Area Forecast Discussion
Issued by NWS Indianapolis, IN

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FXUS63 KIND 161719

Area Forecast Discussion
National Weather Service Indianapolis IN
1219 PM EST Sat Dec 16 2017

The AVIATION Section has been updated below.


Issued at 350 AM EST Sat Dec 16 2017

A mild and quiet day is expected today under the influence of high
pressure off to the southeast. A quick moving upper level wave
will bring some rain showers to the area Sunday, with low chances
for rain or drizzle lingering Sunday night into Monday as
additional weak disturbances aloft pass through the region. The
next widespread chance for precipitation will come toward week`s
end as a frontal system moves through the area.


.NEAR TERM /This afternoon/...

Issued at 952 AM EST Sat Dec 16 2017

Surface analysis late this morning shows broad high pressure in
place across the southeastern states. This was allowing a
warmer...southwest flow of air into Indiana. GOES16 shows clear
skies across the forecast area and the radar was quiet.

Forecast soundings this afternoon reveal a dry column through the
afternoon with unreachable convective temperatures. With good
subsidence in place...mostly sunny skies will be expected through
the afternoon. Given our warmer southwest flow...warmer highs than
the past few days will be expected. Have stuck close to the
forecast builder blend which appears to have a good handle on the


.SHORT TERM /Tonight through Monday Night /...
Issued at 350 AM EST Sat Dec 16 2017

The main focus for the short term will be Sunday, as a compact
upper level wave moves through the area. Precipitation will be
a good bet, and while a brief mix of rain and snow at precip onset
cannot entirely be ruled out due to evaporational cooling effects,
this is looking less likely than previously and will keep grids
all rain. Even if a few flakes were to drop, the ground will be
well warmed by today`s warmth and would anticipate no impact from

Forecast soundings become drier aloft Sunday evening and beyond,
but blends do hold onto some very low pops across portions of the
area, particularly Monday morning as a weak wave passes through
the region. Could see a few showers or perhaps some drizzle and
will hold onto these low pops for now.

Consensus temperatures generally appeared in the ballpark per low
level thermal progs and required few tweaks.


.LONG TERM /Tuesday through Friday/...
Issued at 245 AM EST Sat Dec 16 2017

The upper pattern transitions from a zonal upper flow with an
upper disturbance moving east across the southern U.S. around the
middle of next week to a more amplified upper pattern Friday into
next weekend as an upper trough digs into the upper midwest and
eventually the great lakes.

Both the GFS and GEMNH models keep all precipitation well south
of Indiana...while the 00Z European brings it as far north as
southern Indiana late Wednesday and Wednesday evening.  The 00Z
superblend POPS had precipitation farther north based on the old
Euro.  Will mention slight chance POPS far south late Wednesday and
go dry elsewhere.

Models develop an area of low pressure over the southern plains
move it into the southern Great lakes Friday.  Will lean toward the
slower Euro and Canadian models.  Looks like rain will develop
Thursday night and become mixed with snow north and northwest
sections by Friday.  Could see falling temperatures Friday as colder
air arrives.

Raised superblend temperatures a little Thursday and Thursday night
as we will be mostly in the warm sector.  Otherwise...superblend
temperatures seem reasonable most other periods.


.AVIATION /Discussion for the 161800Z Tafs/...

Issued at 1218 PM EST Sat Dec 16 2017

VFr Conditions are expected for much of this TAF period.

SW flow in place across the forecast area will continue to provide
a flow of warm and dry air to the taf sites. A Strong pressure
gradient in place across the area will result some gusty winds
this afternoon. Time heights and forecast soundings reveal a dry
column through Sunday morning. Thus VFR until at least then.

A strong short wave will then push into the Ohio valley on Sunday
morning and afternoon. Ample moisture and lift will be available.
Time heights and forecast soundings trend toward saturation and
precipitation after 18Z Sun. Thus a trend toward MVFR CIGS and
rain will be expected after 15Z.




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