Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 140402

Area Forecast Discussion
National Weather Service Green Bay WI
1102 PM CDT Thu May 13 2021

Updated aviation portion for 06Z TAF issuance

.SHORT TERM...Tonight and Friday
Issued at 348 PM CDT Thu May 13 2021

High pressure at the surface and aloft will gradually drift
southeast tonight into Friday. Though a very slight increase in
moisture is expected, no rain is anticipated through Friday.

Lows tonight will not be as chilly as last night, but will still
be cold enough (34-37) for frost development over the Northwoods.
Will have one more night of Frost Advisories north of a line from
Merrill to Mountain to Wausaukee tonight.

Look for another day of mild temperatures and low relative
humidity on Friday, along with continued elevated fire weather
conditions in the sandy soil regions. High temperatures should be
similar to day, with readings in the upper 60s and lower 70s,
except lower to middle 60s lakeside.

.LONG TERM...Friday Night Through Thursday
Issued at 348 PM CDT Thu May 13 2021

A gradual rise to above normal temperatures and little to no chances
for precipitation are the main highlights from this forecast period.

Friday night through the Weekend...A shallow layer of low-level
moisture, associated with a weak mid-level shortwave, will attempt
to move across the area from the west Friday night into Saturday.
This will result in increasing clouds Friday night and mostly cloudy
skies into Saturday. As the shortwave shifts overhead on Saturday,
there appears to be enough saturation to produce a few light showers
at times, but confidence is not very high in occurrence as models
continue to show a drying trend. In addition, it will be
difficult for any rain to reach the surface to start, due to a
surface high to the east keeping dry air over eastern WI longer.
As the mid-level shortwave shifts east into Sunday, an area of
high pressure will build over the Upper Mississippi Valley.
Anticipate much of Sunday will be dry as well, but cannot rule out
an isolated diurnally driven shower. This area of high pressure
will start to spread warmer air across the area and allow Sunday`s
afternoon high temperatures to rise above normal in the upper 60s
to lower 70s away from the lake, with upper 50s to lower 60s
along the lake.

Rest of the extended...The forecast area will continue to be under
the influence of the building ridge of high pressure early next
week, leaving next to no chances for rain and above normal
temperatures. The ECMWF shows the potential for showers in southern
WI Sunday night into Monday morning, as a surface low pressure
system lifts into northern IL, which could bring showers to the
forecast area`s most southern tier of counties, but confidence is
not high with this solution due to the variation in the other
guidance. Afternoon high temperatures through midweek will be above
normal with most locations, away from the lake, seeing readings in
the 70s. A few locations could even reach 80 degrees on Tuesday and

.AVIATION...for 06Z TAF Issuance
Issued at 1102 PM CDT Thu May 13 2021

Middle clouds will return Friday afternoon and then
dissipate during the evening hours. Visibility will be excellent
and surface winds light.

An approaching upper level disturbance could bring scattered
showers and MVFR ceilings Saturday afternoon and evening.

Frost Advisory until 7 AM CDT Friday for WIZ005-010>013-018-019-


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