Wednesday, November 2, 2011

1 comment:
Now you can say, 
"Next month is December."

North America snowcover 10/30/11
10:30 PM EDT 11/2/11 | While the East is drenched in welcome sunshine after a historically rare October snowstorm, a Blizzard was raging in central and eastern Colorado. For a local view on the storm, you can visit our Central Colorado Zone in facebook. For a comparison of these two events and a look back on the rarity of the Northeast storm, please visit this article by Meteorologist and Team Advisor Mike Mogil. Our Long Range Team, in examining this apparent "yo-yo" pattern, believes that North America seems caught in a repeating 30- to 45-day cycle of high impact events. Each event, whether in along the West coast, the Plains or the East, has been preceded by or followed by a long-duration high pressure ridge. While Meteorologists and Forecasters alike might say, "Yeah, that's usually how it works... Low pressure, then High pressure, and so on," our point is different. What appears missing from the long range pattern is "zonal flow" during which the atmospheric flow over the U.S. becomes overwhelmed with a west-to-east flow of warm Pacific air. 

Instead,  we  believe the weather pattern, going back to Irene for the short term, and perhaps back to December 2009 in the long term, has fallen victim to an increasingly amplified "long wave" pattern book-ended by major, high impact events.  The current storm is expected to work its way east in the next several days, and bring heavy rain to the Midwest as shown in the enclosed NWS /HPC precipitation projection.  Arrival of  this storm on the East coast by late in the weekend may not cause much beyond heavy rain in the Carolinas, but in its wake will be another storm to take aim on the Northern Plains. The combination of these two events could be the next step toward mid-month warmup in the Eastern U.S., and another dramatic cool down in the West. Why is this significant? Were that to play out, it might allow the overall weather pattern for several weeks to "re-organize" so as to deliver a cold blast inthe East just in time for Thanksgiving Weekend. It happened in 1989, perhaps 2011 is the sequel?

ORIGINS OF OUR IDEAS? Take a look at our 9/30/2011 post titled "HellooOctober!" and a followup report on 10/22/11 titled "Wet Halloween...White Thanksgiving."  The bottom line projection from our Long Range Team targets the next significant rain- and snowstorm for the Mid-Atlantic and Northeast to occur in the period from November 25 to December 5.  If La Nina and the Arctic Oscillation had anything to say, the quote could be, "Not so sure about that 'Black Friday' idea you all have planned. You might end up with some other color.

(Forecasters Foot, Nic R. and Jason Mitchell of the Long Range Team)