Saturday, March 19, 2016

Saturday Morning Update: This Ones For The Birds

Good morning everyone. Well, it was fun to track while it lasted. Our beloved storm threat will stay out to sea this weekend with limited impacts on the tri state area. Up in eastern New England there will be impacts that I will discuss.  This is going to end up being a huge win for the American model suite as it has had this scenario the longest. The higher skill models such as the European, its ensembles, and the UKMET really got burned this time. I will admit I am surprised at the shifts we saw in those higher skill models starting yesterday morning. It did throw me off. Usually 72 hours out you do not see that occur.  Oh well, its more of the same and is quite the appropriate way to end off winter of 2016 with another miss. 

The GFS model is an interesting beast. Its known error bias is to keep things too flat and out to sea. In most cases when you see the GFS out to sea with other major model guidance a hit, it tends to correct back west. However, this is not the first time it scored a big win. Every so often it does pick up on something the other models do not see and what can be mistaken has some merit in it. This usually is apparent when within 72 hours it keeps holding its ground. That appears to be the case this time and some of us are left holding the bag.

So here is a quick summary:


  • Storm mainly stays offshore this weekend with limited impacts over the tri-state
    • expect some snow to break out Sunday with 1 to 2 inches of possible accumulation. 
    • There should be no travel impacts
  • Up in eastern New England especially eastern Mass, impacts will be greater
    • 3 to 6 inches can fall in those areas
Here is updated map. I threw a bone to some areas with the light blue. 1 to 2 is possible but do not get your hopes up. 


The image below shows the storm just skirting by our area tomorrow..


This then could intensify close enough to shore to give the Boston area a notable snow event..




The weather is and always will be a chaotic phenomenon. There is no one perfect model. When I look back on this last season we saw every model have its highs and lows. Think of the NAM model which nailed the Blizzard but usually is always wrong in every other case. Or the UKMET model which was nailing those inland runner rainstorms but completely whiffed this time. To try to combat this, they develop ensemble forecast systems to take these main models and adjust their input values to account for possible errors. You then get up to 51 reruns of the main model and can see where each member is leaning. Probability tables are developed and statistically it sounds like we have a great handle on a situation. Well, not so fast. The mighty European ensemble really failed this time. For the most powerful forecasting tool in the world (just upgraded too) take a look at what it was suggesting just the other day..

You can see each ensemble members listed by the low pressure centers. Notice the strong signal that this storm would trend west as seen by the clustering of those members. If you averaged it all out you got a snow map that looked like this..

This obviously ended up being completely wrong despite the fact the probability of 6+ inches of snow over NJ was over 60%! Get used to it guys it happens all the time! This is why the weather will always have my interest. As humans even in the year 2016 our most powerful computer modeling can completely miss as close as 72 hours away. This is what will always keep my hobby alive.

Thanks for reading guys. It just was not our year.You will find that in other years it will simply just want to snow. This year it did not want to snow. That brings me to the old saying "it snows where it wants to snow" Sometimes simple tag lines like that make a lot of sense when you look back at a season.

Will have a few updates later and tomorrow as this storm approaches.

4 comments:

  1. The Rubik's Cube of combinations of ways for areas that have had little to no snow cannot be beaten. That sounds like a joke, but it does have merit. Weather patterns are hard to break, I am not criticizing anyone here, because I have seen it on other sites as well, it's called "model dancing". The forecaster bends, twists, turns, and pirouettes in tune to the selected forecasting model(s). I recall a few years ago hearing a Meteorologist say that the models are depended upon way too much and allowed to make a forecast that is not what they are for. They are there only as a guide to be added to the forecasters knowledge of past similar weather patterns, weather nuances (effects of mountain ranges, land masses, elevation, location, etc.) of the forecast coverage area, and gut -feeling (the forecaster's experienced feeling on the situation) then the forecast is created. Five days out the forecast is not changed each day by what the models are spitting out. He also said there were too many computer models in the mix-perhaps he is right.

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    1. I do not disagree with you. We have too many models and it does make things very conflicting at times. The pressure rises when you have an idea but models are against it. Many times we all are guilty of folding too early. In this case however I have never seen such high volatility so close to an event. Keeps you on your toes. Lets see how this ends up.

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  2. OK, the overnight Euro operational and 6Z GFS and NAM operationals are snow-free for the NJ 'burbs. The ensembles say "maybe an inch or two on grassy surfaces". And give GFS credit for staying pretty consistent on this one. BUT WAIT, the final bell hasn't rang yet. There's one last hold out, and it too has been pretty consistent over the past few days. Yep, the Canadian. The CMC overnight operational still sez 6+ inches from a slower overnight storm. I don't remember the Canadian getting a "win" over these past few winters, its skill level is GFS or below. Gonna be interesting to see if CMC comes into line with the "fast and farther east" consensus on its mid-day or overnight runs. If it doesn't . . . either we're in for a surprise tomorrow night, or it's another reason not to take the Canadian too seriously. Jim G

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    1. The good old Canadian not backing down! 12z euro gfs and nam have trended slightly west especially at 500mb. UKMET also supports Canadian. This is really the final countdown, we are going 12 rounds.

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