Coldest Air in Two Decades???

I've been following a few sites about our upcoming Arctic blast, due to arrive by later this weekend.

This one is from the WPC Discussion page (formerly known as the HPC).

A FRIGID AIRMASS SPREADING OVER THE MIDWEST...GREAT LAKES...OHIO

VALLEY...NORTHEAST...AND MID-ATLANTIC STATES WILL BE THE BIG STORY
EARLY NEXT WEEK.  WIDESPREAD TEMPERATURE ANOMALIES OF -10 TO -20
DEGREES ARE EXPECTED ACROSS MUCH OF THE CENTRAL AND EASTERN
U.S....BUT THE EPICENTER OF THE BITTER COLD SHOULD BE ACROSS THE
OHIO VALLEY...WHICH COULD SEE TEMPERATURES NEARLY 40 DEGREES BELOW
NORMAL BY MONDAY.  IN ADDITION TO THE COLD...A SWATH OF HEAVY SNOW
SHOULD SET UP TO THE NORTHWEST OF THE SURFACE LOW TRACKING FROM
THE LOWER MISSISSIPPI VALLEY TO INTERIOR NEW ENGLAND.  THE SURFACE
CYCLONE WILL ALSO BRING STRONG AND GUSTY WINDS ACROSS THE GREAT
LAKES REGION AS IT RAPIDLY DEEPENS WHILE WRAPPING INLAND OVER
EASTERN CANADA MONDAY NIGHT INTO TUESDAY.  TEMPERATURE SHOULD
BEGIN TO MODERATE ACROSS THE EASTERN HALF OF THE NATION BY THE
MIDDLE OF NEXT WEEK.

MS