Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 162344

Area Forecast Discussion
National Weather Service Northern Indiana
644 PM EST Tue Jan 16 2018

Issued at 307 PM EST Tue Jan 16 2018

Lake effect snow tonight over far northwest Indiana with 2 to 5
inches of snow expected. Cold tonight and tomorrow before a
warming trend towards the end of the week into the weekend. Highs
in the upper 40s to near 50 this weekend before a system moves
into the area on Sunday with rain likely.


.SHORT TERM...(This Evening through Wednesday)
Issued at 307 PM EST Tue Jan 16 2018

Focus still remains on lake effect event this afternoon through
the overnight. More agreement in the latest guidance to suggest
heavy lake effect band to reside over far northwest portions of
IN. Current radar and satellite imagery show a single north-south
oriented band across lake Michigan with a mesovort along the
southern extent. Band moves inland this afternoon over LOTs CWA
and then will slowly progress eastward.

Biggest uncertainty is the intensity of the band as it moves east
and how far east it will go. While models are in better agreement
on heavy snow band entering Laporte, Berrien, and Starke with snow
accumulations of 3-5 inches with greatest amounts near the lake in
the advisory area NAM12 appears to be handling the band well this
morning and shows a single strong band that remains intense as it
moves towards the east. However, some HIRES guidance wants to
keep the band over our current advisory and not move east. Kept
tight gradient in snow amounts with totals less farther east
outside of the advisory area because lack of agreement. Dropped
the watch from Marshall and St. Joseph due to less expected snow
and not expected to upgrade to warning. Winds begin to back
towards the west this evening ending the lake effect snow.


.LONG TERM...(Wednesday Night through Tuesday)
Issued at 307 PM EST Tue Jan 16 2018

Relatively quiet long term forecast with milder temps into the
weekend. High pressure moves into the area with dry conditions
expected for the first part of the long term. Next system to watch
is starting to move onshore in the pac nw and will dig its way
into the sw CONUS as a trough entrenches itself over the western
US. System tracks to our NW bringing rain into the area by Sunday
bringing heavy rain at times. Concerning is the potential for
flooding due to melting snowpack as well as tropical connections
to the Gulf of Mexico. As system exits by Monday backside snow
with colder air funneling in behind the exiting system.


.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 631 PM EST Tue Jan 16 2018

Main focus for this TAF issuance will be to try to nail down the
timing and intensity for the LES band`s possible arrival into SBN.
Expect the LES band to weaken as it moves onshore, which, on a
north-to-south orientation, would put it just west of SBN. Think
there may be more of a glancing blow to SBN and have hedged for
MVFR flight conditions for now. Will leave it to future issuances
if it appears it will be more impactful. Flight conditions could
reach down into IFR should the LES band hold together longer.
Next, the remnant LE clouds will move through by about 11 or 12z
so have introduced a 12z SCT group to account for that.

FWA has MVFR conditions within light snow approaching from the
west and will continue that for just over an hour this forecast
period. Behind that snow, expect a time of VFR conditions as the
column dries out, but then things look to moisten up again as the
lake effect clouds advect in from the west between 11z and 14z.
While it could approach MVFR during morning commute time, think it
stays just above that threshold for now. Then things dry out at
FWA for the rest of Wednesday.


IN...Winter Weather Advisory until 6 AM CST Wednesday for INZ003-012.

MI...Winter Weather Advisory until 7 AM EST Wednesday for MIZ077.



SHORT TERM...Heidelberger
LONG TERM...Heidelberger

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