Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 240013

Area Forecast Discussion
National Weather Service Northern Indiana
813 PM EDT Fri Sep 23 2016

Issued at 812 PM EDT Fri Sep 23 2016

Clouds will be on the increase overnight and lows will drop into
the middle 50s to lower 60s by Saturday morning. Saturday will be
dry and mostly cloudy, especially in the morning with highs from
the lower 70s to near 80. Sunday will be a few degrees warmer.
Chances for rain then return starting late Sunday afternoon as a
low pressure system moves into the area. Chances for rain will
continue through next week, with cooler temperatures.


.SHORT TERM...(This Evening through Saturday)
Issued at 346 PM EDT Fri Sep 23 2016

A quiet night in store as isolated rain showers diminish early this
evening as surface high pressure builds into the region. Otherwise,
Northwest winds behind the cold front to our south will bring
cooler temperatures and moisture into the area. Tonight, expect
increasing clouds with low level moisture getting trapped beneath
the subsidence inversion and lighter winds. Lows will be in the
upper 50`s along and north of I 80-90, and the low to mid 60`s

Saturday will be dry, with the ridge aloft amplifying in response to
deepening the upper level low over the northern plains. Expect cloud
cover to linger through much of the day, though. High temperatures
will only climb into the 70`s and low 80`s, warmest south of US 24.


.LONG TERM...(Saturday Night through Friday)
Issued at 346 PM EDT Fri Sep 23 2016

Surface high pressure and an upper level ridge will keep weather
quiet Saturday night into Sunday. Lows Saturday and Sunday night
will drop into the 50`s and 60`s.

Models are coming into better agreement for the long term than they
were yesterday at this time, but still not quiet good enough for a
high confidence forecast beyond Sunday night-Monday morning. Models
both keep the upper level low to our north now (ECMWF furthest
north). The question will be timing, with the ambitious GFS bringing
precip chances into the west by Sunday afternoon, and the ECMWF
bringing them in just a tad bit later. For now have chance pops just
entering the western CWA between 21Z Sunday-00Z Monday, and likely
pops after 3Z Monday for areas west of US 31. Thunder is possible.

By Monday afternoon, the surface front is nearly all the way through
the CWA with the low off to our northeast, but the upper level
trough lingers through Wednesday. This will result in sporadic
shower activity, but confidence in exact placement/timing is low
so I used the consensus blend and draped chance/slight chance pops
across the area.

Thursday into Friday it will be dry and seasonable, with high
pressure building in behind the exiting low pressure system.

Temperatures will be more fall like through next week as well. Highs
will only reaching into the upper 60`s and 70`s on most days. Low
temperatures will drop down into the 40`s and 50`s starting Tuesday


.AVIATION...(For the 00Z TAFS through 00Z Saturday Evening)
Issued at 810 PM EDT Fri Sep 23 2016

Expansive upstream cold air advection stratocu to continue
southward advance overnight and trended tafs a bit more
pessimistic. Winds should remain sufficient to preclude all but
minor br formation near daybreak...however continued cooling to
likely allow gradual lowering of ceilings to below
fueling/alternate criteria and perhaps into high end IFR at peak
cooling/near daybreak. With low level cold pool still nw/upstream
of northern Indiana suspect rather slow lift of bases through
Saturday given moisture remaining trapped beneath well established
subsidence inversion.





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