WW 207 SEVERE TSTM IA IL WI 160330Z - 161000Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 207
NWS Storm Prediction Center Norman OK
1030 PM CDT Fri May 15 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Eastern Iowa
Northern Illinois
Southern Wisconsin
* Effective this Friday night and Saturday morning from 1030 PM
until 500 AM CDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph likely
Isolated large hail events to 1.5 inches in diameter possible
SUMMARY...A band of storms is forecast to move west to east across
portions of the Watch area tonight. Scattered damaging gusts (60-70
mph) are possible and will likely focus near the more intense cores
embedded within the band of storms and near bowing segments. Other
isolated storms are possible later tonight and may pose a risk for
isolated large hail.
The severe thunderstorm watch area is approximately along and 45
statute miles north and south of a line from 30 miles north
northwest of Cedar Rapids IA to 10 miles south of Milwaukee WI. 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 205...
AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 450. Mean storm motion vector
27040.
...Smith
WW 205 SEVERE TSTM IA MN NE SD 152215Z - 160600Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 205
NWS Storm Prediction Center Norman OK
515 PM CDT Fri May 15 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Western into Central and Northern Iowa
Southern Minnesota
Eastern Nebraska
Far Southeast South Dakota
* Effective this Friday afternoon and Saturday morning from 515
PM until 100 AM CDT.
* Primary threats include...
Scattered damaging winds and isolated significant gusts to 80
mph likely
Scattered large hail and isolated very large hail events to 3.5
inches in diameter likely
A tornado or two possible
SUMMARY...Thunderstorms are forecast to develop and intensify early
this evening. Supercells capable of very large hail are expected
initially (diameters between 2.5 to 3.5 inches). A tornado or two
is possible later this evening. Upscale growth into one or two
bands or bowing segments is expected later this evening with severe
wind gusts becoming more prevalent. Peak gusts associated with the
thunderstorm bands will probably range 70-80 mph.
The severe thunderstorm watch area is approximately along and 95
statute miles north and south of a line from 60 miles southeast of
Rochester MN to 5 miles north of Columbus NE. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU5).
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 204...
AVIATION...A few severe thunderstorms with hail surface and aloft to
3.5 inches. Extreme turbulence and surface wind gusts to 70 knots. A
few cumulonimbi with maximum tops to 550. Mean storm motion vector
27030.
...Smith
WW 0207 Status Updates
STATUS REPORT ON WW 207
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
..MEAD..05/16/26
ATTN...WFO...DVN...LOT...MKX...ARX...
STATUS REPORT FOR WS 207
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
ILC007-015-085-111-141-177-201-160540-
IL
. ILLINOIS COUNTIES INCLUDED ARE
BOONE CARROLL JO DAVIESS
MCHENRY OGLE STEPHENSON
WINNEBAGO
IAC011-019-031-045-055-061-095-097-103-105-113-160540-
IA
. IOWA COUNTIES INCLUDED ARE
BENTON BUCHANAN CEDAR
CLINTON DELAWARE DUBUQUE
IOWA JACKSON JOHNSON
JONES LINN
WIC025-043-045-049-055-059-065-079-101-105-127-133-160540-
WI
. WISCONSIN COUNTIES INCLUDED ARE
WW 0206 Status Updates
STATUS REPORT ON WW 206
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 S CDS TO
5 ENE LTS TO 35 NW CHK TO 25 NNE OKC.
..SQUITIERI..05/16/26
ATTN...WFO...OUN...
STATUS REPORT FOR WS 206
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
OKC015-017-031-033-051-065-081-103-109-119-141-160340-
OK
. OKLAHOMA COUNTIES INCLUDED ARE
CADDO CANADIAN COMANCHE
COTTON GRADY JACKSON
LINCOLN NOBLE OKLAHOMA
PAYNE TILLMAN
TXC023-155-197-275-485-487-160340-
TX
. TEXAS COUNTIES INCLUDED ARE
BAYLOR FOARD HARDEMAN
KNOX WICHITA WILBARGER
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 0205 Status Updates
STATUS REPORT ON WW 205
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 S OLU TO
15 NE DNS TO 25 ENE FOD TO 30 SSW LSE.
..MEAD..05/16/26
ATTN...WFO...DMX...ARX...FSD...OAX...MPX...
STATUS REPORT FOR WS 205
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
IAC001-003-005-009-013-015-017-023-025-027-029-037-039-043-047-
049-065-069-071-073-075-077-079-083-099-117-121-123-125-127-129-
135-137-145-153-155-157-169-171-173-175-179-181-187-191-197-
160540-
IA
. IOWA COUNTIES INCLUDED ARE
ADAIR ADAMS ALLAMAKEE
AUDUBON BLACK HAWK BOONE
BREMER BUTLER CALHOUN
CARROLL CASS CHICKASAW
CLARKE CLAYTON CRAWFORD
DALLAS FAYETTE FRANKLIN
FREMONT GREENE GRUNDY
GUTHRIE HAMILTON HARDIN
JASPER LUCAS MADISON
MAHASKA MARION MARSHALL
MILLS MONROE MONTGOMERY
PAGE POLK POTTAWATTAMIE
POWESHIEK STORY TAMA
TAYLOR UNION WAPELLO
WARREN WEBSTER WINNESHIEK
WRIGHT
WW 0204 Status Updates
STATUS REPORT ON WW 204
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 55 ENE BGS
TO 50 NNE BGS TO 25 SSW CDS.
WW 204 WILL BE ALLOWED TO EXPIRE AT 160300Z.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0731
..SQUITIERI..05/16/26
ATTN...WFO...MAF...LUB...SJT...
STATUS REPORT FOR WS 204
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
TXC101-125-151-169-207-253-263-269-415-433-447-160300-
TX
. TEXAS COUNTIES INCLUDED ARE
COTTLE DICKENS FISHER
GARZA HASKELL JONES
KENT KING SCURRY
STONEWALL THROCKMORTON
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.
MD 0734 CONCERNING SEVERE THUNDERSTORM WATCH 207... FOR SOUTHERN WISCONSIN AND FAR NORTHERN ILLINOIS
Mesoscale Discussion 0734
NWS Storm Prediction Center Norman OK
1229 AM CDT Sat May 16 2026
Areas affected...southern Wisconsin and far northern Illinois
Concerning...Severe Thunderstorm Watch 207...
Valid 160529Z - 160700Z
The severe weather threat for Severe Thunderstorm Watch 207
continues.
SUMMARY...A damaging wind threat will persist for one to 2 more
hours across southern Wisconsin and far northern Illinois.
DISCUSSION...A small bowing segment persists across southern
Wisconsin where a recent 61 mph measured wind gust was recorded by a
trained spotter and a 72 mph wind gust was measured by a home
weather station. This bow will move into a increasingly stable
airmass as it continues east where low to mid 50s dewpoints are
present. Despite the weakening instability, some damaging wind
threat could persist to the Lake Michigan shore given the 50 knot
southwesterly low-level jet on the MKX VWP.
Despite strong low-level directional and speed shear, expect the
tornado threat to remain low given the 250-350 J/kg MLCIN (per SPC
mesoanalysis and HRRR forecast soundings ahead of the bow).
..Bentley.. 05/16/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LOT...MKX...DVN...
LAT...LON 42399049 42529033 42729026 43049023 43259006 43308970
43348879 43238805 42988784 42428791 42278845 42348985
42399049
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MD 0733 CONCERNING SEVERE THUNDERSTORM WATCH 205... FOR EASTERN NEBRASKA INTO CENTRAL AND NORTHEAST IOWA
Mesoscale Discussion 0733
NWS Storm Prediction Center Norman OK
1053 PM CDT Fri May 15 2026
Areas affected...eastern Nebraska into central and northeast Iowa
Concerning...Severe Thunderstorm Watch 205...
Valid 160353Z - 160600Z
The severe weather threat for Severe Thunderstorm Watch 205
continues.
SUMMARY...Through 05:00 UTC (12:00 AM CDT), the greatest threat for
strong to severe wind gusts (up to 70 mph) will exist east of I-35
in northeast Iowa.
DISCUSSION...Recent trends in mosaic radar data indicate an evolving
QLCS extending from a bookend vortex and adjacent, small-scale bow
nearing the MS River in far northeast IA south-southwest to a couple
of additional bowing structures near Oelwein and west of Waterloo.
The greatest damaging wind potential (gusts up to 70 mph possible)
will exist with those structures as they continue east at 35-40 kt,
and eventually move into the recently issued Severe Thunderstorm
Watch 207.
Elsewhere, more sporadic occurrences of marginally severe hail
and/or locally strong wind gusts will be possible along the cold
front from near Omaha northeast to south and southeast of Fort
Dodge. Surface observations indicate a pocket of drier air in place
across western IA, which is an artifact from earlier convection. The
drier air coupled with a gradually cooling boundary-layer are
expected to limit overall storm intensity across the western half of
the watch area.
..Mead.. 05/16/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DVN...ARX...DMX...EAX...FSD...OAX...
LAT...LON 40299727 41079718 41649657 42199550 42459501 42609429
43039337 43429260 43459168 43129129 42809132 42659206
42279226 41719238 41269250 40989257 40629479 40299727
MOST PROBABLE PEAK WIND GUST...55-70 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
0758 PM CDT Fri May 15 2026
Valid 160100Z - 161200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER MUCH OF
IOWA INTO FAR SOUTHWEST WISCONSIN...
...SUMMARY...
Severe thunderstorms capable of producing severe gusts and large
hail remain likely this evening centered over Iowa. Isolated to
scattered severe gusts also remain possible over a broader area from
parts of the southern High Plains to the Upper Midwest.
...IA and southern WI into northeast KS/northern MO...
Several clusters of severe storms are currently ongoing across
western into northern IA, with other cells into southeast MN. All
this is occurring near and ahead of a cold front associated with the
glancing upper wave to the north. Moderate instability has developed
as lower 60s F dewpoints spread into the area, and effective
deep-layer shear near 50 kt will continue to support organization
into an MCS as outflows aggregate. Until then, large damaging hail
will also be possible. More isolated activity also extends into far
southeast NE, with other failed attempts at initiation toward far
northern KS. The increasing southwest low-level jet this evening may
support additional development later this evening as the 00Z TOP
sounding remains moist and unstable.
For more information see mesoscale discussions #0729 and #0730.
...Western TX...western OK...southwest KS...
Scattered high-based storms continue to produce locally severe gusts
from parts of western TX into western OK. While capping will
increase this evening, a few more hours of damaging wind threat
appear likely with the activity moving into northwest TX. Additional
isolated activity may also develop anywhere from western OK into
southwest KS as moisture wraps around the surface low and lapse
rates remain steep.
..Jewell.. 05/16/2026
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1235 AM CDT Sat May 16 2026
Valid 161200Z - 171200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST
COLORADO INTO WESTERN NEBRASKA AND KANSAS...
...SUMMARY...
Severe storms capable of large hail, wind damage and perhaps a
couple of tornadoes will be possible this afternoon and evening
across parts of the central Plains. Scattered thunderstorms will
also pose potential for strong to severe winds across the lower to
mid Missouri Valley.
...Synopsis...
An upper trough will develop over the western states today, with
increasing southwest winds aloft late in the day and overnight
across the Rockies and into the High Plains. Preceding the western
trough, a progressive shortwave will move from the Great Lakes and
into the Northeast, allowing temporary height rises across the upper
Midwest/MS Valley. Behind this wave, high pressure will bring stable
conditions into the northern Plains.
At the surface, low pressure will develop over the central High
Plains, with a trough extending from eastern WY into western TX.
Meanwhile, a stalled front will be situated across northeast CO into
northern KS and toward IA/northern IL, with easterly winds across NE
and IA. A moist air mass will reside south of this boundary, with
60s F dewpoints prevalent. Backed winds will help bring this
moisture westward toward northeast CO and western NE by late
afternoon as 850 mb winds increase toward evening. Shear profiles
will thus become increasingly favorable from late afternoon through
evening for supercells, with large hail, damaging winds and perhaps
a couple tornadoes from CO into western NE/KS.
East of there, another concentration of strong to severe storms is
expected from eastern NE into IA, northern MO and northeast KS near
the boundary.
Elsewhere, a broad fetch of 20-30 kt southerly 850 mb winds will
maintain a moist air mass across the lower to middle MS Valley and
across the OH Valley. Here, pockets of stronger instability will
support scattered strong storms during the afternoon.
...Central Plains...
Storms are likely to form near the Front Range after 21Z, with
activity developing eastward into NE and KS. A few supercells appear
likely with time, producing damaging hail and severe wind gusts.
Westerly winds aloft atop the deep low-level easterlies will
elongate hodographs with over 50 kt effective shear, while SRH
values favor supercells and severe bows through evening.
Farther east, strong instability will develop near the east-west
boundary, with scattered severe storms developing around 21Z. Some
of these storms may produce hail over 2.00" diameter as lapse rates
aloft will remain steep, and with ample moisture.
Additional isolated activity is possible along the dryline from
southwest KS into the eastern TX Panhandle and western OK. Here,
shear will be weak but a narrow zone of uncapped air mass with a
backing dryline may support isolated storms with locally severe hail
or wind gusts.
..Jewell/Squitieri.. 05/16/2026
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