Area Forecast Discussion
Issued by NWS Green Bay, WI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS63 KGRB 290340

Area Forecast Discussion
National Weather Service Green Bay WI
1040 PM CDT Tue Mar 28 2017

Updated aviation portion for 06Z TAF issuance

.SHORT TERM...Tonight and Wednesday
Issued at 255 PM CDT Tue Mar 28 2017

The latest RAP analysis and satellite/radar imagery show high
pressure stretching from central Canada to the western Great Lakes
early this afternoon.  Skies are mostly clear across the region,
except near the Lake and Bay where low stratus has remained solid so
far today.  But over the past hour, the stratus has been starting to
break up over the Door Peninsula.  This trend should continue for
the rest of the afternoon with further day time heating.  Looking to
the west, clouds are spreading northeast over the northern Plains
and into the northern Mississippi Valley.  Forecast concerns include
cloud trends, and potential for fog tonight.

Tonight...Canadian high pressure will continue to build southward
into the region.  Despite the loss of heating, think the low stratus
deck will continue to erode over Lake Michigan, but not quickly
enough to prevent a mostly cloudy start to the evening along the
lakeshore. Some concern that this cloud mass could surge southwest
and lower late tonight into the Fox Valley and Lakeshore, but
confidence is low for that occurring, so will show clearing skies
overnight. Otherwise, will see mid and high clouds invade the region
from the west late.  With clear skies and light winds, some ground
fog could also reform over north-central WI and eastern WI late.
Lows ranging from the mid 20s in the north to the low 30s near the

Wednesday...Clouds will continue to thicken and lower through the
day as low pressure moves across the central Plains.  Light precip
will try to move to central WI by late in the afternoon, but think
the east winds out of the Canadian high will hold it off.  Temps
will continue to be cooler over eastern WI due to the clouds/east
wind combo.  Highs ranging from near 40 near the Lake to the upper
40s over central WI.

.LONG TERM...Wednesday Night Through Tuesday
Issued at 255 PM CDT Tue Mar 28 2017

Main concern for this period will be the system moving across the
region Wednesday night and Thursday, and then another system early
next week.

The system for Wednesday night and Thursday is a little more
potent on the ECMWF compared to yesterday. This could lead to
a few inches of snow late Wednesday night into Thursday morning
across the southern two-thirds of the forecast area. Highest snow
and precipitation totals will be south of a Marinette to Wausau
line. Per coordination with NWS Milwaukee, bumped up snow totals
across our southern tier of counties. If latest ECMWF is correct,
snow totals may need to be bumped up a little more over the next
day. The snow could make for some hazardous travel for the
Thursday morning commute to work or school. Any lingering rain
should exit east-central and northeast Wisconsin Thursday evening.
High pressure will dominate the weather pattern on Friday and
Friday night.

A weak cold front could bring a chance of rain/snow showers
Saturday afternoon and Saturday night across the north. System
passing to the south could bring a chance of precipitation Sunday
night into Monday, but the next round of significant precipitation
will be Monday night into Tuesday. Temperatures will be close
to normal through Friday, with slightly above normal temperatures
for the weekend.

.AVIATION...for 06Z TAF Issuance
Issued at 1040 PM CDT Tue Mar 28 2017

Low clouds and fog over Lake Michigan should move
west over the land area and bay tonight. These clouds should make
it to MTW, OCQ, SUE, MNM and GRB by late tonight. Might also get
to ATW and OSH. Think the areas to the west will just have
increasing high clouds with maybe local ground fog.

Whatever low clouds and fog there are later tonight should
dissipate from west to east by midday Wednesday. A winter storm
moving across the Midwest could bring a mixture of snow and rain
roughly south of a AUW to GRB line late Wednesday night through
Thursday night.



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