Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 071635

Area Forecast Discussion
National Weather Service Northern Indiana
1135 AM EST Wed Dec 7 2016

Issued at 1134 AM EST Wed Dec 7 2016

A strong low pressure system over southern Ontario will move
slowly east across southeast Canada over the next couple of days
causing cold conditions across our area. Winds will become
northwest Thursday and Friday, causing lake effect snow across
southwest lower Michigan and far northern portions of Indiana.
Significant lake effect snow accumulations are expected for
portions of extreme northern Indiana and southern lower Michigan.
Fair weather is expected Saturday as high pressure moves across
the area. Snow is expected across northern Indiana, northwest
Ohio, and the adjacent counties in southern Michigan Sunday as a
low pressure system moves through. This will be followed by colder
conditions and probably some lake effect snow early next week.


Issued at 1117 AM EST Wed Dec 7 2016

Some changes will be made midday regarding the current winter
weather headlines. The winter storm watch will transition to a
winter storm warning for Berrien/Cass/St. Joseph counties in
southern lower Michigan. The winter weather advisory will remain
in effect for surrounding counties of far northern
Indiana/southern lower Michigan with a slightly delayed start time
of 15Z. New 12Z guidance continues to support period of heaviest
lake effect snow from the late Thursday afternoon through Friday
morning. Given fairly consistent signals with lake effect
parameters and synoptic forcing for this period, will go ahead
with the upgrade at this time. An updated WSW will be sent by
around 17Z.


.SHORT TERM...(Today through Friday)
Issued at 444 AM EST Wed Dec 7 2016

A lake effect snow event will begin to unfold tonight as much colder
air spreads over the relatively warm water of Lake Michigan behind a
cold front. A secondary trof should move across the area late
Thursday and cause winds to veer a little more to the northwest.
Have issued a winter storm watch for lake effect snow and blowing
snow and a winter weather advisory for lake effect snow for late
tonight through Friday. Southern Lake Michigan remains
exceptionally warm for this time of year. Given thermal profiles,
lake fetch and instability, expect 5 to 8 inches over far
southwest Lower Michigan with lesser amounts farther inland by
late Friday. Inversion heights should begin to fall Friday as the
ridge axis approaches.


.LONG TERM...(Friday night through Tuesday)
Issued at 444 AM EST Wed Dec 7 2016

Lake effect snow will continue to diminish Friday night ahead of the
next system poised to arrive this weekend. Even the spectral models
such as the EC and GFS have really been struggling the past several
days handling the short wave energy with a broad and expansive upper
trof over North America. Went with the cooler GFS this weekend
favoring all snow Sunday, although can`t rule out a rain/snow mix
over southern areas. Confidence in any solution is even lower for
next week. A lot of cold air will be over the Canadian interior
stretching down into the Northern Plains with plenty of energy in
both the northern and southern streams. Cross/polar flow with bring
a fresh surge arctic air south, so the wintry pattern is set to
continue next week.


.AVIATION...(For the 12Z TAFS through 12Z Thursday Morning)
Issued at 553 AM EST Wed Dec 7 2016

Widespread mvfr cigs across MI/WI should remain north of nrn IN
today, but overspread the area tonight as an upr level trof moves
across the wrn Grtlks causing winds aloft to slowly veer more
nwly. Light lake effect snow showers expected to reach SBN late
tonight, but little or no accum should occur this taf period,
with more sgfnt impacts psbl later Thu. Winds should maintain
sufficient westerly component to keep lake effect shsn north of
FWA through daybreak Thu.


IN...Winter Weather Advisory from 10 AM Thursday to 4 PM EST Friday
     for INZ004>007.

MI...Winter Weather Advisory from 10 AM Thursday to 4 PM EST Friday
     for MIZ080.

     Winter Storm Warning from 4 AM Thursday to 4 PM EST Friday for

LM...Small Craft Advisory until 7 AM EST Friday for LMZ043-046.



SHORT TERM...Skipper
LONG TERM...Skipper

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