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Area forecast discussion 
National Weather Service Indianapolis in
1236 am EDT Thursday Sep 3 2015

the aviation section has been updated below.


issued at 350 PM EDT Wednesday Sep 2 2015

A warm and humid airmass will remain in place into early next week
as an upper level ridge remains anchored to our west/southwest. Weak
disturbances rounding this ridge over the next several days will
continue to bring low chances for mainly isolated afternoon
thunderstorms to the area.


Near term /rest of tonight/...

Issued at 1011 PM EDT Wednesday Sep 2 2015

current forecast is on no changes. Isolated convection
diminished shortly after sunset as expected with stabilizing
environment. Dry conditions with some patchy fog will prevail
tonight. Overnight lows are still expected to be in the upper 60s.
Currently...temperatures across the area are generally in the low to middle
70s. Updated grids have been sent.

Previous discussion...
will maintain isolated thunder
mention across the east into early evening and then go dry the
remainder of the evening and night as instability wanes.

Temperatures should be near or just above persistence overnight per
low level thickness forecasts. Consensus numbers were slightly too warm
and adjusted accordingly.


Short term /Thursday through Saturday/...
issued at 350 PM EDT Wednesday Sep 2 2015

More of the same is the name of the game over the next few days with
continued warm and humid conditions. Subtle disturbances rounding
the upper ridge will provide slightly more support for isolated
afternoon thunderstorms...but cannot go much higher than a 20 or 30
pop in the absence of more signficant upper support and any sort of
surface reflection.

Thicknesses suggest temperatures will be at or just above
persistence next few days for highs. Consensus numbers were a bit
too cool based on this expectation and were adjusted accordingly.
Mins appeared a bit too warm and were perhaps a result of models
anticipating more cloud cover/precipitation overnights than what will
likely occur.


Long term /Saturday night through Wednesday/...

Issued at 136 PM EDT Wednesday Sep 2 2015

The intialization from the regional software will be accepted with
high confidence through Tuesday. Confidence drops sharply later.

The deterministic fields from all models agree well through
Tuesday...and support the statistical guidance.

Tuesday night a zonal flow replaces ridging aloft and a stronger
cold front than we have seen recently tries to move in.

At that point surface pressure Standard deviations from the ensemble
show a maximum over Indiana from southwest to northeast. This means
the ensemble members cant agree where the front will be with
respect to Indiana. Until we are sure of that we cant be sure of
the forecast.


Aviation /discussion for 030600z taf issuance/...
issued at 1236 am EDT Thursday Sep 3 2015

An upper level wave will move across the Great Lakes during the
period. This will bring only slight chances for vicinity shower and
thunderstorms to klaf nearing the end of the forecast period.

With light winds overnight and a similar air mass as the last
several days...patchy fog is again possible at all sites as early as
08z. MVFR visibilities are expected in areas of fog.


Ind watches/warnings/advisories...none.



near term...tdud/nield
short term...nield
long term...jk

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