Wednesday, March 15, 2017

Wednesday Morning: The Aftermath

Good morning. Our storm is now over, and we can evaluate what happened and why. It is no secret that the snowfall amounts did not live up to expectations around the I-95 but lets take a look at final outcome...

Vs my final forecast...



VS my initial impact map made Friday...



You can see my error was not to bring the 4-8 (light blue zone) further north. In reality it should have be touching the red zone. The red zone overall actually made out well. I reported 16" at  my location  in NW NJ and areas further north and west did see up to a 2 feet and locally more.  We discussed the risk in my video discussions of the I-95 but I was surprised how quickly that warm air moved in yesterday morning.

The crazy thing is (not to make excuses) every major model had all snow for I-95 except for the NAM. Hard to just ride one model into the sunset when making a forecast. However, the one red flag was the temperature profile of the upper atmosphere. Even tho most models had all snow, the margin was so thin that any slight adjustment would bring just enough warm air into the mix to cause sleet.  Thats exactly what happened. Our storm center formed about 30 miles more west than expected and well the rest is history. Places near I-95 were literally right on the edge the whole time which is why snow and sleet kept interchanging.

So moving on, today is cold and blustery (will feel like Feb) with blowing snow and snow showers moving through later..


This is due to the upper level low associated with yesterdays storm moving through...



The colder than normal air will be around at least the next 5 day. This weekend we have to watch the shot for some light to maybe moderate snow as a storm system dives down from the NW. If this system redevelops on the coast we could have an issue but thats not my forecast at this time. New England would be the focus anyway.

Thanks for all the interactions yesterday.

7 comments:

  1. Willy, the NAM hasn't done too badly with snowstorms on the 12-48 hour horizon, at least from my faulty recall (this isn't a rigorous study of "model skill", of course, just my rough impressions). IIRC, most of the long-term models were much higher than the NAM for the Feb 9 storm, but NAM got it about right throughout its 84 hour span. Then go back to the January 2016 storm, NAM was showing a 15+ accumulation before the other models caught up. I recall Joe Cioffi once discussing why he likes the NAM for snowstorms, despite its generally spotty reputation. For now, I see that the big models are all calling for 3-6 inch snow on the 24th, but followed by a few hours of rain. We shall see what the NAM sez, come the 20th-21st. Seems like 'ole man winter' finally woke up, just as it was time to go back to sleep. I've got some pix of blooming daffodils that fell over into the snow. Something to remember winter 2017 by. Jim G

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    1. The good old NAM, sometimes it nails it sometimes its way off. I will say however that last 2 years to your point, its done a decent job. This weekend system is interesting lets see how it does this time

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    2. 3/18

      The NAM and other short term guidance really got burned this time. That upper low is forming more south and is not as closed. This will be a non event. Shows you how even when models are consistent it means nothing. They can shift out of no where, especially with situations like we have today. Looks like you just need to pick you poison with these models and try to put as much as a human element as you can into it.

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  2. Thank you Willy for your part in making this fun for many of us snow lovers. You are clearly the best around; in fact; I probably checked and referenced your site to friends/family 100 times during the 5-day lead up to the Stella.

    Does anyone else feel like today is the day after the Super Bowl?

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    1. Haha thats great, thanks for the promotion!

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  3. Definitely a bust as far as snow totals go for us down in moorestown, but it sure caused a lot of tree damage with all the ice accumulation. Definitely wasn't a storm to have been taken lightly. Looking at your totals map it had a significant impact all across the Northeast and New England. Amazing how 30 miles can make a difference. There's always going to be that line... The question is will we ever be able to predict​ it exactly? No more than we can predict exactly where that baseball is going to cross the plate. Thanks for all the insight once again Willy! Appreciate it

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