mosier.. 07/27/2026
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