Snow lovers across interior NJ and eastern PA are still talking about the "Roidzilla" blizzard that brought parts of southern New England and LI 2-3 feet of snow. The storm was originally forecasted by many to take a track close enough to the coast to bring snow to the aforementioned areas as well, but those forecasts did not work out probably because we threw all our chips into one basket. I can not speak for all the forecasters, but I can speak for myself when I say I was driven by what the EURO and its ensembles were showing for that storm instead of worrying about why the GFS/GGEM consistently kept taking the storm further east. An embarrassing case of "model hugging" on my part, but I'll cut myself some slack due to the complexity of the set-up and the lack of agreement between major models. It's over and done with and it's time to move on.
The next threat is now February 1st-2nd (Sunday night into Monday)
The next system that could potentially bring significant snowfall to the area is scheduled for Sunday night into Monday. As you can see from the 12z EURO H5 Height Anomaly map, there is a -NAO to work with along with a -EPO and a neutral PNA. The Polar Vortex is over the Hudson Bay and in southeast Canada is a strong vortex which actually comes from the Clipper storm we're set to experience tonight into the morning. Notice the mid-level trough down streaming into the eastern CONUS bringing down an arctic air mass.
The positive heights extending into Greenland in the prior graphic is a very nice west-based -NAO setting up. The EURO NAO index graphics clearly shows a -NAO by the time February 1st-2nd comes around. A -NAO in this case is going to do 3 key things:
- Slow down the northern stream jet. The northern jet has kept our pattern really progressive this year
- Allow the Friday Clipper storm to deepen and act as a secondary block, almost like a 50/50 low
- Amplify the Monday mid-level trough and possibly bring it negative which would deepen a storm off the coast
12z GFS Model
The Clipper system may not bring much in the way of snow to the NYC Metro area tomorrow, but it is an important piece to the evolution of the Monday system. Once this clipper reaches New England, it is going to phase with some energy from the PV and undergo bombogenesis. This vortex will then sit over southeast Canada (#1) and act as a psuedo 50/50 low. The PV (#2) is located over Hudson Bay, far enough north to give the Monday storm space to track up the coast instead of sliding out to sea. The mid-level trough (#3) is already entering the Ohio Valley by early Monday morning and the northern stream energy looks fairly potent.
By Monday afternoon, there is a sharp trough along the east coast that has gone from neutral to negatively tilted (#1). This allows the storm to make a slight turn north up the coast instead of meandering out to sea. The confluence in east-central Canada (#2) is a big reason why this storm will not cut to our west, like models were originally showing. Instead, there may actually be additional phasing of northern stream energy into the trough which would strengthen the storm even more. That is not shown on any guidance right now, but it remains a possibility.
12z EURO Model
The EURO model looks like a replica of the GFS. The energy at the base of the trough looks a little more potent which means the storm is stronger. But the way it handles the confluence to the north and how it positions the mid-level trough is almost identical to the GFS.
While it is nice to be seeing this kind of agreement from major global models (the CMC looks like the EURO & GFS as well), there is still plenty of time for this to trend differently. There are 3 different storm tracks I am looking at.
Blue: Rain and mixed precipitation into southern and coastal NJ but very heavy snow north of the baroclinic zone. The best snow usually falls just north of the temp. gradient as that is where there is the greatest frontogenesis, or lift. This solution could bring a Godzilla-type storm to NYC Metro.
Green: The storm takes a track further south and mostly everyone is snowing. The baroclinic zone is pushed south but this also means ratios will be higher since we'll be in more of an arctic air mass thanks to the Clipper system that passes us tomorrow. Since it's a fast-moving system, this track will probably not bring as much snow to the NYC Metro area but it could still be a significant storm.
Purple: This track would bring much less snow to the area, if any. In a case like this I would have to believe the PV squashes the storm or the northern stream energy never digs enough to amplify the mid-level trough. It remains a possibility as much as you do not want to hear that.
We'll see which tracks ends up winning out come Sunday night. We should have an idea by Saturday. I will continue to update you all in the forum.
Have a great weekend
Frank
visit and join forum @ www.njstrongweatherforum.com
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