Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 270434

Area Forecast Discussion
National Weather Service Northern Indiana
1234 AM EDT Thu Jul 27 2017

Issued at 620 PM EDT Wed Jul 26 2017

A cold front will pass through the region Thursday, bringing a few
showers and perhaps a thunderstorm to the area, especially south of
Route 24. Lows will drop into the lower 70s tonight with highs
around 80 on Thursday.


.SHORT TERM...(This Evening through Thursday)
Issued at 337 PM EDT Wed Jul 26 2017

Dry and seasonably warm start to the short term, but focus quickly
shifts to expected upstream convective development and potential
impacts on the area.

Previous MCS undergoing typical diurnal weakening cycle, but MCV
noted over north central Iowa, which may be the focus for additional
convection tonight. However concerns still linger with regards to
coverage, intensity and track of any convection that develops.
Parameters for severe weather continue to look less and less
favorable with rather weak upper level support, poor and decreasing
further mid level lapse rates and weak overall flow (500 mb winds
at best 30 kts) all point towards lower risk of severe (1630Z
SWODY1 agreeing with removal of any Slgt risk). With PWATs still
forecasted to be around 2 inches, can`t rule out a wet microburst
during storm collapses, but greater concern still likely with
heavy rain potential. While a stronger storm could still produce
locally heavy rain think main threat will fall south of the
forecast area. After collaboration with LOT and IND (where
greatest potential impacts may be) have lowered pops and QPF in SW
areas, but still holding with a period late tonight into Thursday
of some likely pops far S/SW with trends to low chc or slgt chc
further north. QPF much lower, cut at least in half. Would not be
surprised for eve shift to be able to trim further.

Lingering pops Thursday as main trough approaches with cold front
moving through. New SWODY2 has eliminated any slight risk as well
and pushed marginal risk essentially south of the area, which is
very reasonable.


.LONG TERM...(Thursday Night through Wednesday)
Issued at 337 PM EDT Wed Jul 26 2017

High pressure will dominate conditions through most if not all of
the period. Several weak fronts will try to move in from the north
but struggle to make any progress. As a result, dry forecast will
prevail with temperatures in the lower to middle 80s and
comfortable humidity levels.


.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 1232 AM EDT Thu Jul 27 2017

Area of showers and thunderstorms ahead of wk low along cdfnt movg e-
se across IL early this morning. Strongest convection will cont to
move se toward great instability, but some SHRA and psbly an
isolated thunderstorm should move across nrn IN this morning.
Scattered showers should cont across the area during the day Thu
as the cdfnt moves slowly se across the area and another wk low
moves ene along it. Flight conditions should remain generally
vfr, but psbly down to mvfr briefly in shra, especially around




LONG TERM...Fisher

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