Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 180540

Area Forecast Discussion
National Weather Service Northern Indiana
140 AM EDT Mon Jun 18 2018

Issued at 139 AM EDT Mon Jun 18 2018

A heat advisory remains in effect through Monday across the area, as
highs Monday will climb up into the low to mid 90s once again. Heat
indices will top out around 100 by late afternoon. Isolated showers
and storms are possible late Monday afternoon north of US 30, and
then again over much of the area overnight. A cold front will bring
high temperatures into the upper 70s and low 80s for the remainder
of the week. Showers and thunderstorms are possible again Tuesday
and Wednesday.


.SHORT TERM...(This Evening through Monday)
Issued at 238 PM EDT Sun Jun 17 2018

Steamy conditions dominate across the area under 594 dm upper level
ridge. Pretty much everyone at or just above 90 with at least a few
more hours of heating. Dewpoints in the lower 70s in most locations
yielding heat indices approaching 100. Few high clouds will pass
through from convection well to the north that pose no threat until
maybe later Monday afternoon.

Temps will be slow to fall this evening through the 80s with
overnight lows settling in the middle 70s for a very rough night of
sleeping for those outdoors camping or without air conditioning.
This warm overnight lows will also allow for a rapid jump in temps
during the morning with many spots likely to hit 90 around or before
noon. Where challenge come in is during the afternoon as models vary
on exactly where the frontal boundary to the north will lie as it
begins its trek south. Much like today will likely be some cirrus
across the area that may begin to thicken somewhat as we go into the
mid to late afternoon hours. Also, some pooling of moisture may
start to occur with higher dewpoints possibly occurring. Have seen
several situations in the summer where dewpoints in the middle 70s
can make it difficult to climb much above the lower 90s. Although an
argument could be made not to issue, discussion with offices that
have them in effect now has lead to general agreement on extending
into Monday.

With regards to precip chances have added low pops across the far
north as the afternoon progresses. Low confidence how it will evolve
with some models keeping precip (and clouds) well north through 00Z
Mon while others allow for more southerly movement. While not
directly in the forecast across the remainder of the area cannot
rule out a stray shower or brief storm with all the instability
around and slowly cooling 700 mb temps.


.LONG TERM...(Monday Night through Sunday)
Issued at 238 PM EDT Sun Jun 17 2018

Potentially more active pattern as upper level ridge continues to
slowly flatten with heights around 582 dm by Weds. Frontal
boundary that will likely be active to our north Monday afternoon
will sink south as combination of approaching shortwave and
potential influence from 1 or more outflow boundaries help give it
a nudge. Have kept with chc pops but held shy of anything higher
with abundant model differences on handling of each wave and where
the front will be. Greatest potential still seems to lie with
Tues into Tues night when front will be draped across the area.
PWATs will be between 1.75 and 2 inches to bring what will
probably be the greatest threat, heavy rain. Overall flow will be
progressive but not overly fast which could cause additional
issues. Lastly, non- zero chance of an isolated strong or locally
severe storm (damaging winds) exists.

Low confidence in forecast the remainder of the period with boundary
to oscillate across northern and central Indiana through the period.
Best chance for a breather from the precip may end up late Weds into
Thursday. EC/GFS shows low pressure and another surge of deeper
moisture heading towards the region this weekend. Some timing and
track differences warrant holding with no more than chance pops
this far out.


.AVIATION...(For the 06Z TAFS through 06Z Monday Night)
Issued at 139 AM EDT Mon Jun 18 2018

VFR conditions are expected at the terminals today as high pressure
lingers over the area. Expect a chance for showers and storms late
in the period at KSBN as a frontal boundary draws near, with winds
becoming more west-northwest. Confidence in these showers and storms
is lower given model discrepancies in location/timing of front.


IN...Heat Advisory until 8 PM EDT /7 PM CDT/ this evening for

MI...Heat Advisory until 8 PM EDT this evening for MIZ077>081.

OH...Heat Advisory until 8 PM EDT this evening for OHZ001-002-004-005-



LONG TERM...Fisher

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