Area Forecast Discussion
Issued by NWS Indianapolis, IN

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FXUS63 KIND 261021
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
621 AM EDT Tue Sep 26 2017

.UPDATE...The AVIATION section has been updated below.

&&

.SYNOPSIS...
Issued at 332 AM EDT Tue Sep 26 2017

The hot weather will continue today under the influence of broad
high pressure. Then, cooler air will move in between a cold front
that will sweep across central Indiana on Wednesday. A few
thunderstorms are are possible behind this front and along and ahead
of a Great Lakes disturbance Wednesday. The cooler air will be even
more noticeable by Thursday and through Saturday as another cold
front moves through. After that, temperatures will be on the rebound
as an upper ridge builds over the Ohio Valley and Great Lakes.

&&

.NEAR TERM /Today and Tonight/...
Issued at 332 AM EDT Tue Sep 26 2017

The main focus for the near term will be on whether not there will
be any isolated showers as some of the models are producing some
blotchy pops today and tonight ahead of an advancing cold front.
However, with the deeper moisture lagging behind the front, there is
moderate or better confidence that it will remain dry through
tonight. There is also good confidence in one more hot day with
little cloud cover. Well above normal superblend highs in the upper
80s to lower 90s look good. Meanwhile, as cloud cover increases some
overnight, lows near or above the blend in the middle to upper 60s
look good.

&&

.SHORT TERM /Wednesday through Thursday night/...
Issued at 332 AM EDT Tue Sep 26 2017

The short term dilemma will be over when, when and even whether or
not to include low chance pops as models slide a cold front over the
area Wednesday ahead a Great Lakes upper system. Lift and moisture
do not look sufficient for much more than isolated convection,
however instability progs do support thunder mention. The blend
suggests the activity will not get going until the afternoon with
peak heating and mainly over our far southeast. This is a 50 mile
further east shift to the previous forecast. Prefer holding onto
small pops a little further west and from 18z-23z near and east of a
Muncie to Franklin to Vincennes line.

Confidence is moderate regarding isolated thunderstorms, moderate
regarding timing but is low regarding location.

Good confidence the remainder of the short term will be dry and
cooler as high pressure builds in from the Plains and the column
dries.

Wednesday, with the front moving through, there will likely be a
northwest to southeast temperature gradient. The Superblend appears
to handle this well. Still, with the front moving through, only low
to moderate confidence in afternoon highs within a couple of
degrees. Went with upper 70s northwest to mid 80s south.

Slightly below normal blend temperatures look good per low level
thermal progs and little expected cloud cover. This equates to highs
in the lower and mid 70s Thursday and lows all the way down to the
upper 40s and lower 50s Thursday night.

&&

.LONG TERM /Friday Through Monday/...
Issued at 234 AM EDT Tue Sep 26 2017

Ensembles in good agreement on the main weather details during this
period. Appears a short wave trough will drift across the Great
Lakes on Friday. Ensembles suggest the precipitation threat with
this feature will remain off to the northeast of the local area.

After Friday, it appears upper ridging will again build over the
Ohio Valley, as deep long wave troughing develops over the Rockies.
The presence of the upper ridge suggests little threat for
precipitation over the weekend and on into next Monday. Will go with
a dry extended.

&&

.AVIATION /Discussion for the 26/1200Z TAF Issuance/...
Issued at 621 AM EDT Tue Sep 26 2017

Would not rule out brief fog at BMG through 13z, otherwise VFR
conditions expected 16z-00z. Could see some post-frontal stratocu
after 13z Wednesday at IND.

Winds will 3 knots or less and variable except northwest and north
around 6 knots at IND after 13z Wednesday, in the wake of the cold
front.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...MK
NEAR TERM...MK
SHORT TERM...MK
LONG TERM....JAS
AVIATION...MK



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