Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 171113

Area Forecast Discussion
National Weather Service Northern Indiana
613 AM EST Sat Nov 17 2018

Issued at 326 AM EST Sat Nov 17 2018

A frontal boundary will bring chances for drizzle and light snow
today through Sunday morning. Light snow accumulations will be
possible in far northwest Indiana and Lower Michigan today and
across the rest of northern Indiana and northwest Ohio tonight
into Sunday morning. Highs each day will generally range between
the mid to upper 30s, with lows tonight in the upper 20s to low
30s. Cold weather pattern then continues into early next week,
with milder conditions more typical for this time of year by
Thursday and Friday.


.SHORT TERM...(Today through Sunday)
Issued at 326 AM EST Sat Nov 17 2018

A period of light snow is still expected to impact mainly far nw IN
and Lower MI this morning as weak isentropic ascent/frontogenesis
overspreads downstream of a sheared mid level disturbance. Best
chances looks to be mid morning through early afternoon with some
lake enhancement possibly giving a boost to snow near Lake MI.
However, marginal near surface temps will limit accums to a
dusting to 1" with little/no impact to travel currently
anticipated. Some drizzle could also mix in given the initial
struggle with saturation in the ice production layer.

Precip chances/coverage taper off near the southward sagging frontal
zone by mid afternoon as transient mid level subsidence/drying
overspreads in wake of the aforementioned upper wave. With that said
did retain low-mid chance type PoPs for areas of light drizzle/snow
given lingering shallow ascent/moisture near boundary. Cloudy
otherwise today with highs generally 35-40F.

00z guidance came in more aggressive overall with a renewed/elevated
frontogenetical response tonight/Sun AM in advance of the next lower
amplitude shortwave in wnw flow aloft. Bumped up PoPs/QPF as a
result south of US 6 in IN/OH, though modest deep layer forcing and
stable profile just above the frontogenetic layer keeps QPF light
overall (0.05-0.20"). Snow should be the primary ptype within this
somewhat narrow west to east band, though some light drizzle should
mix in across the southern half of the forecast area. This marginal
low level thermal environment should once again plague snow ratios
and accumulations/impacts. Overall expectations are for a narrow
zone of light snow accums (dusting to 1") on mainly grassy surfaces
along and just nw of the US 24 corridor in IN/OH.


.LONG TERM...(Sunday Night through Friday)
Issued at 326 AM EST Sat Nov 17 2018

Cold/cloudy cyclonic flow will remain in place then through the
middle of next week under a persistent Hudson Bay upper trough/low.
An embedded shortwave and cold front within this nw flow regime will
bring a chance for snow showers and renewed shot of colder air/gusty
winds Monday night into Tuesday. Some light snow accumulation will
be possible in favored nnw lake effect snow belts. Pattern then
breaks down for the second half of the week allowing for some sun
and milder temps.


.AVIATION...(For the 12Z TAFS through 12Z Sunday Morning)
Issued at 613 AM EST Sat Nov 17 2018

Short amplitude sw trough over ern SD this morning will shear ewd
through MI this aftn yet will spread a brief period of MVFR based
restriction in light snow at KSBN from around noon through mid aftn.
Thereafter secondary frontal scale circulation expected to develop
tonight within ewd translating jet entrance region. Decent fgen
signals noted esp within upward trending 06Z guidance across the
board with a streak of snow likely across the KFWA terminal mainly
between 06-12Z Sun timed with when greatest vsby reductions are
expected. Nevertheless 03Z based FM group timing was inserted to
allude to likely IFR manifestation late tonight.

Otherwise MVFR based cigs will persist elsewhere during this fcst
period with slowly veering winds blo 10kts.




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

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