000
FXUS63 KGRB 221140
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
640 AM CDT THU SEP 22 2016

Updated aviation portion for 12Z TAF issuance

.SHORT TERM...Today...Tonight...and Friday
Issued at 359 AM CDT Thu Sep 22 2016

Surface analysis shows a stationary front draped across northern
Wisconsin early this morning as Doppler Radar shows continued
showers and a few thunderstorms south of the boundary. This
boundary is forecast to slowly sink south as a cold front today,
with continued activity along and south of the boundary. Rain
chances today are forecast to slowly diminish from north to south
as the front sinks south and takes the best dynamics with it.
Current radar and ground truth estimates show a swath of rain of 4
to 6 inches across Wood and Waushara counties. This is buffered by
a swath of 2 to 3 inches to the north and east across Marathon and
Winnebago counties. However farther to the north and east rainfall
amounts were much less, generally 1 to 2 inches. With only 1 to 2
inches of additional rainfall expected across the southern portion
of the area today will take out the northern and eastern portions
of the current Flash Flood Watch as impacts have been minimal with
the additional expected rainfall expected to be handled by the
area rivers will trim some of the area out of the watch and leave
the areas that have had much more rainfall and been impacted in
the current watch. Severe weather potential should be minimal
today with only a few hundred J/kg of MUCAPE across the cwa.

The aforementioned cold front will then stall across the
Wisconsin/Illinois border tonight as additional weak shortwaves
and isentropic lift cause rain chances to increase a bit across
the southern cwa during the overnight hours. However with the best
moisture well to the south and elevated instability minimal,
heavy rainfall is not expected to continue tonight.

Despite the front sinking a bit further south across northern
Illinois on Friday, rain chances will continue across the southern
and central cwa as weak shortwaves and isentropic lift continue
across the western Great Lakes region.

.LONG TERM...Friday Night Through Wednesday
Issued at 359 AM CDT Thu Sep 22 2016

An active pattern with above normal rainfall is expected during
the period. A frontal boundary draped south of the area will begin
to lift north as a warm front Friday night. At this time, the best
chances for rain and a few storms after midnight with the return
flow. Showers and a few storms will linger into Saturday morning
before dry conditions are expected Saturday afternoon and evening.

A slow moving cold will approach Wisconsin from the west late
Saturday night and Sunday. Chances for rain will increase from
west to east during the period. Rain chances will increase into
the likely category across the west Sunday afternoon and across
the entire region Sunday night. Rain will linger into Monday
morning across the east, while a cool northwest flow will bring a
chance of showers to northern Wisconsin, especially during the
afternoon hours. The cool cyclonic flow aloft will be focusing
mechanism for chances of showers Tuesday and Wednesday.
&&

.AVIATION...for 12Z TAF Issuance
Issued at 640 AM CDT Thu Sep 22 2016

A nearly stationary frontal boundary extending from west to east
over the state will be a focus of showers and storms today and
tonight as it slowly sinks south. Cigs and vsbys may come up a
bit today, before deteriorating tonight.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through this evening FOR WIZ030-035-036-045.
&&

$$

SHORT TERM.....Kurimski
LONG TERM......Eckberg
AVIATION.......Kurimski