Forecast Discussion for GRB NWS Office
FXUS63 KGRB 142000

Area Forecast Discussion
National Weather Service Green Bay WI
300 PM CDT Mon Oct 14 2019

Forecast discussion for routine afternoon forecast issuance

.SHORT TERM...Tonight and Tuesday
Issued at 258 PM CDT Mon Oct 14 2019

Mostly sunny skies prevailed across the region this afternoon.
Temperatures were mainly in the middle 40s to around 50 degrees.

For tonight, skies will start out mostly clear then clouds will
be on the increase as the next system approaches from the west.
The chance of showers will increase towards 12z. The main question
is how far east the precipitation will make it into the forecast
area. The latest HRRR model create much uncertainty as this model
focus the precipitation across north- central Wisconsin and the
remainder of the region is dry as of 12z. The other models have
chances of rain spreading all the way east into northeast
Wisconsin. Will have the highest chances of rain across north-
central Wisconsin, then taper precipitation chances to the east.
Low temperatures tonight will likely occur this evening or
shortly after midnight, then slowly rise towards sunrise on

For Tuesday, low pressure and the associated cold front will
move across the region. Models indicated 850mb LI`s down to
near zero and steep mid level lapse rates to support the mention
of an isolated thunderstorms. The track of the low will allow
for the warm sector to make it into our southern counties where
highs in the lower to middle 50s are expected. Highs across the
north will only be in the lower to middle 40s.

.LONG TERM...Tuesday Night Through Monday
Issued at 258 PM CDT Mon Oct 14 2019

Low pressure will be situated over far northeast WI/south central
Upper Peninsula on Tuesday evening, as a powerful upper level low
moves through northern WI. Likely/Categorical pops are warranted
across northern WI during the evening, with chance pops farther
south. Dynamic cooling may cause the rain to mix with snow across
far north central WI, but any accumulations should remain under an
inch. Favorable over-water fetch (NNW) and instability (Lake-H8
delta-t`s of 14-16 C increasing to 16-18 C) will support continued
lake-enhanced shower activity over north central WI and northern
Door county through Wednesday morning, but showers should decrease
elsewhere. A few snow showers may continue to mix in across
northern WI. Strong north-northwest winds will develop late
Tuesday night and continue into Wednesday, with possible gales on
Lake Michigan.

A surface ridge will bring dry conditions Wednesday night through
Friday. As the ridge shifts east on Friday, much milder air will
arrive, with highs rising into the upper 50s and lower 60s.

A chance of showers will arrive Friday night into Saturday as a
cold front and short-wave trof arrive. This system should shift
east of the region by Saturday evening, bringing a mainly dry end
to the weekend.

A stronger low pressure is expected to arrive Sunday night into
Monday, along with a threat of widespread rain.

.AVIATION...for 18Z TAF Issuance
Issued at 1154 AM CDT Mon Oct 14 2019

VFR conditions expected this afternoon through much of
tonight. The low clouds will erode by sunset, with
mid and high clouds on the increase tonight. The next round
or rain will arrive across central and north-central Wisconsin
between 09z and 12z, then into  northeast Wisconsin between 12z
and 15z. Rain will continue through the morning as an area of low
pressure and associated cold front move across the region. CIGS
are expected to drop into the IFR/MVFR category on Tuesday. Also
add low level wind shear late tonight into Tuesday morning from
160-180 degrees around 35 knots. The wind shear will come to an
end Tuesday morning as the system moves across the region. Some
snow is possible across the far north Tuesday night as the system
departs the area.



SHORT TERM.....Eckberg
LONG TERM......Kieckbusch

NWS GRB Office Area Forecast Discussion