Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 140022

Area Forecast Discussion
National Weather Service Northern Indiana
822 PM EDT Fri Oct 13 2017

Issued at 820 PM EDT Fri Oct 13 2017

Unseasonably mild conditions are expected into overnight into
Saturday in advance of a low pressure system. Lows tonight will
drop into the middle to upper 50s, with highs on Saturday
generally in the 70s. Chances for showers and perhaps a few
thunderstorms will increase late tonight into Saturday across
northwest Indiana and southern Lower Michigan, while mainly dry
conditions persist across northeast Indiana into northwest Ohio.
The low pressure system moves through Saturday night into Sunday
with chances for showers and gusty winds. Cooler and drier air
will filter in for early next week, with temperatures gradually
on the rise thereafter.


.SHORT TERM...(This Evening through Saturday)
Issued at 310 PM EDT Fri Oct 13 2017

Strengthening southwest flow into tonight and Saturday in advance of
a potent upper trough ejecting east into the Northern Rockies and
High Plains will result in unseasonably mild temperatures into
tomorrow. This will also help to transport moisture into a
developing/leading baroclinic zone from Iowa east-northeast into the
Lower/Central Great Lakes. Weak elevated instability and ample
moisture return/advection into this front will likely allow showers
and perhaps a few thunderstorms to blossom...bringing increasing
chances for precipitation later tonight into Saturday into our nw IN
and sw Lower MI counties. The initial warm advection surge favors
higher PoPs late tonight/early Saturday morning, a possible lull
by the midday tomorrow, and then possible re-development by later
in the day as stronger forcing overspreads. Clouds and showers
will likely limit temp rises a bit tomorrow in these areas, while
ne IN/nw OH experiences highs in the upper 70s to near 80 within
dry/well mixed warm sector.


.LONG TERM...(Saturday Night through Friday)
Issued at 310 PM EDT Fri Oct 13 2017

Strong mid level height falls/DCVA associated with the above
mentioned upper trough, and an emerging coupled upper jet
structure, will allow sfc low pressure to deepen northeast
through the Western/Northern Great Lakes Saturday night and into
Quebec Sunday. This will force a strong trailing cold front
through later Saturday night/Sunday morning with gusty winds and
chances for a period of rain across the entire forecast area.
Strong wind field could support some stronger gusts > 40 mph with
any fine line and/or decent pressure rises in pronounced cold
advection wing post-frontal.

Shot of cool/seasonable air will be short-lived late Sunday into
Monday as pattern flattens out with positive temp anomalies
returning mid-late week.


.AVIATION...(For the 00Z TAFS through 00Z Saturday Evening)
Issued at 816 PM EDT Fri Oct 13 2017

Primarily VFR conditions through the forecast period, save for
some minor deterioration at KSBN/northwest Indiana towards
daybreak as a series of shortwaves move east-northeast along
frontogenetic boundary from northern MO into the southwest portion
of the Upper Great Lakes.


LM...Gale Watch from Saturday evening through Sunday evening for



SHORT TERM...Steinwedel
LONG TERM...Steinwedel

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