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Area forecast discussion 
National Weather Service northern Indiana
318 PM EDT Thu Oct 20 2016

issued at 318 PM EDT Thu Oct 20 2016

Rain will continue for much of the area through this evening as a
low pressure system lingers overhead. Otherwise, expect a chance
of rain showers overnight, with lows dropping into the 40s. There
is a chance for rain showers Friday, especially near Lake
Michigan. Highs will be in the 50s.


Short term...(this evening through friday)
issued at 304 PM EDT Thu Oct 20 2016

Trough will continue to shift slowly east into the region and
become negatively tilted over the next 24 hours, causing a slower
eastward progression. Large band of rain associated with the
deformation zone of low pressure moving through the Ohio Valley,
has been slowly shifting east to areas along and east of I-69 with
lighter rain/drizzle to the west. Several models want to linger
this area well into the evening before finally shifting out
towards 6z. Have trended slower with departure but updates will be
needed into the evening. Focus shifts west and north with strong
northerly flow ushering in much colder air over Lake Michigan with
lake effect rainshowers expected to develop. May end up being one
band that initially resides mainly over NE Illinois/northwest in before
shifting towards far west/northwest sections of the forecast area. Have
increased pops somewhat with a period of likely pops warranted
given favorable long axis fetch, Delta t's into the mid and upper
teens and strong convergence. Later shifts will likely need to
adjust final resting place of features as track of surface low
will be key in movement of the band and eventual northwest to southeast
orientation. Away from the lake, skies will slowly clear out with
partly to mostly cloudy conditions. Temperatures will drop into
the 40s tonight with highs struggling into the 50s on Friday.


Long term...(friday night through thursday)
issued at 304 PM EDT Thu Oct 20 2016

Lake effect rain showers should be winding down Friday evening as
flow weaken and deeper moisture departs. Away from the lake effect
clouds overnight lows will likely drop into the middle to upper
30s. Frost may become an issue but concerns still exist with winds
decoupling and to a lesser extent cloud cover. Frost has been
removed from neighboring offices to the north for the same basis.

Otherwise forecast should be quiet into Tuesday before the next
system arrives to bring a chance of showers to the area as well as
somewhat warmer temperatures Wednesday into Thursday.


Aviation...(for the 18z tafs through 18z Friday afternoon)
issued at 120 PM EDT Thu Oct 20 2016

With a cold front dropping through the area expect winds to
gradually become more north-northwest overnight. Rain currently
impacting kfwa will gradually shift out of the region later this
evening. Ksbn will continue to see shower activity on and off
through Friday, but only felt confident including vcsh this
evening. Models suggest the development of a lake effect rain
band developing overnight and moving into ksbn Friday
morning/afternoon, but again-left it out of taf for now.
Otherwise, lower ceilings continue to fluctuate between
800ft/1500ft at kfwa, and I expect this to continue along with
br/-ra through the first part of the taf period. As rain showers
move southeastward, expect conditions to improve gradually.


Iwx watches/warnings/advisories...
Lm...Small Craft Advisory until 5 am EDT Saturday for lmz043-046.



Synopsis...mesoscale discussion
short term...Fisher
long term...Fisher
aviation...mesoscale discussion

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