Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 301118
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
618 AM CDT TUE AUG 30 2016

Updated aviation portion for 12Z TAF issuance

.SHORT TERM...Today...Tonight...and Wednesday
Issued at 224 AM CDT Tue Aug 30 2016

Early this morning radar shows a gradually diminishing line of
convection extending from around Florence county to central
Minnesota and gradually sagging south or southeast. Convection was
maintaining a bit more around MSP area due to higher pwats. The
Strongest storms over far northeast Wisconsin were in a region of
MU capes around 1500. Storms over northeast Wisconsin were also
tracking in a weak sheared environment. A short wave trough
extending over northeast Wisconsin to southeast Iowa early this
morning were also assisting the storms over northeast Wisconsin
and developing convection over southwest Wisconsin into northern
Illinois. This trough will pass over mainly southeast Wisconsin
this morning.

A cold front was lagging just behind this line of convection and
will continue to drop south over the area today before departing
east central Wisconsin this evening. Progs indicate a diminishing
period of convection this morning with the short wave trough
dropping southeast, then some redevelopment again along the front
this afternoon and evening. Current forecast timing and coverage
of convection looks reasonable and will add a diminished period
for a time this morning.

Later tonight and well after the cold front passage and
continuing into Wednesday, north to northeast winds between the
departing low pressure system to the northeast and ridging to the
west will allow a much drier and more comfortable air mass to
filter into the area. Later Wednesday 850 mb winds will be on the
increase, with the potential of gusty winds along the lake shore
region Wednesday afternoon.

.LONG TERM...Wednesday Night Through Monday
Issued at 224 AM CDT Tue Aug 30 2016

500mb ridge will build into the western Great Lakes early in the
period. At the surface, Canadian high pressure will bring mild
days and cool nights for early September. By the weekend, the
500mb pattern will be dominated by a west/southwest flow as upper
trough moves into the western half of the United States.

Dry conditions are expected Wednesday night through Saturday
evening as high pressure dominates the weather pattern. Northeast
flow off Lake Michigan and cool air aloft should allow for
stratocumulus clouds to develop over the lake and move onshore.
Although the forecast is dry, still can`t rule out a stray lake
effect rain shower.

The first opportunity for chances of rain come late Saturday
night. Latest ECMWF model would delay the onset of rain until
Sunday. The chances of showers and storms will increase
across the west Sunday and across the remainder of the region
Sunday afternoon or Sunday night. A cold front will move across
the region on Monday, bringing a continued chance of showers and
storms for this period. Did lower minimum temperatures a few
degrees each night from Thursday through Saturday.
&&

.AVIATION...for 12Z TAF Issuance
Issued at 618 AM CDT Tue Aug 30 2016

Light winds combined with surface dewpoints in the
60s overnight produce areas of ground fog early this morning.
The fog is locally dense but should diminish shortly after
sunrise. Otherwise there is a chance for showers and storms today
into this evening as cold front slides through.  Mainly vfr
conditions expected today and tonight with the exception of the
showers and storms. Light winds tonight may again produce patchy
fog late tonight.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....TDH
LONG TERM......Eckberg
AVIATION.......TDH



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