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Area forecast discussion 
National Weather Service northern Indiana
1213 am EST Thursday Feb 11 2016

issued at 1210 am EST Thursday Feb 11 2016

Lake effect snow showers will continue today for areas mainly
north of US 30. Highs today will reach the low to middle 20s.
Another round of lake effect snow showers is expected later Friday
into Saturday...though lighter amounts are forecast. will remain cold through the weekend with highs
generally in the teens and 20s.


issued at 836 PM EST Wednesday Feb 10 2016

Lake effect snow showers will continue overnight with moderate
lake induced instability persisting. Steep low level lapse rates
have allowed for continued significant inland penetration with the
strongest of these bands at 0130z from Three Rivers Michigan to
northwest of Defiance. This band also appears to be aligned with
Better Lake Superior connection. Main tweak for evening update was
to increase accumulations slightly across the far north/northeast
to account for ongoing more pronounced banding. Otherwise...will
continue with categorical probability of precipitation for favored lake effect areas with
little change in lake induced instability magnitude overnight.
Great Lakes middle level trough will begin to pull off to the east
overnight with increasing middle level subsidence in the 06-12z
timeframe. Middle level dry air may also become an increasing factor
to consider overnight into early Thursday morning. Previous
forecast thoughts still appear to be valid with above factors
supporting general downward trend in intensity late
tonight/Thursday morning as inversion heights begin to lower more


Short term...(this evening through thursday)
issued at 337 PM EST Wednesday Feb 10 2016

Northwest flow and lake induced moderate instability with Delta t's near
20c and 300-400j/kg cape should allow lake effect snow showers to
persist overnight and at least through midday Thursday. Lowering
inversion, dry air advection, and backing winds should cause a
diminishing trend to the lake effect snow beginning late tonight
and continuing through the day Thursday. Additional accums tonight expected
to be similar to today, in the 1-3" range across the northwest portion of
the County Warning Area and generally <1" farther inland, with an additional inch
or less in the Winter Weather Advisory area on Thursday. This should bring
the storm total for this prolonged event up to around a foot in
some locations in the advisory area.

Gradient mixing and some cloud cover should limit radiational
cooling again tonight. Lows expected to be in the high single
digits SW and NE where partial clearing expected, and in the 10-15
range over the rest of the County Warning Area which should stay mostly cloudy. Weak
warm air advection and a little more sunshine Thursday should result in a little
warmer temperatures than today with highs in the l-m20s.


Long term...(thursday night through wednesday)
issued at 337 PM EST Wednesday Feb 10 2016

Backing flow and lowering inversion heights to stiffle les
production along southern periphery late Thursday/Thursday night...
retreating northward into Michigan. Weak clipper system dives toward Ohio
Valley early Friday in temporary relaxation in southern periphery
of Great Lakes. However as a strong 65n originating vortex plunges
south-southeastward into response to high amplitude Canadian rockies ridging.
More Arctic frontal forced shsn into Friday afternoon followed by return
of les. Have ramped les probability of precipitation substantially Friday night into Sat with
near 20/lower 20s Delta T. Less remarkable moisture depth and
thin/mostly sub cloud dgz to afford to likely keep overall
quantitative precipitation forecast/accums/slr in check...though would not rule out potential for
targeted advection. Coldest temperatures Sat night in heart of 925mb thermal
trough with les response quickly waning amid descending inversion
heights/nearly veering flow likely pushing les into northwestern in/northestern Illinois.
Flatter more progressive flow into middle week to embarq of thermal
moderation along with episodic low chance precipitation.


Aviation...(for the 06z tafs through 06z Thursday night)
issued at 1210 am EST Thursday Feb 11 2016

Lake effect shsn will continue to impact mainly ksbn with variable
flight conditions (vis ranging MVFR to lifr) through at least the
early afternoon. Lesser impacts expected at kfwa but could see
brief IFR/MVFR restrictions with any shsn through middle afternoon.
Backing/weakening winds will allow any lake effect activity to
diminish by this evening with VFR conditions anticipated.


Iwx watches/warnings/advisories...
in...Winter Weather Advisory until 10 am EST /9 am CST/ Thursday for

Michigan...Winter Weather Advisory until 10 am EST Thursday for miz077>079.

Lm...Small Craft Advisory until 4 PM EST Thursday for lmz043-046.



short term...jt
long term...Murphy

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