785
fxus63 kiwx 051039
afdiwx
area forecast discussion
national weather service northern indiana
539 am est thu feb 5 2026
.key messages...
- scattered snow showers are expected this afternoon with a
light dusting of accumulation possible.
- a period of freezing drizzle is possible tonight but
confidence in area, intensity and impacts is very low.
- around an inch of snow is expected friday morning, with
additional light lake effect friday night.
&&
.discussion...
issued at 330 am est thu feb 5 2026
next shortwave to impact our cwa is currently digging into the
arrowhead of minnesota on the cyclonically sheared side of a 140+ kt
jet at 300mb. this jet streak and attendant trough will tend to get
sheared out as they dive southeast and interact with broad southeast
conus trough. a modest surge of 280-285k system-relative isentropic
ascent is noted over our area this afternoon with the best ascent in
our n/ne counties. still, the llj and associated theta-e advection
is relatively weak considering the degree of dry air in place.
expect a brief window of some light snow showers 18-00z but they
will remain scattered and any accumulation will be a dusting at
best. will hold pop`s in the mid chance category and lower qpf/snow
to a tenth or two. stratus leading to another challenging temp
forecast but expect overcast skies to rule the day with highs in the
low/mid 20s. still think there is some potential for freezing
drizzle tonight. a more lackluster moisture profile from shearing
initial wave does raise some doubts, especially early in the
evening given limited near-surface omega and some hints of residual
dry air. however, several hi-res models show moisture advection
increasing through the night ahead of the next clipper system.
better mid/upper level saturation does occur by 09z fri with the
arrival of this shortwave but there does appear to be a few hour
window where there will be sufficient moisture advection/weak ascent
without ice nucleation. will therefore maintain some freezing
drizzle mention, but confidence in duration, area, and impacts
is low and no headlines planned at this time.
friday`s wave still appears to start a little stronger and will not
have the shearing influence of the southeast conus trough. it
features stronger isentropic upglide, better moisture convergence
and a better fgen signal. the only negative is that the window for
good ascent is very short, likely only a few hours on either side of
15z (earlier nw/later se). a quick inch or so is likely for most
areas with the best chance for slightly higher amounts still east of
i-69 but synoptic precip ends everywhere by 18z and highs climb into
the mid 30s given strong waa. this will likely limit impact on the
roads, especially given increasing sun angle in feb. some lake
response is expected fri afternoon through sat morning as caa ramps
up behind the wave. fetch is good with a large northerly component
but streamlines show an origin over the western u.p./wisconsin
limiting good superior connection. inversion heights are also not
great (around 5 kft at best) with increasing dry air entrainment and
limited theta-e lapse rates as the night goes on. expect some sct
snow showers in our nw zones with some localized amounts of an inch
or two possible (mainly la porte county) but overall limited
scope/impacts. sat morning will also be cold away from the lake
clouds with lows near zero and wind chills near -10f.
a more substantial warmup still appears possible next week. cold,
deep snowpack will modulate highs quite a bit, especially if
dewpoints stay below freezing, but a run at 40f is possible. there
will also be increasing precip chances by the middle of next week.
precip types may be something to watch here with abundant waa aloft
and surface temps stuck around freezing but details remain very
uncertain at this time range.
&&
.aviation /12z tafs through 12z friday/...
issued at 538 am est thu feb 5 2026
a couple of vort maxes slide southeastward affecting the area over
the course of this taf period. the first begins affecting the area
during the morning to midday hours today. looking at dew point
depressions, they aren`t all that bad at between 3 and 7 degrees
with the lowest actually occuring closer to sbn at around 18z
although it wouldn`t be too long before fwa saw precip as well and
it would start as snow. only up to around 0.5 inch snow accums are
expected with this wave. this evening, dgz saturation dries out so
ptypes would probably become more freezing-drizzly, but this
requires ample lift in the cloud layer, which is still in question.
it is a little bit more uncertain how long the drizzle would last
and if it could dry out/weaken. the next wave arrives friday morning
with renewed dgz saturation meaning ptypes would turn to snow again.
friday sees the greater snow accumulation totals.
low stratus has hung tough overnight, but arriving cirrus clouds has
begun eroding them from the west. we`ll have a period of vfr cigs
before the the system arrives during the midday to afternoon period
when mvfr conditions return.
wind-wise, trajectories look to stay out of the southwest through
the period. a llj begins to move into the area during the daytime,
but low level lapse rates are relatively weak limiting mixing and
probably keeping gusts below 20 kts. therefore, sustained winds will
be capped in the upper single digits to mid teens of kts.
&&
.iwx watches/warnings/advisories...
in...none.
oh...none.
mi...none.
marine...none.
&&
$$
discussion...agd
aviation...roller