Wednesday, March 11, 2015

Wednesday Morning: Atmosphere is a Loaded Gun...Will Old Man Winter Pull the Trigger?

Good morning everyone! I discussed in my last post in great detail how and why the pattern was going to shift to cold and stormy last 2 weeks of March. I also highlighted the period from the 19-24th for potential storm development. I want to make clear that just because the pattern is loaded does not mean a storm will occur it just INCREASES the chances. This late in the season you need everything to come together perfect. With that being said, lets have a little fun and highlight two areas of concern for storm development.

Concern #1 Tuesday into Wednesday

A nothern disturbance is expected to dive down towards the east coast on Tuesday. As this disturbance dives down we have a developing block or negative NAO downstream of the disturbance. Because of this developing block we need to be on alert for this disturbance to close off and amplify off the east coast. If this occurred a big storm would happen. Image below highlights my points. Ignore concern #2 as I will get to that in a min.

You can see the developing ridge near Greenland along with a vortex near eastern Canada also known as a 50/50 low. The placement of those variables along with how amplified the western ridge become will determine the fate of the northern disturbance and if that things really cracks up into a significant storm for Wednesday. We will keep a close eye on that.

Moving on, notice how I highlighted concern #2. That represents an active southern jet cutting underneath the ridge out west. With again that blocking in place downstream we need to be on alert for a northern disturbance to dive down and interact with this southern disturbance later in the period say towards the end of next week. The block over Greenland slows down the flow, thus it gives all these ingredients a better chance of coming together and forming a big storm. Make the block too strong however and you get a suppressed solution. 

We have not had a pattern this good all winter for storm development along the east coast in particular that negative NAO. Now that it is projected to be in place we have to be on high alert from next week on. Lets see how this plays out over next few model runs. 

Stay tuned for a video this eve! 


  1. Hey Will,
    Headed to Okemo for the weekend. Looks like we are right on the line.
    Whats your call? Rain or Snow?

    1. On Saturday looks like you can have quick burst of snow changing to sleet or rain at base unfortunately..the gfs has colder solution but it is an outlier. However, looks like Saturday night into Sunday it will def snow.

    2. I don't want this winter to end. 30 days on the snow and counting!
      Thank you for your winter enthusiasm - Wearher Willy is a household name for us!

    3. Haha thats great thanks for the support