Special Weather Statement, NWS Milwaukee, WI

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
727 PM CDT Fri Jun 15 2018

.UPDATE...Expecting areas of convection over northern and central
WI to shift more swd with time via Corfidi Vectors and along the
warm front. Gusty winds will occur with the storms with a Marginal
Severe area toward central WI. Thus updated the forecast for
likely showers and storms for much of srn WI late this evening
into the early morning hours of Sat. Areas west of Madison may
stay dry. Still would expect a hot day on Sat but there could be a
decent surge of ely winds off Lake MI due to the departing
convection over the lake. This is why the Heat Advisory excluded
seven counties in far ern WI.

&&

.AVIATION(00Z TAFS)...Showers and tstorms will move sewd across
srn WI late this evening and during the early morning hours on
Sat. The prevailing conditions will be VFR but low vsbys and cigs
would occur within the storms and shortly afterward. The forecast
is dry for Sat but fog may develop over Lake MI and affect the
shoreline areas. There is a marginal case for LLWS late this
evening into the overnight and once again for Sat nt.

&&

.PREV DISCUSSION... (Issued 242 PM CDT Fri Jun 15 2018)

DISCUSSION...

Rest of this Afternoon through Saturday Afternoon...Forecast
Confidence is Low...

The showers and thunderstorms that affected the region this
morning have moved east of the area, and a warm front has lifted
northeast into and through much of the region. Mid afternoon
temperatures were in the 80s across much of the forecast area,
with cooler readings in the 60s and 70s close to Lake Michigan.

There are a couple of potential wrinkles in the forecast for this
evening and tonight, which is resulting in lower than usual
confidence for the short term forecast.

The first challenge will be the evolution of an outflow boundary
which has moved south from central Wisconsin. As of 2 PM, this
boundary stretched from roughly Montello to Fond du Lac to
Sheboygan. Its southward progress should slow over the next hour
or two, and current expectations are for the boundary to
eventually mix out by this evening. Between now and then, however,
we will need to watch for the potential for additional shower and
thunderstorm activity across the northern CWA, along with a
moderating effect on temperatures and dewpoints. This may
necessitate a few forecast updates this afternoon and evening,
especially if more robust convection is able to develop along the
boundary.

Later this evening and tonight, attention then turns to the
evolution of convection from the Twin Cities into central and
north central Wisconsin. Thunderstorms are expected to form and
move east and perhaps south or southeast. With the northward
progress of the warm front being modified by the cooler waters of
Lake Michigan, thunderstorms may try to progress south along the
lake later tonight, and could move into the forecast area late
this evening into tomorrow morning. This is a very low confidence
forecast at this point. Once the thunderstorms actually form
later this evening, we should be able to fine tune this forecast.

Much warmer and more humid conditions are expected for Saturday
and Sunday, with heat indices both days around 100 degrees. A Heat
Advisory will be in effect for the western 3/4 or so of the
forecast area starting Saturday afternoon. Forecast confidence in
the excessive heat is highest across this area. For those areas
close to Lake Michigan, the evolution of thunderstorms this
evening/tonight (and possibly a lake breeze on Saturday) will
have an impact on temperatures on Saturday. Because of this lower
confidence, have held off on an Advisory for now for this area.
Later forecast updates may add some or all of these counties if
confidence grows in 100 degree or higher heat indices.

Aside from any lingering morning shower or thunderstorm activity,
most of the day Saturday should be dry.

Sunday - Confidence...Medium
Hot dome will be entrenched across the area with primary forcing
to our north and northwest closer to jet stream and low level
frontal forcing. So southwest winds will continue to pump in the
hot/humid airmass. 925 temps proggd to 27-29c range so plenty of
90s across the area with less likelihood of any lake influence.

Monday - Confidence...Medium
Hot airmass likely lingers though extent of heat in question as
frontal forcing will gradually impinge on southern WI, which will
result in increasing threat of showers/thunderstorms.
Clouds/precip trends as we draw closer to Monday will dictate
whether the heat advisory will need to be extended into this
period but for now timing of front, clouds and precip would
suggest criteria would fall short.

Tuesday through Friday - Confidence...Medium
Cooler and less humid airmass will dominate this period as weak
though broad high pressure area takes hold.  Some waa may return
heading into Friday but at this time prefer the GFS thermal regime
which favors keeping that waa largely west of our area so will opt
to keep pops quiet for now.

AVIATION(21Z TAFS)...There will be a slight chance for thunderstorms
to impact the terminals this evening or tonight, but overall
forecast confidence is too low for TAF inclusion at this time.
Outside of any thunderstorm potential, VFR should prevail, with
southerly to southwesterly surface winds.

MARINE...Thunderstorms will be possible at times tonight and early
tomorrow morning across the nearshore waters. Some fog will also be
possible, especially closer to open waters. Otherwise, a fairly quiet
weekend is expected on the lake, with offshore winds limiting wave
action to 1-2 feet. Additional thunderstorm chances will be possible
Sunday into Monday as a front moves south through the area. This
front will result in northerly winds across the lake by Monday.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Heat Advisory from 1 PM Saturday to 7 PM CDT Sunday for WIZ046-
     047-051-056>058-062>064-067>070.

LM...None.
&&

Update...Gehring
Tonight/Saturday and Aviation/Marine...Boxell
Saturday Night through Friday...Collar

Hazardous Weather Outlook
National Weather Service Milwaukee/Sullivan WI
806 PM CDT Fri Jun 15 2018

WIZ046-047-051-052-056>060-062>072-170115-
Marquette-Green Lake-Fond Du Lac-Sheboygan-Sauk-Columbia-Dodge-
Washington-Ozaukee-Iowa-Dane-Jefferson-Waukesha-Milwaukee-
Lafayette-Green-Rock-Walworth-Racine-Kenosha-
806 PM CDT Fri Jun 15 2018

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

.DAY ONE...Tonight

Scattered thunderstorms with gusty winds will occur this evening
into the overnight.

.DAYS TWO THROUGH SEVEN...Saturday through Friday

A Heat Advisory is in effect for all of south central and portions
of southeast Wisconsin from midday Saturday into early Sunday
evening. Hot and humid conditions are expected this weekend. Heat
index values will likely reach around 100 degrees across southern
Wisconsin both Saturday and Sunday.

A backdoor cold front will then bring relief from the heat early
next week. Chances of thunderstorms are forecast with the passage
of the front.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed.

LMZ643>646-170115-
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-
806 PM CDT Fri Jun 15 2018

This Hazardous Weather Outlook is for portions of Lake Michigan.

.DAY ONE...Tonight

Scattered thunderstorms with gusty winds will occur this evening
into the overnight.

.DAYS TWO THROUGH SEVEN...Saturday through Friday

Areas of fog, possibly dense, may form over Lake Michigan for
Saturday and Saturday night.

More chances of thunderstorms are expected Monday with the passage
of a cold front.

www.weather.gov/mkx

Special Weather Statement
National Weather Service Milwaukee/Sullivan WI
854 PM CDT FRI JUN 15 2018

WIZ047-051-160230-
Green Lake-Fond Du Lac-
854 PM CDT FRI JUN 15 2018

...AN AREA OF STRONG THUNDERSTORMS WILL AFFECT GREEN LAKE AND FOND DU
LAC COUNTIES...

At 854 PM CDT, strong thunderstorms were clustered near Green Lake,
or near Ripon, moving east at 45 mph.

Winds in excess of 40 mph are possible with this storm.

Locations impacted include...
Fond Du Lac, Waupun, Ripon, North Fond Du Lac, Berlin, Markesan,
Oakfield, Rosendale, Green Lake, Brandon, Southern Lake Winnebago,
Taycheedah, Lamartine, Byron, Alto, Manchester, Eden, Fairwater,
Peebles and Oak Center.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 4390 8888 4389 8841 4394 8840 4394 8831
      4360 8839 4363 8841 4363 8911 4398 8905
      4398 8889
TIME...MOT...LOC 0154Z 277DEG 40KT 4380 8894

HENTZ

Special Weather Statement
National Weather Service Milwaukee/Sullivan WI
927 PM CDT FRI JUN 15 2018

WIZ047-051-052-057>059-160300-
Dodge-Columbia-Green Lake-Sheboygan-Washington-Fond Du Lac-
927 PM CDT FRI JUN 15 2018

...AN AREA OF STRONG THUNDERSTORMS WILL AFFECT SOUTHEASTERN GREEN
LAKE...FOND DU LAC...NORTHEASTERN COLUMBIA...NORTHERN WASHINGTON...
SHEBOYGAN AND NORTHERN DODGE COUNTIES...

At 925 PM CDT, strong thunderstorms were clustered over Fond Du Lac,
moving east at 45 mph. More storms were forming along the south part
of the storm.

Winds in excess of 40 mph are possible with this storm.

Locations impacted include...
Fond Du Lac, West Bend, Beaver Dam, Waupun, Plymouth, Mayville, North
Fond Du Lac, Kewaskum, Horicon, Lomira, Pardeeville, Campbellsport,
Randolph, Random Lake, Markesan, Theresa, Oakfield, Rosendale, Rio
and Elkhart Lake.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 4393 8816 4389 8816 4389 8785 4354 8790
      4354 8804 4345 8804 4344 8945 4390 8868
      4389 8841 4394 8840 4394 8832
TIME...MOT...LOC 0225Z 277DEG 40KT 4375 8846

HENTZ

Special Weather Statement
National Weather Service Milwaukee/Sullivan WI
1000 PM CDT FRI JUN 15 2018

WIZ047-051-052-057>060-160330-
Dodge-Columbia-Green Lake-Sheboygan-Washington-Ozaukee-Fond Du Lac-
1000 PM CDT FRI JUN 15 2018

...AN AREA OF STRONG THUNDERSTORMS WILL AFFECT NORTHERN OZAUKEE...
SOUTHERN FOND DU LAC...NORTHEASTERN COLUMBIA...NORTHERN WASHINGTON...
SHEBOYGAN AND NORTHERN DODGE COUNTIES...

At 956 PM CDT, strong thunderstorms were clustered near Plymouth,
moving east at 40 mph.  Thunderstorms also extended west to east
across southeast Columbia County then across the Beaver Dam to
Mayville in Dodge County.

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

Locations impacted include...
Sheboygan, Fond Du Lac, West Bend, Beaver Dam, Waupun, Plymouth,
Sheboygan Falls, Mayville, Kewaskum, Horicon, Howards Grove, Juneau,
Oostburg, Lomira, Belgium, Fredonia, Kohler, Pardeeville, Cedar Grove
and Campbellsport.

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

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 4357 8779 4349 8779 4343 8783 4337 8939
      4351 8935 4364 8897 4363 8889 4366 8889
      4389 8819 4389 8773 4385 8772 4383 8773
      4378 8771 4370 8770
TIME...MOT...LOC 0256Z 282DEG 33KT 4370 8809

HENTZ

Special Weather Statement
National Weather Service Milwaukee/Sullivan WI
1040 PM CDT FRI JUN 15 2018

WIZ056>060-063>066-160415-
Dodge-Columbia-Waukesha-Sauk-Milwaukee-Washington-Ozaukee-Jefferson-
Dane-
1040 PM CDT FRI JUN 15 2018

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT SOUTH OZAUKEE...
MILWAUKEE...SOUTHERN COLUMBIA...WAUKESHA...EAST CENTRAL SAUK...
DANE...SOUTHERN WASHINGTON...JEFFERSON AND SOUTHERN DODGE COUNTIES...

At 1038 PM CDT, radar indicated strong thunderstorms were located
along a line extending from near Sauk City to near Bayside. Movement
was southeast at 30 mph.

Winds in excess of 30 mph are possible with these storms.

Locations impacted include...
Milwaukee, Madison, Waukesha, West Allis, Wauwatosa, New Berlin,
Brookfield, Greenfield, Menomonee Falls, Oak Creek, Sun Prairie,
Fitchburg, Muskego, Watertown, Mequon, South Milwaukee, Cudahy,
Middleton, Hartford and Whitefish Bay.

heavy rainfall is occurring with these storms, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 4289 8785 4288 8963 4339 8979 4338 8787
      4324 8791 4318 8788 4312 8790 4307 8787
      4302 8790 4296 8785
TIME...MOT...LOC 0338Z 336DEG 30KT 4324 8965 4325 8788

HENTZ

Special Weather Statement
National Weather Service Milwaukee/Sullivan WI
1108 PM CDT FRI JUN 15 2018

WIZ063>066-068>072-160430-
Green-Walworth-Rock-Waukesha-Milwaukee-Racine-Jefferson-Dane-Kenosha-
1108 PM CDT FRI JUN 15 2018

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT MILWAUKEE...
NORTHEASTERN GREEN...WALWORTH...ROCK...RACINE...WAUKESHA...DANE...
AND JEFFERSON COUNTIES...

At 1106 PM CDT, radar indicated strong thunderstorms were located
along a line extending from Madison to near Palmyra to Milwaukee.
Movement was south at 45 mph.

Winds in excess of 30 mph are possible with these storms.

Locations impacted include...
Milwaukee, Madison, Kenosha, Racine, Waukesha, Janesville, West
Allis, Wauwatosa, New Berlin, Brookfield, Greenfield, Menomonee
Falls, Oak Creek, Sun Prairie, Mount Pleasant, Fitchburg, Muskego,
Watertown, South Milwaukee and Pleasant Prairie.

Heavy rainfall is also occurring with these storms, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 4267 8948 4327 8966 4323 8901 4320 8901
      4319 8790 4307 8787 4302 8790 4296 8785
      4285 8783 4278 8775 4261 8782 4251 8781
      4251 8850
TIME...MOT...LOC 0406Z 347DEG 39KT 4307 8942 4294 8863 4295 8790

HENTZ

Special Weather Statement
National Weather Service Milwaukee/Sullivan WI
1121 PM CDT FRI JUN 15 2018

WIZ063>066-068>072-160445-
Green-Walworth-Rock-Waukesha-Milwaukee-Racine-Jefferson-Dane-Kenosha-
1121 PM CDT FRI JUN 15 2018

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT MILWAUKEE...
NORTHEASTERN GREEN...WALWORTH...ROCK...RACINE...WAUKESHA...DANE...
JEFFERSON AND KENOSHA COUNTIES...

At 1118 PM CDT, radar indicated strong thunderstorms were located
along a line extending from near Fitchburg to Palmyra to Oak Creek.
Movement was south at 35 mph.

Winds in excess of 40 mph are possible with these storms.

Locations impacted include...
Milwaukee, Madison, Kenosha, Racine, Waukesha, Janesville, West
Allis, Wauwatosa, New Berlin, Brookfield, Greenfield, Menomonee
Falls, Oak Creek, Sun Prairie, Mount Pleasant, Fitchburg, Muskego,
Watertown, South Milwaukee and Pleasant Prairie.

Heavy rainfall is also occurring with these storms, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 4267 8948 4327 8966 4323 8901 4320 8901
      4319 8790 4307 8787 4302 8790 4296 8785
      4285 8783 4278 8775 4261 8782 4251 8781
      4251 8850
TIME...MOT...LOC 0418Z 344DEG 30KT 4300 8938 4287 8859 4287 8786

HENTZ