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Area forecast discussion 
National Weather Service Green Bay WI
1033 PM CDT Tuesday Sep 16 2014

Updated aviation portion for 06z taf issuance

Short term...tonight and Wednesday
issued at 239 PM CDT Tuesday Sep 16 2014

Temperatures and small precipitation chances will be the main forecast concerns.

A cold front over Lake Superior will Sage south to near the
Wisconsin/Upper Peninsula border late tonight...then move through
the forecast area Wednesday and Wednesday evening. The main impact
should be an increase in cloud cover...though a small chance of
showers is warranted over northern WI on Wednesday due to the passage
of a weak short wave trough and the lfq of a 75 knots jet.

Temperatures will be a little tricky tonight...due to increasing
clouds over the north...and boundary layer winds of 15-20 kts
preventing a complete decoupling of the winds. Have used a blend
of the top-performing guidance sets for min temperatures...with a few
tweaks. Should see mainly upper 30s and lower 40s for min temperatures...
with spotty middle 30s (and patchy frost) possible. Maximum temperatures will
warm well into the 60s in advance of the front on Wednesday...though
some cooling will be felt in the north late in the day.

Long term...Wednesday night through Tuesday
issued at 239 PM CDT Tuesday Sep 16 2014

Will probably see a period of gusty NE winds in the Fox Valley and
Lakeshore areas Wednesday night...and perhaps a narrow band of
the wake of the cold frontal passage. Dry conditions should prevail
through Thursday strong Canadian high pressure remains
ridged to our northeast. Below normal temperatures are expected on
Thursday...though a moderating in temperatures is expected ahead of a
cold front on Friday and Saturday.

Have continued with the general idea of the previous several
forecasts...with a chance of showers and thunderstorms arriving as return
flow strengthens over the region on Friday. Have increases probability of precipitation
to likely over mainly our northwest counties on Friday night as the cold
front approaches...then over the entire forecast as the frontal
passage occurs on Saturday. Models show marginal instability
ahead of the front on Saturday...with cape around 1000 j/kg...
but decent deep layer shear (30-40 kts). Suspect that abundant
cloud cover will prevent a significant severe weather event. Precipitation
should taper off Saturday evening...with scattered wrap-around
showers lingering over NC WI on sun/Sun night.

Models have come into better agreement on a strong upper low
dropping into the Great Lakes region early next week. Canadian
high pressure should keep the region generally dry...but cool
temperatures look like a good bet.

Aviation...for 06z taf issuance
issued at 1026 PM CDT Tuesday Sep 16 2014

VFR conditions expected tonight into Wednesday.
Isolated light showers or sprinkles will be possible Wednesday
afternoon into Wednesday evening with the passage of a weak
frontal system.

Grb watches/warnings/advisories...


Short term.....Kieckbusch
long term......kieckbusch

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