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fxus63 kiwx 171148 

Area forecast discussion
National Weather Service northern Indiana
648 am EST Fri Jan 17 2020

issued at 303 am EST Fri Jan 17 2020

Dry and seasonable conditions today will give way to a period of
accumulating snow tonight as a winter storm tracks into the
region. The snow will then change over to a wintry mix of freezing
rain, sleet and snow later tonight, eventually becoming all rain
on Saturday. Gusty west winds and much colder air will then filter
in behind this system Saturday afternoon into Sunday. This will
also set the Stage Lake effect snow showers and flurries into
Sunday and Monday. Highs by Sunday will only reach the mid teens
to low 20s, with the low to mid 20s by Monday. Temperatures will
then gradually moderate into the middle of next week.


Short term...(today through saturday)
issued at 303 am EST Fri Jan 17 2020

Wintry mix to bring difficult travel tonight-Saturday...

Mainly dry and seasonable weather can be expected today in advance
of tonight's wintry mess as an expansive ~1045 mb surface
anticyclone translates east through the Great Lakes. This feature
will provide enough cold/dry air to keep precipitation mainly snow
to start this evening into the early overnight as a classic
overrunning event unfolds in advance of a warm front and approaching
shortwave. The initial elevated fgen band will be fighting dry low
level antecedent conditions which brings into question how quickly
snow breaks out this evening. Precipitation definitely fills in
regardless late evening into Saturday morning as deep isentropic
ascent overspreads within the preceding low level jet core. Warm
layer near 775-800 mb noses in from SW to NE overnight into Saturday
morning which still looks to bring an eventual mix with
sleet/freezing rain. Enough warm air eventually saturates down along
the near sfc portion of the warm front for mainly rain after
daybreak Saturday morning, though sfc temps could remain near
freezing into early Saturday afternoon across far northern zones.
Timing of this changeover and ptypes remain the biggest forecast
uncertainty Saturday morning.

Overall expectations for snow accums are for 3-5" north of US 30
(locally higher up to 6" in lower michigan) to 1-3" south of US 30.
Some ice accretions remain possible in the transition, especially
across our in and Ohio counties later tonight.

Strong cold advection and isentropic descent behind the system cold
front will support gusty winds, falling temps, and only some
lingering flurries/drizzle into Saturday afternoon.


Long term...(saturday night through thursday)
issued at 303 am EST Fri Jan 17 2020

Lingering broad cyclonic flow, with 850 mb temps in the negative low-
mid teens, will result in below normal temps and periodic chances
for lake effect snow showers/flurries across WNW flow lake belts
Saturday night through Monday. Highs on Sunday will likely only
reach the mid-upper teens. This shot of cold air and actual winter
like weather looks shortlived as mild Pacific air overspreads mid
week in split flow.


Aviation...(for the 12z tafs through 12z Saturday morning)
issued at 638 am EST Fri Jan 17 2020

MVFR lake clouds have scattered out with the flow becoming east
and briefly drying out. The flow will become southeast and
increase as a large 1045 mb high drifts east and allows return
flow to increase. Moisture and clouds will surge north with
precipitation starting as snow close to 00z. It looks like mixed
precipitation will begin around 08z at both sites with
temperatures rising above 0c close to 12z. Given impressive isentropic
lift, brief heavy snow is possible.


Iwx watches/warnings/advisories...
in...Winter Weather Advisory from 7 PM EST /6 PM CST/ this evening to
10 am EST /9 am CST/ Saturday for inz003-012-014-016>018.

Winter Weather Advisory from 7 PM this evening to 1 PM EST
Saturday for inz004>009.

Lakeshore Flood Warning from 9 am Saturday to 6 PM CST Sunday
for inz003.

Winter Weather Advisory from 7 PM EST /6 PM CST/ this evening to
7 am EST /6 am CST/ Saturday for inz013-015-020-022>027-

Michigan...Winter Weather Advisory from 7 PM this evening to 1 PM EST
Saturday for miz077>081.

Lakeshore Flood Warning from 10 am Saturday to 7 PM EST Sunday
for miz077.

Ohio...Winter Weather Advisory from 7 PM this evening to 10 am EST
Saturday for ohz015-016.

Winter Weather Advisory from 7 PM this evening to 1 PM EST
Saturday for ohz001-002-004-005.

Winter Weather Advisory from 7 PM this evening to 7 am EST
Saturday for ohz024-025.

Lm...Gale Warning from 1 am Saturday to 7 am EST Sunday for lmz043-



short term...steinwedel
long term...steinwedel

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