Portage, Indiana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

932
FXUS63 KIWX 241142
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
642 AM EST Sat Jan 24 2026

.KEY MESSAGES...

- A Cold Weather Advisory remains in effect through this
  morning. Wind chills of 10 to 20 below zero are expected.

- A low pressure system will bring heavy snow to the area
  tonight into Sunday night, followed by lake effect snow into
  Monday afternoon. Winter Storm warnings and advisories are in
  effect, with greater than 6 inches of snow accumulation
  expected in the warning areas. Travel impacts are expected
  through Monday morning, with the worst conditions Sunday into
  early Sunday evening. See the latest winter weather statement
  for details.

- Temperatures will remain well below freezing for at least the
  next 7 days, with periods of sub zero wind chills along with
  some lake effect snow showers.

&&

.DISCUSSION...
Issued at 635 AM EST Sat Jan 24 2026

The main changes made to the forecast overnight were:

1. Expanded the winter storm warning further northwest and added the
remainder of the CWA into a winter weather advisory. Confidence is
high in us seeing 6 inches of snow or more for the warning areas,
and 3 inches or more for the advisory areas. I have greater
confidence in totals of 4 to 6 inches in the advisory areas that
border the warning, with lesser confidence further northwest and
inland from Lake MI. See below for details.

2. Extended the winter storm warnings/advisories through late Sunday
night (1 am ET) as the timing of the system is slightly slower than
planned. Left the start time as 7 pm ET as it will likely start
snowing shortly after that-but amounts will be on the lighter side
until after 1 am ET. The greatest impacts/accumulations will occur
Sunday into Sunday evening. Lake effect snow moves in behind the
system, which will add additional accumulations to areas favored by
W-NW winds through Monday. It`s possible we may need to extend the
advisories through Monday in LaPorte/Western St. Joseph Counties in
IN and Berrien/Cass Counties in MI.

Greater details...

Cold weather Advisory Today and Outlook

Left the cold weather advisory in place with no change-as wind
chills of 10 to 20 below are expected through roughly 10 am ET. High
temperatures will range from the single digits into the teens and
low 20s through the week, with lows in the single digits above/below
zero. Overnight/early morning wind chills appear to remain in check
through much of the week, generally ranging from single digits and
low teens above/below zero. Monday night into Tuesday morning could
warrant another cold weather advisory, with values of 10 to 20 below
possible. There will be several chances for system/lake effect snow
through the week as an upper level trough moves through mid week,
followed by a closed low over the Great Lakes Thursday into Friday.

Winter Storm tonight into Sunday night

As mentioned above, expanded the winter storm warning northwestward
and added the remainder of the CWA to a winter weather advisory. I
also extended the time until 1 am ET Sun night. Thanks to the
overall synoptic pattern/phasing systems (higher bust
potential)...There is still a bit more waffling than I`d like
amongst the models with regards to the QPF and subsequent snow
accumulations, which gives me some uncertainty in terms of
primarily the advisory area- particularly for areas further
north and west. I split the advisory into segments with slightly
different wording to communicate this uncertainty-with lesser
amounts of 2 to 5 inches in the far NW and closer to 3 to 6
inches along the warning borders. If some of the more northward
shifted and slower moving models are correct-we`d need to
upgrade the advisories along the warning edge and more of the
warning area would likely see totals closer to 9-11 inches. If
the more southward shifted/faster moving models are correct-we
could end up seeing only the low-end of advisory totals further
northwest (2 inches in southwest Lower MI/Far NW IN) and the low
end of warning criteria (around 6 inches in the southernmost
extent of the warning).

That being said, I used what was available from the high res models
to try to narrow down where the advisory/warning lines would be in
terms of snow totals-and provide greater detail on the event
timing/evolution. Assuming middle of the road solutions, I have 2 to
5 inches from St. Joseph county westward for the Michigan counties
and northern La Porte/St. Joseph counties in IN. I almost left the
farther southwest Michigan counties out of the advisory all together
given the current forecast totals through the advisory time of 1 am
ET are only about 2-3" --however right behind the system a N-S
oriented lake effect band develops down the long axis of Lake MI (by
00-3z Sun evening) and travels eastward into at least La
Porte/Berrien counties by the 3-6z timeframe. As winds shift more
northwest towards monday morning (and west Mon afternoon)-we see the
band drift eastward into far northern IN and Cass/St. Joseph
counties MI before dissipating. Some of the models have another
tenth of QPF with this band-and though it`s transient we could see a
period of heavy snow that persists beyond the current advisory time
into Monday. This was what pushed me over the edge in terms of
advisory/no advisory for these areas. Right now we only have the
advisory until 1 am ET Sunday night (greatest confidence). Later
shifts will likely need to extend this segment depending on how the
lake effect situation evolves. Even with lesser QPF there could be a
decent period with moderate/heavy snow that causes impacts to travel
(especially if the system snow has already left around 3 inches of
accumulation). Inversion heights linger around 5-7Kft with an
initially long fetch down Lake MI for moisture/instability through
Mon AM, then shorter fetch and gradually crashing inversion heights
through Mon PM (especially for La Porte county by then).

Lastly, the timing of the heaviest snow has shifted more into
Sunday-early Sunday evening. For simplicity-and in
collaboration with neighboring WFO`s-I left the start time the
same as the earlier headlines as we`ll likely have at least
some light/moderate snow tonight. However, the end time was
extended to 1 am EST Sun night (vs. 7 pm EST).

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 635 AM EST Sat Jan 24 2026

Today will feature VFR conditions, increasing mid level clouds and
developing easterly winds (5-10 mph) in advance of a storm system on
target to bring increasing chances for light snow later this evening
into Sunday morning. There is lot of low level dry air to overcome
which could delay the start time of light snow and associated IFR-
MVFR conditions tonight (low confidence).

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Cold Weather Advisory until 10 AM EST /9 AM CST/ this morning
     for INZ005>009-012>015-017-018-020-022>027-032>034-103-
     104-116-203-204-216.
     Winter Weather Advisory from 7 PM EST /6 PM CST/ this evening
     to 1 AM EST /midnight CST/ Monday for INZ005>008-012>015-
     020-103-104-116-203-204-216.
     Winter Storm Warning from 7 PM this evening to 1 AM EST Monday
     for INZ009-017-018-022>027-032>034.
OH...Cold Weather Advisory until 10 AM EST this morning for OHZ001-
     002-004-005-015-016-024-025.
     Winter Storm Warning from 7 PM this evening to 1 AM EST Monday
     for OHZ001-002-004-005-015-016-024-025.
MI...Cold Weather Advisory until 10 AM EST this morning for
     MIZ078>081-177-277.
     Winter Weather Advisory from 7 PM this evening to 1 AM EST
     Monday for MIZ078>081-177-277.
MARINE...None.

&&

$$

DISCUSSION...MCD
AVIATION...Steinwedel