Area Forecast Discussion
Issued by NWS Indianapolis, IN

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926
FXUS63 KIND 170211
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1011 PM EDT Wed Aug 16 2017

.UPDATE...
The NEAR TERM and AVIATION Sections have been updated below.

&&

.SYNOPSIS...
Issued at 325 PM EDT Wed Aug 16 2017

A frontal system will bring chances for showers and thunderstorms
to central Indiana through Thursday evening. After that dry
weather will move in to end the week, but the weekend could begin
with a shower or storm on Saturday. After that look for dry
conditions and mostly clear skies until late Monday night, along
with slowly increasing temperatures.

&&

.NEAR TERM /Rest of Tonight/...

Issued at 1002 PM EDT Wed Aug 16 2017

Update...
Convective activity is approaching from the southwest at this
time. As a result, increased pops across the southern half of
central Indiana from slight chance to chance through Thu 06Z. At
that point, high chance pops will encompass all of central Indiana
through the course of the night as a cold front moves closer.
Meanwhile, overnight lows are still expected to be in the low 70s.
Updated grids have been sent.

Previous Discussion...
Will see chances for showers and thunderstorms increase over the
next few hours initially, then drop off, then increase again later
tonight from the west as a surface frontal system impacts the
area. With the forcing and ample moisture should see some precip
coverage and mostly cloudy skies, but capping over the area is
keeping extent limited thus far and will likely continue to impede
development. Convection allowing models continue to show
development over Illinois moving this way but deteriorating as it
gets close to the forecast area, likely due to the aforementioned
capping. Better potential for more shower coverage will arrive
late during the overnight ahead of the approaching cold front, but
with that time of day thunder should be only isolated to widely
scattered.

Low temperatures should remain in the low 70s with southerly flow
and more cloud cover.

&&

.SHORT TERM /Thursday through Saturday/...

Issued at 325 PM EDT Wed Aug 16 2017

A cold front will be moving through the area on Thursday and it
will increase chances for showers and thunderstorms ahead of it.
Could see some instability build ahead of the front, and should
there be breaks in the clouds could develop some steep lapse rates
rather quickly. That said, dynamics are not impressive over this
area, so expect severe threat to be limited. For the western
counties, expect the front to move through during the morning with
less of an opportunity for much development other than showers
with embedded thunderstorms, but the eastern counties could see
more thunderstorm coverage. Expect temperatures to reach the mid
80s under warm southwesterly flow but not a lot of sunshine.
Confidence is moderate, with some model differences in timing and
coverage.

After the front passes, could still see some showers in its wake
with the passage of the upper trough early Thursday night, but by
late Thursday night have removed all pops. High pressure will
briefly pass through, but another upper wave could bring a slight
chance for a shower or storm on Saturday. Temperatures should
remain near normal.

&&

.LONG TERM /Saturday night through Wednesday/...

Issued at 157 PM EDT Wed Aug 16 2017

Upper trough exiting the region Saturday will bring precipitation
chances with it, and dry weather will prevail Saturday night into
Monday night. The next short wave trough will approach Monday
night with a low chance of precipitation. It`s associated surface
trough and increased moisture flow ahead of it will bring more
widespread showers and scattered storms Tuesday that will exit the
area Wednesday.

Temperatures through the period will be should be within just a
few degrees above seasonal norms, and blended initialization
handled this well.

&&

.AVIATION /Discussion for the 17/03Z TAF Update/...

Issued at 1002 PM EDT Wed Aug 16 2017

Update...
No changes.

Previous Discussion...
Convection has been minimal this evening, so trended toward VFR
conditions and a drier forecast for this evening. However, do
expect shower and thunderstorm chances to pick up overnight. VFR
conditions should persist through the overnight hours though. MVFR
conditions will be possible closer to daybreak as a cold front
moves closer and shower and thunderstorm chances increase. Winds
through the period will generally be south/southwesterly at 5 to
10 kts.

&&

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

&&

$$

SYNOPSIS...CP
NEAR TERM...CP/TDUD
SHORT TERM...CP
LONG TERM....Tucek
AVIATION...TDUD



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