Thursday, March 13, 2014

March 22-26 Potential Weak Storm System

There's the potential for a weak storm system in the March 22-26 timeframe.

It's looking like we'll be seeing a storm system cut across Japan on March 16th, with rather meager negative height anomalies, indicating a weak storm system. There is a rule, well explained by Joe Renken, that states a weather phenomenon in East Asia will be reciprocated in the United States 6-10 days later. This means that if there is a storm system in Japan on a certain day, we can expect a storm in the US 6-10 days after that. The same goes for high pressure and warm weather. Thus, 6-10 days after the date where we see a storm hit Japan (March 16) brings us to a potential storm system in the US around the March time period.

Looking deeper into that ECMWF forecast, we see strong high pressure over the West Coast. This is strongly indicative of a positive Pacific-North American pattern (positive PNA), which is demonstrated in the above graphic. The positive phase of the PNA sees high pressure form over the West Coast, which then leads to storminess and cold weather in the Plains. This sort of pattern can give snow to the Midwest and Ohio Valley in situations where ridging tries to push north in the Southeast, but can also send wintry weather to the East Coast if we see high pressure over Greenland.

If we go out in the long range, we can see what the weather pattern may be like on March 22nd, the first day of this window that has been designated for a storm system. We see that the pattern includes warm weather in the West, as persistent ridging continues, but also pushes east into the Plains. More importantly is the presence of a piece of the polar vortex digging well into the Northeast, likely providing the chance for another intense round of cold weather. This sort of pattern tells me we would likely see some severe weather in the South Plains, but that would be about it. This pattern isn't conducive for wintry weather in the Plains, Midwest or Ohio Valley, and the polar vortex will be suppressing the storm south to likely keep it away from the East Coast.

This looks to be a weak storm, and impacts should be minimal on the wintry side. I would monitor severe weather prospects in the near future, however.


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