NWS-Green Bay Forecast Discussion

 

						FXUS63 KGRB 171102
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
602 AM CDT Tue Jul 17 2018

Updated aviation portion for 12Z TAF issuance

.SHORT TERM...Today...Tonight...and Wednesday
Issued at 244 AM CDT Tue Jul 17 2018

High pressure will bring mostly sunny conditions to the western
Great Lakes region through Wednesday. Other than a few fair
weather cumulus clouds during the daytime hours, not much weather
is expected during the next few periods. Much lower dew points and
cooler temperatures will make for a much more pleasant day today
as highs range from the lower to middle 70s across the north, with
highs around 80 further south. Light northeast winds will allow a
lake breeze to make its way inland during the afternoon hours.

Mostly clear skies and light winds will allow lows to fall into
the 40s across the north, with lower to middle 50s across the
south tonight. Slightly warmer temperatures are expected on
Wednesday as the region gets on the backside of the departing high
with temperatures in the upper 70s to lower 80s. Dew points on
Wednesday will be a bit higher, but still relatively comfortable
with readings in the 50s.

.LONG TERM...Wednesday Night Through Monday
Issued at 244 AM CDT Tue Jul 17 2018

With the sub-tropical ridge suppressed to the southern tier of the
conus, northern stream systems will mainly impact the western Great
Lakes through this part of the forecast.  One of these systems is
forecast to pass across the area on Thursday night into early this
weekend.  Based upon model comparisons, have a slight preference for
the ecmwf over the gfs, which looks to be on the faster side of
guidance.

Wednesday night through Thursday night...High pressure will be
centered across the area at the start of Wednesday evening before
shifting to New England by 12z Thu.  Dry air associated with the
high should keep clouds at bay for much of the night, though some
cirrus could invade the region late ahead of the next system moving
across the northern Mississippi Valley.  As low pressure draws
closer on Thursday, clouds will continue to increase from southwest
to northeast.  Increasing moisture transport in the mid-levels will
lead to a chance of showers pushing into central WI in the
afternoon.  Better chances will arrive on Thursday night as the low
moves into western Wisconsin, with elevated moisture transport and
instability axis sliding northeast across most of the region. Though
the low level jet is projected to reach above 30 kts, the threat of
severe weather looks low due to marginal capes.  Temps to remain
seasonable during this period.

Rest of the forecast...The vertically stacked low pressure will
drift overhead on Friday and Friday night, leading to periods of
showers and storms.  With the low directly overhead, wouldnt be
surprising to see an isolated cold air funnel, though temps aloft
dont look all that cold.  The low will shift east of the region for
the weekend, but will be in close enough proximity for a few showers
to develop with the heat of the day, and perhaps a little more
widespread over the northwoods.  The low will finally depart early
next week, which should lead to a few dry periods.  Due to the
clouds and precip potential, temps to remain near or slightly below
normal into early next week.
&&

.AVIATION...for 12Z TAF Issuance
Issued at 602 AM CDT Tue Jul 17 2018

VFR conditions will prevail through the TAF period. Other than a
few fair weather cumulus clouds during the daytime hours not much
weather is expected as high pressure slides across the western
Great Lakes. Light northerly winds expected to veer to the
northeast or east across eastern Wisconsin this afternoon.
&&

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

$$

SHORT TERM.....Kurimski
LONG TERM......MPC
AVIATION.......Kurimski