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A man walks past nearly buried shopping carts at the Kings
Soopers in Monument, Colo., on Tuesday, Nov. 17, 2015. (Jerilee
Bennett/The Gazette via AP)
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November 20, 2015 - UNITED STATES - Winter Storm Bella will bring the first, not to mention locally heavy,
accumulating snow of the season for some in the Upper Midwest, Corn
Belt, and Great Lakes.
Winter storm warnings have been posted from
northeast Nebraska and southeast South Dakota into much of Iowa,
northern Illinois and southern Wisconsin, including Des Moines, the Quad
Cities, Madison, Rockford, Milwaukee and Chicago.
In the much of
the Upper Midwest, this means a likelihood for at least 6 inches of snow
in 12 hours, or 8 inches of snow in 24 hours.
Winter storm
watches are posted for much of Lower Michigan and extreme northern
Indiana, including Detroit, Grand Rapids and Lansing.
Winter Storm Bella's snow has laready spread into the Plains and Missouri Valley.
With
the cold air in place, another jet-stream level disturbance will
intensify as it sweeps eastward over the newly-arrived cold air from the
northern Rockies to the Great Lakes and eastern Canada into the
weekend.
Moisture will be markedly more limited with this system than with
Winter Storm Ajax, as well as the
severe weather and
flooding rain that plagued the Plains and South.
However,
the strength of the jet-stream disturbance, forcing a wave of low
pressure along the frontal boundary, then strengthening it over the
Great Lakes, will still squeeze out a swath of significant snow Friday
and Saturday from the Plains to the Great Lakes.
Winter Storm Bella Snow Forecast
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Winter Weather Alerts
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Latest Winter Weather Radar - Areas of snow show up in shades of blue. Possible frozen precipitation (sleet, freezing rain) shows up in pink.
Rain shows up in shades of green, with heavier rain showing up in yellow, orange and red shadings. |
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Snowfall Forecast
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The relative lack of moisture and quick-moving nature of Winter Storm
Bella should mitigate this from becoming a crippling, heavy snowstorm
for many.
However, a swath of moderate to locally heavy snow is
still expected from northern Nebraska and southern South Dakota to
Michigan. Where smaller-scale, more intense snowbands temporarily set
up, we can't rule out some 1 inch per hour snowfall rates for a time.
These
are the areas where at least 6 inches of snow is most likely through
Saturday. Some of the highest snow totals may even approach a foot.
Warm
ground from what had been an exceptionally warm first half of November
may take a small cut from total accumulations of snow, particularly on
pavement. Also, while winds off Lake Michigan will contribute low-level
moisture to the storm, relatively warm lake temperatures may also
mitigate snowfall totals a bit near the lakeshore.
Surface low
pressure is expected to strengthen a bit once it reaches the Great
Lakes, thanks to the intensifying jet stream disturbance.
The
pressure gradient between this developing low and high pressure building
in the Rockies and High Plains will produce increasing winds in the
snow area Friday night and Saturday, leading to some reduced
visibilities in blowing snow, and some minor drifting, but we are not
anticipating blizzard conditions with Winter Storm Bella.
Once the surface
low wraps up in eastern Canada, some bands of lake-effect snow are
possible off Lakes Ontario and Erie, and a little wrap-around snow may
blanket the Allegheny Plateau, Appalachians, Adirondacks and high
country of northern New England.
Given this first snow of the
season in some of these areas may be locally heavy, slow down, leave
extra time if you must travel, or consider postponing your trip.
Flight
delays are probable Saturday, possibly even late Friday night, out of
Chicago-O'Hare Airport, and are possible out of smaller regional
airports, as well. Check your flight status before leaving for the
airport.
Winter Storm Bella Snow Timing
Friday
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| Friday's Forecast - Blue areas indicate areas of forecast snow, pink indicates either rain or snow, and green indicates rain. |
Snow
will spread from the northern Rockies, northern High Plains and
Missouri Valley during the day, into the Mississippi Valley and western
Great Lakes (southern Wisconsin, northern Illinois) Friday night.
Some
blowing and minor drifting snow is possible in Iowa, northeast Nebraska
and southeast South Dakota, particularly Friday night.
Season's first accumulating snow cities:
Saturday
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| Saturday's Forecast - Blue areas indicate areas of forecast snow, pink indicates either rain or snow, and green indicates rain. |
Snow
continues in northern Illinois and southern to eastern Wisconsin,
spreading and intensifying in much of Lower Michigan and northern
Indiana.
Snow will end by afternoon in Iowa and northern Missouri.
Any rain may change to snow in northern Ohio, northwestern Pennsylvania and western New York Saturday night.
Increasing
winds Saturday night may produce areas of reduced visibility in
Michigan, and all the Great Lake snowbelts with the exception of the
Lake Ontario snowbelt.
Season's first accumulating snow cities:
Sunday
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| Sunday's Forecast - Blue areas indicate areas of forecast snow, pink indicates either rain or snow, and green indicates rain. |
Lake-effect
snow will linger in the Great Lakes snowbelts, near and south of
Buffalo, New York, and north of Syracuse toward Oswego, New York, and
the Tug Hill Plateau.
A brief round of light snow is also possible in parts of northern New England before ending.
Gusty winds may persist around the eastern Great Lakes and New England.
A few flakes may even fly across the central Appalachians from West Virginia into interior Pennsylvania.
November Heavy Snow: It's Been Awhile For Some
Despite
the Upper Midwest's snowy reputation, heavy snow in November outside
the Great Lakes snowbelts isn't as common as you might think.
According
to National Weather Service data, Chicago hasn't seen a November with 6
inches or more of snow since 1978, much less 6 inches of snow in one
November storm.
Average November snow in the Windy City is only
1.4 inches, just under 4 percent of their average seasonal snow. Their
average date of the season's first 1 inch-plus snow is December 7.
Last
season, it took the Windy City until January 5 to accumulate a season
total of 6 inches, which they may do so with Bella here in late
November. In fact, their first 6-inch-plus snow event of last season was
Winter Storm Linus just before Groundhog Day.
Similarly,
Milwaukee hasn't seen a 6-inch-plus November snow total in 20 years. In
terms of snowfall so early in the season, Milwaukee has only recorded
four 2-day snowfall totals of greater than 6 inches before Nov. 22,
dating back to the late 1800s.
Five of the past nine Novembers in the Brew City haven't even produced one-half inch of snow, total.
Across
the lake, however, Grand Rapids, Michigan, has had a break so far this
November, lacking measurable snow prior to this weekend system. November
2014 was their record snowiest November, with 31 inches of snow during
the month.
Also of interest is the tendency for less snowy seasons during strong El Niños, which we are currently in.
In
five previous strong El Niño seasons (1997-98, 1982-83, 1972-73,
1965-66, 1957-58), Chicago has picked up an average of only 23 inches of
seasonal snow, which is 15.4 inches below the 1950-2015 average of 38.4
inches. -
Weather.
