497
fxus63 kiwx 140011
afdiwx
area forecast discussion
national weather service northern indiana
711 pm est sat dec 13 2025
.key messages...
- a period of accumulating snow (1-3", locally higher far south)
for areas mainly along and south of us 30 in in, and areas
south of us 24 in nw oh, through the early evening.
- 1-3" of lake effect snow expected tonight into sunday morning in
northwest in and southwest mi.
- below zero wind chills tonight and sunday night, with values
of -15 to -20 south of us-30 tonight.
- warmer temperatures by tuesday and wednesday.
&&
.discussion...
issued at 133 pm est sat dec 13 2025
accumulating snow moving through the southern half of the area
this afternoon into early this evening. a mid level perturbation
and associated corridor of pacific moisture is driving this
swath of snow, with noted baroclinic enhancement within the
right entrance region of a ~140 kt upper level jet. these
features are phasing with an impressive polar vort lobe flirting
with the northern shores of lake superior. the quick clipper
movement likely holds snow totals to 1-3" for the southern half
of the forecast area, with locally 3-5" up against our bordering
counties with ind. sfc temps in the mid-upper teens will make
for slick travel into the early evening.
arctic air fully wraps in tonight into sunday with dangerous wind
chills and les in our northwest flow snow belts. strong dry
advection from the upper midwest and a low dgz favor small flake
size within the le plume despite impressive delta t magnitudes,
though there could be a period later this evening into early sunday
morning where better flake size will be possible. overall
expectations remain unchanged with snow amounts generally in the 1-
3" range in the south bend area and southwest mi. reduced
visibilities and snow covered roads will create hazardous travel
in spots. this lake plume likely keeps wind chills from
reaching advisory criteria (15 below or colder) for most
locations along and north of us 30, with areas to the south in
in experiencing wind chills as cold as -20f sunday am with no
changes to the cold weather advisory.
a warm advection regime develops sunday night and continues
through mid week as sfc high pressure settles off to the
southeast under flattening flow aloft. with that said, sub-zero
wind chills will persist into sunday night and monday morning as
the near sfc arctic wedge is slow to erode with increasing
southwest winds. probs for advisory or colder wind chills by
this time are relatively low per href/nbm probs, but any minor
adjustments to temps and winds could easier push values to -15f
or colder for a time. dry otherwise as waa induced snow likely
bypasses northeast later sun night-monday.
&&
.aviation /00z tafs through 00z monday/...
issued at 650 pm est sat dec 13 2025
the system snow is currently diminishing for both taf sites and
will continue to do so through the remainder of the evening
tonight. as this disturbance moves eastward caa will be on the
increase within a west to northwesterly flow and this will lead
to a transition to lake effect snow showers for ksbn which will
mainly be light in nature however a few bursts of heavier
showers will be possible through 20z sunday before diminishing.
during the heavier showers and expected small snowflake size
some vsby reductions down to ifr will be possible but the main
expectation will be for mvfr vsbys and cigs for ksbn through
20z sun when cigs/vsbys return to vfr category. for kfwa, with
the system snow moving out the expectation will be for just some
light snowshowers with perhaps some light snow showers from the
steel mill to the northwest of the terminal possible. vsbys
should improve to vfr by 01z sun and cigs will remain mvfr
through 23z sun before improving to vfr. temperatures will be
very cold for airport operations with wind chills down to around
-15 degrees f overnight into sunday morning with the gusty west
to northwesterly winds with gusts around 20 kts for both taf
sites.
&&
.iwx watches/warnings/advisories...
in...cold weather advisory from midnight tonight to 1 pm est sunday
for inz013-015-020-022>027-032>034.
winter weather advisory until 7 pm est this evening for inz020-
022-023-032>034.
oh...none.
mi...none.
marine...small craft advisory until 10 pm est sunday for lmz043-046.
&&
$$
discussion...steinwedel
aviation...andersen