December 2017 - January 2018 Arctic Outbreak (humidity, sunshine, cloudy, Washington)

[Cambium]

Where do I start? It's -1.2° here this morning.


Jan 1, 2018:


Every State in the CONUS has a freezing temp this morning.
White = Sub 0°F. Pink = 0-20°F. Blue = 20-32°F






41 States have a Wind Chill Advisory





6amCST temps.. These are not wind chills! 20s down to the gulf coast.




Single Digits down to Virginia.

[Shalop]

Went outside to measure, was -14.3C or 6F.

First occurrence of -30F at Saranac Lake this morning, looks like good radiative cooling up there!

^Still no -40s in Quebec or Ontario though, sometimes our first single digits coincides with that.

[Infamous92]

Bottomed out at 6.4°F (-14.2°C), first single digits since Feb 2016.

My lowest temp last winter (Dec-Feb) was 16.0°F (-8.9°C).

[Cambium]

Current Wind Chills 8amEST Jan 1, 2018.

Feels Like....

-39° Greenville, Maine
-32° Des Moines
-27° Chicago
-19° Hartford
-17° Boston
-11° JFK
2° Birmingham
4° Atlanta
5° Dallas
11° Mobile
16° New Orleans

[jbgusa]

I am surprised that a cold spell lasts this long in a La Niña. Previous epic-length spells have been in neutral or near-neutral ENSO conditions. Examples are 1917-8 (over New Years), January 18 (or so) 1961 to February 3, 1961, January 1970, 1977, 1982, 1994 and 2004.

[Cambium]

Coming up.........Colder than this one? Sure, why not.

Area Forecast Discussion
National Weather Service New York NY
704 AM EST Mon Jan 1 2018

Otherwise...before this storm, a moderation in temps to about 10
degrees below seasonable expected Wednesday ahead of developing
polar trough. After the storm, the hazard once again becomes
the arctic cold. In fact, this could be the coldest air thus
far, with signal for 850 temps of -25 to -30c into the region
for Friday into the weekend. This would likely have temps
struggling to get out of the single digits to lower teens
Fri/Sat, with widespread wind chills of
-10 to -20 degrees early Fri and Sat mornings.

Area Forecast Discussion
National Weather Service Gray ME
648 AM EST Mon Jan 1 2018

While cold conditions will be the norm through the long term
forecast period the most significant impacts will be the result
of Thursdays coastal low. All guidance continues to strengthen
this low to below 960mb, and in a very short time. The result is
a large wind field with 35kt wind gusts extending outwards over
200 miles from the storm center. Hurricane force winds are
expected within the core of the storm. Similar to the wind field
the precipitation, which will be all snow due to the cold
temperatures, will also extend far from the storm center. Strong
bands with very intense snowfall are likely near the core of
the system. A storm of this magnitude is clearly capable of
significant impacts, including blizzard conditions near the
storm center. However the track guidance has held fairly steady
overnight, and keeps the core of the storm offshore in the Gulf
of Maine. If this near miss track is able to hold land areas
will see some snow, as well as gusty winds of 20-30 mph but
miss the core of the system. A more westward deviation would
result in increased snow and wind approaching blizzard
conditions, while an eastward deviation would bring snow to only
the immediate coastline. All of the track variation is sourced
from the variability in the short wave diving southward to
create the storm, which means much of this variability is
unlikely to be resolved until late Tuesday making this a nail
biter right through to the end.

Following the low we get another arctic outbreak, this one even
colder than the current with 850mb temperatures dropping to a
frigid -30C across the northern mountains. If that sub 30 below
air is able to make it all the way to GYX it will be at or near
record cold 850mb temperature for the GYX sounding for Saturday
morning.

[snj90]

Single digits here this morning. Very light snow cover still. 9 F or -13 C. I believe they're actually going to go forward with the Mummers Parade in Philadelphia today.

[BMI]

We stayed above 0F along the lakeshore in Burlington.

On the other end of the lake, Kingston not so fortunate, they had a bone chilling -30.9C

[ilovemycomputer90]

Originally Posted by Cambium

Current Wind Chills 8amEST Jan 1, 2018.

Feels Like....

-39° Greenville, Maine
-32° Des Moines
-27° Chicago
-19° Hartford
-17° Boston
-11° JFK
2° Birmingham
4° Atlanta
5° Dallas
11° Mobile
16° New Orleans

Something tells me that -43 F in Alabama is off lol. Crazy to see near zero windchills in the deep south.

Of course my location station (KFWN) has gone offline so I have to use data from another station (Andover, NJ K12N). Andover is reporting a low of -5 F/-21 C this morning. Forecast keeps getting colder for the week.

[Cambium]

Boston streak staying under 21°F. Its been a long timesince experiencing this!

https://twitter.com/NWSBoston/status/947481952071897088