Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 142043

Area Forecast Discussion
National Weather Service Northern Indiana
343 PM EST Thu Dec 14 2017

Issued at 337 PM EST Thu Dec 14 2017

A weak system will pass across the northern Great Lakes, bringing
increasing chances for mainly lake effect snowshowers Friday into
Friday night. Some light accumualtions are possible north of the
Toll Road with other areas seeing little more than flurries.
Temperatures will remain cold with lows tonight in the teens and
highs Friday in the 20s. Warmer weather will begin to arrive next
week but several weak systems will bring chances for rain or snow
through mid week.


.SHORT TERM...(This Evening through Friday)
Issued at 337 PM EST Thu Dec 14 2017

After a cold night in many spots, temperatures have managed to
recover into the 20s, coolest northeast. Clouds have been slowly
increase from west to east and while majority of lake effect has
remained north a small area of enhancement looks to be drifitng
across NW counties with maybe a few snow flakes. Handling with
slgt chc as it works east. Upper level system will move through
the northern lakes late tonight into Friday night. Main impacts
will be in favored WNW or W fetch areas from Lake Michigan with
any light accumulations confined north of the Toll Road and little
more than some flurries or light snow showers north of US-30.
Winds will pick up somewhat into the 10 to 20 mph range, enough
for some slick spots and drifting snow but well shy of any
advisory criteria at this time.

Temperatures on Friday will make it a few degrees warmer, but
still remain below normal with readings only in the middle 20s to
lower 30s.


.LONG TERM...(Friday Night through Thursday)
Issued at 337 PM EST Thu Dec 14 2017

For those wanting to get rid of the cold and snow, your wish is
coming as flow becomes more zonal for the start of the weekend and
eventually southwesterly as deep trough digs into the western
states. Any light snow across southern Lower Michigan will quickly
wind down Friday night. Focus then shifts to closed low over the
4 corners region which is forecast to phase with the northern
trough by Monday as strong low pressure moves across Hudson Bay
through much of the period. Quick batch of rain or rain/snow mix
will arrive Sunday night with what will likely be a weak sfc low
moving NW of the area. Not expecting any impacts at this time with
this feature, but with cold ground and thermal profiles still
bouncing around will need to monitor somewhat.

Either zonal or slightly amplified flow will remain in place much
of the week allowing for above normal temperatures. Weak
disturbances will pass through every once in a while to bring at
least a chance of rain or snow, depending on the time of day.
Towards the end of the period, deepening low pressure over the
southern Plains will track towards the area and pose a potential
problem for travelers late Thursday into Fri. Exact track remains
uncertain with ECMWF keeping well NW of the area (all rain) and
GFS tracking southeast of the area (Snow or snow/rain). Something
that will be closely monitored in the coming days.


.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1226 PM EST Thu Dec 14 2017

Backing flow and increasing dry air entrainment has disrupted
lake effect snow as expected this morning. KSBN could experience a
few brief periods of MVFR early this afternoon but confidence in
duration is too low for even a TEMPO mention given recent obs and
radar/satellite trends. Primarily VFR expected to continue through
tonight. Next clipper system arrives late tomorrow morning with
another round of light lake effect snow and lower ceilings that
could cause a period of MVFR conditions.


LM...Small Craft Advisory until 4 PM EST this afternoon for LMZ043-



LONG TERM...Fisher

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