Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 221854

Area Forecast Discussion
National Weather Service Northern Indiana
254 PM EDT SUN MAY 22 2016

Issued at 250 PM EDT Sun May 22 2016

Quiet and seasonably warm conditions will prevail through Tuesday
with highs in the 70s to near 80. A frontal boundary and series of
weak systems will set the stage for an increase in shower and
thunderstorms chances starting Tuesday night and persisting into
the holiday weekend.


.SHORT TERM...(This Evening through Monday Night)
Issued at 250 PM EDT Sun May 22 2016

Combination of late May sun angle and dry atmosphere has allowed
temperatures to over achieve once again even along the lake shore
areas with highs in the mid-upr 60s along the lake shore and well
into the 70s inland (even some 80s in far SW).

Next 36 to 48 hours will continue to be rather uneventful as high
pressure moves across the region with any convective concerns
remaining generally west of the mississippi river through the
period. Previous shift increased highs above guidance given trends
of overachieving and see no reason to change anything.


.LONG TERM...(Tuesday through Sunday)
Issued at 250 PM EDT Sun May 22 2016

Main influx of moisture and instability will remain to the west of
the area at the start of the period. Showers and thunderstorms will
develop or move into Illinois during the afternoon hours and may try
to shift east into western portions of the forecast area Tuesday
evening as moisture slowly begins to increase across the southern
Great Lakes. Can`t justify anything more than chance pops Tuesday
night given less than favorable diurnal setup and lack of overall
support as it moves in.

NAM12 becomes more and more convectively contaminated as it attempts
to resolve what should be several rounds of showers and storms not
only upstream...but also potentially across the forecast area as a
baroclinic zone sets up across the region. Modest instability will
be in place Wednesday afternoon and evening as a disturbance moves
into the area with potential for several mesoscale boundaries around
to act as focus for convection. Inherited likely pops Wednesday
night, which should suffice given best timing of any activity.
Precipitable water values over 1.25 inches and freezing levels above
10,000 ft may set the stage for some locally heavy rain. Should
not pose any hydro concerns initially...but something to be
watched as additional shower/storm chances linger through the
period with no major pattern change in store. MEX guidance still
seems rather optimistic later this week with low to mid 80s given
amount of cloud cover that will likely be in place. However, if
breaks can occur between period of precip, won`t take much to jump
several degrees in a few hours.


.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 202 PM EDT Sun May 22 2016

High pressure and continued weak subsidence will prevail through
most of the forecast period. Boundary layer moisture will increase
later in the TAF period...however no significant impact to
aviation expected.


.IWX Watches/Warnings/Advisories...


LONG TERM...Fisher

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