Sunday Accumulating Snow Update (7pm Saturday):
A rare late season accumulating snowfall is on the way late tonight through Sunday. The highest accumulations on grassy/colder/elevated surfaces are currently favored generally along and northwest of I-55, where 2-4″ are likely and localized amounts of ~5″ are possible. However, the exact placement of this fairly narrow area is still subject to change.
The heaviest snowfall will occur Sunday morning through the early to possibly mid afternoon, when visibility will likely be sharply reduced to under 1 mile at times. Outside of the heaviest snowfall, lighter snow will limit any accumulation and could even mix with or change back to rain. Due to the warm ground, high sun angle in mid April, and temperatures generally above freezing, roads may remain mostly wet. However, some slush may cover bridges, overpasses, and less traveled roadways.
Northerly winds gusting up to 25-35 mph could plaster the very wet and heavy snow onto tree branches and powerlines, so minor tree damage and sporadic power outages are possible. If you have travel plans, be prepared for potentially adverse travel conditions.
SPECIAL WEATHER STATEMENT UNTIL 5AM CDT SUN .
LATE SEASON ACCUMULATING SNOW ON SUNDAY…
A strong spring storm system will likely bring an accumulation of
very wet and slushy snow to portions of northern Illinois and
extreme northwest Indiana on Sunday.
The heaviest snowfall rates
are expected to occur from a bit prior to sunrise through mid day
or the early afternoon, with lower intensities during the
afternoon. The snow will end by early evening.
There will likely
be a fairly narrow band where these heavy snowfall rates of up to
one inch per hour are most persistent.
Exactly where this sets
up, two to four inches of accumulation are likely on colder or
elevated surfaces, with locally higher amounts possible.
With warm road temperatures and the strong April sun, roads will
likely be mainly wet most of the time. However, it’s possible that
some slush may cover bridges or overpasses and less traveled
roadways during the heaviest snowfall.
While overall lack of
accumulation on roads may limit the magnitude of travel impacts,
visibility will likely be sharply reduced at times. In addition,
northerly winds gusting up to 25 to 35 mph could plaster the very
wet and heavy snow onto elevated surfaces, including tree
branches, so minor tree damage is possible.
Motorists are advised
to prepare for potentially adverse travel conditions on Sunday.
Continue to stay tuned for the latest forecast updates.
Slushy snow accumulations are appearing more likely for some locations on Sunday, with the axis north and east of I-55 favored. The most likely time for accumulation would be Sunday morning, with grass and elevated surfaces more likely as surface temperatures will remain at or above freezing. Expect reduced visibility in snow as it may fall fairly heavy in the morning.
Rain and areas of wet snow will overspread northern Illinois late tonight and continue into Sunday morning.
Most areas will see little or no snow accumulation. However, a few isolated areas could see snow fall heavily for some slushy accumulations Sunday morning, especially on grassy and elevated surfaces.
The threat of isolated slushy snow accumulations will end Sunday afternoon as precipitation gradually changes to mostly rain before ending.