In Depth: Beyond the 10 Day

ROCHESTER, N.Y. (WHEC) — Right now, we still have our upper level ridge over the Western US and a trough over the Eastern US. The jet stream remains over Western Canada before dipping across the Eastern US, but things are generally quiet locally and will remain quiet the next few days. The reason is due to a lack of interaction between the Polar Jet and Subtropical Jet. Also, a lack of blocking near Greenland is playing a role. Without those two pieces, things remain quiet. A lobe of the Polar Vortex remains near the Hudson Bay, and will likely continue to spin north and south over the couple of weeks and play a role in our weather locally from time to time.

Locally, over the next few days not much is expected. A couple of Alberta Clippers will move across the Great Lakes over the next few days, but nothing significant is expected. As mentioned above, a lack of interaction of the Polar Jet and Subtropical Jet will keep these clippers on the weak side with minor snow accumulations possible. However, things will turn a bit interesting towards Valentine’s Day. The second clipper that swings through Friday, will bring another surge of Arctic air and supply that to an area of low pressure forming off the East Coast Sunday. We have been talking about this timeframe for a while now, but it still looks like a miss for us locally. Some models have begun to trend back towards the coast and they do have snow for the coastline, but there isn’t much curve up the coast dynamically to bring us snow. This is due to a lack of blocking ahead of this storm. Blocking to the east would bring us a greater chance to see this are of low pressure hug closer to the coast, but there is little evidence of that and none forecasted. With that I’d expect this to miss for our region locally but watch out if traveling towards the I-95 corridor Sunday/Monday. Locally, we may see a few snow showers off of Lake Ontario as winds turn out of the north.

So, after a miss things will turn active for our region towards the middle and end of next week (Feb 16th-Feb 18th). Once again ahead of this system, we will see a milder pattern before colder air tries to enter our region. This storm is a bit of deja-vu as this is the exact same situation as our last storm. A cold front will swing through our region and settle to our south. An area of low pressure over the Central US will then form on the tail end of this front and begin to move north. Per our last storm, three scenarios are on the table; a northern, southern, and overhead track. The northern track will bring us mainly rain, overhead track introduces mixing and the potential for freezing rain, and the southern track will once again bring us snow accumulations. We will again be analyzing models and figuring out which track this storm will take. The ridge to the east of this storm will be important as too strong of a ridge will push this storm north, regardless of low pressure strength, while too weak of a ridge may let this slide too far south. Another thing to monitor in the upper levels will be the interaction between the lobe of the Polar Vortex and the southern branch of energy (our storm). Too much of an interaction will pull this storm north, while less interaction will open the door for heavy snow accumulations as this storm has a chance to track south. A lot to take in, but they do go hand in hand. A weaker ridge will allow greater interaction between the northern and southern branches of energy while a stronger ridge will help keep things separate. Even then, a stronger ridge will not lock in snow for us locally as we will need a supply of cold air. This will depend on high pressure to the west. Will high pressure be strong enough to keep us on the snowy side and push this area of low pressure south? These are the details that make winter forecasting a headache, but fun to follow along and watch how models evolve.

As far as the overall pattern over the next two weeks, temperatures locally will be up and down but generally near or slightly above average. Besides the ebb and flows of the pattern the next week temperatures overall will average near normal. After our storm chance towards the middle and end of next week, things get a little dicey and uncertainty is high. This high uncertainty after day 8 has to do with ridging over the Western US and Pacific. Models are split between how strong this ridging persists. Over the last month and more now this ridge has been consistently strong, but may be coming to an end towards the end of February. Models are split as the GFS wants to keep this ridge going, while the Euro is weaker with it and has a trough sliding in over Alaska. Might not seem much as the Euro still has it, but these differences cause the jet stream to flow through different regions and bring different air into the Lower 48. The Euro’s solution has milder air being brought in from the Pacific with the jet stream south, while the GFS has colder air over Alaska being brought down south in the Lower 48 which introduces cooler weather locally. Fun to follow, but based on how February has gone already I’d expect seasonable air across our region with a chance here and there for snow through the remainder of this shortened month. Our next update will come on Sunday, February 13th.

Temperatures: Besides an shot of Arctic air this weekend, temperatures will generally be near or slightly above average the next two weeks.

Precipitation: Above average the next two weeks.

Storm Chances:

February 13th-February 14th: Low pressure off the East Coast, remains a miss for us locally but still monitoring.

February 16th-February 18th: Watching this time period for our next real shot for snow. A cold front will try and swing through with low pressure on the tail end moving northeast. Track and cold air supply will be determinants of what we see. Rain, snow, sleet, and freezing rain on the table.

February 22nd-February 24th: Potentially another situation for low pressure into the Ohio River Valley as a ridge to the East will favor this track.