Area Forecast Discussion
Issued by NWS Northern Indiana

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44

FXUS63 KIWX 131910

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

Issued at 310 PM EDT Fri Oct 13 2017

Unseasonably mild conditions are expected into tonight and
Saturday in advance of a low pressure system. Lows tonight will
drop into the 50s, with highs on Saturday generally in the 70s.
Chances for showers and perhaps a few thunderstorms will increase
later tonight into Saturday across northwest Indiana and southern
Lower Michigan, while mainly dry conditions persist across
northeast Indiana and 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 later Sunday
into Monday, 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 18Z TAFS through 18Z Saturday Afternoon)
Issued at 116 PM EDT Fri Oct 13 2017

Satellite shows clearing finally working through terminals at 17z
and expect VFR to start the valid TAF period with only some SCT
clouds around 3kft. Cu rule suggest scattered clouds this
afternoon so VFR remainder of today. Mid level clouds to move
into the area tonight ahead of next system with weak surface front
nearing the northwest late tonight. Several weak waves and a
moisture surge after 06z will likely bring some showers back into
KSBN...especially after 09z. Opted to keep conditions VFR with
these showers for now though later forecasts may need to adjust
toward MVFR Vis.


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



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

Visit us at

Follow us on Facebook...Twitter...and YouTube at: is the U.S. government's official web portal to all federal, state and local government web resources and services.