344
fxus63 kiwx 111728
afdiwx
area forecast discussion
national weather service northern indiana
1228 pm est wed nov 11 2026
.key messages...
- rain showers develop and spread across the area this afternoon
and early evening. an isolated thunderstorm is possible across
portions of northwest indiana this afternoon and early evening
with isolated wind gusts of over 40 mph possible with any
showers or isolated storms.
- lake effect showers impact areas mainly west of us-31 in
northwest indiana and far southwest lower michigan thursday
through friday night. snow is expected to mix in by late
thursday night into friday morning. additional lake effect
snow showers are possible early saturday. some slushy snow
accumulations are possible with the lake effect, mainly early
friday morning across northwest indiana.
- below normal temperatures thursday through this weekend before
moderating midweek next week.
&&
.discussion...
issued at 1200 pm est wed nov 11 2026
a vigorous shortwave continues moving southeast from ia this morning
through central il today, reaching central in this afternoon. the
eventual placement of the warm front will be key in understanding
severity, but there appears to be some southward trend in that
placement in models between yesterday and today. key to thunderstorm
development appears to be the mid level lapse rates. hail was
forming across eastern ia this morning right on the northern
gradient from high to low within an elevated area of instability.
this would be the cause of hail should it form across the area
today. such an area of mid level lapse rates moves into areas south
of us-30 midday into the afternoon before vacating by 20z. this area
is well out in front of the forcing and would likely not be where
storms form. the other area into our southwest 1 to 2 tiers of
counties has mid level lapse rates from 6.5 to 7c. this overlaps
with an area of very weak mucape right around 100 to 250 j/kg in the
20 to 00z window. there is some low level turning to work with
within the lowest 1 to 2km of the atmosphere, but given the weak
instability and what appears to be an elevated instability nature to
the atmospheric column, the tornado threat appears to be low unless
we can realize a taller surface instability column. soundings appear
to show a sort of an onion-shaped or shallow inverted-v profile that
may be conducive to bringing winds down to the surface alluding to
the gusty to damaging wind possibility.
hot on the heels of this wave is an area of vorticity traveling
southward from canada. as this area travels southward, it
deepens and interacts with the departing low pressure area.
what`s interesting is the deeper cold is delayed and farther
west of lk mi on thursday. the ecmwf almost has a drainage
signal where the eastern lk mi area is cold, but over the lake
is warmer, even at 850 mb. so, while the qpf signal appears lake
effect/lake enhanced, we haven`t gotten the cold air enough to
change it over to snow yet. a couple of compact waves traverse
southward nearby lk mi and the rrfs seems to show a trough
kicking off a more sustained band thursday evening. by the time
we get to early fri am, enough cold air has wrapped in that
soundings are beginning to get snow mixed in or changed over. -5
to -6c at 850 mb is right over the southern tear drop of lk mi
on the ecmwf so that makes sense. as various waves/instability
troughs traverse southward, finding the exact trajectory will be
difficult because there will be some east-west wavering. a
slight eastward change can mean the relatively vigorous lift
going on from the relatively warm lake and cold airmass
interaction can mean quick snow rates getting into laporte and
maybe starke counties. these could be rates that overcome the
warm ground from how anomalously warm we`ve been this late fall.
as such, will continue the mention of the 1 to 2 inches of snow
through friday that could result in laporte county especially
with that wavering. model guidance with variable snow ratios
continues to back this up. it`ll be interesting to see what
happens with snow and if it`ll stay mainly on grassy surfaces or
if it`ll have enough oomph to accumulate on roads. some
guidance say it`ll struggle to accumulate on roads friday
morning. the snow band may push eastward saturday morning toward
us-30, but it would appear to be more diffuse at that point and
in its dying trend. it`ll also trend back to rain or drizzle as
the column warms. lake clouds could continue through sunday
with the northwest trajectories continuing. it is interesting to
see the highs are still forecast to warm into the 40s on friday
and saturday. that would cut into the accumulation ceilings and
i`m curious if we`d have refreezing overnight with sub-freezing
lows. this would depend on having standing water left on roads
that, with light to calm wind, would indicate it`s possible.
finally, by the time we get to monday, trajectories change even as
the last vigorous wave traverses the lake saturday. surface high
pressure is already working to dry low level moisture out this
weekend. highs trend warmer through the 40s to reach the 50s by the
middle of next week as the surface high slowly translates eastward.
there is a vigorous wave south of the high that moves into the gulf
states, but it`s far enough south to avoid our area. the warm
advection pattern returns midweek next week as a wave shifts
northeastward from the central plains into south-central canada. as
a result, the work week looks dry monday through at least thursday.
however, lows won`t rise above freezing until thursday morning.
&&
.aviation /18z tafs through 18z thursday/...
issued at 1222 pm est wed nov 11 2026
a complex of scattered showers and storms north of a frontal
boundary in northern ia and il is moving west towards northwest
indiana this afternoon. winds will shift from the southeast to
northeast later this afternoon as showers arrive. scattered
light to moderate rain showers will move through late this
afternoon and evening, with mvfr ceilings and visibilities
expected at both ksbn and kfwa. peak chances for showers will
occur from 22-00z tonight at ksbn and from 00-02z tonight at
kfwa. with cyclonic, northwest flow developing tonight and
overnight, ceilings will be prevailing mvfr at least through
thursday morning as additional clouds advect in off of lake
michigan. lake effect showers quickly develop in response
following the frontal passage. there may be a brief lull in
showers at ksbn between 02-06z for a few hours before starting
up again after 06z thursday morning.
&&
.iwx watches/warnings/advisories...
in...none.
oh...none.
mi...none.
marine...small craft advisory from 7 pm this evening to 7 am est
saturday for lmz043-046.
&&
$$
discussion...roller
aviation...johnson