Special Weather Statement, NWS Green Bay, WI

Area Forecast Discussion
National Weather Service Green Bay WI
403 AM CDT Tue Jul 27 2021

Forecast discussion for routine morning forecast issuance

.SHORT TERM...Today...Tonight...and Wednesday
Issued at 402 AM CDT Tue Jul 27 2021

The first linear MCS that produced widespread damaging winds over
northern and eastern WI has weakened and shifted across Lake
Michigan, while another west to east oriented line of storms was
dropping south across the forecast area. This line was being
sustained by WAA/moisture convergence and a weak short-wave
trough, and MUCAPE of 1500-2000 j/kg over north central/central
WI. Expect the strrongest cells to move through central WI early
this morning, with convection weakening in the east as it
encounters an air mass that was overturned by earlier storms. All
of this convection will result in the frontal boundary getting
shoved to our south this morning, which should bring a lull in the
precipitation this afternoon into tonight, with only isolated
storms anticipated. Highs today should be in the upper 70s and
lower 80s north, and middle to upper 80s south, with an easterly
wind component keeping the lakeshore counties in the 70s. Lows
tonight should be in the upper 50s to middle 60s.

On Wednesday, a surface/850 mb warm front will lift back toward
the region, as low pressure moves into MN. Strong WAA will cause
scattered/numerous thunderstorms to develop during the afternoon.
With increasing instability and very strong deep layer
shear/helicity, severe thunderstorms (including supercells) look
like a good bet. High temperatures will be in the lower 80s north,
and middle to upper 80s south, with slightly cooler readings
along the lakeshore. Heat indices may reach the middle 90s in
parts of central WI.

.LONG TERM...Wednesday Night Through Monday
Issued at 402 AM CDT Tue Jul 27 2021

Severe weather indices are pointing toward a potentially
significant severe weather and heavy rainfall event Wednesday
night. A warm front will lift into central WI, accompanied by
MUCAPE of 2000-4000 j/kg, deep layer shear of 55-70 knots, 0-3km
helicities of 400-600, low LCL heights and abundant low-level
CAPE. Supercells, including potential for a high-end severe event
and a few tornadoes, are a concern for especially the southwest
half of the forecast area, where SPC has highlighted an enhanced
risk of severe storms. With PWATS around 2 inches and 850 mb Tds
of 14-17 C, torrential rainfall is also a significant concern.
Most of the convection should shift south of the region by
Thursday morning.

The next chance of thunderstorms will be late Friday night into
Saturday, when a cold front and associated short-wave trough
move through. Instability, moisture and shear are much more modest
than the midweek set-up, but could still see a few strong to
severe storms.

Canadian high pressure should bring drier and somewhat cooler
weather for the end of the weekend and early part of next week.
&&

.AVIATION...for 06Z TAF Issuance
Issued at 1241 AM CDT Tue Jul 27 2021

A line of thunderstorms with strong to damaging winds will
continue to progress through far northeast and east central WI
early in the TAF period. At this time, it appears that the worst
of the storms will stay north of OSH, but a gust front will pass
through with a wind shift to the north shortly after 06z, and
there is a chance of storms between 07z-09z. More thunderstorms
are developing in an area of WAA/moisture convergence and
increasing elevated instability over northwest WI, and these
storms will likely track southeast through parts of central WI
early this morning. It appears that weather will quiet down later
this morning/afternoon, but will take a closer look at these trends
with the 12z TAFs.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SHORT TERM.....Kieckbusch
LONG TERM......Kieckbusch
AVIATION.......Kieckbusch

Hazardous Weather Outlook
National Weather Service Green Bay WI
419 AM CDT Tue Jul 27 2021

WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-280930-
Vilas-Oneida-Forest-Florence-Northern Marinette County-Lincoln-
Langlade-Menominee-Northern Oconto County-Door-Marathon-Shawano-
Wood-Portage-Waupaca-Outagamie-Brown-Kewaunee-Waushara-Winnebago-
Calumet-Manitowoc-Southern Marinette County-
Southern Oconto County-
419 AM CDT Tue Jul 27 2021

This Hazardous Weather Outlook is for north-central and northeast
Wisconsin.

.DAY ONE...Today and Tonight

There is a chance of thunderstorms this morning. Brief gusty winds
and heavy downpours are anticipated with any storms. There should
be lull in thunderstorm activity this afternoon and tonight,
though an isolated storm or two cannot be ruled out.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

A significant severe weather event is looking more likely Wednesday
afternoon into Wednesday night. Any of the thunderstorms could be
severe and produce damaging winds and large hail. A tornado or two
will also be possible, especially from central Wisconsin into the
southern Fox Valley. Torrential rainfall is also likely, and may
lead to flooding.

Humid conditions are also likely through Wednesday. The heat
index could reach the lower to middle 90s across central Wisconsin
and the southern Fox Valley. The combination of heat and humidity
will result in an elevated risk of heat related illness, especially
for individuals in poor health.

There is also a threat of thunderstorms on Saturday, though it is
too early to determine if severe weather will occur.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed Wednesday afternoon and night.

LMZ521-522-541>543-280930-
The Bay of Green Bay south of a line from Cedar River MI to Rock
Island Passage-Lake Michigan from Washington Island to Sheboygan-
419 AM CDT Tue Jul 27 2021

This Hazardous Weather Outlook is for portions of northwest Lake
Michigan and the waters of Green Bay.

.DAY ONE...Today and Tonight

There is a chance of thunderstorms, especially this morning. Gusty
winds and brief heavy rainfall will be possible with the storms.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Thunderstorms will continue to be possible at times Wednesday
afternoon and Wednesday night. Any storms that develop will be
capable of producing strong winds, hail, torrential rainfall, and
lightning.

There is also a chance of thunderstorms on Saturday.

Kieckbusch

Special Weather Statement
National Weather Service Green Bay WI
230 AM CDT Tue Jul 27 2021

WIZ011-019-021-270815-
Langlade WI-Northern Oconto County WI-Forest WI-
230 AM CDT Tue Jul 27 2021

...SPECIAL WEATHER STATEMENT...

At 230 AM CDT, Doppler radar was tracking a strong thunderstorm over
Veterans Memorial County Park, or 13 miles north of Antigo, moving
southeast at 45 mph.

Heavy rain, pea size hail and winds in excess of 30 mph will be
possible with this storm.

Locations impacted include...
Antigo, White Lake, Parrish, Pearson, Gardner Dam Scout Camp,
Woodlawn, Veterans Memorial County Park, Ma Ka Ja Wan Scout
Reservation, Langlade and Elcho.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

&&

LAT...LON 4547 8943 4547 8905 4548 8905 4549 8879
      4532 8864 4512 8865 4512 8942
TIME...MOT...LOC 0730Z 298DEG 39KT 4533 8915

Bersch

Special Weather Statement
National Weather Service Green Bay WI
241 AM CDT Tue Jul 27 2021

WIZ018>020-030-031-270830-
Shawano WI-Langlade WI-Marathon WI-Menominee WI-Lincoln WI-
241 AM CDT Tue Jul 27 2021

...SPECIAL WEATHER STATEMENT...

At 240 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Veterans Memorial County Park to near
Medford. Movement was southeast at 50 mph.

Pea size hail, winds in excess of 30 mph, and torrential rainfall
will be possible with these storms.

Locations impacted include...
Wausau, Shawano, Antigo, Marshfield, Weston, Merrill, Rib Mountain,
Mosinee, Abbotsford and Spencer.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

&&

LAT...LON 4503 9031 4504 9020 4512 9020 4512 9005
      4534 9005 4543 8893 4538 8893 4538 8886
      4467 8849 4468 9032
TIME...MOT...LOC 0740Z 312DEG 44KT 4524 8906 4511 9026

Kurimski

Special Weather Statement
National Weather Service Green Bay WI
320 AM CDT Tue Jul 27 2021

WIZ019>021-030-031-035>039-074-270900-
Southern Oconto County WI-Waupaca WI-Shawano WI-Langlade WI-
Outagamie WI-Northern Oconto County WI-Wood WI-Marathon WI-
Portage WI-Brown WI-Menominee WI-
320 AM CDT Tue Jul 27 2021

...SPECIAL WEATHER STATEMENT...

At 320 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Gillett to near Mosinee to near Owen.
Movement was southeast at 50 mph.

Pea size hail and winds in excess of 30 mph will be possible with
these storms.

Locations impacted include...
Green Bay, Wausau, Stevens Point, Wisconsin Rapids, Shawano, Antigo,
Waupaca, Marshfield, Weston and New London.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

&&

LAT...LON 4503 9031 4504 9020 4512 9020 4511 8843
      4445 8781 4432 8883 4440 9032
TIME...MOT...LOC 0820Z 307DEG 42KT 4491 8842 4477 8957 4491 9054

Kurimski

Special Weather Statement
National Weather Service Green Bay WI
351 AM CDT Tue Jul 27 2021

WIZ022-030-031-035>040-045-048>050-074-271000-
Calumet WI-Waupaca WI-Outagamie WI-Winnebago WI-Wood WI-Marathon WI-
Portage WI-Brown WI-Southern Oconto County WI-Shawano WI-Kewaunee WI-
Waushara WI-Manitowoc WI-Door WI-
351 AM CDT Tue Jul 27 2021

...SPECIAL WEATHER STATEMENT...

At 351 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Bay Shore Park to 10 miles north of
Waupaca to 11 miles west of Greenwood. Movement was southeast at 55
mph.

Pea size hail, winds in excess of 30 mph, and torrential rainfall
will be possible with these storms.

Locations impacted include...
Green Bay, Appleton, Oshkosh, Manitowoc, Stevens Point, Wisconsin
Rapids, Shawano, Waupaca, Kewaunee and Wautoma.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

&&

LAT...LON 4390 8889 4398 8889 4398 8960 4425 8960
      4425 9032 4501 9032 4486 8915 4487 8777
      4486 8777 4471 8792 4463 8793 4487 8760
      4466 8733 4433 8748 4418 8745 4389 8770
      4389 8816 4394 8816 4394 8840 4389 8840
TIME...MOT...LOC 0851Z 305DEG 50KT 4464 8792 4451 8906 4476 9084

Kurimski

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREEN BAY WI
558 AM CDT TUE JUL 27 2021

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

1207 AM     TSTM WND GST     5 NNE BREED             45.12N 88.37W
07/27/2021  M77 MPH          OCONTO             WI   MESONET

            MOUNTAIN RAWS FIRE OBSERVATION.

&&

ECKBERG

Special Weather Statement
National Weather Service Green Bay WI
616 AM CDT Tue Jul 27 2021

WIZ030-035-036-271200-
Wood WI-Marathon WI-Portage WI-
616 AM CDT Tue Jul 27 2021

...SPECIAL WEATHER STATEMENT...

At 615 AM CDT, Doppler radar was tracking a strong thunderstorm near
Marshfield, or 24 miles northwest of Wisconsin Rapids, moving
southeast at 35 mph.

Heavy rain, pea size hail and winds in excess of 30 mph will be
possible with this storm.

Locations impacted include...
Stevens Point, Wisconsin Rapids, Marshfield, Mosinee, Spencer,
Whiting, Bevent, Amherst, Pittsville and Lake Wazeecha.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

&&

LAT...LON 4483 9032 4482 8922 4436 8922 4438 9032
TIME...MOT...LOC 1115Z 303DEG 30KT 4471 9007

Bersch