…Wet and windy weather to continue across the Northwest into tonight…
…Strong to severe storms and heavy rain forecast to develop from the
southern Plains to the Tennessee Valley tonight into Wednesday…
…Periods of snow for the Northern Plains through mid-week with heavier
accumulations most likely Wednesday night…
…Much above average temperatures expected for most of the Lower 48 into
mid-week…
The atmospheric river event impacting the Northwest will continue
overnight into Wednesday, with precipitation spreading from western
Washington and Oregon through the northern Intermountain West and into the
northern Rockies. Along the coast, windy conditions with periods of heavy
rain are expected tonight. Further inland, apart from the higher
elevations of the Cascades and the northern Rockies, snow will likely
change to a wintry mix and rain as a strong warm front lifts across the
region.
Precipitation will wane from the Pacific Northwest to the northern Rockies
as an associated upper-level wave moves east of the region by late
Wednesday. Precipitation will develop and spread east across the northern
Plains into the Upper Midwest as this upper system and an associated area
of surface low pressure drops across the region Wednesday night and
Thursday. This storm will bring light to moderate snows from North Dakota
to Wisconsin, with a wintry mix further south and west, including the
threat of accumulating ice from northeastern Montana to eastern South
Dakota.
Further south and east, a slow-moving frontal boundary extending across
portions of the Tennessee Valley back into the southern Plains will become
a focus for showers and thunderstorms, with the potential for severe
weather and heavy rain. Isolated strong to severe thunderstorms are
possible tonight through early Wednesday morning from parts of
northeastern Texas to western Tennessee, with the threat continuing across
western Tennessee and spreading through Middle Tennessee mid-day.
An area of low pressure is expected to organize and track northeast,
bringing unsettled weather from the Ohio Valley into the Mid-Atlantic and
Northeast late Wednesday. Rain is forecast for most areas from the Ohio
Valley to the Mid-Atlantic and the coastal Northeast. Wintry precipitation
will be mostly limited to Upstate New York and northern New England, with
the more significant threat of accumulating snows confined to the
mountains.
Further to the south, showers and thunderstorms will develop ahead of the
low’s trailing cold front as it advances across the Southeast late
Wednesday.
Apart from the northern Plains and Upper Midwest, temperatures will remain
above average across much of the country. Temperatures will be well above
average across portions of the southwestern U.S. and may reach record
highs from Southern California into the Desert Southwest on Wednesday and
Thursday.
Pereira
Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php