WW 593 SEVERE TSTM MN 172355Z - 180500Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 593
NWS Storm Prediction Center Norman OK
655 PM CDT Mon Aug 17 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
West-Central Minnesota
* Effective this Monday night from 655 PM until Midnight CDT.
* Primary threats include...
Scattered large hail and isolated very large hail events to 2.5
inches in diameter possible
Scattered damaging wind gusts to 70 mph possible
SUMMARY...Supercells may continue to pose a threat for large to very
large hail up to 1.5-2.5 inches in diameter as they track
east-southeastward this evening. Occasional severe/damaging winds
may also occur if a cluster can eventually form.
The severe thunderstorm watch area is approximately along and 45
statute miles east and west of a line from 45 miles northeast of
Alexandria MN to 60 miles south of Alexandria MN. 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 590...WW 591...WW 592...
AVIATION...A few severe thunderstorms with hail surface and aloft to
2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
30035.
...Gleason
WW 592 SEVERE TSTM NE 172240Z - 180500Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 592
NWS Storm Prediction Center Norman OK
440 PM MDT Mon Aug 17 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Northwest Nebraska and the Nebraska Panhandle
* Effective this Monday afternoon and evening from 440 PM until
1100 PM MDT.
* Primary threats include...
Scattered damaging winds and isolated significant gusts to 75
mph possible
Scattered large hail and isolated very large hail events to 2.5
inches in diameter possible
A tornado or two possible
SUMMARY...Ongoing supercells will continue to pose a threat for
large to very large hail up to 1.5-2.5 inches in diameter as they
move east-southeastward this evening. Severe/damaging winds may also
occur if a cluster develops later this evening.
The severe thunderstorm watch area is approximately along and 45
statute miles north and south of a line from 40 miles north
northwest of Scottsbluff NE to 40 miles east southeast of Ainsworth
NE. 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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 590...WW 591...
AVIATION...A few severe thunderstorms with hail surface and aloft to
2.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
30030.
...Gleason
WW 591 SEVERE TSTM SD 172100Z - 180400Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 591
NWS Storm Prediction Center Norman OK
300 PM MDT Mon Aug 17 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
South Dakota
* Effective this Monday afternoon and evening from 300 PM until
1000 PM MDT.
* Primary threats include...
Scattered damaging winds and isolated significant gusts to 80
mph possible
Scattered large hail and isolated very large hail events to 2.5
inches in diameter possible
A tornado or two possible
SUMMARY...Several corridors of severe storm development are expected
through late afternoon/early evening, including a
southeastward-spread of storms into central South Dakota, with
additional development expected across far eastern Wyoming and the
Black Hills vicinity. Supercells are possible, and one or more
clusters could evolve by evening with heightened damaging wind
potential.
The severe thunderstorm watch area is approximately along and 65
statute miles north and south of a line from 50 miles west southwest
of Rapid City SD to 35 miles south southeast of Aberdeen SD. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU1).
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 590...
AVIATION...A few severe thunderstorms with hail surface and aloft to
2.5 inches. Extreme turbulence and surface wind gusts to 70 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
29025.
...Guyer
WW 590 SEVERE TSTM GA KY NC TN VA WV 171835Z - 180200Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 590
NWS Storm Prediction Center Norman OK
235 PM EDT Mon Aug 17 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Northern Georgia
Southeast Kentucky
Western North Carolina
Middle and Eastern Tennessee
Western Virginia
Far Southern West Virginia
* Effective this Monday afternoon and evening from 235 PM until
1000 PM EDT.
* Primary threats include...
Scattered damaging wind gusts to 65 mph likely
SUMMARY...Intensifying thunderstorm development is expected the
remainder of the afternoon, influenced by a remnant convective
cluster/MCV and its enhanced winds aloft, orographic/mountain
influences, and a very moist environment. Downbursts capable of
damaging winds will be possible, particularly late this afternoon
through early evening.
The severe thunderstorm watch area is approximately along and 95
statute miles east and west of a line from 20 miles northeast of
Dublin VA to 25 miles southeast of Chattanooga TN. 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.
&&
AVIATION...A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 55 knots. A few
cumulonimbi with maximum tops to 550. Mean storm motion vector
30020.
...Guyer
WW 0593 Status Updates
STATUS FOR WATCH 0593 HAS NOT BEEN ISSUED YET
WW 0592 Status Updates
STATUS REPORT ON WW 592
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 SE AIA TO
35 E AIA TO 55 S PHP.
..SQUITIERI..08/18/26
ATTN...WFO...LBF...CYS...
STATUS REPORT FOR WS 592
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
NEC005-009-015-017-031-041-071-075-089-091-101-103-111-113-115-
117-149-171-183-180240-
NE
. NEBRASKA COUNTIES INCLUDED ARE
ARTHUR BLAINE BOYD
BROWN CHERRY CUSTER
GARFIELD GRANT HOLT
HOOKER KEITH KEYA PAHA
LINCOLN LOGAN LOUP
MCPHERSON ROCK THOMAS
WHEELER
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.
WW 0591 Status Updates
STATUS REPORT ON WW 591
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 E CDR TO
55 NE CDR TO 55 ESE 2WX.
..SQUITIERI..08/18/26
ATTN...WFO...UNR...ABR...
STATUS REPORT FOR WS 591
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
SDC007-013-017-021-031-041-045-049-055-059-065-069-071-075-085-
089-095-107-115-117-119-121-123-129-137-180240-
SD
. SOUTH DAKOTA COUNTIES INCLUDED ARE
BENNETT BROWN BUFFALO
CAMPBELL CORSON DEWEY
EDMUNDS FAULK HAAKON
HAND HUGHES HYDE
JACKSON JONES LYMAN
MCPHERSON MELLETTE POTTER
SPINK STANLEY SULLY
TODD TRIPP WALWORTH
ZIEBACH
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.
WW 0590 Status Updates
STATUS REPORT ON WW 590
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 WNW CHA
TO 20 WNW CHA TO 35 E CHA TO 60 S TYS TO 55 NW AND TO 35 SW AVL
TO 10 ESE AVL TO 30 WSW HKY TO 15 WNW HKY TO 20 NNE HKY TO 40 ENE
HKY.
..JIRAK..08/18/26
ATTN...WFO...FFC...GSP...JKL...RNK...MRX...RAH...OHX...
STATUS REPORT FOR WS 590
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
GAC047-055-083-085-111-123-129-137-187-213-227-241-281-291-295-
311-313-180140-
GA
. GEORGIA COUNTIES INCLUDED ARE
CATOOSA CHATTOOGA DADE
DAWSON FANNIN GILMER
GORDON HABERSHAM LUMPKIN
MURRAY PICKENS RABUN
TOWNS UNION WALKER
WHITE WHITFIELD
NCC003-023-035-045-097-109-149-161-180140-
NC
. NORTH CAROLINA COUNTIES INCLUDED ARE
ALEXANDER BURKE CATAWBA
CLEVELAND IREDELL LINCOLN
POLK RUTHERFORD
MD 2020 CONCERNING SEVERE THUNDERSTORM WATCH 592... FOR MUCH OF CENTRAL AND NORTHERN NEBRASKA
Mesoscale Discussion 2020
NWS Storm Prediction Center Norman OK
0802 PM CDT Mon Aug 17 2026
Areas affected...much of central and northern Nebraska
Concerning...Severe Thunderstorm Watch 592...
Valid 180102Z - 180200Z
The severe weather threat for Severe Thunderstorm Watch 592
continues.
SUMMARY...Severe wind gusts and hail should continue to accompany
ongoing supercells for at least a few more hours. Some supercells
may exit the eastern bounds of Severe Thunderstorm Watch 592.
DISCUSSION...Multiple supercells are in progress across much of
central and northern NE, with a severe-wind producing supercell also
poised to cross into Cherry County, NE from SD. The 00Z LBF observed
sounding showed minimal capping in place, with near 8 C/km mid-level
lapse rates overspreading a well-mixed boundary layer amid an
elongated straight hodograph (and 30+ kts of effective bulk shear).
These conditions will support continued severe wind/hail potential
for at least a few more hours, until boundary layer stabilization
sets in. An instance of 2+ inch diameter hail or a 75+ mph gust
cannot be ruled out. Some of the latest HRRR runs also depict
upscale growth into an MCS in central NE. However, confidence in
this scenario remains uncertain given the resistance of storms to
grow upscale thus far. Some of the supercells in central NE are
splitting and approaching counties outside of the ongoing Severe
Thunderstorm Watch. A WW issuance may be needed farther to the east
if confidence increases in a longer-term severe threat for eastern
NE.
..Squitieri/Gleason.. 08/18/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FSD...OAX...GID...LBF...BOU...CYS...
LAT...LON 42940283 42989835 42769713 42419676 42099681 41179824
40729950 40590054 40570116 40640160 40950208 42940283
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN
MD 2019 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF EASTERN SOUTH DAKOTA
Mesoscale Discussion 2019
NWS Storm Prediction Center Norman OK
0716 PM CDT Mon Aug 17 2026
Areas affected...portions of eastern South Dakota
Concerning...Severe potential...Watch possible
Valid 180016Z - 180145Z
Probability of Watch Issuance...40 percent
SUMMARY...At least a few severe gusts may occur with the stronger
storms that manage to intensify and become sustained. A WW issuance
is possible pending favorable intensification trends.
DISCUSSION...Scattered supercells and multicells continue to track
across central SD with a history of producing measured severe gusts.
MRMS mosaic radar trends suggest that some weakening of the ongoing
storms has taken place over the past hour or so, casting some
uncertainty to the long-term severe potential. Nonetheless, these
storms are preceded by a favorable thermodynamic and kinematic
environment. The 00Z ABR observed sounding depicted a buoyant
airmass and no MLCINH, with nearly 2000 J/kg MLCAPE amid an
elongated hodograph with over 30 kts of effective bulk shear. The
00Z mesoanalysis also depicted similar conditions present across
most of eastern SD. Such conditions would support a continued severe
gust threat into the evening hours. As such, convective trends will
continue to be monitored for the possibility of a Severe
Thunderstorm Watch issuance.
..Squitieri/Gleason.. 08/18/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MPX...FSD...ABR...LBF...
LAT...LON 43129660 42939704 42869789 43039896 43349940 44209867
44879787 45709747 45879706 45769658 45359643 44609622
43769628 43129660
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0759 PM CDT Mon Aug 17 2026
Valid 180100Z - 181200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL AND NORTHERN PLAINS...AND FROM NORTHEASTERN ALABAMA INTO
WESTERN NORTH CAROLINA...
...SUMMARY...
Thunderstorms with severe wind gusts and large hail are expected
this evening across parts of the central and northern Plains.
Isolated severe gusts will also be possible from parts of the
northern Gulf Coast States into the southern Appalachians and
Carolinas.
...Central and Northern Plains...
The latest water vapor imagery shows west-northwesterly flow over
much of the northern U.S., with a low-amplitude shortwave trough
moving through the flow in the northern Plains. At the surface, a
cold front is advancing southeastward through the Dakotas. Ahead of
the front, surface dewpoints are in the 60s F. The RAP has an axis
of moderate to strong instability located from central Nebraska
northeastward into eastern South Dakota, along which MLCAPE is
estimated in the 2500 to 3500 J/kg range. Isolated thunderstorms are
ongoing near the instability axis with scattered storms ongoing to
the west of the instability max in western Nebraska and southwestern
South Dakota.
These storms are located along the eastern edge of an elevated mixed
layer extending eastward from the central Rockies. Near the storms,
the RAP is estimating 700-500 mb lapse rates in the 7.5 to 8.5 C/km
range. In addition, the North Platte WSR-88D VWP has 0-6 km shear
near 50 knots with significant directional shear evident in the
lowest 3 km above ground level. This environment will support
supercells with large hail and severe wind gusts this evening. The
more intense storms could produce hailstones exceeding 2 inches in
diameter. Short-term model forecast suggest that the storms will
continue to move east-southeastward toward the instability axis this
evening, remaining relatively discrete. However, a transition to a
broken line segment should eventually occur, which would result in a
greater wind-damage threat. A few severe gusts above 75 mph will be
possible. The severe threat should persist into the mid to late
evening...See MCD 2019.
...Northern Gulf Coast States/Southern Appalachians/Carolinas...
The latest surface analysis shows a distinct outflow boundary from
northern Alabama eastward into the western Carolinas. Strong to
severe thunderstorms are ongoing near the outflow boundary. To the
south of the boundary, surface dewpoints are in the 70s F and the
RAP is estimating MLCAPE in the 2000 to 3500 J/kg range. Within the
most unstable air, RAP forecast soundings early this evening have
0-3 km lapse rate in the 7.5 to 8 C/km range, with precipitation
water above 2 inches. In addition, the WSR-88D VWP in northeast
Alabama has 0-6 km shear in the 20 to 25 knot range. This
environment will support a potential for severe wet downbursts for a
couple more hours this evening.
..Broyles.. 08/18/2026
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0500 PM CDT Mon Aug 17 2026
Valid 191200Z - 251200Z
...Synopsis...
A ridge continues to slowly build over the Great Basin to start the
extended forecast period. The pressure gradient will tighten on Day
4/Thursday as a trough approaches the west CONUS coast. A mid-level
low pressure system will near the Pacific Northwest coast on Day
5/Friday as the upper-level jet max peaks over northern CA and
southern OR. This will provide synoptic lift to portions of
north-central OR and then much of central WA under the left exit
region of the jet streak on the afternoon of Day 5/Friday. The
trough will begin to lift northeastward as it becomes slightly
negatively-tilted progressing into Day 6/Saturday. High pressure
remains in place over much of the southwestern half of the CONUS
with shortwave trough passages periodically moving across the crest
of the high through the northern states. While slight differences in
timing of the aforementioned trough exist, the overall pattern
evolution remains similar amongst various ensemble forecast
guidance.
...Pacific Northwest/Northern California/Great Basin...
The Pacific Northwest and immediately neighboring areas of northern
California and the Great Basin will remain foci through much of the
extended forecast. Starting on Day 4/Thursday and continuing through
Day 6/Saturday, expect multiple consecutive days of gusty
southwesterly winds combined with warm and dry weather as the
aforementioned large trough approaches from the west. Near-normal
conditions in the short-term followed by increasing above-normal
temperatures Day 3/Wednesday through Day 5/Friday will culminate in
a cold front passage on Day 6/Saturday as the trough approaches.
Given the jet aloft and surface conditions that would support deep
daytime mixing, a favorable pattern remains in place for dry and
breezy weather to overlap very dry fuels across northeastern CA,
southern OR, and northwestern NV; thus, 40% Critical probabilities
were maintained on Day 4/Thursday through Day 6/Saturday. Given the
aforementioned upper-level support, limited (but sufficient enough
to support deep instability) moisture, and dry fuels still in place
over much of the area immediately east of the Cascades, an area of
10% Dry Thunderstorm risk was introduced over much of the central
and northeastern Pacific Northwest region on Day 5/Friday, which may
linger through the night in some areas. This dry thunderstorm
potential may reemerge on Day 6/Saturday, particularly across far
northeastern WA, northern ID, and far western MT, but precipitation
received on Day 5/Friday will preclude an additional area for now.
..Stearns.. 08/17/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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