Thursday: A Look at The Long Range

Summary:

• Cold air moderates a little heading into this weekend but still remains on the chilly side
• Chance for coastal storm development Monday or Wednesday
• No threat for winter weather except at higher elevations of interior New England 
• Models are spread on what system they want to strengthen 
• Long range pattern is becoming favorable for colder and stormy weather due to high pressure (-NAO) pattern projected to form over Greenland
• Target period is end of next week through Thanksgiving
• Patterns like this allow cold air to lock in over the eastern US and energy to consolidate to form storms
• Will be important to see if the models verify on this pattern**
• There is a chance some moderation develops and things warm up for a period in December.
• Jury is still out on this 

Good morning. We are now on the back end of this impressive cold spell. Things will start to moderate a little towards this weekend but still stay on the colder than normal side overall. In terms of storms, one storm should develop offshore Sunday into Monday while another one can potentially target the east coast on Wednesday. Not necessary a winter storm but something to keep an eye on over the next few days.

You can see below how models are flirting with two storm systems. One for Monday and one of Wednesday...

The GFS is more bullish for Monday...

The European model for Wednesday...

The atmosphere is starting to develop a "blocking pattern" which I will discuss more below.  Due to this I think the chance that one of these storm threats can hit. The GFS is more bullish on Monday the European on Wednesday. There will not be a lot of cold air aloft available this time around so if a storm forms it is again an interior higher elevation snow threat. I will keep an eye on this. 

The main thing I wanted to discuss today is how the overall weather pattern is setting up in the long range. I am seeing very favorable indicators being projected for the end of November to support cold and storm development along the eastern seaboard.

I try to keep things simple, so the image below sums up what I am looking at...

This image is valid for the week of Thanksgiving. A few key things that most of the models are showing for this time period that I like to see:

• A negative north Atlantic oscillation which is seen by high pressure over Greenland. 
• When high pressure forms here, especially in western Greenland there is a favorable atmospheric response for cold and stormy weather
• A block in the Jet Stream
• Aided by the -NAO pattern the jet stream buckles over the east coast
• This means energy entering the pattern can consolidate and form storms
• Potential for cold high pressure to get locked in
• essential ingredient for snow closer to the coasts otherwise storms wash cold air away
• Usually aided by a -NAO pattern

We have not see too much of a -NAO pattern over recent years except for March of 2018 which was a wild month weather wise. It is the single most important factor for increasing the likelihood of storms developing and giving areas near the coast the shot at snow.

Now that doesn't guarantee anything but it does increase the chances IF THIS PROJECTION VERIFIES. Considering there is a lot of cold air available up in Canada due to increased snow cover late November and Early December are periods to watch for a winter storm. When long range forecasting, all we can do is target peroids that have an increased likelihood then hone in on anything that might develop.

Thats all for now.