…Heavy lake-enhanced snow downwind from the Great Lakes on Wednesday
evening into Thursday; light lake-effect snow downwind from most of the
Great Lakes on Friday; light to moderate snow over parts of the Sierra
Nevada Mountains on Wednesday into Friday…
…Moderate to heavy lake-effect snow downwind from Lake Ontario on
Friday…
…Temperatures will be 15 to 25 degrees below average over parts of the
Northern Plains and Upper Mississippi Valley…
…There is a Slight Risk of excessive rainfall over parts of New
England…
A deep upper-level trough over the Upper Midwest to the Mid-Atlantic
weakens slightly while upper-level energy continues to move across the
Great Lakes through Friday. The system will produce heavy lake-enhanced
snow downwind from the Great Lakes Wednesday evening into Thursday.
Overnight Thursday into Friday, the lake-enhanced snow will become light
lake-effect snow downwind from most of the Great Lakes. However, moderate
to heavy lake-effect snow will develop downwind from Lake Ontario on
Friday.
Additionally, a front along the Northeast Coast will move quickly out over
the Western Atlantic by late Wednesday night. Rain will develop along the
boundary over most of the East Coast, ending from the Mid-Atlantic
southward overnight Wednesday. Over New England, the rain will change over
to light snow overnight Wednesday into Thursday. The system will produce
heavy rain over parts of New England. Therefore, the WPC has issued a
Slight Risk (level 2/4) of excessive rainfall over parts of New England
through Thursday morning. The associated heavy rain will create mainly
localized areas of flash flooding, with urban areas, roads, small streams,
and low-lying areas the most vulnerable.
On Wednesday, high pressure over Central Canada will move southeastward to
the Great Lakes and Mid-Atlantic by Friday evening. Cold air associated
with the high will move over the Upper Midwest, bringing temperatures 15
to 25 degrees below average over parts of the Northern Plains and Upper
Mississippi Valley. The cold weather has prompted Cold Weather Advisories
over parts of North Dakota, Minnesota, and Wisconsin.
Meanwhile, another front over the Eastern Pacific will move onshore over
California by early Thursday, dissipating as the boundary moves from
Southern California into Mexico overnight Thursday. The system will
produce coastal rain and higher elevation snow over parts of the Pacific
Northwest and Northern California overnight Wednesday into Thursday. On
Thursday, the rain and higher-elevation snow will move into Central
California, producing light snow over the Sierra Nevada Mountains over the
next few days.
On Friday, another front over the Eastern Pacific will move onshore over
parts of the Northwest and California. The storm will produce more coastal
rain and higher-elevation snow over parts of the Pacific Northwest and
Northern California.
Elsewhere, return flow off the Western Gulf of Mexico will produce light
rain over parts of the Western Gulf Coast on Friday.
Ziegenfelder
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php