Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 302337

Area Forecast Discussion
National Weather Service Green Bay WI
637 PM CDT Thu Mar 30 2017

Updated aviation portion for 00Z TAF issuance

.SHORT TERM...Tonight and Friday
Issued at 231 PM CDT Thu Mar 30 2017

Low pressure moving south of Wisconsin this afternoon will
continue to bring rain and snow into central and northeast
Wisconsin into late evening. There could be some minor
accumulation of snow from Green Bay to Marinette into Door County
this evening, but should be just mainly on grassy surfaces. There
could be a few slick spots on the roads if more intense
precipitation rates fall over the same area for a period of time.

The precipitation should taper off to drizzle late tonight or
Friday morning as drier air begins to filter into the region
from the northeast and east. Skies will become mostly sunny
from north to south as the afternoon progresses. Leaned toward
the warmer met guidance north and west of the Fox Valley for
highs on Friday. Stayed near guidance across the Fox Valley
and lakeshore due to northeast winds off the cooler waters.

.LONG TERM...Friday Night Through Thursday
Issued at 231 PM CDT Thu Mar 30 2017

The main forecast concerns include determining how much of the
weekend will remain dry, followed by the track and precipitation
trends with two low pressure systems next week.

High pressure will arrive for the weekend, bringing primarily dry
weather to the region. Clouds will be on the increase on Sunday as
return flow and associated WAA increases on the back side of the
retreating surface high. Models are in general agreement that
showers will develop Sunday afternoon, aided by the arrival of a
jet streak aloft. The shower chances will continue Sunday night
and early Monday as a short-wave trof and surface cold front move
through the western Great Lakes.

Low pressure will develop in the Southern Plains Sunday night and
track northeast Monday and Monday night. Models vary wildly on the
track of the low, with the GFS ensemble mean bringing it into the
Great Lakes region, while the operational GFS and ECMWF keep it
much farther south. For now, will bank on the farther south track
and keep the forecast area mainly dry from Monday afternoon into

A second low is expected to develop in the Central Plains on
Tuesday and track toward southern Lake Michigan by Wednesday.
Although the GFS/ECMWF are fairly similar with the speed and track
right now, this was not the case with the previous runs, so would
like to see more continuity before raising pops real high in any
given period. If nothing changes, the most concentrated
precipitation should occur in our southern and eastern counties
Tuesday night into Wednesday. A deep upper trof will likely
linger Wednesday night into Thursday, and combine with cyclonic
flow at the surface to continue the shower threat. Will carry
chance or low-end likely pops from Tuesday night through
Thursday, and fine tune as timing becomes clearer with
subsequent forecasts.

.AVIATION...for 00Z TAF Issuance
Issued at 636 PM CDT Thu Mar 30 2017

IFR ceilings will rise to MVFR range from west to
east overnight as low pressure over Illinois and Indiana moves
slowly away. Skies should become VFR by midday Friday over the
entire region.



SHORT TERM.....Eckberg
LONG TERM......Kieckbusch
AVIATION.......RDM is the U.S. government's official web portal to all federal, state and local government web resources and services.