COLD US: 2nd Near 1060 Arctic High Could Rival Arctic Outbreak Of Jan 2014…

Written by Mark Vogan on January 3, 2015 in United States of America, Winter 2014/15 with 0 Comments

The air mass that’s ready to drop out of Canada sure means business. On the charts certainly but will it deliver the kind of severity we saw last early/mid-January when Green Bay hit 18 below, Chicago hit 16 below, Cleveland 9 below, Charlotte and Atlanta 6?

Snow cover has increased significantly in the last 5 days from the 1st of two waves of arctic air. Modelling shows a cross polar connection which should enhance the arctic air mass with Siberian air. However the bulk of the 50% US snow cover is in the Western US and the focus of this upcoming cold blast will be in the East, the very areas which bore the brunt around this time last year. The intensity of air mass coming is strikingly similar but I believe a lot will ride of snow cover because it’s snow cover that helps hold together the severity with minimal modification outwith the source region.

Here was US snow cover Jan 7, 2014 as a piece of the ‘polar vortex’ dove into the Midwest and East.

thSRN7YWUD

Interestingly, notice the lack of snow covering the Big Cities of the East Coast. Though cold with lows down to mid-single digits, New York, Philly and DC probably would have fallen below zero for the first time since the 90s had there been snow on the ground.

Here’s the current snow cover below. If the Midwest and Northeast can be filled in then the power of the coming cold will be maximised and may easily rival last January’s outbreak if not exceed it for some.

nsm_depth_2015010305_National

[s2If current_user_can(access_s2member_level1)]

There is snow falling in the Northeast today and both GFS and ECMWF see snowfall through the next 7 days. Often with these arctic air masses come clippers on the leading edge. These can drop surprising amounts of snow across large areas ahead of the high which follows.

Credit: AccuWeather Pro

The GFS 850 temps & anomalies are very impressive. Similar to this time last January.

Credit: AccuWeather Pro

114h (if you look at this closely, we’ve got temps 22 to 26 CELCIUS BELOW NORMAL at 5,000ft over the southern Appalachians.

Credit: AccuWeather Pro

GFS 2-metre temps Thur AM.

Credit: AccuWeather Pro

ECMWF Thur AM

Credit: AccuWeather Pro

RARE: 2ND MONSTER ARCTIC HIGH TO APPROACH 1060MB IN LESS THAN A WEEK

Got a bit of a surprise this evening to see that the GFS shows surface pressure approaching 1060 like last week when it hit around 1059 and broke an all-time record in the Pacific Northwest. This time the core is aimed at the central Plains, driving the core of cold into the Midwest and Southeast.