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Area forecast discussion
National Weather Service Green Bay WI
855 PM CDT sun Sep 15 2019

New information added to update section

Update...
issued at 849 PM CDT sun Sep 15 2019

Fog has developed quickly across north central and central WI
early this evening, where skies had already cleared. Expect the
clearing to continue to spread east through midnight, which should
allow similar fog development to occur there a little later. Will
start up a dense fog advisory for the western half of the County Warning Area
right away, but delay the start time until midnight in eastern WI.
Have also noticed some fog on the marine web cams, so will also
start a marine dense fog advisory at midnight.

The dense fog will impact the Monday morning commute, followed by
rapid improvement in visibilities between 9 and 10 am.

&&

Short term...tonight and Monday
issued at 255 PM CDT sun Sep 15 2019

Cloudy skies continued across the region this afternoon.
A few showers were noted across northeast Wisconsin.
Temperatures were in the middle 60s to lower 70s.

For the remainder of the afternoon, isolated showers are
possible across northeast Wisconsin until sunset. Otherwise,
clouds will be on the decrease late this afternoon or this
evening. The combination of clearing skies and light winds
should allow for widespread dense fog to form across much
of the area, resulting in hazardous travel and possible
Airport delays Monday morning. Low temperatures tonight
will be in the middle 50s to around 60 degrees.

On Monday, the fog will burn off by 9 am at most spots.
Partly cloudy skies are expected for the remainder of the
day. Based on upstream observations, will lean toward the
warmer mav guidance for highs, except near the Bay and lake
where winds are expected to turn easterly during the day.
Highs should be mainly in the 70s, cooler near Lake Michigan.

Long term...Monday night through Sunday
issued at 255 PM CDT sun Sep 15 2019

Unusually strong upper ridging from the Gulf Coast to the Great
Lakes will make for a warm week of weather for mid September. The
ridge will keep the threat of precipitation west of the forecast
area for the most part. Upper troughs passing well to our northwest
and weak surface cold fronts will bring a chance of showers and
thunderstorms at times. The best chances seem to be Wednesday and
Saturday. Temperatures will be about 10 degrees above usual.
&&

Aviation...for 00z taf issuance
issued at 641 PM CDT sun Sep 15 2019

Low clouds were gradually clearing from west to east early this
evening, and models suggest that the clearing trend will continue,
reaching the Lakeshore by around midnight. As this occurs, areas
of fog will quickly develop due to the combination of light winds
and clear skies. If the low clouds remain in place in eastern WI,
the fog may not be as dense compared to central and north central
Wisconsin. Will bank on the clearing trend to continue, and
forecast dense fog at all of the taf sites overnight into early
Monday. The fog is expected to improve by around 15z/Mon, though
IFR/MVFR ceilings will probablly linger for another hour or two
after that. Expect VFR conditions across most of the forecast
area by midday.
&&

Grb watches/warnings/advisories...
dense fog advisory from midnight tonight to 10 am CDT Monday for
wiz013-021-022-038>040-048>050-073-074.

Dense fog advisory until 10 am CDT Monday for wiz005-010>012-
018>020-030-031-035>037-045.
&&

$$

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