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Area forecast discussion 
National Weather Service Indianapolis in
330 PM EST Friday Feb 12 2016

synopsis...near term and short term sections have been updated below.


issued at 330 PM EST Friday Feb 12 2016

We will transition from a cold pattern to mild pattern over the next seven
days as strong upper trough over Ontario...eastern Great Lakes and New
England moves on to the east and is replaced by a broad upper ridge
over much of the U.S.

In near term...a clipper which brought light snow showers today will move
quickly eastward. Lake effect snow showers are possible over northeast
sections through early Saturday as a very cold northwest flow picks
up some moisture off of Lake Michigan. A stronger disturbance will bring
a likelihood of snow to most areas Sunday and Sunday night. Then a couple of
other disturbances will bring chances of mixed precipitation or snow Monday
through the middle of next week and a chance of rain by day 7.


Near term /tonight and Saturday/...
issued at 330 PM EST Friday Feb 12 2016

Light snow showers have increased this afternoon as an upper disturbance
moves east southeast across our region. The snow showers should end over
western and southern sections by evening...but will continue east of a
Frankfort to Indianapolis and Shelbyville line overnight and some areas
early Saturday as a northwest flow off of Southern Lake mihcigan produces
scattered light snow showers. Accumulations up to a third of an inch are
possible over the far northeast...while little or no accumulation occurs

Other issues tonight will be low temperatures in the single digits and wind
chills of around 10 below late tonight. Raised temperatures slightly in the
far northeast...otherwise stayed close to a MOS blend on temperatures.

Saturday will be cold with highs in the teens...but with temperatures
approaching 20 far south which was near a MOS blend. High pressure over
the upper Midwest Saturday morning will build to northern Indiana late Saturday.


Short term /Saturday night through Monday/...
issued at 330 PM EST Friday Feb 12 2016

Main focus will be snow chances and accumulations Sunday into Monday
as a could of systems move our way.

High pressure over northern Indiana and the Great Lakes Saturday
evening will move quickly eastward as a couple of upper disturbances
move our way. Warm advection ahead of this system will cause precipitation
to spread into our region by Sunday morning. Started slight chance probability of precipitation
over southwest sections after 09z Sunday and elsewhere had probability of precipitation increasing
to likley's during the day Sunday.

Models indicate one disturbance will move east across the southern Great
Lakes as another disturbance causes a low pressure system to develop over
the lower Mississippi Valley Sunday night. Most of our weather will be
from the northern system which will produce a couple inches of snow Sunday
and Sunday night. Precipitation from this system will gradually end from
Monday over northern and western sections. But will keep low chances
across our south and east through the short term.

Models indicate some warming by Monday...but GFS seems a bit too warm and will
lean towards the cooler NAM on Monday. But this warming may still be
enough for mixed precipitation or low chances of rain Monday afternoon
in the south.


Long term /Monday night through Friday/...

Issued at 234 PM EST Friday Feb 12 2016

One wave is exiting the area as the long term starts but it is
quickly followed by another wave bringing more precipitation chances to
central Indiana for Tuesday and Tuesday night. With high
variability in ensembles and cips analogs not keying in on any
significant event accepted the initialization low chance probability of precipitation for
that time frame. Could see enough warming for Tuesday to be a mix
of rain and snow for much of the area switching back over to snow
Tuesday night. A warming trend will ramp up from Wednesday through
Friday with highs climbing from the middle 30s to the middle 50s.


Aviation /discussion for 121800z taf issuance/...

Issued at 1201 PM EST Friday Feb 12 2016

MVFR ceilings expected through the afternoon. Could see a few
light snow showers move through the sites but high res guidance
doesn/T show these producing much of anything in terms of
visibility restrictions so just including as a vcsh at this time.
Wind gusts should pick up over the next couple of hours to 20-30
kts out of the northwest. Gusts will decrease slowly overnight but
soundings indicate they will continue until around 10-13z
Saturday. MOS and sref probabilities show ceilings improving to
VFR tonight between 0 and 6z. Soundings still indicate some low
level moisture Saturday morning but sref probabilities and MOS indicate
no restrictions so went with a sct025 deck below some cirrus.


Ind watches/warnings/advisories...


near term...jh
short term...jh
long term....cp

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