557
fxus63 kiwx 120205
afdiwx
area forecast discussion
national weather service northern indiana
905 pm est thu dec 11 2025
.key messages...
- overnight, there is a slight chance (20%) of snow across far
southern portions of the forecast area, including white and
cass counties in indiana.
- periods of light system snow and lake effect snow friday
night through sunday night.
- very cold temperatures are expected this weekend. there is at
least a 50 percent probability of wind chills at or below -20
degrees f on sunday morning over much of the area.
- warmer weather returns next week.
&&
.update...
issued at 903 pm est thu dec 11 2025
have updated the forecast this evening to depict less than 1/2 inch
of snow across far southern counties and have limited pops to only a
slight chance (20%).
clipper system moving from central il through south-central in this
evening is on track to overall miss our forecast area. water vapor
imagery depicts a steady northwest to southeast track while high
resolution guidance shows the best upper-level forcing confined to
southern il and eastern mo. local dew point depressions as great as
nine degrees beneath weak mosaic radar returns bolster confidence
that snowfall will pass to our south. there is a small area of
expanding radar returns across the greater davenport, ia, area where
dew point depressions are much smaller. however, given thick cloud
cover, a quick drop in our temperature profiles into the teens this
early in the night is not expected, nor is there enough forcing to
saturate or wet-bulb the column. time-height cross sections depict a
deep, mid-level dry layer as well. all of these ingredients (or lack
thereof) necessitated this forecast update. &&
.discussion...
issued at 220 pm est thu dec 11 2025
no major changes to the inherited forecast this afternoon. a few
light snow showers persist across the cwa w/ some local enhancements
noted in and around the fort wayne metro area likely courtesy of
added moisture/condensation nuclei induced by steam from nearby
industrial facilities. in general, most activity has been
limited to flurries or a quick burst of light to moderate snow
with no notable impacts reported. still anticipating the quick
passage of another clipper system tonight, with frontogenetic
forcing and isentropic ascent very briefly allowing snow to
spread into our far southwestern zones. trends in high-res
models have continued to signal a southward shift in the band of
accumulating snowfall w/ href members suggesting around a
60-70% probability of at least one half inch of snow. the hrrr
has consistently trended south over the past several runs w/ the
18z iteration keeping any notable accumulation entirely south
of the cwa. did consider an sps for a quick 1-2 inch snowfall,
but given the forecast trends decided to hold off on this
messaging for now.
quiet weather on friday will give way to a more active weekend, but
winter impacts should still be relatively marginal for most. first
short wave disturbance passes friday night into saturday morning
with lake enhanced snow developing in westerly flow. some snow
showers may spread into the us-6 corridor as well, but the best
chance for any accumulation would likely be found across
berrien/cass counties in mi. even so, current ensemble suites
suggest likely accumulations in the 1-3 inch range with lesser
chances of advisory level amounts. the second and more vigorous
short wave arrives saturday night w/ the best forcing focused mainly
south of us-30. the parade of clipper systems naturally results in a
low predictability storm track with each subsequent wave being
influenced by the previous, so considerable uncertainty still
exists with regard to the overall degree of winter travel
impacts from this system. nonetheless, some additional
accumulation is probable. one thing is for certain, much colder
air will filter in behind this system. 75th percentile gefs h85
temperatures plunge to -20 deg c by 12z sunday, strongly
suggesting potential for temperatures in the single digits (both
above and below zero) with wind chills possibly approaching
cold weather advisory criteria. will need to monitor for a
potential lake response saturday night into sunday.
a pattern shift is still expected beyond monday of next week w/
highs climbing above freezing and periods of rain expected through
mid-week.
&&
.aviation /00z tafs through 00z saturday/...
issued at 608 pm est thu dec 11 2025
isolated instances of vfr ceilings amid a sea of mvfr ceilings
decreases forecast confidence this evening. the synoptic
environment favors mvfr ceilings overall, so i do anticipate
that to be the case for most of the night before a period of vfr
can be realized near or after daybreak friday when the low-
level inversion eases. a clipper system is tracking through
central il and central in. i have removed any sn mention from
kfwa as the track will be well south of the terminal.
the next clipper system approaches late in this period, bringing
ceilings back down to mvfr especially at ksbn.
&&
.iwx watches/warnings/advisories...
in...none.
oh...none.
mi...none.
marine...none.
&&
$$
update...brown
discussion...hammer
aviation...brown