Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 261021

Area Forecast Discussion
National Weather Service Northern Indiana
621 AM EDT Mon Jun 26 2017

Issued at 406 AM EDT Mon Jun 26 2017

A cold day by late June standards is in store for the region with
highs only reaching the upper 60s to lower 70s. A series of
disturbances may bring isolated showers and thunderstorms to the
area through early evening. Tuesday will be dry with slightly
warmer temperatures. Rain chances will increase Wednesday night
into early Thursday and Friday into early Saturday with locally
heavy rain possible.


.SHORT TERM...(Today and Tonight)
Issued at 406 AM EDT Mon Jun 26 2017

Today will be the coolest of the next several days as highs reach
the upper 60s to lower 70s. Series of weak disturbances noted on
water vapor and also reflected on radar with light showers here and
there from north central Indiana back into southern Wisconsin. Hi
Res models all shows at least some limited shower development the
remainder of the night into Monday morning with HRRR slightly more
robust with a few heavier showers/isol thunder. Afternoon heating
across the south as well as slightly steeper lapse rates from cold
pool aloft may also allow for isolated showers south of US-30. Hi
res models have backed a fair amount on coverage/location of this
activity with much of it either isolated and/or south of the area.
Enough factors still in play to warrant holding onto slgt chc to chc
pops through the day, focused north in the morning and then just
about anywhere afternoon. A few of the stronger showers or storms
could product locally gusty winds and some small hail given 500 mb
temps -20 to -22C.

A few showers may still linger early this evening, but expecting dry
conditions after as high pressure moves overhead. Lows will drop
into almost chilly values in the upper 40s to around 50 for late


.LONG TERM...(Tuesday through Sunday)
Issued at 406 AM EDT Mon Jun 26 2017

Tuesday still looks to be the driest of the upcoming days as high
pressure drifts overhead. Despite abundant sunshine, temperatures
will still be several degrees below normal. Upper level flow will
become somewhat zonal with a series of waves still expected to
move towards the Great Lakes by mid week with main trough digging
and moving in towards Friday.

Models continue to vary on eastward extent of convective potential
Weds afternoon into Thurs morning with one of these waves. GFS may
be suffering a touch of convective feedback, but nonetheless
signals a potential for heavy rainfall and possibly some severe
weather, mainly to locations just to our north and west.
Superblend of models increases pops to categorical late Weds ngt,
which at this juncture may be overdone. Inherited likely pops in
the NW Weds ngt and while some apprehension to leave in will keep
running with and remove any categorical mention. If rain can move
in, warm layer depth pushing 12,000 ft and PWATs around 1.75
inches would yield some efficient rainfall. Similar, if not
somewhat higher numbers come into play by Friday with what may be
more widespread coverage across the area, especially Fri
afternoon/evening. Have held with likely pops as well in this

Drier conditions will move in for the weekend with rain chances in
the offing just outside the current forecast period.


.AVIATION...(For the 12Z TAFS through 12Z Tuesday Morning)
Issued at 609 AM EDT Mon Jun 26 2017

Not much change expected for the 12Z TAFS with main forecast
challenge on extent of any afternoon isolated-scattered
showers/storms. Upper vort max slowly drifting across western
Great Lakes may be enough to generate an isolated shower or
sprinkle this morning across far northern Indiana, but best chance
of isolated shower/thunderstorm activity still appears to be this
afternoon as an upper speed max nosing into Corn Belt region this
morning progresses southeast to the Ohio Valley. Moisture is
quite limited but relatively steep mid level lapse rates and
approach of this forcing could yield a few showers/storms in the
20-23Z timeframe. With coverage quite limited, confidence in
occurrence for point terminal forecasts remains too low for VCSH
mention and will defer to later forecasts/amendments for possible
inclusion. Diurnal mixing and steep low level lapse rates should
support a few west-northwest gusts into the 20 to 25 knot range
again today, with gusts dropping off after 23Z. VFR conditions to
persist through the forecast valid period with cloud bases
generally AOA 5K feet.


Issued at 504 AM EDT Mon Jun 26 2017

Winds and waves will increase through the day as 10 to 20 kts
winds occur with gusts to 25 kts. Wave model heights were coming
in much lower than buoy data with Cook buoy already in the 5 to 7
foot range and Michigan City a touch lower. While waves may
decrease somewhat through sunrise, expect them to pick up again.
For the lakeshore areas, this will translate to dangerous swim
conditions into tonight.


IN...Beach Hazards Statement through late tonight for INZ003.

MI...Beach Hazards Statement through late tonight for MIZ077.

LM...Small Craft Advisory until 4 AM EDT Tuesday for LMZ043-046.



LONG TERM...Fisher

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