Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 172312

Area Forecast Discussion
National Weather Service Green Bay WI
612 PM CDT Sat Mar 17 2018

Updated aviation portion for 00Z TAF issuance

Issued at 210 PM CDT Sat Mar 17 2018

Quiet weather will continue through the rest of the weekend and the
upcoming work week.

The large scale flow across North America is split in the west,
then consolidates into a deep trough over southeast Canada. The
trend during the period will be for the pattern to reverse, with
the flow out west splitting while the flow to the east
consolidates. The forecast area has been near a col between the
main branches of the westerlies, and despite the expected
reversal of the pattern, is likely to remain so. The dominant
weather feature will be a sprawling anticyclone ridging south
from the Hudson Bay region. That will continue to shunt
significant precipitation producing cyclones south of the area,
and result in little if any precipitation until until possibly
late in the period. After another mild day tomorrow, temperatures
will return to near or a little below seasonal normals for the
rest of the period.

.SHORT TERM...Tonight and Sunday
Issued at 210 PM CDT Sat Mar 17 2018

High pressure dominated the weather pattern across the region this
afternoon. Temperatures were in the 40s, except 50 at Waupaca,
away from the bay and lake. Afternoon relative humidity readings
were from 10 percent to 25 percent away from the lake. In matter
of fact, the temperature dewpoint spread reached 50 degrees at
Land O` Lakes, something you typically see in the southwestern
United States.

For tonight, a few mid clouds may clip portions of far northeast
Wisconsin for a few hours late this afternoon into the early
evening hours. Otherwise, clear skies will prevail. With light
winds and clear skies, lowered minimum temperatures a few degrees
most places, and several degrees at our typical cold spots across
the north that still have snow cover.

For Sunday, it will be another mild day for most, except for
Door County where north/northeast winds off the bay/lake will
keep temperatues in the 30s to around 40. A back door cold front
will move across the remainder of northeast Wisconsin Sunday
afternoon, thus by sunset it will not feel warm from the Fox
Valley east to the lake. The colder air will not work into central
Wisconsin until early evening. Leaned toward the warmer guidance
across central and north-central Wisconsin, and stayed closed to
guidance for Door County. A blend of the warmer mav and colder met
guidance was used for the Fox Valley east to the lake.

.LONG TERM...Sunday Night Through Saturday
Issued at 210 PM CDT Sat Mar 17 2018

Colder air associated with the Hudson Bay high will continue to
surge into the area Sunday night. Flow across the Great Lakes
would normally favor some flurries. But the air/water temperature
differences will initially be modest, and by the time colder air
arrives aloft the air will be increasingly dry.

A weak northern stream shortwave peeling off into the southern
stream may generate some light precipitation across the far west
Tuesday night into Wednesday. Just reflected this with a chance
of flurries for now.

The medium range guidance continues to suggest a strong southern
stream cyclone heading east across the Plains late in the week or
next weekend will track farther north than its predecessors, and
bring significant precipitation to the area. There has been some
run to run consistency in this idea. But given the likelihood of
strong high pressure still residing near Hudson Bay and feeding
dry air into the area, prefer to downplay the system for now.
For the most part, capped PoPs in the chance category.

.AVIATION...for 00Z TAF Issuance
Issued at 612 PM CDT Sat Mar 17 2018

VFR conditions should continue through the TAF period. The main
feature of interest during the TAF period will be a back door cold
front slated to move through the area Sunday afternoon and
evening. The front is expected to move through the eastern and far
northern TAF sites between 18Z and 22Z, while central Wisconsin
sites will not see the front until closer to around 00Z. The front
will turn the winds from a northwesterly to a northeasterly
direction, with gusts approaching 20 knots at times at KGRB and
KMTW where winds will arrive unabated from the bay of Green Bay or
Lake Michigan. Sites further inland will still see the wind shift
but wind gusts are not expected to be as high.



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