Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 240458

Area Forecast Discussion
National Weather Service Northern Indiana
1258 AM EDT SUN JUL 24 2016

Issued at 730 PM EDT Sat Jul 23 2016

Isolated thunderstorms are possible this evening...mainly over
northwest Indiana. Chances for storms will increase over much of
the area late tonight and on Sunday ahead of a cold front This
front is expected to move across the area Sunday night and Monday
with storms again possible along and ahead of the front. Slightly cooler
and less humid conditions expected by Tuesday and Wednesday.
Highs Sunday are expected to be in the lower 90s with lows
tonight in the lower 70s.


.SHORT TERM...(This Evening through Sunday)
Issued at 156 PM EDT Sat Jul 23 2016

Convective complex currently moving through the upper MS valley as
short wave energy from the plains impinges on upper ridge this
afternoon. Latest Meso-analysis indicating sharp instability and
Theta-E gradient and expect complex to continue eastward into the
great lakes region along this boundary. HIRES guidance suggesting
southern edge of this complex may clip our far N/NW CWA later
tonight so will follow current forecast of chance/slight chance POPs
in this area.

Cold front approaching the region on Sunday will provide synoptic
scale forcing to act on unstable warm sector airmass to bring
another chance for thunderstorms to the area. Debris clouds from
previous nights convection may initially hinder destabilization but
still expect CAPE in excess of 3000J/kg by late afternoon. Despite
good instability expect a weakly sheared environment to limit any
severe potential. Areal coverage still somewhat in question so will
keep POPs in chance range. With additional cloud cover expected
Sunday will hold off on any further heat advisories for now and see
how nocturnal convection evolves...have adjusted maxT down a degree
or two to account for this.


.LONG TERM...(Sunday Night through Saturday)
Issued at 156 PM EDT Sat Jul 23 2016

Frontal passage may linger into Monday for the southern CWA as front
becomes more E-W oriented. Models also have varying solutions for
timing of front to clear our area so will continue with small chance
in the south. High pressure then builds into the region on Tuesday
and will bring temps back into the 80s and closer to normal along
with less humid conditions which will allow for more comfortable
overnight lows in the mid 60s. Upper flow becomes more zonal and
will keep temps near normal for the remainder of the forecast
period. Pacific energy streaming in on zonal flow will bring precip
chances back into the forecast by the end of the week.


.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 100 AM EDT Sun Jul 24 2016

Discussion prior to valid time of 6z TAFs...
Line of thunderstorms was making steady progress eastward and will
impact KSBN prior to the valid taf time. Amendment just sent to
address. Wind gusts of 30 to 35 knots have been reported with the
line which was showing some signs of moving more southeast than
east. Regardless at least a period of thunder expected at KSBN
prior to valid time. No impacts for KFWA prior to valid time.

Discussion for valid period...
Large area of rain will likely be working across northern Indiana.
Questions remain as to the eastward extent of the activity,
including any storms that may be on the leading edge. No plans to
introduce thunder at KFWA prior to 12z but will monitor trends for

Thunder chances this afternoon and evening will be highly
dependant on if clearing occurs in the wake of the current
convection and timing of approaching front. For now with at best
scattered coverage expected with the front will hold off on adding
thunder and let later shifts evaluate how things unfold.


.IWX Watches/Warnings/Advisories...



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