Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 200951

Area Forecast Discussion
National Weather Service Green Bay WI
451 AM CDT Thu Apr 20 2017

Forecast discussion for routine morning forecast issuance

.SHORT TERM...Today...Tonight...and Friday
Issued at 451 AM CDT Thu Apr 20 2017

Moderate to heavy rain continues to slowly pull out of the region
early this morning as a low pressure system lifts northeast
through the western Great Lakes region. After the rain ends the
region should end up with a solid 1 to 1.5 inches of rainfall. As
this rain works its way through the area tributaries there could
be some flooding concerns as many rivers are within 2 feet of
flood stage.

Once this initial band of moderate to heavy rain exits to the
east, additional showers are expected through the day as the mid
level trof, seen on water vapor imagery over the upper Mississippi
Valley, slowly tracks east through the western Great Lakes today.
Rain chances will slowly end from south to north as drier air
sneaks its way in from the west which can be seen on the mid and
low level GOES-16 Water Vapor imagery channels over southern
Minnesota. Precipitation chances across the north will not end
until later tonight when the main mid level trof exits off to the
east. Colder air advecting in could introduce some snow across far
north-central Wisconsin, however snowfall amounts are expected to
be very light if it indeed accumulates at all.

Gusty easterly winds this morning will slowly back to a
northwesterly direction through out the day and this evening as
the aforementioned low tracks towards the SOO around midnight and
cooler air advects in from the northwest. The abundant cloud cover
and cold air advecting in will keep highs today muted, ranging
from the upper 30s to lower 40s across the north, and around 50
across the far south. Lows tonight are expected to plummet into
the lower to middle 30s.

Friday should be relatively quiet, as clouds break up from west to
east making for a mostly sunny day by the afternoon. Despite a
northerly wind, daytime highs are expected to recover back into
the 50s across the area with abundant sunshine from a late April
sun angle.

.LONG TERM...Friday Night Through Wednesday
Issued at 451 AM CDT Thu Apr 20 2017

Dry conditions can be expected through Sunday. The exception is
north central Wisconsin where there is a slight chance for rain
late Saturday night as a cold front pushes south into northern
Wisconsin. There is a slight chance for rain again Sunday
afternoon in the vicinity of the front. PoPs reach the chance
category in the north Sunday evening when the rain may mix with
or change to snow as temperatures fall during the night.

Rain chances spread across the entire forecast area Monday night
and continue on Tuesday as a surface low pressure system and mid
level short wave trough move across Wisconsin. Rain chances should
spread across most of the area again starting late Tuesday night
and then persist through the day on Wednesday as the next low and
mid level short wave pass to our south.

High temperatures should be above normal on Saturday, with plenty
of sunshine, but locations downwind from Lake Michigan will be
quite a bit cooler. Highs for the rest of the period are expected
to be near or a little below normal.

.AVIATION...for 06Z TAF Issuance
Issued at 1005 PM CDT Wed Apr 19 2017

Rain with isolated thunderstorms will continue to spread over much
of the state overnight. Cigs lower from vfr to mvfr as rain moves
in. Cigs will deteriorate further to LIFR/IFR conditions overnight
into Thursday morning. Rain and cyclonic flow Thursday will
continue to produce mainly MVFR/IFR cigs with periods of light
rain. Rain expected to diminish Thursday evening from southwest to
northeast as the low pressure system departs eastward.

Issued at 451 AM CDT Thu Apr 20 2017

An area of low pressure is forecast to slowly strengthen as it
moves through Wisconsin this morning. Winds will continue to ramp
up this morning as the pressure gradient tightens across the
region. Gale force wind gusts are expected near Death`s Door and
around the northern portion of Door County during the morning
hours. Therefore, a Gale Warning remains in effect for the
central Bay of Green Bay and the Lake Michigan nearshore waters
north of Sturgeon Bay. Once the Gale force winds subside, a Small
Craft Advisory will be issued for these zones as winds and waves
remain elevated through tonight.

Farther south closer to the low, winds will gust to 20 to 25
knots along with higher waves with a brief period of light winds
late this morning and early this afternoon as the low passes
through the area. A small craft advisory remains in effect for the
rest of the zones through tonight for the Lake Michigan nearshore



SHORT TERM.....Kurimski
MARINE.........Kurimski is the U.S. government's official web portal to all federal, state and local government web resources and services.