Area Forecast Discussion
Issued by NWS Northern Indiana

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805
FXUS63 KIWX 091124
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
624 AM EST Fri Dec 9 2016

.SYNOPSIS...
Issued at 438 AM EST Fri Dec 9 2016

Cold west to northwest winds will continue to cause lake effect snow
through this morning, mainly across southwest Michigan and the
adjacent counties in northern Indiana. High pressure will build
into the area by evening causing the lake effect to diminish to
flurries. Low pressure will move northeast from the southern
plains across the Midwest over the weekend causing snow Saturday
night and Sunday, possibly lingering into Monday. The snow will
mix with or change to rain south of U.S. Route 30 before ending.
A cold front will move through the Midwest early next week,
followed by very cold temperatures for mid to late week.

&&

.SHORT TERM...(Today and Tonight)
Issued at 437 AM EST Fri Dec 9 2016

...Headlines to continue...

Trough was dropping south of the area and allowing a few much more
organized bands to setup as expected. A weaker band has been rather
persistent across NE LaPorte county into portions of St Joseph IN
and Marshall counties where a few inches of snow has likely
accumulated. Further northeast a rather pronounced lake effect band
was oriented from south of Muskegon to north of Kalamazoo and taking
aim on Branch county. In between these additional snow showers were
noted starting to work into the warning area. For the time being
will leave headlines intact with many areas only seeing light
accumulations (South Bend locally seen 1 to 3 inches overnight) with
lesser amounts thus far across the rest of the area. These areas
should catch up into this morning. Also with exact evolution of
these bands still unfolding somewhat any dropping or changes would
be premature for headlines. That being said, will be watching Branch
county closely to see if this main band sits for a while with
potential for 1 to maybe 2 inch per hour rates for 2 to 4 hours
yielding close to warning criteria. Did drop any mention of blowing
snow as wind speeds seem to be just low enough no major blowing of
snow.

Have backed off somewhat on duration of weaker lake effect later
today into tonight as flow turns more westerly with time.

&&

.LONG TERM...(Saturday through Thursday)
Issued at 437 AM EST Fri Dec 9 2016

Several inches of snow still look to be in store for parts of the
area starting as early as Saturday evening, but overnight Sat into
much of Sunday and strong low level flow ushers in moist airmass
with soundings showing all snow into late Sunday afternoon. Exact
amounts still need pinning down and are likely to fluctuate until
the energy we will be contending with comes onshore today. Sunday
night, low level temperatures will climb above 0 C across southern
portions of the area, but exactly how warm as well as how far
north the warm air will get remains a point of contention and a
huge issue with regards to precip type. Top down methods bring
just about any precip type depending on final surface temperatures
and low level profiles. Headlines will likely be needed for much
of this period, but will keep out for now given current headlines.

All precip will quickly change to snow and end Monday with some
lingering light lake effect snow showers followed by a brief
breather before much colder air arrives for the area and renewed
potential for lake effect. More on this in later forecasts as models
still varying on magnitude and timing of cold air.

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 619 AM EST Fri Dec 9 2016

Heavier lake effect snow bands have shifted south along
migrating trof/meso-low to near the IN/MI border, but still north of
the sbn terminal attm. Expect these bands will at least impact sbn
with a glancing blow this morning so contd with mvfr/ifr conditions
through 16z. Some improvement this aftn as inversion heights
lower... but mvfr cigs should persist through tonight. Moist
cyclonic flow will cont strato cu deck at FWA with low vfr to mvfr
cigs. Fcst ocnl lower vsbys in -shsn this morning as some of the
lake effect bands should reach there in a diminished state.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Winter Weather Advisory until 4 PM EST /3 PM CST/ this afternoon
     for INZ003>007.

MI...Winter Weather Advisory until 4 PM EST this afternoon for MIZ080-
     081.

     Winter Storm Warning until 4 PM EST this afternoon for
     MIZ077>079.

OH...NONE.
LM...Small Craft Advisory until 7 PM EST this evening for LMZ043-046.

&&

$$

SYNOPSIS...JT/Fisher
SHORT TERM...Fisher
LONG TERM...Fisher
AVIATION...JT


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