Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 181828

Area Forecast Discussion
National Weather Service Northern Indiana
228 PM EDT Mon Sep 18 2017

Issued at 1242 PM EDT Mon Sep 18 2017

A weak cold front may touch off a few showers and perhaps a
thunderstorm south of Route 24 this afternoon into early this
evening. Dry and mild conditions are expected elsewhere with highs
in the upper 70s. An upper level system will bring increasing
chances for rain to the entire area later tonight into Tuesday
morning. Lows tonight will drop into the 60s, with highs in the
mid 70s to low 80s on Tuesday. Unseasonably warm and dry
conditions are then expected for the remainder of the week into
next weekend as an upper level ridge builds in.


.SHORT TERM...(Late This Afternoon through Tuesday)
Issued at 227 PM EDT Mon Sep 18 2017

A weak front has stalled out just south of US 24 this afternoon and
will remain in place into this evening. There may be just enough
diurnal heating/instability to pop a few showers/storms here,
though weak convergence/forcing should limit coverage to iso-sct at
best. Warm and dry otherwise into this evening on the southern
fringe of high pressure shifting east through the Western/Northern
Great Lakes.

Rain chances increase later tonight into Tuesday morning as mid
level shortwave over the Central Plains lifts northeast through the
OH Valley and Great Lakes. Showers and perhaps a few rumbles of
thunder (thanks to some elevated instability) should tend to focus
along the returning/aforementioned frontal zone under weak upper
divergence/height falls aloft. Bumped up QPF/PoPs a bit during this
time across the entire forecast area given good moisture return and
modest forcing. Shower coverage should wane from sw to ne later in
the morning/early afternoon in wake of the upper wave and deeper
moisture. However, similar to today, there could be some iso-sct
redevelopment during the afternoon near the leftover frontal
boundary as any filtered sunshine allows boundary layer to become
at least marginally unstable.


.LONG TERM...(Tuesday Night through Monday)
Issued at 227 PM EDT Mon Sep 18 2017

A 588 dm plus upper ridge will build over the region mid week
through next weekend supporting unseasonably warm and mainly dry
conditions. The only low chance for showers appears to be later
Wednesday night/early Thursday into nw IN/sw Lower MI as a decaying
line of showers attempts to survive east into the building ridge.


.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1242 PM EDT Mon Sep 18 2017

A BKN/high MVFR stratocumulus deck at KFWA should lift/mix out to
VFR by 19/20z as drier air mixes in post-frontal. Dry/VFR
conditions and light nne winds can be expected otherwise into this
evening before the front lifts back north as a warm front with
deteriorating flight conditions and increasing rain chances.




SHORT TERM...Steinwedel
LONG TERM...Steinwedel

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