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Area forecast discussion
National Weather Service Green Bay WI
1028 PM CDT Tue Sep 17 2019

Updated aviation portion for 06z taf issuance

Short term...tonight and Wednesday
issued at 300 PM CDT Tue Sep 17 2019

Skies were partly to mostly cloudy across the region this
afternoon. Dense fog, with visibilities of a quarter of a
mile or less was noted across the coastal waters of Lake Michigan
and across portions of the central Bay of Green Bay. It was warm
and humid away from Lake Michigan with readings well into the
70s to lower 80s. Temperatures remained in the 60s along the
Lake Michigan shoreline due to the clouds and fog.

For tonight, expect the dense marine fog to expand inland
across door, Kewaunee and Manitowoc counties. A dense fog
advisory may be needed later tonight for these counties if
the fog expands far enough inland. The fog may also expand
over the southern Bay of Green Bay and impacts the coastline
of Oconto and Marinette counties as well. The remainder of the
region will be partly cloudy. Low temperatures will be in
the upper 50s and lower 60s.

For Wednesday, marine fog will continue to impact the Lake
Michigan shoreline during the morning. Low confidence that the
fog will erode during the afternoon, thus kept patchy fog along
the lake into mid afternoon hours. Otherwise, the biggest change
is to slow down the arrival of the chances of showers and storms.
Although have a small chance of showers and storms across our
northwest counties during the afternoon, think most of the rain
will hold off until 7 PM. Trended toward the warmer mav guidance
for highs on Wednesday.

Long term...Wednesday night through Tuesday
issued at 300 PM CDT Tue Sep 17 2019

An upper ridge from the Gulf of Mexico to the Great
Lakes will keep very warm weather across the region through the
end of the week. Chances for showers and thunderstorms will
increase as the week GOES on as the ridge moves slowly east and
the upper flow becomes more southwesterly.
&&

Aviation...for 06z taf issuance
issued at 1020 PM CDT Tue Sep 17 2019

Patchy fog and low stratus will continue near the Lake Michigan
shoreline tonight into Wednesday morning, with occasional LIFR/vlifr
flight conditions possible at the mtw taf site. Improving conditions
are anticipated there by mid to late morning, as winds increase.
For the rest of the forecast area, VFR conditions should prevail
until late tonight, when some IFR/MVFR stratus is expected to
develop in north central WI. MVFR conditions may linger at the
rhi taf site through most of Wednesday afternoon and evening, and
possibly lower to IFR toward the end of the taf period. MVFR
should also move into the auw/County Warning Area areas Wednesday evening.

Low-level wind shear will affect north central WI, including
the rhi taf site, overnight into Wednesday morning. Southerly
surface winds will increase across the entire forecast area by
late Wednesday morning, with gusts over 20 knots at times through
the afternoon. Low level wind shear is expected to redevelop at rhi early
Wednesday evening.

Showers and scattered thunderstorms are expected to arrive in
north central and central WI during the mid to late evening on
Wednesday.
&&

Grb watches/warnings/advisories...
none.
&&

$$

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