Severe Thunderstorm Warning 145, NWS Milwaukee, WI

295 
WWUS53 KMKX 210012
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
712 PM CDT WED SEP 20 2017

WIC025-049-210030-
/O.CON.KMKX.SV.W.0145.000000T0000Z-170921T0030Z/
Iowa WI-Dane WI-
712 PM CDT WED SEP 20 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM CDT
FOR EAST CENTRAL IOWA AND NORTHWESTERN DANE COUNTIES...

At 711 PM CDT, a severe thunderstorm was located 7 miles southwest of
Black Earth, or 7 miles northwest of Mount Horeb, moving northeast 
at 30 mph.  The storm is currently diminishing in strength, but 
other storms are nearby and could intensify over the next few 
minutes. 

HAZARD...60 mph wind gusts and quarter size hail. 

SOURCE...Radar indicated. 

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees. 

Locations impacted include...
Mount Horeb, Mazomanie, Black Earth, Barneveld, Blue Mounds, Ridgeway
and Blue Mound St Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4293 9000 4305 9007 4325 8974 4298 8969
TIME...MOT...LOC 0011Z 243DEG 28KT 4307 8986 

HAIL...1.00IN
WIND...60MPH
 
$$

DAVIS

388 
WWUS53 KMKX 210017
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
717 PM CDT WED SEP 20 2017

WIC025-049-210026-
/O.CAN.KMKX.SV.W.0145.000000T0000Z-170921T0030Z/
Iowa WI-Dane WI-
717 PM CDT WED SEP 20 2017

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL IOWA AND
NORTHWESTERN DANE COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore the warning has been cancelled. But, keep an eye out for 
more storms through the evening. 

LAT...LON 4293 9000 4305 9007 4325 8974 4298 8969
TIME...MOT...LOC 0015Z 243DEG 28KT 4309 8981 

$$

DAVIS

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
547 PM CDT Wed Sep 20 2017

.UPDATE...

Not much to add for an update to the previous discussion. We have
an incredible amount of CAPE out there, but the deeper forcing is
pushing off to the north and that's where the severe storms have
been up to this point. Our main forcing across southern WI will be
with the low level convergence along the front and also a weaker
prefrontal convergence band just west of Madison. Things are
starting to get more organized late this afternoon and nearly all
the guidance gives us a peak of activity between now and about 10
pm. Thereafter, we start to lose the instability, so a diminishing
trend should take over. Severe storms are certainly possible with
the main threat at this point looking like large hail, followed
by strong gusty winds. The more isolated nature of the severe
activity expected over southern WI is what's keeping a watch from
being issued at this point. But, that could change if things
become more organized.

&&

.AVIATION(00Z TAFS)...

Thunderstorms associated with an approaching cold front will
mainly impact KMSN tonight, with a lower threat across the
southeast due to the weakening nature of the front. The storms
will peak between about 00z and about 04z this evening, then
diminish. Look for VFR conditions through much of tonight, except
brief lower conditions in any thunderstorms. We should see an area
of MVFR and IFR conditions develop toward sunrise north of a line
stretching from Dubuque to Sheboygan. This is post frontal and in
an area that will likely see rain this evening. The southeast
should stay VFR, though we'll have to keep an eye on fog rolling
in off the lake. The lower stuff to the north will push north by
Thursday afternoon.

&&

.PREV DISCUSSION... (Issued 245 PM CDT Wed Sep 20 2017)

SHORT TERM...

Tonight - Confidence...Medium
Convection firing from ne IA into SW WI ahead of low level
frontal boundary. Airmass is very unstable with MLCAPE values
reaching 3000 j/kg into sw WI. Dynamics proggd to ride to our
north so lower level forcing to be the primary forcing mechanism.
Mid level lapse rates not favorable though some higher 0-6km
shear sneaking into the cwa, upwards of 30 to 35 knots. Best combo
of forcing and instability looks to be lined up in SC WI where
meso progs show convection at its peak very late in the afternoon
through about 02z or 03z. So have highest pops in that area and
this is also where SPC has the SLight Risk placed and that looks
fine. Coverage of any shra/tsra proggd to diminish with time
overnight with decreasing instability. Depending on degree of
clearing fog may set up once again with the lighter winds
associated with weak winds in vicinity of the boundary.

Thursday - Confidence...Medium
The front is then proggd to lift back to the north. The GFS is
most aggressive with developing some shra/tsra. Mid level flow is
southwest with a broad anticyclonic look and building heights. 850
LLJ is also proggd to remain to our west, so forcing looks again
to be in the lower levels. 925 temps bounce back into the low or
mid 20s celsius so toasty temps and high dew points expected once
again.

Thursday night through Sunday...Forecast confidence high.

An upper ridge will hold from the ern Great Lakes to E TX through
this period with a longwave upper trough over the wrn USA. S WI
will experience sly flow and very warm and humid conditions. Heat
index values will reach the upper 80s to lower 90s through the
weekend with cooler conditions near Lake MI via sely flow.

LONG TERM...Monday through Wednesday...Forecast confidence
medium.

The upper trough over the wrn USA will slowly progress ewd during
this period. Thus the sfc trough/cold front will eventually move
into the region. Chances of showers and tstorms return for Mon-Tue
with temps gradually cooling, but still mild for this time of
year.

AVIATION(18Z TAFS)...Main story will be arriving shra/tsra with
approaching trough/wind shift into srn WI this evening. Still
expect potential for some stronger storms esp into sc WI where
frontal forcing will interact with peak instability. Meso models
decrease precip coverage overnight as instability wanes and better
dynamics ride to our north. Will have to watch for fog
development later tonight with lighter wind regime and lingering
low level moisture with higher dew points still in place.

MARINE...Small Craft Advisory continues into this evening due to
a gusty southeast wind and higher waves which have built highest
towards Sheboygan. No changes planned.

BEACHES...Breezy south to southeast winds have built waves
around 4 feet at beaches in Sheboygan and Ozaukee counties, thus a
Beach Hazard Statement remains in effect. The highest waves and
strongest currents are expected into the evening.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement until 9 PM CDT this evening for WIZ052-
     060.

LM...Small Craft Advisory until 9 PM CDT this evening for LMZ643.

&&

Update...Davis
Tonight/Thursday and Aviation/Marine...Collar
Thursday Night through Wednesday...Gehring

Hazardous Weather Outlook
National Weather Service Milwaukee/Sullivan WI
324 PM CDT Wed Sep 20 2017

WIZ046-047-051-052-056>060-062>072-212030-
Marquette-Green Lake-Fond Du Lac-Sheboygan-Sauk-Columbia-Dodge-
Washington-Ozaukee-Iowa-Dane-Jefferson-Waukesha-Milwaukee-
Lafayette-Green-Rock-Walworth-Racine-Kenosha-
324 PM CDT Wed Sep 20 2017

This Hazardous Weather Outlook is for portions of east central
Wisconsin, south central Wisconsin, and southeast Wisconsin.

.DAY ONE...Tonight

There is a chance for thunderstorms late this afternoon through
mid evening, with the potential for a few storms to become severe
mainly in south central Wisconsin.

There is a high swim risk for the beaches along Lake Michigan in
Sheboygan and Ozaukee counties through 9 pm. Life threatening
waves and currents are expected along the shore. Stay out of the
water.

There is a moderate swim risk for the beaches along Lake Michigan
in Milwaukee, Racine, and Kenosha counties through 9 pm. Breaking
waves and currents are expected. Stay away from dangerous areas
like piers, breakwalls, and river outlets.

.DAYS TWO THROUGH SEVEN...Thursday through Wednesday

There is a chance for thunderstorms Monday and Tuesday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed late this afternoon into mid
evening.

LMZ643>646-212030-
Sheboygan to Port Washington WI-
Port Washington to North Point Light WI-
North Point Light to Wind Point WI-
Wind Point WI to Winthrop Harbor IL-
324 PM CDT Wed Sep 20 2017

This Hazardous Weather Outlook is for portions of Lake Michigan.

.DAY ONE...Tonight

A small craft advisory is in effect for the nearshore waters
from Port Washington to Sheboygan until 9 pm.

There is a chance for thunderstorms this evening.

.DAYS TWO THROUGH SEVEN...Thursday through Wednesday

There is a chance for thunderstorms Tuesday.

Collar
www.weather.gov/mkx

Special Weather Statement
National Weather Service Milwaukee/Sullivan WI
609 PM CDT WED SEP 20 2017

WIZ047-051-210000-
Green Lake-Fond Du Lac-
609 PM CDT WED SEP 20 2017

...A STRONG THUNDERSTORM WILL AFFECT WESTERN FOND DU LAC AND
SOUTHEASTERN GREEN LAKE COUNTIES...

At 608 PM CDT, a strong thunderstorm was located over Brandon, or
near Ripon, moving northeast at 35 mph.

Winds in excess of 30 mph and dime size hail are possible with this
storm.

Locations impacted include...
Waupun, Ripon, North Fond Du Lac, Rosendale, Brandon, Southern Lake
Winnebago, Alto, Manchester, and Lagoda.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 4363 8870 4364 8912 4390 8885 4389 8841
      4394 8840 4394 8832
TIME...MOT...LOC 2308Z 223DEG 28KT 4377 8881

MRC

Special Weather Statement
National Weather Service Milwaukee/Sullivan WI
654 PM CDT WED SEP 20 2017

WIZ062-063-210045-
Iowa-Dane-
654 PM CDT WED SEP 20 2017

...AN AREA OF STRONG THUNDERSTORMS WILL AFFECT IOWA AND NORTHWESTERN
DANE COUNTIES...

At 653 PM CDT, strong thunderstorms were clustered near Dodgeville,
moving northeast at 30 mph.

Winds in excess of 30 mph are possible with this storm.

Locations impacted include...
Mount Horeb, Dodgeville, Sauk City, Mineral Point, Cross Plains,
Mazomanie, Black Earth, Barneveld, Blue Mounds, Arena, Ridgeway,
Hollandale, Governor Dodge St Park, Edmund, Blue Mound St Park,
London and Marxville.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 4316 9009 4315 9005 4320 8999 4319 8986
      4324 8980 4324 8977 4328 8971 4324 8951
      4281 8990 4281 9043
TIME...MOT...LOC 2353Z 223DEG 28KT 4302 9006

MRC