Better Get Those Xmas Lights Up Now...

Here comes the Arctic Chill as forecasted earlier this month on here...See Forecast Post

Per NAO and AO as you can see below which would indicate arctic intrusion and trough in the east.

And it looks like this will continue into the start of December as higher pressures in Alaska continues the arctic slide south with the NAO staying negative.

Looking towards Thanksgiving week, an arctic wave drifting south will meet up with an Pacific system. This will likely pull the bitterly cold air sitting to the north southward. As a wave of low pressure or a couple waves slides along the front while the cold air drifts south and east. Models continue to disagree on the evolution of cold air and storm system. However it looks like you definitely need to get those Christmas lights up if you live in the east. The cold is coming and looks to be sticking around for a while as the month of December looks pretty cold from the Mississippi river east.

Here are examples of the two main long range models the GFS(US Model) and the EURO( European). Right now I believe the 500mb pattern looks better on the Euro than the GFS. The GFS is sending too much energy ahead of the main trough (feedback). This will in turn help pump the ridge across the southeast and help phase the jet streams to dig in the trough as it slides east.

 

Trust me I'm tracking this closely because Laura and I will be flying on Thanksgiving day back to Indy. 

The Cold Builds to the North as Active Jet Stream Moves In

As mentioned last week, an active pattern is setting up across the central portion of the US. Current temperatures during the warmest part of the day are quite cold across Canada as you can see below.

This build up of cold air is just asking to be sent south and some will over the next couple of weeks. The kicker will be an active jet stream and low pressure across the interior west of the United States. The cold air looks to come down in waves so will likely modify some as it heads south. So portions of the central Plains could see snow falling by this upcoming weekend (north of I-70).

As several areas of low pressure come out of the west and head east/northeast towards the Great Lakes. Producing rain and some storms from the Southern Plains northeast into the Great Lakes region. Now this will just be the first of likely 3 or 4 storms over the next two weeks. Each one producing heavy rains but each one will likely press the snow line to the south. Right now the ensembles and long range models continue to point to a very cold(relative to average) mid month and Thanksgiving week across most of the US.

So anyone from the Texas Panhandle to Louisville to New York City and points to the north better be on guard for shoveling snow by Thanksgiving week. Places east of the Mississippi will likely see the real cold air not arrive till Thanksgiving week. So here comes the cold air as it will likely feel like late December in the third week of November. So I warned you and you better get those thermal long johns ready.

Here is the latest 8-14 day analomy and the latest 8-14 day outlook from CPC

Here Comes Winter....With A Sneak Peak This Weekend

The first nor'easter of the year is about to develop across the East as cold modified air rushes in from Canada. This will likely produce the first snow flurries all across the Ohio Valley and eventually as far south as the Appalachians and into the interior Northeast.


What I have my eyes on is a developing cold air mass in NW Canada and Pacific Jet stream that will likely buckle by mid month. As we could see our first major snowstorm of the year from the Central Plains and East into the Mid-Atlantic. Followed by freezing temperatures into the south from Texas to Georgia as temperatures could be in the single digits to teens across the north. Right now the time of arrival for this first major bout of winter looks to arrive between the 13th-16th of the month. Below is first the latest ensemble run of the 500mb anomaly and the latest 8-14 anomaly composite.