Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 272221

Area Forecast Discussion
National Weather Service Green Bay WI
521 PM CDT THU OCT 27 2016

Updated aviation portion for 00Z TAF issuance

.SHORT TERM...Tonight and Friday
Issued at 316 PM CDT Thu Oct 27 2016

There were still some showers across Door County at 19Z in
moisture wrapped around a departing surface low. Expect this to
end/exit by 00Z. A surface high and approaching mid level ridge
should help to keep the forecast area dry overnight, with just
patchy fog in central Wisconsin. 12Z soundings from the region
showed moisture trapped below an inversion. Clouds should keep
temperatures from dropping like a rock after sunset so lows
should not get much colder than the mid 30s tonight.

Winds will increase on Friday in return flow around the departing
surface high and ahead of an approaching low pressure system.
Models kept moisture and clouds around for the daytime on Friday
so that will keep temperatures down a little. Still, there is
enough warm advection for most locations to reach highs in the
upper 50s to mid 60s, around 10 degrees above normal. Short wave
energy passing north of the state, combined with isentropic lift
from strong warm advection will likely produce afternoon showers,
but they should stay north of the forecast area. Winds will
increase considerably during the day on Friday as the surface
pressure gradient increases and winds just a few thousand feet
above the surface reach the 40 to 60 knot range.

.LONG TERM...Friday Night Through Thursday
Issued at 316 PM CDT Thu Oct 27 2016

Mild weather looks to continue for the next week and
a half, as the upper air pattern resembles more of a late summer
look than fall.

An upper trough will move through Saturday, along with a surface
cold front. There`s not much moisture to work with, but probably
enough dynamics to produce showers as it moves across the area.
Then a surface high moves in from the northern Plains and should
provide dry and cooler weather Sunday.

Strong low pressure moving from North Dakota towards James Bay
will bring a chance of showers Monday and Monday night along with
breezy conditions. Fast nearly zonal flow with several short waves
will make for some showers at times during the middle and end of
next week, but not much in the way of significant precipitation.

.AVIATION...for 00Z TAF Issuance
Issued at 521 PM CDT Thu Oct 27 2016

Isolated light showers were gradually diminishing near Door
County late Thursday afternoon. In addition to the Lake boundary
instability, showers were being aided with the diminishing upper
cyclonic flow and a LFQ region of an upper jetlet passing through
early evening. Observations indicate mainly mvfr cigs over the
area as well upstream over western Wisconsin and much of
Minnesota. Anticipate little change overnight with the exception
of some patchy fog. Cloud trends become a bit more challenging for
Friday as increasing winds in the boundary layer may promote
mixing but warm air aloft may create an inversion in the lower
levels and keep the MVFR cigs around for Friday. LLWS conditions
may develop Friday night, but after the taf period for now.

Issued at 316 PM CDT Thu Oct 27 2016

Winds and waves will increase Friday as a low pressure system
tracks across the northern Great Lakes and upper level winds
increase considerably. Wind gusts are expected to reach gale force
Friday afternoon through Friday evening.



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