Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 230240

Area Forecast Discussion
National Weather Service Northern Indiana
940 PM EST Sun Jan 22 2017

Issued at 700 PM EST Sun Jan 22 2017

Areas of dense fog are expected across much of the region from
tonight through Monday morning. Low temperatures tonight will
range from the upper 30s to lower 40s. High temperatures on Monday
will range from the mid to upper 40s. A weather system will bring
a good chance for rain late tonight into Monday. Looking ahead,
cool but still above normal temperatures can be expected through
mid week, trending to more seasonable by Thursday and Friday with
several chances of rain and snow showers.


Issued at 930 PM EST Sun Jan 22 2017

Visibilities exhibiting quite a bit of variance this evening
across the area with the more widespread under one mile vsbys
being reported northern half of the forecast area. Maintenance of
strong low level inversion with northeast winds and anomalous near
sfc moisture should promote expansion of fog tonight with
increasing likelihood of dense fog after 03Z. A couple of areas
over lower confidence across western fringes of the forecast area
where some entrainment of slightly drier air is expected, and
across the extreme southeast. Currently not anticipating any
changes to current advisory outside of a small expansion across
northwest Ohio to include Putnam county, but will need to monitor
trends over next few hours for possible expansion of the advisory
across remainder of northeast Indiana/northwest Ohio counties.
Visibilities still above 5 miles across most of northeast Indiana
including the Fort Wayne vicinity, but with northeast
trajectories, would expect fog to increase in coverage across
these locations over the next few hours. Dense fog concerns may be
more prolonged across eastern portions of the advisory area
through midday Monday, but will keep current timing in place.

Did shave PoPs a bit during the overnight hours but will keep low
to mid chances in overnight as some deformation forcing north-
northwest of parent upper low and increased low level moisture
wrapping around this circulation should promote some light rain
late tonight/Monday morning, especially eastern half.


.SHORT TERM...(This Evening through Monday)
Issued at 354 PM EST Sun Jan 22 2017

Dense fog had lifted temporarily over far southwest Lower Michigan
into Northern Indiana, although visibilities were a mile or less in
a number of spots. Have extended and expanded the dense fog advisory
tonight after coordinating with surrounding offices. Given the
latest trends and high resolution models, fog should become dense
over much of the area overnight. At the same time, the northwest
fringe of a strong weather system to the south will bring a chance
of rain to the area tonight into Monday. The mild pattern continue
with highs Monday well into the 40s.


.LONG TERM...(Monday Night through Sunday)
Issued at 354 PM EST Sun Jan 22 2017

Mild weather will persist into Wednesday followed by much colder
temperatures starting Thursday as a longwave trof becomes
established across the interior of North America. Highs will be
falling back to near normal which will feel chilly with the recent
mild weather. Otherwise, lake effect snow chances are favorable from
Thursday into the weekend as 850 mb temperatures fall below -10C.
Delta T values should rise to between 12C and 15C with some snow
accumulations likely downstream of Lake Michigan.


.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 655 PM EST Sun Jan 22 2017

Moist northeast flow will continue across northern Indiana into
Monday as a strong area of sfc low pressure progresses to the mid
Atlantic states. Enhanced low level moisture and a stalled low
level baroclinic zone across the region will continue to be a
focusing point for additional areas of dense fog through Monday
morning with LIFR/IFR conditions this evening into at least Monday
morning. Some drier air may try to entrain across northwest
Indiana early Monday morning with confidence in more prolonged
LIFR conditions at KFWA through midday Monday. Short waves
rotating around parent low to the south of the area will bring a
chance of rain to far northeast Indiana late tonight/Monday but
will not hit this too hard for the 00Z TAFS with low confidence in
occurrence/timing for terminals.


IN...Dense Fog Advisory until 9 AM EST /8 AM CST/ Monday for

MI...Dense Fog Advisory until 9 AM EST Monday for MIZ077>081.

OH...Dense Fog Advisory until 9 AM EST Monday for OHZ001-002-004-005-

LM...Dense Fog Advisory until 9 AM EST Monday for LMZ043-046.



SHORT TERM...Skipper
LONG TERM...Skipper

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