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Area Forecast Discussion
National Weather Service Indianapolis IN
430 AM EDT MON AUG 29 2016

.UPDATE...
Aviation sections updated

&&

.SYNOPSIS...
Issued at 328 AM EDT Mon Aug 29 2016

A warm humid air mass will hold sway over central Indiana keeping
thunderstorm chances in the forecast today and at times through
Wednesday when a cold front moves through. After that expect
cooler and drier air to take over going into the holiday weekend.

&&

.NEAR TERM /Today/...

Issued at 328 AM EDT Mon Aug 29 2016

Early this morning radar mosaic shows a small thunderstorm cluster
up near Lafayette, but IR satellite shows cloud tops warming
a little so expect these showers and storms to decrease in
intensity over the next couple of hours. With convective
boundaries still around there though may not dissipate completely.
With humid airmass still in place could see some patchy fog
through daybreak.

Pattern has changed little in the past 24 hours, so think today
will be similar to yesterday. Could see a little less
thunderstorm coverage this afternoon as surface high pressure is
supposed to build a bit further south and east. Again best chances
for storms should be this afternoon into the evening with mainly
diurnally driven storms. Storm motion for the day should again be
slow and tropical moisture hasn't moved so any storms that form
could wind up producing some flash flood problems.

High temperatures should be similar to yesterday in the mid 80s to
around 90 and bumped up from consensus.

&&

.SHORT TERM /Tonight through Wednesday night/...

Issued at 328 AM EDT Mon Aug 29 2016

Tonight high pressure should usher in dry weather during the
overnight. On Tuesday could see a slight chance sneak into the
western counties during the afternoon on the edge of the surface
high. Late Tuesday night/Wednesday morning chances for storms move
in from the northwest as an upper wave approaches ahead of a cold
front. The cold front will move through during the day on
Wednesday and produce mid range chances for thunderstorms
Wednesday afternoon and evening. Cooler and drier air will arrive
behind the front.

For temperatures generally leaned on the warmer end of guidance
based on recent verification in the warm and humid air mass.

&&

.LONG TERM /Thursday through Sunday/...

Issued at 244 AM EDT Mon Aug 29 2016

Outstanding weather for the end of the work week and Labor day
weekend is ahead. ECMWF continues to suggest cooler Canadian air
settling across Central Indiana on Thursday associated with a
strong High pressure system that will slowly move across the
forecast area through Sunday. Aloft strong Ridging is expected to
build across the area...keeping any upper waves well north of
central Indiana. Excellent subsidence also seen through the
period...and with dew points expected to fall into the 50s and
low 60s...diurnal convection threat appears minimal. Have followed
superblends suggestion of a dry forecast which seems reasonable.
Temps will begin to warm slightly by Sunday as the surface high
should begin to reach points east of Central Indiana...allowing
warmer...southerly...return flow back into the state.

&&

.AVIATION /Discussion for the 290900z ind TAFs update/...

Mainly VFR conditions at the taf sites. Fog development has been
slower than orginally anticipated tonight...thus have trended
toward tempo groups for MVFR fog over the next few hours at the
TAF sites as dew point depressions are expected to reach their
lowest values. 

Previous Discussion below

/Discussion for the 290600Z TAFS/...
Issued at 1225 AM EDT Mon Aug 29 2016

Convective threat expected to end in the vicinity of terminals by issuance
time. Very light flow under 10 kts at 850mb suggests additional nocturnal
development not likely.

Otherwise, crossover temperatures suggest IFR conditions in fog should 
develop overnight, but earlier convection and remnant outflows may keep
things mixed up a bit more than usual. Will keep some IFR visibility 
restrictions in fog at all the terminals through about 291200Z, except 
for KIND, where a light wind off the city will keep the threat for IFR lower 
there.

Should see some diurnal cloud cover based around 025 develop by the late 
morning hours of Monday. Light surface winds overnight expected to become
060-080 degrees at 6-8 kts by midday Monday.


&&

.IND Watches/Warnings/Advisories...
NONE.
&&

$$

SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....PUMA
AVIATION...JAS/JP

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