Special Weather Statement, NWS Milwaukee, WI

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
645 PM CDT Sat Jun 30 2018

.UPDATE...Scattered t-storms moving into far western CWA with
sporadic strong winds and large hail just to the west. Wind gusts
up to 40 knots associated with outflow boundary from these storms
moving through Sauk, Iowa and Lafayette Counties. Severe weather
threat continues in the west this evening. Expect thunder threat
to continue in the west this evening, with a chance farther west,
possibly reaching eastern areas later this evening.

&&

.AVIATION(00Z TAFS)...Scattered t-storms will result in pockets
of lower visibility and ceilings overnight.

&&

.PREV DISCUSSION... (Issued 154 PM CDT Sat Jun 30 2018)

SHORT TERM...

Tonight and Sunday - Confidence...Medium
Convection likely to organize in more dynamical region well to
our west and in closer proximity to low level forcing with frontal
zone. The meso models show quite a bit of this activity may peel
in to especially the western cwa later this evening while Corfidi
vectors carry this more to the north of our area. The models show
that this activity may have a hard time holding together as it
outpaces the better dynamics which hold off to our west. Will have
a gradient in pops from northwest to southeast to account for the
uncertainty, but by and large any storms are expected to weaken
the deeper they traverse into the cwa. Given the premise that the
storms will weaken/dissipate with the main front well back to our
west into Sunday, we are going to extend the Excessive Heat
Warning for parts of our southeast to account for the warm
overnight temps through 10z and then with the expectation that
convective debris or any outflow modified air would lose influence
early, the potential is certainly there to heat up again before
the FROPA and additional storms (possibly severe) towards the
early to mid afternoon hours. Further headline adjustments likely
based on how the convective trends play out but for now wanted to
extend at least these southeast counties which would be least
affected by this overnight convection and last areas to see
FROPA/storms Sunday afternoon.

Sunday night...Forecast Confidence Is Medium.

The mid/upper level shortwave lifts northeast of lake Superior,
with southeast Wisconsin in the right entrance region of the upper
jet especially Sunday evening. Weaning upper level divergence and
700 mb upward motion. Southeast Wisconsin is in the entrance
region of the departing 850 mb wind max, As such the moisture
convergence is weak as the cold front moves. Still enough of a
window for thunderstorms, mainly early evening, before mid level
drying begins. Precipitable water values are still near an inch
far southeast early evening, so any thunderstorms could produce
brief heavy rains.

LONG TERM...

Monday Through Independence Day...Forecast Confidence Is Medium.

A strong, more zonal or west/southwest upper flow will extend across
the U.S. Canadian border areas. Then a weak mid/upper ridge will
develop by Independence Day Wednesday.

Very warm and more humid air will return. Instability and
increasing CAPE also return, but any forcing is weak.

Thursday Through Saturday...Forecast confidence is medium:

Models are showing a rather strong shortwave in the northern
stream jet across south central Canada, so continued with the
chance for thunderstorms. Lingered a chance into Friday south with
the moisture/instability hanging around, though chances decrease
through the day as high pressure builds in from the north.

Temperatures up near 90 once again Thursday (with heat indices
pushing 100) should cool back a few degrees Friday and Saturday,
somewhat closer to normal values for early July.

AVIATION(21Z TAFS)...

VFR this period. One round of showers/storms
expected to move into south central WI this evening before losing
steam/dissipating as it draws closer to se WI. Then expect more
storms to redevelop on Sunday around midday through late afternoon
ahead of approaching cold front. Would appear these storms may
pack a little more punch due to help from mid/upper level energy
coming more into play.

MARINE...Look for southerly winds into Sunday, but winds and
waves should remain below small craft advisory levels. The highest
waves would be toward Sheboygan and points north. Winds will
shift to the west Sunday evening in the wake of a passing weak
cold front.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Excessive Heat Warning until 4 PM CDT Sunday for WIZ065-066-
     070>072.

     Heat Advisory until 10 PM CDT this evening for WIZ052-060.

     Excessive Heat Warning until 10 PM CDT this evening for WIZ046-
     047-051-056>059-062>064-067>069.

LM...None.
&&

Update...MBK
Tonight/Sunday and Aviation/Marine...MBK
Sunday Night through Saturday...Hentz

Hazardous Weather Outlook...UPDATED
National Weather Service Milwaukee/Sullivan WI
447 PM CDT Sat Jun 30 2018

WIZ046-047-051-052-056>060-062>072-012200-
Marquette-Green Lake-Fond Du Lac-Sheboygan-Sauk-Columbia-Dodge-
Washington-Ozaukee-Iowa-Dane-Jefferson-Waukesha-Milwaukee-
Lafayette-Green-Rock-Walworth-Racine-Kenosha-
447 PM CDT Sat Jun 30 2018

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

.DAY ONE...Tonight

A Severe Thunderstorm Watch is in effect until 11 pm for much of
south central Wisconsin including Madison, Baraboo, Reedsburg and
Monroe.

An Excessive Heat Warning remains in effect for most of the area
this evening, with a Heat Advisory for Sheboygan and Ozaukee
Counties.

There is a moderate swim risk into the evening, especially for
beaches in Ozaukee and Sheboygan County. Breaking waves and
currents are expected. Stay away from dangerous areas like piers,
breakwalls, and river outlets.

.DAYS TWO THROUGH SEVEN...Sunday through Saturday

The Excessive Heat Warning continues for parts of southeast
Wisconsin until 4 PM Sunday.

There is a chance for thunderstorms Sunday, with a slight risk
for severe storms for much of southern Wisconsin.

There are small chances for thunderstorms at times Tuesday
through Friday.

Heat index values could approach 100 degrees on Independence Day
and again on Thursday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed later tonight into Sunday
evening.

LMZ643>646-012200-
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-
447 PM CDT Sat Jun 30 2018

This Hazardous Weather Outlook is for portions of Lake Michigan.

.DAY ONE...Tonight

There is a chance for thunderstorms toward sunrise.

.DAYS TWO THROUGH SEVEN...Sunday through Saturday

A Small Craft Advisory may be needed Sunday, with south to
southwest wind gusts approaching 25 knots.

There is a chance for thunderstorms Sunday, with a few severe
storms possible in the afternoon and evening.

There are small chances for thunderstorms at times Tuesday
through Friday.

www.weather.gov/mkx

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
645 PM CDT SAT JUN 30 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0635 PM     TSTM WND GST     REEDSBURG-AIRPORT       43.53N 89.98W
06/30/2018  M46 MPH          SAUK               WI   AWOS

            AWOS STATION C35, REEDSBURG-AIRPORT.

&&

WOOD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
652 PM CDT SAT JUN 30 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0648 PM     TSTM WND DMG     REEDSBURG               43.54N 90.00W
06/30/2018                   SAUK               WI   LAW ENFORCEMENT

            MODERATE SIZED TREE BRANCHES DOWN ON ROADS.
            TOPS OF TREES SHEARED OFF.

&&

WOOD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
653 PM CDT SAT JUN 30 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0646 PM     TSTM WND GST     4 WSW WESTFIELD         43.87N 89.56W
06/30/2018  M52 MPH          MARQUETTE          WI   TRAINED SPOTTER

&&

WOOD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
720 PM CDT SAT JUN 30 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0630 PM     TSTM WND DMG     BARABOO                 43.47N 89.74W
06/30/2018                   SAUK               WI   911 CALL CENTER

            TREES DOWN ALL OVER SAUK COUNTY. TIME
            ESTIMATED FROM RADAR.

&&

WOOD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
721 PM CDT SAT JUN 30 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0700 PM     TSTM WND DMG     MONTELLO                43.79N 89.33W
06/30/2018                   MARQUETTE          WI   911 CALL CENTER

            TREES AND POWER LINES DOWN ALL OVER
            MARQUETTE COUNTY. TIME ESTIMATED FROM RADAR.

&&

WOOD

Special Weather Statement
National Weather Service Milwaukee/Sullivan WI
722 PM CDT SAT JUN 30 2018

WIZ047-051-057-058-063-064-010100-
Dodge-Columbia-Green Lake-Fond Du Lac-Jefferson-Dane-
722 PM CDT SAT JUN 30 2018

...A LINE OF SHOWERS WILL AFFECT GREEN LAKE...WESTERN FOND DU LAC...
EASTERN COLUMBIA...NORTHEASTERN DANE...NORTHWESTERN JEFFERSON AND
DODGE COUNTIES...

At 720 PM CDT, radar indicated showers and thunderstorms located
along a line extending from near Redgranite to near Randolph to
Waunakee. Movement was east at 40 mph.

Wind gusts up to 50 mph are possible with these showers.

Locations impacted include...
Madison, Fond Du Lac, Sun Prairie, Middleton, Beaver Dam, Waunakee,
Waupun, Ripon, Windsor, Mayville, North Fond Du Lac, Columbus,
Marshall, Horicon, Waterloo, Juneau, Deforest, Berlin, Lomira and
Randolph.

If you are on a lake, get out of the water and move indoors or
inside a vehicle. Move to safe shelter now! Do not be caught on the
water.

LAT...LON 4390 8888 4389 8840 4354 8841 4312 8891
      4310 8961 4358 8908 4398 8917 4398 8889
TIME...MOT...LOC 0020Z 274DEG 35KT 4398 8908 4358 8899 4316 8946

BOXELL