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Thursday, December 11, 2008

12/11 UPDATE: Forecast: New Orleans: Snow. Baltimore: Rain.
Are current anomalies indicators for the upcoming winter pattern?

I thought you might appreciate (or be jealous of) this unusual radar from the Southeast today, and powderhounds will no doubt wince at these hard facts: NWS reports accumulations of 2 to 8 inches throughout central and southern Louisiana. Here's "ground truth" proof. Scroll to end of the post for more details and links to news sites reporting on today's pre-season freak snow.


My analysis and forecast for the Northern Hemisphere seasonal pattern from December 1 to January 15. I realize the graphic below may be hard to read, so for those with unfiltered access to flickr, a copy of the image is available here. I will also post a written explanation of this graphic in the event you wish to use this as a teaching tool for your students. This approach enables climate teleconnection watchers to do exact comparison of the forecast versus the actual, as by the 15th it should become clear if this pattern I have laid out is developing or not.

The graphic above is why I have reason yet to "just believe" in the potential for a major snow and ice event for the Mid-Atlantic and Northeast corridor before December ends. Although I originally targeted the first week of December as the likely period, a slowing of the pattern progression has delayed this possibility by 2-3 weeks. That places the next period conducive for measureable, significant snow (greater than 4") or ice (greater than 1/4") to December 17-25. That does not automatically mean I am alluding to a white Christmas, so do not interpret this as a signal to activate false hopes. As you will read later, I am a lifelong skeptic of ever seeing the aforementioned highly-sought after winter weather event occur on a specific date so tied into our contemporary holiday lore. Not to dash you out of the snow, but my next essay in progress is titled: "Blame it on Dickens and Sunspots: The inconvenient truth about white Christmases." For now, you'll have to live vicariously through this video montage from the Polar Express, and ask yourself if you "believe."




"WHITE IS IN THE...DEEP SOUTH ?"


Certainly, the folks along the Gulf coast must still believe, because it seems that if you want real measureable snow these days..forget Baltimore, Washington or New York. The place to find that wintery white stuff is in the usual spots, like Houston, Jackson, Miss. or New Orleans. Just take a look at the current NWS US watch and warning map. notice where the Winter Storm Warnings are? Yeah, where you'd expect them this time of year: Southeast Louisiana, southern Mississippi, places that are so accustomed to snow, it probably did not even make headlines. (Oh wait, that's in the alternate universe Ice Age version).




Looks like the NOLA Times-Picayune is reliving their inner childhood, because when you see "white in the 'not-even-winter-yet' night in a place like "Southtown", there's no better way to describe it than simply with the headline of: "It's Snowing!" 9:30 AM update: The editors have since changed that to "Snow falling throughout the metro area"