567
fxus63 kiwx 252059
afdiwx
area forecast discussion
national weather service northern indiana
359 pm est sun jan 25 2026
.key messages...
- winter storm warnings and winter weather advisories remain in effect
through this evening, and have been extended through late
morning monday morning due to lake effect snow showers on
backside of this system.
- dangerous wind chills expected tonight through tuesday morning
of 10 below to 20 below. cold weather advisories periodic
dangerous wind chills will continue through much of the work
week.
- additional rounds of lake effect snow showers are expected,
especially tuesday and wednesday.
&&
.discussion...
issued at 350 pm est sun jan 25 2026
no major changes to the forecast this afternoon with the
ongoing winter storm. the main headline changes of note were to
include winter storm warnings for additional lake effect snow
later tonight/monday morning for berrien/laporte counties and
also to move up the expiration of the remaining counties in
winter weather headlines to 03z. cold weather advisories have
also been extended into tuesday morning for all of the forecast
area.
the lead mid level short wave and accompanying mid level speed max
across the ohio valley have shifted east of the area. some mid level
fgen induced bands did lead to some periodic episodes today of
larger flake size and better dendrite production, but expecting
this potential has mainly ended locally. some lagging upper
level 600-500 mb fgen forcing is providing some forcing for
additional short-lived banding, but this elevated forcing is
tending to occur in a layer too cold for optimal snow growth. a
strengthening upper jet streak downstream of next larger scale
upstream upper level trough across the upper midwest will help
continue some large scale forcing for ascent. this next upstream
trough will also allow another modest low/mid level front to
push across the area through early evening. additional light
snow accumulations of 1 to 2 inches are expected into early
evening, with perhaps locally higher amounts around 3 inches
where any short lived highly elevated fgen forced bands can
develop across especially southeast portions of the forecast
area in the winter storm warning area.
low level flow trajectories with track of this storm system have
yielded best lake effect/enhancement to snow from chicago metro
area into portions of extreme nw indiana. as the ohio valley
sfc reflection pulls off to the east this evening, low level
flow will back to the north allowing this lake
enhancement/effect to shift east across la porte/berrien/cass
mi/st. joseph in counties late evening into the morning hours
tuesday. inversion heights building to 7-8k feet and strong lift
in low level dgz should provide favorable instability/thermo
environment for lake effect snow showers. expected land breeze
development and development of a northerly fetch should promote
dominant single band development across porter county this
evening, with band expected to be somewhat progressive across
laporte into southwest berrien late evening/overnight. lake
aggregate trough should tend to slow and anchor this band across
favored nw flow lake effect areas for monday morning, although
low level convergence should tend to wane a little after
daybreak following diurnal tendencies. this lake effect setup
should also be aided by some synoptic enhancement with the
approach of the next larger scale upper trough. href
probabilities continue to indicate higher probs for periods of
1"+/hour snowfall rates across laporte/berrien during this time.
given recent snowfall of 2 to 5 inches across these areas and a
potential of 2 to 6 inches with additional lake effect snow
showers tonight/early monday, did go ahead and transition
berrien/la porte counties to a warning with impacts to the
monday morning commute likely. have maintained the advisory
across st. joseph in/cass mi/st. joseph mi where confidence in
amounts is lower due to higher likelihood of less organization
and transition to multiband setup during the day monday. a time
extension past 15z is also possible monday depending on how lake
effect evolves overnight, but confidence is high in monday
morning commute impacts.
otherwise, a cold weather advisory has been maintained for
western/southeast locations as core of low level thermal trough
drops across the western great lakes bringing wind chills of 10
below to 20 below across the advisory area. the cold weather
advisory has been expanded area-wide for monday evening through
tuesday morning.
the progressive pattern continues on tuesday with a brief shot of
"warm" advection early tuesday preceding the next northwest
flow digging trough and accompanying reinforcing cold front.
one item which may need monitoring for late monday night into
tuesday is some impacts from strong pre-frontal and post-
frontal winds on the existing dry, fluffy snowpack. some patchy
blowing and drifting snow is likely, especially across open and
rural areas. lake effect snow shower potential will increase
again early tuesday with the renewed cold advection push. lake
induced instability depths are not as deep as that of tonight
with fetch a little more west-northwest in nature, but some
impacts are possible early tuesday, especially during the period
of peak synoptic enhancement.
little change made to previous forecast post-wednesday with a
continuation of current synoptic pattern of frequent additional
reinforcing arctic intrusions keeping temperatures below normal
through the period along with some favored periods for more lake
effect snow showers.
&&
.aviation /18z tafs through 18z monday/...
issued at 1227 pm est sun jan 25 2026
the back edge of < 2sm snow is moving out of ksbn thus,
conditions should improve notably over the next couple of
hours. 3sm to 5sm snow may persist beyond the advertised time
due to highly variable observations over eastern il. high
confidence in at least a brief period of vfr conditions before a
heavy band of lake effect snow quickly tracks from the western
lake michigan shoreline to the eastern shore. duration of this
band of les is uncertain, but models are in good agreement for
an arrival time near 06z. les showers may come and go
thereafter before lake effect ends just outside this taf
period.
at kfwa, isolated bands of heavy snow continue to be noted on
radar, including one extending northeast from klaf. thus, kfwa
is not quite done with instances of heavy snow. conditions will
improve quickly late this afternoon and especially by 00z.
after 12z, cannot completely rule out lake effect clouds
bringing a period of mvfr conditions. otherwise, low-end vfr
conditions anticipated.
&&
.iwx watches/warnings/advisories...
in...winter weather advisory until 10 pm est /9 pm cst/ this
evening for inz005>008-012>015-020-116-216.
cold weather advisory from 6 pm monday to 10 am est tuesday
for inz005>009-018-104-204.
winter storm warning until 10 pm est this evening for inz009-
017-018-022>027-032>034.
cold weather advisory from 1 am est /midnight cst/ monday to
10 am est /9 am cst/ tuesday for inz012>015-017-020-
022>027-032>034-103-116-203-216.
winter storm warning until 9 am cst monday for inz103-203.
winter weather advisory until 10 am est monday for inz104-204.
oh...cold weather advisory from 6 pm monday to 10 am est tuesday
for ohz001-002-004-005-015-016-024-025.
winter storm warning until 10 pm est this evening for ohz001-
002-004-005-015-016-024-025.
mi...winter weather advisory until 10 pm est this evening for
miz080-081.
cold weather advisory from 6 pm monday to 10 am est tuesday
for miz078>081-177-277.
winter storm warning until 10 am est monday for miz177-277.
winter weather advisory until 10 am est monday for miz078-079.
marine...none.
&&
$$
discussion...marsili
aviation...brown