Forecast Discussion for GRB NWS Office
FXUS63 KGRB 170352

Area Forecast Discussion
National Weather Service Green Bay WI
1052 PM CDT Sat Oct 16 2021

Updated aviation portion for 06Z TAF issuance

.SHORT TERM...Tonight and Sunday
Issued at 223 PM CDT Sat Oct 16 2021

Windy and seasonably cool temperatures were noted this afternoon
with readings in the 50s to near 60. Northwest winds were from 15
to 25 mph with gusts of 25 to 35 mph.

For tonight, the fair weather cumulus will dissipate around sunset.
Clear skies will continue through the night with diminishing winds.
The greatest chance for a widespread frost will be across central
Wisconsin where winds become the lightest toward sunrise on
Sunday morning. Have issued a frost advisory for Marathon, Wood
and Portage Counties. We no longer issue frost/freeze headlines
across the far north.

Sunny skies are expected on Sunday with highs a few degrees
above normal with readings in the lower to middle 60s. A west
to northwest wind will gust to 20 to 25 mph during the afternoon.

.LONG TERM...Sunday Night Through Saturday
Issued at 223 PM CDT Sat Oct 16 2021

The main forecast concerns include frost potential Sunday night,
precipitation trends Wednesday into Thursday, and a return to
cooler temperatures for the latter half of the week.

Sunday night through Tuesday night...A surface ridge and upper
level ridge will reside over the region early in the period,
before gradually shifting east into midweek. One more cool night
is anticipated Sunday night, with clear skies, light winds and
temperatures in the 30s leading to areas of frost west and north
of the Fox Valley and lakeshore areas. Developing southwest winds
will result in a warming trend, with highs reaching the middle 60s
to lower 70s by Tuesday.

Wednesday through Thursday...A surface low is forecast to track
from the MN/IA border to central WI on Wednesday afternoon and
evening. Expect scattered showers and a few thunderstorms to
develop by Wednesday afternoon, as a warm front lifts into the
forecast area. Showers will increase Wednesday night, especially
over northern WI, as an upper level trough moves through. A cold
front will move through after the surface low shifts east
Wednesday night, resulting in gusty northwest winds and much
cooler (but closer to normal) temperatures. Showers should
gradually taper off from west to east on Thursday, with high
temperatures only reaching the 50s.

Rest of the extended...Aside from a small chance of lake-effect
showers over north central WI and northern Door County Thursday
night into Friday, this is looking like a fairly dry period. Cool
temperatures will prevail, with highs only in the lower to middle

.AVIATION...for 06Z TAF Issuance
Issued at 1051 PM CDT Sat Oct 16 2021

The main concern will be the gusty wind potential for late Sunday
morning through much of the afternoon. Winds will diminish in the
evening and overnight. Otherwise, good flying conditions expected
through this TAF issuance with respect to ceilings and

Frost Advisory from 2 AM to 8 AM CDT Sunday for WIZ019-030-035-


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

NWS GRB Office Area Forecast Discussion