Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 101645
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
1145 AM EST Tue Jan 10 2017

.SYNOPSIS...
Issued at 1130 AM EST Tue Jan 10 2017

Very windy conditions are expected to develop today as a low
pressure area strengthens across the western Great Lakes. Wind
gusts to 45 to 50 mph are possible from later this afternoon into
this evening, along with a likelihood of rain. Dry conditions are
then expected overnight through Wednesday morning. Rain chances
will increase again Wednesday afternoon, and especially by
Wednesday night and Thursday. A cold front will settle south of
the area late this work week, but several additional disturbances
may interact with this front to produce a wintry mix and a
potential of ice accumulation this upcoming weekend.

&&

.UPDATE...
Issued at 1130 AM EST Tue Jan 10 2017

Low level wet bulbs are starting to exhibit a sharper increase
late this morning as southerly winds continue to strengthen. Any
lingering hazardous travel conditions should be confined across
extreme northeast portions of the area across south central lower
Michigan, but suspect slick roadways will become increasingly
isolated over next hour and have allowed winter weather advisory
to expire at 11 AM. Attention for the remainder of the
afternoon/evening will shift to wind speeds. Low pressure across
northeast Iowa will deepen steadily as it tracks across western
Great Lakes this evening. While low level winds are very strong,
low level inversion should provide some limit to higher end gusts,
although onset of low level cold advection late afternoon/early
evening could promote a brief period of isolated 50+ mph gusts.
Will hold with the current wind advisory for all of the forecast
area through this evening.

&&

.SHORT TERM...(Today and Tonight)
Issued at 350 AM EST Tue Jan 10 2017

Main concerns for the short term will be potential for ice
accumulations early this morning, and wind/rain through the
afternoon. An upper level trough extending from the closed low
moving through the canadian prairie will become negatively tilted,
and the corresponding surface low pressure over IL/WI will lift
northeastward as it deepens. Stronger isentropic ascent on the 290K
sfc will continue to overspread the area through Tuesday afternoon,
with a 75-80 knot LLJ pumping PWATS upwards of 200 percent of normal
northeastward into the CWA. Moisture dwindles behind the passing
cold front this evening, and brings a break to the precipitation for
Wednesday.

Precipitation type is the primary concern this morning, with a messy
morning commute expected for most areas as road temperatures remain
at or just below freezing. We are getting reports of rain, snow, and
freezing rain from observers and from observation stations across
the east at this time, so will not make any winter weather advisory
headline changes. After this morning batch of precipitation moves
through there will be a brief lull before it fills back in again
later this morning. Precipitation type the remainder of the
afternoon will be rain.

Second concern is the winds today. With the surface low drifting to
the NE and deepening, and high pressure building in its wake we have
a decent pressure rise/fall couplet across the CWA. 925mb winds are
up to 50-55 knots by early afternoon, though we are still stable
with the warm nose aloft. Winds across the southern portions of the
CWA are already gusting to near 30 knots as of 6Z, which is in line
with some of the higher-end model guidance. Thinking we could easily
get gusts upwards of 40 knots. The only limitation to even stronger
gusts at this point is the stability...with rainfall and extensive
cloud cover through the afternoon. Opted to hoist a wind advisory as
a result, for the entire CWA until 4Z this evening. Also issued a
gale warning for the nearshore waters.

&&

.LONG TERM...(Wednesday through Monday)
Issued at 350 AM EST Tue Jan 10 2017

The fun forecast doesnt stop at mixed precipitation and high winds.
After a brief break in the action later Tuesday night into Wednesday
morning, precipitation returns late Wednesday afternoon as the next
shortwave graces us with its presence. With high temperatures rising
into the 40`s and 50`s...well above the normals...precipitation type
concerns are nil...at least until Thursday night where we could see
some rain/snow mix briefly as the system moves out. Friday will be
dry, with highs in the 20`s and low 30`s.

Friday night we`ll have snow lifting into the area as the system
everyone has been worried about lifts northeast towards the Great
Lakes. Still looking good for a potential ice storm given the set up
as previous discussions elude to...but models still not cooperating
on timing/details. Held high pops through the weekend and into
Tuesday for now.

But wait...theres more! As mentioned in the hydrologic
outlook...with rainfall and frozen ground...expect increased
runoff and rises on area rivers and streams. Be on the look out
for flooding later this week and next week.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1130 AM EST Tue Jan 10 2017

Mixed precipitation has come to an end across the terminals with
occasional rain expected to continue through the afternoon. Lower
end MVFR/IFR conditions are expected along with the rain this
afternoon. Of greater concern is a period of strong wind gusts
anticipated this afternoon into this evening as a low pressure
strengthens as it tracks across the western Great Lakes. Will
continue to carry 35 to 40 knot gusts this afternoon-early
evening. This system is also associated with extremely strong low
level winds, so will continue to carry LLWS mention with continued
60 knot 2000 ft winds. Conditions should improve tonight as low
level dry air advection works into the area behind a cold front,
with diminishing winds late evening/overnight.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Wind Advisory until 11 PM EST /10 PM CST/ this evening for
     INZ003>009-012>018-020-022>027-032>034.

MI...Wind Advisory until 11 PM EST this evening for MIZ077>081.

OH...Wind Advisory until 11 PM EST this evening for OHZ001-002-004-
     005-015-016-024-025.

LM...Small Craft Advisory until noon EST today for LMZ043-046.

     Gale Warning until 11 PM EST this evening for LMZ043-046.

&&

$$

UPDATE...Marsili
SYNOPSIS...Marsili
SHORT TERM...MCD
LONG TERM...MCD
AVIATION...Marsili


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