Area Forecast Discussion
Issued by NWS Indianapolis, IN

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FXUS63 KIND 210800

Area Forecast Discussion
National Weather Service Indianapolis IN
400 AM EDT Wed Mar 21 2018

The SYNOPSIS...NEAR TERM and SHORT TERM Sections have been updated below.


Issued at 358 AM EDT Wed Mar 21 2018

Snow will move out of the area later this morning and then expect
dry conditions as high pressure quickly moves through. More
chances for precipitation return for the weekend, with some
potential for a wintry mix and some snow Friday night. Saturday
could see some rain in the afternoon before changing back to snow
Saturday night before dry weather comes in for Sunday.
Temperatures should warm back to near normal to start the work


.NEAR TERM /Early this morning and today/...

Issued at 358 AM EDT Wed Mar 21 2018

Surface analysis shows low pressure centered over NE TN into WV,
with GOES-16 showing deformation zone across much of Ohio and stretching
back into E and SE Indiana and northern Kentucky. Radar loop and
observations at 330 am EDT show light snow across southwestern
parts of central Indiana, dry conditions over the west and
northwest, and mostly moderate snow over much of the eastern half
of central Indiana. Some bands of heavier snow exist within the
larger area of moderate snow. Temperatures in the snowfall area
ranged from 28 to 32, with dewpoint depressions of a couple
degrees at most. Over the northwest, dewpoint depressions were on
the order of 5 to 8 degrees, and this ingest of drier air seemed
to be helping to erode the southwestern light snow echoes.

With few reports this time of the morning, uncertain how forecast
snowfall totals are comparing to observations. Based on
reflectivity and visibilities, though, think totals could be
running a little high, but not confident enough to cut them now.
Road temperatures are below freezing, and have seen reports of
snowy/slushy/slippery roadways coming in via social media. Will
continue to run the headline as is with this morning issuance.

Models indicate precipitation type will remain snow through the
morning hours, and snow will come to an end from northwest to
southeast during the morning hours, and should see some clearing
in the western counties by late afternoon.


.SHORT TERM /Tonight through Friday Night/...

Issued at 358 AM EDT Wed Mar 21 2018

Tonight skies will clear across central Indiana and this will allow
temperatures to drop into the low to mid 20s, with the lower 20s
occurring over eastern Indiana where snow cover will be in place.
Thursday temperatures will slowly warm with highs in the low 50s
southwest to low 40s northeast. A weak upper wave and a surface
warm front will start to approach central Indiana and bring low
chances for precipitation in the southwest overnight Thursday, but
forcing and moisture with this wave are weak so probabilities
will remain low.

Friday afternoon the warm front will get a bit closer and bring a
small chance into the southwest counties. The front enters the
area Friday night and an upper wave will interact with it,
providing better forcing and thus much higher probabilities for
initially rain but then transitioning to a wintry mix and then
snow during the overnight hours. At this time around an inch of
snow looks possible in parts of central Indiana, and light icing
is possible as well. Confidence regarding exact precip type late
Friday night is low considering the marginal sounding profiles.


.LONG TERM /Saturday through Tuesday/...
Issued at 333 AM EDT Wed Mar 21 2018

Models in good agreement that a pair or low pressure systems will
bring more precipitation to central Indiana this weekend and early
next week. The latter system will see a better fetch of return flow
that should allow temperatures to return to at or above normal early
next week per the blend with high confidence. A wintry mix or snow
will be a threat with the first, while the second should be
accompanied by mostly rain with high confidence. In between systems,
mostly dry weather is expected Sunday through early Monday.


.AVIATION /Discussion for the 21/06Z TAFs/...
Issued at 1200 AM EDT Wed Mar 21 2018

Periods of MVFR or worse conditions, mainly at IND/BMG in snow.
LAF will remain VFR. HUF will be predominantly VFR.

Snowfall across central and eastern portions of the area will
continue at times through the night. Expect this to gradually
taper off later tonight from west to east.

Winds will be northerly early in the period, becoming a bit more
northwesterly with time. Speeds will generally be 8-12KT.


Winter Weather Advisory until 2 PM EDT this afternoon for INZ041-

Winter Storm Warning until 2 PM EDT this afternoon for INZ057-



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