Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 201311

Area Forecast Discussion
National Weather Service Northern Indiana
911 AM EDT Thu Oct 20 2016

Issued at 638 AM EDT Thu Oct 20 2016

A storm system will approach from the central United States today
resulting in a continued likelihood of rain showers across most of
the area. The exception will be across far southwest lower
Michigan and northwest Indiana where rain coverage is expected to
be more limited. Scattered rain showers will likely persist into
this evening before diminishing overnight. However, lake effect
rain showers are expected to develop late tonight into Friday.
High temperatures today will range from 55 to 60. Low temperatures
tonight will drop into the 40s.


Issued at 906 AM EDT Thu Oct 20 2016

Morning grids being updated to reflect a further NW trend in

Deformation zone beginning to take shape with brunt of rainfall
currently NW of a Portland IN to Ottawa OH line. Furthest NW
extent looks to take aim on South Bend through the remainder of
the morning. Locations SE of Portland to Ottawa will still see
some showers/drizzle with an increase in coverage towards/after
noon as next wave moves in from the SW. For the time being,
thunder has been residing well southwest of the area and appears
to be diminishing somewhat. Will continue to leave out of zones
and monitor trends.

Remainder of the forecast generally on track.


.SHORT TERM...(Today and Tonight)
Issued at 440 AM EDT Thu Oct 20 2016

The front had moved south to near the Ohio River early this
morning. Nearly all of the showers and storms were north of the
front across Illinois, Indiana, and Ohio where the storms had
become elevated. A narrow band of moderate to heavy rain was
supported by upper level jet dynamics and had developed across
northern Indiana into far southern Lower Michigan. Several factors
favorable to supporting moderate to occasionally heavy rain will
persist today over the southeast half of the area; especially
south and east of Warsaw. There is still some chance for thunder
this morning over this area; have kept thunder out for now but may
add thunder by daybreak. A wave on the front will travel northeast
and help the rain continue over the area. Plenty of upper level
jet support and even some jet coupling will be favorable for rain
support. The GFS has trended north and now supports the ECMWF
which has favored the precipitation axis between Ft Wayne and Lima
for several past days. Much cooler air will spread into the area
tonight. Some lake enhanced showers area possible over far
northwest areas near the lake.


.LONG TERM...(Friday through Wednesday)
Issued at 440 AM EDT Thu Oct 20 2016

Very chilly air will be spreading across the area behind the
wave and upper level system early Friday. Some lake enhanced
showers are possible Friday near Lake Michigan; otherwise,
conditions will be cool and dry. One cold night is expected Friday
night will lows dropping into the 30s. Frost may needed to be
added to a portion of the area. Otherwise, conditions should be
dry through Tuesday with moderating temperatures.


.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 638 AM EDT Thu Oct 20 2016

The combination of an approaching upper level trough and a strong
baroclinic zone will continue to provide a focus for rain today
across northern Indiana, with the greatest coverage anticipated at
KFWA where have maintained rain mention through much of the
afternoon. Intrusion of slightly drier air to the northwest of the
primary low level boundary should keep rain shower coverage more
limited and scattered at KSBN. Did maintain trend to MVFR cigs in
the 1-2k ft range for a time later this morning/early afternoon at
KFWA in better proximity to more significant low level moisture
axis/precip. Some post-frontal MVFR/IFR cigs are evident across
southern Wisconsin and extreme northeast Illinois, but confidence
in MVFR cigs is lower at KSBN given somewhat drier low level air
in place. May opt to hold in some diurnally enhanced MVFR cigs at
KSBN late morning/this afternoon as secondary low level front
settles across the area. Will also likely maintain MVFR cigs at
KFWA into this evening as frontal inversion develops with some
trapped low level moisture. While have not included a mention with
this forecast, may need to watch potential for some lake effect
rain showers impacting KSBN toward the end of the period, although
with overall drier low level air advecting into the area tonight
will keep KSBN primarily VFR.


LM...Small Craft Advisory until 5 AM EDT Saturday for LMZ043-046.



SHORT TERM...Skipper
LONG TERM...Skipper

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