383 
FXUS63 KIND 291732
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
132 PM EDT Mon Apr 29 2019

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

&&

.SYNOPSIS...
Issued at 343 AM EDT Mon Apr 29 2019

An active weather pattern will be in place over central Indiana
this week as a frontal system stalls over the area. This will keep
chances for rain showers and thunderstorms in the forecast through
Thursday night. Chances for rain for the weekend are much lower
than the work week as the front finally moves away and broad upper
ridging builds in. Temperatures will run above normal for most of
the area through the period, but could see some lower temperatures
across the northern counties at times depending where the front 
sets up.

&&

.NEAR TERM /This afternoon/...

Issued at 1004 AM EDT Mon Apr 29 2019

Surface analysis this morning shows Low pressure was in place over
Missouri...with a warm front stretching east across Illinois and
Indiana. Radar shows a couple of areas of showers over Illinois
poised to push across Indiana in the next several hours.

GFS 300K Isentropic surface shows good lift across the area late
this morning and early this afternoon...with favorable specific
humidities over 7 g/kg. Time heights also show good lower level
moisture and lift through the day. meanwhile aloft the models
suggest a moderate short wave pushing across Indiana. Thus with
plenty of forcing in play...have trended pops higher than the
previous forecast. Furthermore given the expected cloud and
precipitation have trended temps a little cooler than the previous
forecast.

&&

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

Issued at 343 AM EDT Mon Apr 29 2019

A frontal system stalling across the area will keep chances for
showers and thunderstorms in the forecast through the short term.
The best upper forcing appears to be across northern parts of the
forecast area most of the time, and thus highest PoPs are
generally confined there. It is likely that the gradient of
rain/no rain area will fall somewhere in the forecast area, but
pinpointing that is low confidence so generally kept at least a
slight chance for rain going nearly the entire short term for the
whole area. With the influx of warm and moist air should see
enough instability to merit at least a slight chance for
thunderstorms most of the time as well.

A marginal risk for Wednesday/Wednesday night encompasses the
entire forecast area, likely due to the stalled front, a good
upper wave moving across it during the day, and a low level jet
enhancing shear. 

Currently appears the highest rainfall amounts will be possible
across the northern counties, but even there looks like less than
previously thought with the axis of highest amounts still well
west of the forecast area.

&&

.LONG TERM /Thursday through Sunday Night/...

Issued at 407 AM EDT Mon Apr 29 2019

Confidence remains high in shower and thunderstorm chances through
Thursday night as an area of low pressure continues its track
across the Ohio Valley. Latest model runs have slowed the surface
low and a trailing upper low though, and rain is now expected to
linger into Friday. Any thunderstorm threat should subside by
Thursday night, however. At that point, dry conditions will
prevail for Friday night and through Saturday for the northern
portions of central Indiana. The only caveat will be low chances
for some rain showers across the southern counties on Saturday as
models now trend toward a weak upper trough over the Tennessee
Valley. The low rain chances will move through quickly though, and
dry conditions will return for all of central Indiana for Saturday
night and Sunday. The next chance for rain will be on Sunday night
with the next front. Meanwhile, temperatures through the period
will fluctuate a bit between below and above normal.

&&

.AVIATION /Discussion For the 291800Z TAFS/...

Issued at 132 PM EDT Mon Apr 29 2019

Short wave producing light rain showers across Central Indiana is
quickly sweeping across the TAF Sites as Low pressure arrives in
western Central Indiana. Best forcing and lift appears to be 
ahead of this system...thus precipitation should end across the
TAF sites within the first hour of issuance.  

VFR Cigs within the warm sector of the passing low will be
expected this afternoon...expect at LAF...where begin on the cool
north side of the track...MVFR to IFR Cigs will be possible this
afternoon and evening.

This evening as a weak cold front stalls across Central 
Indiana...IFR to MVFR conditions are expected to settle across
central Indiana tonight. Time heights show saturated lower levels
through the night. 

Some SHRA will be possible overnight as the front lingers and the
models suggest a poorly defined short wave passing aloft. Have
used another period of VCSH...but confidence is low.

&&

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

$$

SYNOPSIS...CP
NEAR TERM...Puma
SHORT TERM...CP
LONG TERM....TDUD
AVIATION...JP