The Plot Thickens – A Shift Offshore

There’s no question the odds of a major snowstorm on Sunday have gone down overnight. The European model which was consistent in showing a major (12″+ storm) pulled the rug out from underneath that idea last night.

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So what’s going on? Why the shift? The European model now is showing what the GFS model did yesterday with the storm not intensifying early – and waiting a bit.

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Put simply, the above map shows where we have upper level disturbances. The disturbance over western New York and Pennsylvania is the one that is spoiling the party here. Unless it can get out of the way the stronger disturbance over Tennessee will not be able to amplify and we wind up with a weaker and more strung out system.

So, what’s the deal? Is this a hiccup or a real trend. It’s hard to say without seeing another run of computer models which will come out earlier this afternoon. There’s still quite a bit of spread – check out the overnight GFS ensemble members for Hartford showing anywhere from northing to a sizable 10″ snowstorm.

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The European Ensembles have also made a jump to a less impressive solution. Yesterday, the odds of seeing >6″ of snow from the 51-member ensemble suite was nearly 70%. Overnight, those odds have gone down to between 30 and 40% – that’s a big drop especially since we’re closer to the event occurring.

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So – there you have it. We’ll know a whole lot more this afternoon when the midday computer guidance comes out.

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