Update: Mild in East, Changes Ahead

[CaptinCrunch]

Update: Mild in East, Changes Ahead
December 31, 2003

The mild conditions experienced
recently in much of the east and Plains
will continue for the next few days, but
strong signs of change are evident as
very cold air builds in central Canada.
Even though a cold front has passed off
the Atlantic seaboard, 50s and 60s
were common along the eastern
seaboard from Georgia to
Massachusetts this afternoon as
downsloping westerly winds kicked in.
A WeatherBug live sensor in Rye, NH
hit 52 degrees.

Cooler air was surging in more rapidly
on the other side of the Appalachians.
A WeatherBug live sensor in Pittsburgh,
PA reported 31 degrees late Tuesday
afternoon, 27 degrees cooler than the
temperature at the same time on
Monday.

The cold front, however, will not change
the overall pattern across the nation. A
fast westerly flow aloft will continue to
keep mild Pacific air dominant and
prevent arctic air over Canada from
advancing very far south over the next
few days.

Meanwhile, some of the bitter cold air
building in central Canada was spilling
into the northern Plains. Temperatures
held in the teens today in much of
eastern Montana, North Dakota and
northwest Minnesota. Readings are
forecasted to plunge to 0 to -10 tonight
with wind chills below -20 in some
areas.

Long range forecast models suggest a
large chunk of that frigid air mass will
spread into the northern Rockies and
northern Plains late Friday into the
weekend with a significant cooldown
also reaching the Midwest and
northeast by the end of the weekend.
There are also signs that a significant
storm will form along the boundary
between the mild and much cooler air,
potentially spreading snow or ice into
parts of the Great Lakes and northeast
late in the weekend into early next
week.