Area Forecast Discussion
Issued by NWS Indianapolis, IN

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FXUS63 KIND 270647

Area Forecast Discussion
National Weather Service Indianapolis IN
247 AM EDT Thu Apr 27 2017


The Long Term section has been updated below.


Issued at 248 PM EDT Wed Apr 26 2017

Several weather systems will affect Indiana now through the
weekend with periods of thunderstorms and heavy rain that may
produce flooding. Rain amounts will range from 2 to 4 inches
from Friday into Monday.

After a mild night tonight...temperatures below normal will
prevail for the most part, but another warm-up to near 80 will
take place Sunday before another cool down to near normal for
next week.


.NEAR TERM /Rest of Tonight/...
Issued at 1005 PM EDT Wed Apr 26 2017

Will continue with a weakening trend in regard to thunderstorm
activity for tonight. Cannot rule out an isolated thunderstorm or
two early in the night as cold front moves through, however, the
severe threat has ended. Isolated thunderstorm chances will
persist through Thu 09Z, but expect mainly rain showers after
that. Overnight lows are expected to be in the mid 50s to mid 60s.
Current temps across the area are ranging from the upper 50s/low
60s across the northwest to low to mid 70s over the southeast
counties. Updated grids have been sent and severe thunderstorm
watch has been cancelled.

Previous Discussion...
Showers and thunderstorms have been progressing steadily northeast
ahead of the surface trough across the mid Mississippi valley and
will continue that movement across the NW half of our forecast
area this evening. During the overnight as the air stabilizes
thunderstorms will become more isolated while showers continue
ahead of the front. All models have produced similar guidance in
these trends and will be followed. Rainfall amounts from a quarter
to half inch, especially across western counties should cause no
flooding issues.


.SHORT TERM /Thursday through Saturday/...
Issued at 248 PM EDT Wed Apr 26 2017

Models have been in fairly good agreement with a blended solution
working fairly well.

The first weather systems cold front will sweep across Indiana
early Thursday bringing and end to the showers with a cloudy and
breezy morning. A gradual clearing and settling of winds will take
place Thursday afternoon as ridging between weather systems
occurs. A calm night follows Thursday night.

Friday, the next system begins developing across the southern
Plains while high pressure builds east across the Great Lakes.
A weak short wave in southwest flow aloft begins to overspread
clouds and some showers into our area Friday. More substantial
convergence along a surface boundary across our southern counties
Friday night will yield a couple surges of heavy rainfall
...initially Friday night across the south that spreads north
Saturday as the boundary shifts north.

Rainfall totals Friday and Saturday will average above one inch
across most of the area...raising stream levels and likely
setting the stage for flooding when the final surge of rain and
storms comes Sunday and Sunday night.


.LONG TERM /Sunday through Thursday/...
Issued at 247 AM EDT Thu Apr 27 2017

The active weather that will begin early in the forecast period
will continue into the long term portion of the forecast. Low
pressure will push northeast into the Great Lakes early in the
period, with the cold front moving through the area Sunday night.
Expect widespread showers and thunderstorms ahead of the front
with heavy rain and flooding remaining a distinct threat with
precipitable water values approaching the climatological maximum
for the time of year.

Additional showers will be a possibility with the upper low Monday
into Monday night, and then again Tuesday into mid week as
additional upper level disturbances and then a more organized
upper level trough move into the region. Convective indices show a
limited thunder threat and will keep it out of these periods for

Blended initialization handled things well with only minor tweaks


.AVIATION /Discussion for the 27/0600Z TAF Issuance/...
Issued at 120 AM EDT Thu Apr 27 2017

An area of rain showers with a few thunderstorms will spread east
overnight and slowly weaken.  Area will spread into KHUF and KLAF
sites within an hour and reach KINd towards 09z.  Lightning has
diminished and will mainly go with showers or VCSH after the
first few hours.  Ceiling will lower to MVFR with arival of
cold front and then improve to VFR ceilings this afternoon as weak
high pressure approaches from the west.

South winds around 10 knots will become southwest around 15 knots
towards daybreak and west this afternoon.  Could see gusts to
around 25 knots.  Winds will diminish tonight.





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