311
FXUS63 KIWX 102336
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
636 PM EST Mon Nov 10 2025

.KEY MESSAGES...

- Another band of lake effect snow is expected this afternoon
  and evening. A Winter Weather Advisory is in effect with 2-5"
  of additional accumulation expected, especially for areas
  north of I-80/I-90.

- Light rain/snow showers are possible on Tuesday but no
  accumulation or impact is anticipated.

- The rest of the week will be mainly dry with moderating
  temperatures.

&&

.DISCUSSION...
Issued at 216 PM EST Mon Nov 10 2025

On radar imagery, a single lake effect snow band can be seen
currently impacting our far northwest CWA, including Berrien, La
Porte, Starke and Pulaski counties. INDOT webcams show near-whiteout
conditions along the I-94 and I-80 corridors in far NW Indiana. With
northwest/west winds, the band will continue to shift southeast/east
throughout the afternoon and evening. Visibilities within the
heaviest part of the band may be near zero times. With inversion
heights between 10 to 15 kft and strong low level convergence,
snowfall rates of 2"+ per hour will be possible before sunset in the
heaviest parts of the band. Accumulations of 2-5" are expected in
the usual snowbelts across NW Indiana and SW Lower Michigan,
with locally higher amounts possible. Because of the nature of
the lake effects, amounts may vary across short distances. Be
prepared for low visibilities as well as slick, snow-covered
roads for the evening commute, especially along the I-80/I-90
and I-94 corridors!

Tonight, lake effect snow is expect to persist through 06Z-09Z.
Negative theta-e lapse rates will allow for snow to extend further
inland, especially late Monday into early Tuesday north of US 30. It
is worth noting though that the 12Z suite of hi-res model guidance
is much less aggressive in bring lake effect snow inland than
it was yesterday or earlier this morning. Nevertheless, still
thinking lake effect snow showers will likely make it as far
east as I-69 and as far south as US 24 overnight. Inversion
heights crash at South Bend around 1-2 AM EST Tuesday and at
Fort Wayne around 4-5 AM EST. Winds will also back west and with
a decrease in fetch, lake effect snow will gradually taper off
between 06Z-09Z. The greatest accumulations of 3-5" are expected
north of I-80/I-90 in far northern Indiana and southern Lower
Michigan; between I-80/I-90 and US 30, accumulations should
generally be between 1-3". Locally higher amounts are possible,
especially if the lake effect band becomes stationary.
Visibilities will likely be reduced and highly variable at times
overnight, especially between South Bend and Fort Wayne
wherever the lake effect persists. Slick spots and black ice
are expected for the Tuesday morning commute, even in areas that
don`t get any lake effect. The sun has helped to melt snow
today and with lows in the mid 20s overnight, melted snow will
likely refreeze overnight.

The biggest change to the forecast today was the changes made to
winter weather headlines. With the 12+ hour lull in lake effect snow
earlier this morning, the decision was made to replace the Winter
Storm Warning with a Winter Weather Advisory. Several counties that
were not in a previous headline were also added as confidence is
increasing in lake effect snow expanding inland overnight. A multi-
segment Winter Weather Advisory is or will be in effect north of US
30 and west of I 69. For La Porte and Starke counties, the Advisory
is already in effect and should last through late evening. For
Berrien County, MI, the Advisory is in effect and lasts through
early Tuesday. For all other counties in the Advisory, it will go
into effect at 4 PM EST today and last through early Tuesday.

The rest of the week is expected to be mostly dry with a gradual
trend back towards seasonable temperatures. A warm front will move
through during the day on Wednesday, bringing chances for scattered
light rain and snow showers. Dry air will limit accumulations and
impacts. Dry Wednesday and Thursday as high pressure moves in. The
next chance for rain will be Saturday night into Sunday.
Temperatures gradually warm from highs in the mid 30s to near 40 on
Tuesday to the low to mid 60s by Saturday.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 622 PM EST Mon Nov 10 2025

Another swath of lake effect snow is currently swinging back
eastward across northwest Indiana will shift eastward. Some of
the lake effect bands have been rather robust and has brought
LIFR vsbys for KSBN but there will continue to be short breaks
of shower intensity due to the more cellular nature of the
western fringe of the LES band where there will be slight
improvement of vsbys into IFR category through about 04z-05z
Tuesday. With the rather strong flow there has been decent
inland penetration which will bring some snow showers southeast
into KFWA through about 05z-06z Tue. Continued backing of the
northeasterly low level winds will help to diminish the lake
effect potential for both sites after 06z Tue and will also see
an increase in wind speeds with around 20 to 25 knot gusts
through the remainder of this TAF period and beyond.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Winter Weather Advisory until 7 AM EST Tuesday for INZ005-006-
     008-014-017-104-116-204-216.
     Winter Weather Advisory until 9 PM CST this evening for INZ012-
     103-203.
OH...None.
MI...Winter Weather Advisory until 7 AM EST Tuesday for MIZ078-079-
     177-277.
MARINE...Small Craft Advisory until 1 AM EST Thursday for LMZ043-046.

&&

$$

DISCUSSION...Johnson
AVIATION...Andersen