River Flood Warning 20, NWS Green Bay, WI

Area Forecast Discussion
National Weather Service Green Bay WI
527 PM CDT Wed Apr 12 2023

Updated aviation portion for 00Z TAF issuance

.SHORT TERM...Tonight and Thursday
Issued at 223 PM CDT Wed Apr 12 2023

Sunny skies, unseasonably warm temperatures in the 70s to middle
80s and gusty southwest winds were occurring across the forecast
area this afternoon.

Clear skies will continue tonight with winds diminishing in the
evening. It will be a mild night, with lows in the middle 40s to
lower 50s north, and middle 50s elsewhere. Patchy fog may develop
late tonight in far northern WI, where a deep snowpack remains.

Sunny skies will continue into Thursday with highs once again
approaching or exceeding record values in the upper 70s to middle
80s. Cooler readings are expected near the Lake Michigan
shoreline, as winds turn more to the south and the lake breeze
makes a minor push inland.

.LONG TERM...Thursday Night Through Wednesday
Issued at 223 PM CDT Wed Apr 12 2023

The unseasonably warm conditions will come to an end this weekend
as a shortwave trough moves into the Great Lakes and becomes a
closed upper low. Models differ on the eventual movement of this
upper low, but the overall slow movement will keep northeast WI
unsettled from Saturday through Monday. This system will also
bring much cooler air into the region with temperatures falling
below normal for the start of next week. The next chance for any
precipitation looks to hold off until the later part of next week.

Thursday night and Friday...
Quiet and mild conditions to continue Thursday night with a
quasi-stationary front to our north and the region to be located
on the western fringes of an upper-level ridge. Mostly clear skies
and light south-southeast winds will send min temperatures down
into the 45-50 degree range north/near Lake MI, mainly lower 50s
south. Southerly winds to persist on Friday and as a weak system
moves up the OH River Valley. Expect to see some increase in
clouds during the afternoon, otherwise another warm day is on tap
with max temperatures in the lower 60s near Lake MI, lower to
middle 70s north-central WI and middle to upper 70s elsewhere.

Friday night and Saturday...
A cold front is forecast to move into the Upper Midwest Friday
night which should thicken up the cloud cover, but it appears that
the bulk of any precipitation is along or slightly behind the cold
front. Therefore, do not see the need for any pops Friday night.
Min temperatures to be in the upper 40s lakeside, upper 40s to
lower 50s north and middle to upper 50s south. This cold front
will push east toward central WI on Saturday, but tend to slow
down due to the upper ridge over the northeast CONUS and a surface
wave developing on the front. Anticipate rain chances to gradually
increase through the day, reaching central WI in the morning and
eastern WI in the afternoon. PW values are forecast to rise to
around one inch, so moisture will not be a problem. Some
instability will be present by the afternoon with MUCAPES up to
400 J/kg and mid-level lapse rates around 6.5 C/km, so have kept
thunder in the forecast, although severe is not expected. Max
temperatures on Saturday to range from around 60 degrees near Lake
MI, upper 60s to lower 70s inland.

Saturday night and Sunday...
The forecast becomes more uncertain for the latter half of the
weekend as some models keep the cold front in the vicinity, while
other models shift the front to the east. Meanwhile, a trailing
shortwave trough will move across the Upper MS Valley and close
off into an upper low over the western Great Lakes. The location
of the cold front will not make a difference Saturday night with
rain showers/few evening thunderstorms anticipated. It is Sunday
that the location of the cold front and upper low will make a
difference with scattered rain showers or even a rain/snow mix
over north-central and central WI as colder air begins to
overspread the region. Max temperatures on Sunday to only be in
the lower to middle 40s central WI, upper 40s to around 50 degrees
eastern WI.

Sunday night and Monday...
A cyclonic flow and wrap-around moisture are forecast to keep pops
in the forecast through Monday. Steadier precipitation should
occur across northern WI with the help of some lake enhancement
from Superior. Precipitation type will transition to mainly all
snow over northern and central WI, while east-central WI to be a
mix. Max temperatures Monday to generally be in the lower to
middle 40s.

Monday night and Tuesday...
Northeast WI to finally get rid of this system by Tuesday as a
ridge of high pressure builds into the area. A return of at least
some mixed sunshine will help to provide a minor boost to
temperatures with readings in the middle 40s near Lake MI, middle
to upper 40s north and upper 40s to lower 50s south.

Tuesday night and Wednesday...
The ECMWF has backed off from sending the next shortwave trough
toward northeast WI next Wednesday. Anticipate most of the day to
be dry with max temperatures warming in the upper 40s to lower 50s
near Lake MI, lower to middle 50s north and upper 50s to lower 60s
south.
&&

.AVIATION...for 00Z TAF Issuance
Issued at 526 PM CDT Wed Apr 12 2023

VFR conditions will continue through Friday, with
mainly clear skies and good visibility. Low level wind shear is
possible tonight and Thursday night with south winds around 10
knots at the surface and southwest winds around 40 knots at 1000
feet.
&&

.FIRE WEATHER...
Issued at 223 PM CDT Wed Apr 12 2023

The current Red Flag Warning will be allowed to continue through
expiration early this evening. Relative humidities have been a
bit slow to drop, but a few locations in central WI have dropped
into the 20s to around 30 percent range. Otherwise, temperatures
have warmed into the lower to middle 80s, and southwest winds
have been gusting to 25 to 30 mph in central WI, and 30 to 40 mph
in the Fox Valley.

After coordination with surrounding WFOs and the WI DNR, another
Fire Weather Watch will be issued for parts of central WI and the
western Fox Valley from 11 am to 8 pm Thursday. Temperatures and
relative humidities are expected to reach criteria, but wind
speeds may be marginal.
&&

.HYDROLOGY...
Issued at 223 PM CDT Wed Apr 12 2023

No major changes to the flooding risk late this week, as minor to
possibly moderate river flooding, along with low-land flooding,
will persist as we continue to melt the deep snowpack across
northern WI. A fairly quick melting process will continue over
northern WI as snow pack continues to warm and is or will become
primed to melt. Still another 1 to 4 inches to melt over northern
WI. Most or all of the snowpack looks to be gone by the end of the
week, which will continue the flooding for the foreseeable
future, especially over northern WI (especially the Menominee
River). Will continue with the ESF, river flood warnings and
hydrologic statements to handle the flooding risk.

On the Wisconsin River, a crest mainly on Thursday is expected,
then slowly fall into the weekend. Moderate flooding is possible
near Rothschild, but the latest forecast has the crest right at
moderate stage. On the Menominee, a slow and steady rise is
expected into the weekend, peaking this weekend or early next
week. Minor to possibly moderate flooding is expected. On the Wolf
River, there is still plenty of water to push through the basin,
so look for minor flooding to continue into next week. Other minor
flooding is possible on the other smaller rivers in central/northern
WI.
&&

.CLIMATE...
Issued at 223 PM CDT Wed Apr 12 2023

With highs in the upper 70s and 80s for much of the area, many
record highs are likely to be broken. Records highs for the
climate sites are:

Today:		Green Bay...80 (1977) 			Rhinelander...79 (1930)
			Wausau...78 (1931)

Thursday: 	Green Bay...78 (1938) 			Rhinelander...77 (1931)
			Wausau...77 (1938).
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
&&

SHORT TERM.....Kieckbusch
LONG TERM......Kallas
AVIATION.......RDM
FIRE WEATHER...Kieckbusch
HYDROLOGY......Kallas
CLIMATE........Kieckbusch

Hazardous Weather Outlook
National Weather Service Green Bay WI
229 PM CDT Wed Apr 12 2023

WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-131930-
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-
229 PM CDT Wed Apr 12 2023

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

.DAY ONE...Tonight

The combination of gusty southwest winds, low relative humidity,
and very warm temperatures will create critical fire weather
conditions in central and east central Wisconsin through early
evening. A Red Flag Warning remains in effect until 8 pm.

Runoff from snow melt will continue to cause high water levels,
fast flows on rivers and streams, along with low-land flooding.

.DAYS TWO THROUGH SEVEN...Thursday through Wednesday

The combination of low relative humidity, very warm temperatures
and gusty southwest winds will result in critical fire weather
conditions in central Wisconsin and the western Fox Valley on
Thursday. A Fire Weather Watch has been posted.

Flow rates and levels on streams and rivers in northern Wisconsin
will continue to increase as unseasonably warm temperatures
result in a significant melting of the snowpack. Some rivers will
reach or have already exceeded minor flood stage, including the
Menominee, where flooding is expected through early next week.

Most rivers in central and east-central Wisconsin are expected to
slowly recede this week. The exception will be large rivers with
headwaters to the north, including the Wisconsin and Wolf. These
rivers will remain high as the snowmelt from the north flows
downstream.

A few thunderstorms are possible Saturday afternoon and evening
as a low pressure system tracks through the western Great Lakes
region. These storms are not expected to be severe.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed tonight.

LMZ521-522-541>543-131930-
The Bay of Green Bay south of a line from Cedar River MI to Rock
Island Passage-Lake Michigan from Washington Island to Sheboygan-
229 PM CDT Wed Apr 12 2023

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

.DAY ONE...Tonight

Conditions hazardous to small craft are expected early this
evening.

.DAYS TWO THROUGH SEVEN...Thursday through Wednesday

A few thunderstorms are possible Saturday afternoon and evening.
These storms are not expected to be severe.

Kieckbusch/Kallas