362
fxus63 kiwx 130819
afdiwx
area forecast discussion
national weather service northern indiana
319 am est fri nov 13 2026
.key messages...
- light lake effect/enhanced rain showers, possibly mixed with
some snow, will continue early this morning across southwest
lower michigan and northwest indiana. no snow accumulation is
expected as most of the lake effect precipitation will remain
anchored across extreme northwest indiana/far northeast
illinois.
- a more dominant band of lake effect rain and snow showers is expected
to shift east into northwest indiana and southwest lower
michigan late tonight into saturday morning. some localized
light snow accumulations of less than an inch are possible
inland and mainly across grassy areas.
- below normal temperatures continue today through the weekend
followed by slowly moderating temperatures into the mid and
upper 50s by the middle of next week.
&&
.discussion...
issued at 318 am est fri nov 13 2026
dominant single lake effect band continues to affect extreme nw
indiana early this morning in the gary vicinity. some synoptic
enhanced light precipitation extends east across the local area from
south bend vicinity into southern lower michigan. this area of light
precip appears tied to a lagging secondary low level baroclinic zone
and weak accompanying low level frontogenesis forcing. through the
morning, this band of precip should tend to diminish with near term
low level fgen progs depicting some weakening of this synoptic
forcing.
the dominant band across far nw indiana may try to exhibit some
slight eastward adjustment after daybreak as a broader synoptic
scale upper level short wave drops south across the mid ms valley.
some subtle uptick in low level fgen forcing could aid in some
eastward development this morning as 950-900 mb speed convergence
associated with better northerly flow working south across western
great lakes interacts with thermally modified mass fields over
far southern lake michigan. the more pronounced low level cold
advection this morning working across the western shore of lake
michigan will continue to allow for development of a weak
northerly low level jet across western lake michigan and a
pronounced horizontal shearing zone across the western third of
the lake. this should keep the higher precip rates and dominant
single band anchored along this horizontal shearing instability
axis through the morning hours to the west of the local area.
with some uncertainty in other synoptic factors coming into play
discussed above, did maintain some low to mid range chance pops
extreme west, but not expecting any snow accumulation locally
at this time.
by this afternoon southward passage of another upper level trough
across the western great lakes will likely allow for better lake
effect precip to shift back to the chicago metro area into portions
of far nw indiana. did maintain high chance/low likely rain pops
across far western portions of the forecast area this afternoon, but
it is possible this can be adjusted downward depending on trends.
otherwise for today, little temperature recovery is expected given
weak ongoing cold advection and cloud cover. between clouds across
the west and a possible maintenance of higher cloud cover in east
with lake huron connection, a zone from southwest lower michigan
into the us-15 corridor could experience some sun today. highs will
likely be limited to the low-mid 40s.
for tonight, there should be a lull in the parade of stronger short
waves rotating through the broad negative upper height anomaly which
should allow for some backing of the flow to eventually take better
lake effect precip chances into nw indiana/sw lower mi later tonight
into saturday am. thermal profiles and sfc/near sfc wet bulbs do
appear on the marginal side of rain vs snow in modified airmass
downwind of warmer lake michigan waters. it also appears by late
tonight, some drying of the dgz should take place which will make
snowfall production less efficient and possibly promote more of a
cellular character. did maintain some light accums across la porte
of less than a half inch across mainly grassy areas farther inland,
but currently not expecting any significant travel impacts. lake
effect rain showers in scattered fashion may continue into midday
saturday but should become less organized and cellular through time.
a weak short wave spilling down the central conus/south central
canadian ridge may cause some isolated-scattered light lake effect
rain again by saturday evening, but otherwise dry conditions are
expected through the remainder of the weekend as a stable longwave
pattern featuring central conus ridging remains established. this
pattern will be characterized by weak baroclinicity and little day
to day thermal advection. this will promote continued below normal
temperatures through the weekend. looking ahead to next week, the
broad eastern conus negative upper height anomaly should finally
begin to break down allowing for eastward progression of the
longwave ridge as stronger pacific systems moves inland.
temperatures should moderate back to above normal in this pattern
for middle and latter portions of next work week. while thee are
some indications a stronger eastern pacific wave will dampen the
longwave ridge, better quality low level moisture should remain
confined to the southern/central plains so a dry forecast has been
maintained through this forecast valid period.
&&
.aviation /06z tafs through 06z saturday/...
issued at 1244 am est fri nov 13 2026
predominantly mvfr conditions at the terminals, with potential
for ifr briefly at ksbn with rain showers over the next couple
hours. otherwise, continued northerly flow with gradual
improvement to more persistent vfr conditions.
&&
.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...mcd