Monday, February 22, 2016

Monday Morning Weather Discussion: Rainstorm On Tap This Week, Return to Cold This Weekend

Good morning everyone. We had a beautiful weekend and now its time to focus our attention to the unsettled weather this week. I have discussed extensively the details behind this weeks storm and hopefully by now you all know why it will be rain. In any event, lets summarize what to expect:


  • An initial wave of rain enters the area tomorrow afternoon
    • There is a chance that some snow can mix in in northern counties Tuesday night
    • I do not expect any high impacts from this
  • The main storm moves into the area Wednesday and lasts through Thursday morning
    • expect heavy rain and wind all the way up into New England
    • How depressing
  • In the wake of this storm cold air moves back into the region for this weekend
  • Although we are close to spring, there are very strong signals pointing to an active 1st half of march
    • These signals include stratospheric warming, which will cause the polar vortex to weaken and funnel cold air into the east.
    • Along with this, all models indicate a persistent ridge of high pressure out west which will also enhance colder than normal conditions
  • We are not out of the woods till after March 16th in my opinion.
So lets take a look at the graphics behind my bullet points..

An initial wave moves through Tuesday night..

There will be some cold air ahead of this as a high pressure system departs the area but I do not expect any high impacts. Just do not be surprised if some flakes are flying. 

The main storm then hits Wednesday into Thursday morning with all that rain..


As I discussed this week the ridge out west being to far west caused this storm to track inland..

I will admit I did not expect a full blown cutter but oh well.

In the wake of this storm cold air moves in for the weekend...


Expect high temps in the 30's. Moving into March, all signs point to a pattern like this..


This keeps things active. Notice the big trough of low pressure south of the Aleutian Islands, the massive ridge out west and the trough in the east. Also, we have high pressure over Greenland which is a negative NAO. This is not a spring pattern!

Yes, I know its easy to just say winters over and it was nothing more than a one hit wonder. However, we can not ignore these strong signals for March. This means can not be surprised if a big storm forms sometime in the first two weeks. 

Like I mentioned in my summary, the stratospheric warming is a huge driver of this..

Notice the polar vortex trying to split near Greenland. This should prevent any full blown surge of spring. 

We will keep track of all this over the next few weeks. Lets just get through this miserable rainstorm first. Sometimes mother nature just does what it wants regardless of what the weather patterns look like. Will that be the case for this home stretch of winter? Time will tell.

Thanks for reading. 

4 comments:

  1. Hi Willy, I took a look at the Wx tea leaves this AM, and I am pretty much in synch with you here. Looks like a really wet week, although for laughs, the NAM this AM indicates up to 6 inches of snow for most of northern NJ (within I287) tomorrow !! But SREF ensembles average 1/2 at best, so that may just be the NAM going off on one of its tangents (although that's what I thought for the January blizzard, which the NAM got right). As to weekend temps, looks like some model disagreement but nothing radical, just a choice between 30 to 45 or 20 to 35. For March 1 to 16 --- yup, winter is definitely still in the game. The polar stratosphere temps have leveled off their declines in the past few days, seem ready for an uptick. You can see it starting on the lower end, 50 / 30 mb, with 10 mb at a turning point, 5, 2 and 1 mb still cooling. As to the magnitude of the warming spike and what it will do to the polar vortex, stay tuned I suppose. The current AO projections I saw today indicate that it is going negative this week, but may get back to neutral in the first days of March. The NAO seems to slip a little, but stays above 0 and goes into March fairly strong. The PNA stays strongly + (good for your western ridge), but your EPO looks pretty lame, close to neutral. So the strength and extent of your western ridge may be problematic. MJO is wandering around in 7 (seemingly good for an eastern trough), but seems headed for the circle of neutrality in early March. It may interact or interfere with the Nino, but Pacific SSTA's seem to be declining, just about back to normal along the South American coast. My SWAG guess just for laughs is that cold and some snow is pretty certain for March; but as to a big snow event for northern NJ and over the Eastern metro corridor, it's gonna take some luck; a lot of things will have to come together just right. Never know though, could happen. But after that, it's time to talk about La Nina. A strong Nina may follow the strong Nino, or so I read. If it happens fast enough, we might have some Atlantic hurricanes to watch in Sept and October. After that, on to what a Nina will do to winter here on the East Coast . . . well, that will be a learning experience for me! Always something to learn regarding BIG WX. Jim G

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    Replies
    1. Hey Jim,

      Aside from the big storm all it wants to do is rain this year! The pattern is there with the NAO going negative and PNA positive (strat helping) but HP doesn't seem to want to lock in this year. I think we just need to focus on 50/50 lows developing to at least give us the shot of that cold air getting locked. Otherwise we will see more of the same. If we can pull one more decent storm off the winter will not be a total failure for our region. Can not be too upset with NESIS Cat 4 winter storm! Thanks for reading

      Delete
    2. Hey Jim,

      Aside from the big storm all it wants to do is rain this year! The pattern is there with the NAO going negative and PNA positive (strat helping) but HP doesn't seem to want to lock in this year. I think we just need to focus on 50/50 lows developing to at least give us the shot of that cold air getting locked. Otherwise we will see more of the same. If we can pull one more decent storm off the winter will not be a total failure for our region. Can not be too upset with NESIS Cat 4 winter storm! Thanks for reading

      Delete
  2. Sorry to spoil the mood, but very big storms (>6 inches) are very rare in March. We had one last year and in 2009 but both happened at the very beginning (1st or 2nd day). The last >6 inch snowstorm well into March happened in 1993 when 10 inches fell. It's possible but not that common, looking at data going back into the last 100 years, huge March snowfalls were more common before the mid 90s.

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