Area Forecast Discussion
Issued by NWS Indianapolis, IN

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FXUS63 KIND 211359

Area Forecast Discussion
National Weather Service Indianapolis IN
959 AM EDT THU JUL 21 2016

The NEAR TERM Section has been updated below.


Issued at 225 AM EDT Thu Jul 21 2016

Indiana weather will be controlled through the weekend by high
pressure sprawling across the country east of the Mississippi. A
cold front is forecast to pass the Hoosier State late Sunday or
Monday. High pressure following behind the front should move east of
our region by midweek.


.NEAR TERM /Update for today/...

Issued at 954 AM EDT Thu Jul 21 2016

Given temperatures and dewpoints today already running several
degrees above this time yesterday, have adjusted maximum
temperatures today to reach 90 everywhere.

Still expecting cumulus development by midday with convective
temperatures around 90. Also anticipating some cirrus spilling
down from the northwest from the Great Lakes convective cluster
but still not enough to deter 90 from occurring everywhere.


.SHORT TERM (Tonight through Saturday Night)...

Issued at 225 AM EDT Thu Jul 21 2016

The main question is whether there will be precipitation.

This is a low confidence issue.  The models all have ample
instability for convection should anything initiate it. They also
agree this is the type of situation where any such initiation will
be driven by small,hard to forecast,features.

For now it is best to use the Superblend model to get the most from
each forecast method.

Skies should be partly cloudy from diurnal cumulus and convective

For temperatures, there is excellent agreement across a variety of
methods. A blend should work well overall. In a few places it may
turn out several degrees too high depending on when storms hit.


.LONG TERM /Sunday through Wednesday Night/...

Issued at 309 AM EDT Thu Jul 21 2016

The heat wave is expected to persist through the weekend with
highs topping off in the 90s and lows only falling into the low
70s. Meanwhile, a surface frontal system will track farther into
the Midwest and Great Lakes Regions, triggering periods of
showers and thunderstorms across Central Indiana on Sunday. The
associated cold front will sweep through central Indiana on
Monday, continuing to spark some showers and thunderstorms along
and ahead of it over all but the northwestern portions of central
Indiana. Slightly cooler air and northerly flow will follow in the
wake of the cold front, so the heat wave will break a bit from Monday
through Wednesday with highs in the mid to upper 80s and lows in
the mid to upper 60s. Dry conditions will prevail from Monday
night through Wednesday as high pressure strengthens over the
Upper Midwest. Focus then turns to the next upper level trough,
progged to enter the Great Lakes Region on Wednesday night. This
disturbance will be the next chance for showers and thunderstorms
commencing Wednesday night.


.AVIATION /Discussion for the 21/1200Z TAF Issuance/...

Issued at 648 AM EDT Thu Jul 21 2016

Visibility restrictions will continue to impact outlying TAF sites
for a few more hours. Conditions are generally at the IFR level
where fog is currently present. Otherwise, expect VFR conditions
for duration of TAF period starting around mid-morning.

Inserted mention of VCTS at KLAF and KIND starting tomorrow
morning...but that is a low confidence forecast. Timing and
location of any convective initiation near frontal boundary will
need to be monitored.

Winds will generally be southwesterly at 4 to 8 kts.


.IND Watches/Warnings/Advisories...
Heat Advisory from 10 AM Friday to 8 PM EDT Saturday for INZ021-



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