Thursday, February 26, 2015

Thursday Morning Weather Discussion: Pattern Staying Active!

Doesn't guarantee a big snowstorm but it does gives us the chance to track a few storm systems over the next few weeks. We have a very active jet stream regime and that means we need to monitor how all the puzzle pieces will come together to forms storms. 

To start off, we have a storm system now that is going to pass to our south. It was pretty amazing how far north this thing trended since a few days back but it will not effect most of the area, just extreme south jersey will see come accumulating snow..

In the wake of this storm a big arctic high reestablishes itself over our area bringing more frigid temps as we head into the weekend. The image below shows the air temps departure from normal by Saturday morning. 

Earlier in the week I talked about how we could see a brief warm up by the time we get to late weekend/early next week but that I was not sold on a full blown March warm up. The reason is that the pacific is driving this pattern meaning that the warm water off the cost is supporting a semi permanent ridge of high pressure that is drilling down arctic air. Well, it appears that will be the same old story for March and this brief warm up will prob not occur either early next week. In fact we need to now monitor two weather systems that will effect the regions Sunday night and again for the middle of next week. Lets take a look..

As we approach Sunday night a shortwave or kink in the jet stream approaches our area..

You can see the kink entering the great lakes region above. This kink is a disturbance that will bring unsettled weather to our area. The origin of this disturbance is arctic in nature so warm air is not the issue if we just look at it alone. However, if this where to really dig in to the flow earlier then we could see southwest winds ahead of it which could warm the upper layers of the atmosphere causing mixed precipitation. I do not support that scenario at this time based on seasonal trends. I think if this thing digs more it will be later and not earlier which would preserve the cold air in place ahead of it. Bottom line, I am giving us a chance at light to moderate snow Sunday night. Here is the GFS' models projection..

Things then get very interesting as this storm passes as the jet stream really fires up. Check out all the energy on the field by the time we get to Monday night..

Yes all this energy is hanging back near the west but that storm that moves through on Sunday night can effect how this energy effects our region by the time we get to Wed and Thursday. Here is the reason why...

Naturally when we have energy hanging back near the pacific with a lack of a western ridge it could result in a surge of warmth near the east as the jet stream rises over that region. The end result is a storm that effects the central part of the country. 

However, if we have a strong area of high pressure in place to the north the storm cant just simply cut into the central US and instead slides along the boundary and redevelops along the east. 

As of  now the model is showing my point..

You can see that storm system developing in the central US with high pressure over PA. If that high pressure is allowed to slide out of region then the storm is warm for us and we get snow to ice to rain. The model is currently showing that..

But lets go back to that disturbance from Sunday night. You can see the remains of it off of eastern Canada on Tuesday.

The key here is this: If that storm really blows up over eastern Canada more than expected then it helps to lock in that high pressure area I showed two images back over PA. If that was to occur this storm Wed would be colder and snowier. This is something that we will have to monitor for sure.

As if that wasn't enough, we will have a building western ridge later next week. That means we have to be on the lookout again for unsettled weather that could naturally form further east over our region.

The bottom line is this: 

  • Very active weather over next 10 days
  • Each wave of weather will effect the next wave due to it's influence on the pressure pattern
  • This doesn't mean we get a lot of snow but it gives us a shot at more winter weather
  • Cold air looks like its here to stay although it will moderate with the season in March
Thanks for checking in.