Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 120934

Area Forecast Discussion
National Weather Service Northern Indiana
434 AM EST Thu Jan 12 2017

Issued at 1218 AM EST Thu Jan 12 2017

A cold front will continue to work through the area today.
Rain showers can be expected in many areas this morning, with some
areas of freezing rain possible where temperatures hover around
freezing, mainly across northwestern Indiana and far southwestern
Lower Michigan. High pressure will move into the Great Lakes
tonight and Friday resulting in dry conditions. Some freezing rain
is possible, mainly across southern portions of our area, over the
weekend as low pressure moves through the Ohio Valley.


.SHORT TERM...(Today and Tonight)
Issued at 415 AM EST Thu Jan 12 2017

Main focus on brief icing potential in NW parts of the area this

Rapid uptick in convective development across western and central
Illinois over the past few hours, as advertised by several of the
hi res models. Stronger cells already producing lightning.
Temperatures overnight have fallen much faster than previously
forecasted (or handled by any model) resulting in increasing
concerns for a period of light icing in far NW parts of the area
in the 11 to 15Z window. Recent mesoscale discussion from SPC
highlights concerns in greater detail. While air temperatures were
on the warmer side yesterday, current temps have likely reduced
any effects of that warming. Given main impacts may occur near the
end of morning commute, opted to issue SPS highlighting concerns
with trends closely monitored over the next hour or 2 for possible
freezing rain advisory. Forward speed of convection could also
allow the activity to get in sooner.

For the remainder of the area this morning, narrow band of
showers has been lingering across SE parts of the area overnight
with SE movement slowed with arrival of next wave moving along the
front. Eventually this should slide east around 12Z and not pose
an issue. Additional showers will also likely move in from
upstream warranting increase in pops through 18Z before rapidly
ending. Temperatures will continue to fall through the morning
and potential does exist for a brief period of freezing rain on
the back edge of the rain as it departs.

Once this wave departs and the main cold front clears the area,
quiet weather will settle for the remainder of the short term


.LONG TERM...(Friday through Wednesday)
Issued at 415 AM EST Thu Jan 12 2017

With main focus on near term, only minor changes to long term with
concerns still lingering over the weekend as series of waves move
along stalled frontal boundary to our south. Impacts Friday night
into Saturday morning still look to be mainly confined south of
US-24 but could edge as far north as US-30 corridor. Mix of snow,
sleet or freezing rain all possible but appear amounts should be
on the light side.

As noted by previous shift greater concern may come Sunday
night/Monday morning and pronounced surge of warmer low level air
rides over cold dome in place initially across the area. All areas
would stand a chance for some sleet or freezing rain that could
cause some impacts to the Monday morning commute. Have continued
mention with trends needing to be monitored in coming forecasts.
By Monday afternoon temperatures should be far enough above
freezing to end any threat. Much like was seen over the past few
days, large temperature variations will occur Monday into Tuesday
NW to SE with many spots climbing into the 40s and also some 50s
the further SE you go. Additional waves will bring chances for
showers through much of the remainder of the period with temps
remaining in the 40s for highs.


.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 1218 AM EST Thu Jan 12 2017

Band of shra has moved out ahead of cdfnt movg through
nw IN. Winds at FWA should diminish and veer wly after shra move
through but cdfnt movg slowly and not expected to reach FWA until
shortly after sunrise. Vort max lifting ne from KS expected to
cause more shra to move across nrn IN this morning keeping flight
conditions ifr. Some potential for zr at SBN but for now sided
with mos temp fcst just above freezing. High pressure building
into the upr midwest/upr grtlks tonight should result in
conditions improving to vfr.


LM...Small Craft Advisory until 4 PM EST Friday for LMZ043-046.



LONG TERM...Fisher

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