Special Weather Statement, NWS Green Bay, WI

Area Forecast Discussion
National Weather Service Green Bay WI
1123 AM CDT Wed Aug 7 2019

Updated aviation portion for 18Z TAF issuance

.SHORT TERM...Today...Tonight...and Thursday
Issued at 307 AM CDT Wed Aug 7 2019

A cold front and attendant PV anomaly will bring an increased
chance for showers and thunderstorms throughout the day as it
sinks south. There is currently activity along the front, which
could impact north-central Wisconsin this morning. The better
chance for rain will be this afternoon and this evening when
daytime heating is maximized as CAPE values rise to 1000 to 2000
J/kg. In addition to the instability bulk shear values will rise
to a respectable 25 to 35 knots which will increase the risk for
severe weather across the region. There will be a slight risk for
severe weather this afternoon and this evening due to the
instability and shear values with damaging winds, large hail and
localized flooding due to heavy rainfall. Hi-res models indicate
the main storm mode across our area will be multicell clusters
with the possibility of a few lines forming as well. High
temperatures today ahead of the cold front will rise into the
lower to middle 80s across central and east-central Wisconsin,
with highs in the upper 70s across north-central Wisconsin given
an earlier fropa.

Once the storms end later tonight a cooler airmass will settle in
across the western Great Lakes with quieter weather as well.
Overnight lows will sink to around 50 across north-central
Wisconsin with lows in the lower 60s across east-central
Wisconsin. Thursday will be noticeably cooler with much lower dew
points behind the front as daytime highs range from around 70
across the north, with middle to upper 70s across central and
east- central Wisconsin.

.LONG TERM...Thursday Night Through Tuesday
Issued at 307 AM CDT Wed Aug 7 2019

High pressure will bring dry conditions to the region Thursday
night into Saturday morning. Based on the latest numerical
guidance, did lower minimum temperatures on Friday and Saturday
mornings due to dry air mass in place and longer nights, combined
with slightly cooler MEX guidance values. This would allow
temperatures to fall into the middle and upper 40s on one or both
nights across the north. Highs Friday and Saturday will be in the
70s to around 80.

Still a lot of uncertainty when rain chances arrive Saturday or
Saturday night. Will have small chances across the west Saturday
afternoon and a chance across the entire area Saturday night. The
models tonight have the big discrepancy in location of the rain
on Sunday, but converge to a dry solution on Monday although the
Canadian model brings a complex just south of the area during the
day Monday. The chances of rain may return on Tuesday. High
temperatures should be in the 70s to around 80 during the
remainder of the forecast period.
&&

.AVIATION...for 18Z TAF Issuance
Issued at 1122 AM CDT Wed Aug 7 2019

A cold front remains expected to move across the region this
afternoon and evening. VFR conditions can be expected until
thunderstorms become more widespread this afternoon. Some of the
thunderstorms could be strong to severe during the middle
afternoon to early evening hours, with strong winds and large hail
being the main threats. Winds will shift to the west and
northwest behind the front by early evening as showers and
thunderstorms come to an end from northwest to southeast. Good
flying weather is expected thereafter with relatively light winds
and fair weather clouds popping across the area by late Wednesday
morning.

&&

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

SHORT TERM.....Kurimski
LONG TERM......Eckberg
AVIATION.......MPC

Hazardous Weather Outlook
National Weather Service Green Bay WI
407 AM CDT Wed Aug 7 2019

WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-080915-
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-
407 AM CDT Wed Aug 7 2019

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

.DAY ONE...Today and Tonight

There is a slight risk of severe thunderstorms with damaging
winds and large hail this afternoon and and evening. Heavy
rainfall could also lead to localized urban flooding.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

There is a chance of thunderstorms at times from Saturday
afternoon through next Tuesday. It is too early to determine
if any of the storms would become severe.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is anticipated, especially this afternoon
into this evening. Spotters are requested to report wind gusts
over 40 mph, wind damage, hail over a half inch in diameter,
and heavy rainfall or flooding.

LMZ521-522-541>543-080915-
The Bay of Green Bay south of a line from Cedar River MI to Rock
Island Passage-Lake Michigan from Washington Island to Sheboygan-
407 AM CDT Wed Aug 7 2019

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

.DAY ONE...Today and Tonight

Thunderstorms with strong winds and hail may pose a serious
risk for mariners this afternoon into this evening. Small craft
should exercise caution this afternoon due to gusty southwest
winds.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Thunderstorms may pose a risk to mariners at times from Saturday
night into early next week.

Kurimski/Eckberg

Special Weather Statement
National Weather Service Green Bay WI
1230 PM CDT Wed Aug 7 2019

WIZ011>013-071845-
Florence WI-Forest WI-Northern Marinette County WI-
1230 PM CDT Wed Aug 7 2019

...SIGNIFICANT WEATHER ADVISORY FOR FOREST...FLORENCE AND NORTHERN
MARINETTE COUNTIES UNTIL 145 PM CDT...

At 1229 PM CDT, Doppler radar was tracking a strong thunderstorm over
North Otter Creek Natural Area, or near Crandon, moving east at 40
mph.

Penny size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Crandon, Kingsford, Florence, Pembine, Goodman, Homestead, Fern,
Tipler, Popple River and Headwaters Wilderness.

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.

Persons in campgrounds should consider seeking sturdy shelter until
this storm passes.

&&

LAT...LON 4596 8833 4596 8825 4592 8810 4587 8807
      4581 8813 4578 8809 4579 8799 4576 8796
      4575 8787 4568 8778 4566 8783 4560 8777
      4556 8779 4556 8783 4550 8779 4544 8786
      4539 8786 4548 8902 4582 8900 4598 8836
TIME...MOT...LOC 1729Z 268DEG 35KT 4560 8879

Bersch