388
fxus63 kiwx 120737
afdiwx
area forecast discussion
national weather service northern indiana
237 am est thu nov 12 2026
.key messages...
- lake effect rain showers develop today with a mix of lake
effect rain and snow showers later tonight into friday
morning. some light accumulations are possibly on grassy
areas, mainly west of us route 35, with the greater potential
of over 1 inch accumulations closer to the indiana/illinois
stateline into far northwest indiana.
- additional lake effect snow showers are possible for southwest lower
michigan into far northwest indiana late friday night into
saturday morning, but confidence in any travel impacts is low.
- below normal temperatures today through the weekend followed
by slowly moderating temperatures into the mid and upper 50s
by the middle of next week.
&&
.discussion...
issued at 235 am est thu nov 12 2026
the vigorous upper level short wave which brought the rain and
isolated thunderstorms yesterday is departing the area across ohio.
some deformation type forced precip continues across nw ohio
early this morning with fairly tight low/mid level thermal
packing on backside of this system. this precip should
wane/depart to the east over the next few hours. meanwhile,
precip has transitioned to cellular lake effect rain showers
across southwest lower michigan into northwest indiana as cold
air builds south behind this wave. some respectable depth to
lake induced instability is noted in latest gfs/rap forecast
soundings even this morning, but low level wet bulbs should keep
precip types primarily in the form of rain. will be monitoring
the next significant upper level trough across the northern
great lakes as it sags southward to the southern great lakes
late this afternoon into this evening. this system should allow
for continuation of lake effect rain showers and a period of
scattered to numerous showers associated with upper level
vorticity advection and some weak low-mid level frontogenesis
forcing with a reinforcing southward sinking baroclinic zone.
highs today will likely be reached early afternoon and then
possibly become more steady in the mid 40s as low level cold
advection becomes established with a good deal of cloud cover.
the secondary strong synoptic trough should clear the area by late
this evening, but guidance has been consistent in another small
compact vort dropping through western portion of broad negative
upper height anomaly across the western great lakes overnight.
the evolution of these successive short waves may take focus for
more dominant single banding west of the local area tonight
into extreme northwest indiana closer to in/il stateline. little
movement in larger scale negative mid/upper height anomaly
combined with collective warming effects from anomalously warm
great lakes waters should allow the much more aggressive cold
advection push tonight into friday am to affect eastern
wisconsin/northeast illinois and extreme northwest indiana.
these type of setups sometimes tend to favor an induced weak
northerly low level jet closer to the western shore of lake
michigan which may end up being more of a focal point for
stronger low level convergence tonight into friday am. nbm probs
of greater than 1" of snow tonight into friday am remain
maximized west of the local area. some uncertainty remains
whether any one area will be affected by dominant banding for an
extending period with some potential that smaller scale
misovorts could be embedded in any banding given good deal of
horizontal shear across western portion of lake michigan.
with focus for tonight into friday am looking to be shifting a bit
farther west than previous indications, confidence remains low on
any impacts as far east as local forecast area. some modest drying
in dgz could also occur briefly in wake of the stronger secondary
upper trough this evening with better mid level rh profiles in dgz
displaced to the west. low level wet bulbs will also likely be quite
marginal which raises questions as to what could be very low snow to
liquid ratios, particularly if stronger banding and higher
precip rates are west of the area. did maintain some high
chance/low likely pops tonight across far western portions of
laporte/starke counties but it is possible these pops may need
to be lowered if mesoscale trends discussed above continue to
support more of an extreme ne il/nw in setup.
forecast confidence diminishes heading into friday and saturday
with continued indications that focus for daytime lake effect
rain showers should be across extreme northwest indiana. by
friday night into saturday, trends continue to point toward
preference to eastward migrating dominant banding with slight
eastward progression of stagnant longwave pattern. this could
provide another window of some lake effect snow showers to mix
in friday night into saturday am with some light accums possible
inland for grassy areas, but dgz should begin to dry out more
sharply during the day saturday. confidence in travel impacts
remains quite low for friday night/saturday given drying dgz and
diminishing depth of lake induced instability.
the longwave pattern will remain relatively stable this weekend into
first part of next week with only a slow moderation in temperatures
back to near normal or slightly above normal. medium range guidance
does suggest stronger southwest flow upper level short wave lifting
out of sw conus for middle of next week, but background mean upper
ridging may be strong enough to keep bulk of precip chances nw of
local area with this system.
&&
.aviation /06z tafs through 06z friday/...
issued at 1146 pm est wed nov 11 2026
deformation rain on the backside of an exiting sfc low will exit
kfwa at or shortly after taf issuance. mainly vfr/dry with
lighter northerly winds expected otherwise overnight, though a
few lake enhanced showers with likely be in the vicinity of
ksbn.
cold advection deepens in northerly flow on thursday with cigs
expected to lower into mainly mvfr. gusts up to near 20 knots
will be possible late morning and afternoon. scattered showers
will likely accompany a secondary trough thursday afternoon-
evening with brief vis restrictions possible.
&&
.iwx watches/warnings/advisories...
in...none.
oh...none.
mi...none.
marine...small craft advisory until 7 am est saturday for lmz043-046.
&&
$$
discussion...marsili
aviation...steinwedel