Forecast Discussion for GRB NWS Office
000
FXUS63 KGRB 230813
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
313 AM CDT Tue Apr 23 2019

Forecast discussion for routine morning forecast issuance

.SHORT TERM...Today...Tonight...and Wednesday
Issued at 312 AM CDT Tue Apr 23 2019

Satellite imagery shows a low pressure system over southern Lake
Michigan just east of Port Washington, Wisconsin as evidenced by
the curl in the IR imagery. Rain will continue to wind down across
east-central Wisconsin this morning as this low continues moving
east and high pressure builds in across the western Great Lakes
region. The high will bring drier air with mostly sunny skies
later this morning and into the afternoon hours as high
temperatures range from the middle to upper 50s across the north,
with highs of 60 to 65 across the south.

The high will drift slowly southeast tonight, as dry weather and
mostly clear skies continue. An approaching low will bring
increasing clouds to the north Wednesday afternoon, however dry
weather is expected to continue across the area. Lows tonight will
be in the 30s, with highs on Wednesday climbing into the middle
60s to around 70 degrees.

Much of the area only received around one half of an inch
of rain from this system, save for a thin swath of 1 to 2 inches
along a line from Algoma, to Green Bay, to Appleton, to Omro.
Given this thin swath of heavy rain is mainly outside of the area
of central and northeast Wisconsin that got copious amounts of
rain last week and with only light rain in the forecast for the
next few days will cancel the Flood Watch for the area with the
new forecast package.

.LONG TERM...Wednesday Night Through Monday
Issued at 312 AM CDT Tue Apr 23 2019

Much of the next week will be characterized by low amplitude flow
across the northern tier of the conus, which will keep temps near to
above normal into the start of the weekend.  As the jet stream sags
south, temps will likely fall below normal this weekend into early
next week.  Forecast concerns, however, generally revolve around
precip chances due to high water levels and fast flows on area
rivers.  The models generally have some differences with the
forecast rainfall on Wednesday night night and Thursday.  Since it
appears that much of the moisture will get soaked up by low pressure
over the Ohio Valley, will put more stock into the lower qpf
producing solutions, like the ecmwf. A second round of precip is
then possible over the weekend, but the spread is rather large so
will stick with a general model blend.

Wednesday night through Thursday night...Shortwave energy moving
across the northern Great Lakes will push a cold front across the
region during the Wednesday night into Thursday time period.  Will
see a ribbon of higher dewpoints accompany the front, but its
difficult to find much in the way of instability or higher values of
moisture transport along the front.  As a result, precip looks
likely along the front, but amounts look relatively light, perhaps
up to a quarter inch.  The chance of precip will likely end on
Thursday afternoon and will see clearing behind the front for
Thursday night. With the clouds and rainfall, temps on Thursday will
be cooler than on Wednesday.

Rest of the forecast...Temps will continue there cooling trend on
Friday into Saturday thanks to passage of a secondary cold front.
Otherwise, will be watching the track of a low pressure system
during the Friday night into Saturday time period.  A farther north
track could lead to a more substantial precip threat than depicted
in the ecmwf solution.  Temps may also be cold enough for some
flakes over parts of the area on late Friday night and early
Saturday morning. Cooler weather will continue into early next week
with another chance of precip on next Monday.
&&

.AVIATION...for 06Z TAF Issuance
Issued at 1059 PM CDT Mon Apr 22 2019

Lower ceilings and a few lower visibilities will linger at each of
the TAF sites through the early overnight hours before steadily
improving early Tuesday morning. Showers and a few thunderstorms
will slowly end over the eastern TAF sites after midnight.
Cigs/vsbys will be in the MVFR to IFR tonight before improving
Tuesday morning. VFR conditions can be expected over central WI
by around 12Z and eastern WI by 15Z. Good flying conditions can
then be expected late Tuesday morning through the rest of the TAF
period.
&&

.HYDROLOGY...
Issued at 312 AM CDT Tue Apr 23 2019

Much of the area only received around one half of an inch
of rain from this system, save for a thin swath of 1 to 2 inches
along a line from Algoma, to Green Bay, to Appleton, to Omro.
Given this thin swath of heavy rain is mainly outside of the area
of central and northeast Wisconsin that got copious amounts of
rain last week and with only light rain in the forecast for the
next few days will cancel the Flood Watch for the area. Despite
the cancellation of the Flood Watch, additional rises in river
levels are expected across central and northeast Wisconsin as this
latest rain filters into the local tributaries. Please monitor the
latest river forecasts for further information on flooding in your
local area.
&&

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

$$

SHORT TERM.....Kurimski
LONG TERM......MPC
AVIATION.......Cooley
HYDROLOGY......Kurimski

NWS GRB Office Area Forecast Discussion