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Area forecast discussion 
National Weather Service Green Bay WI
629 am CDT Thursday Oct 2 2014

Updated aviation portion for 12z taf issuance

Short Friday
issued at 326 am CDT Thursday Oct 2 2014

Warm air advection showers continue over mainly the southeast half of the
forecast area early this morning or southeast of a line from imt
to ste. An isolated storm was located over Shawano County around 3
am. Larger area of convection departing northeast of the area
with the main short wave. Surface analysis early this morning
shows a surface trough over Minnesota extending south to a low
pressure region over the Central Plains. Stronger convection noted
near the warm front extending from the low over northern MO and
central Illinois. Widespread dense fog was located in this region of
high surface dewpoints and light winds in the surface trough over
Minnesota and Iowa. Will continue to monitor for fog this am...but
appears enough wind and mixing with showers to hold off fog

Forecast challenge turns to developing convection today as this
low pressure region lifts northeast toward the Great Lakes
region. Deeper moisture lifting north with the low will produce a
widespread rain over much of the forecast area tonight. Elevated
thunderstorms possible tonight as well.

Forecasts suggest a dry slot to advance toward the area late tonight
and pass over early Friday before wrap moisture drops in later
Friday. Will again trend down probability of precipitation for Friday...but will not
remove probability of precipitation completely due to cooler air aloft settling into the

Long term...Friday night through Wednesday
issued at 326 am CDT Thursday Oct 2 2014

Cold northwest flow will continue across the region Friday night
into the weekend. Weak disturbances or cold air aloft/daytime
heating will be sufficient for chances of rain showers Friday
night and Saturday across the region. Still some questions on
evolution of colder air working into the region...with the coldest
air wrapping south of northwest Wisconsin. Several models show warm
pocket (relatively speaking) around Lake Superior/northern Wisconsin
at 06z then collapses by 12z Saturday. If this scenario plays out...
the precipitation may mix with snow later in the night...probably closer
to 12z as colder air at 850mb moves into northern Wisconsin and would
be cold enough for snow. A weak disturbance and heating of the day
combined with cold air aloft should trigger more rain showers Saturday.
The rain would be mixed with snow across the north during the morning.
Precipitation should be on the decrease late in the day.

For Saturday night and Sunday...drier air will work into the region.
Continued the small chance of rain/snow showers across northern
Wisconsin where there is a little more moisture. Another disturbance
would bring a chance of rain showers on Monday...with a chance of
instability showers across northern Wisconsin Tuesday.

Temperatures will remain below normal into early next week...but
there is some indication temperatures should be close to normal
by Wednesday.

Aviation...for 12z taf issuance
issued at 629 am CDT Thursday Oct 2 2014

A period of IFR ceilings and visibilities due to fog may spread
into parts of central and north central Wisconsin this morning.
Otherwise mainly MVFR ceilings today before deteriorating to IFR
conditions tonight as a low pressure system with widespread rain
spread over the region. Isolated storms will be possible later
today into tonight.

Grb watches/warnings/advisories...


Short term.....Tdh
long term......eckberg

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