December 9, 2004
East on Alert, here comes the snow!
I got a phone call from Jim Roemer www.bestskiweather.com this morning (12/9), he was speaking elatedly of much needed snowfall for the East! A huge shot in the arm just in time for the Holidays. He is the only meteorologist out there calling for this snowfall event. Jim is predicting 1 to 2 feet in some places across New England by the end of the day Tuesday. No doubt more of them will eventually follow. Giving his track record, you would be wise to acknowledge the forecast. Make plans to get north. His entire report is attached below….
Content supplied by www.bestskiweather.com
ROEMER..THURSDAY DEC. 9TH, 2004
NEW ENGLAND/QUEBEC/CATSKILLS--IMPROVING WEATHER NEXT WEEK--COLD AND SNOW
*FRIDAY NIGHT/SAT. STORM SNOW TO MIXED PRECIP NORTH-SNOW TO HEAVY RAIN SOUTH/CENTRAL.MAINE SKI AREAS COULD GET NAILED
*MODEST TO HEAVY SNOWS MONDAY/TUESDAY
*ROSSBY WAVES AND WHY THE PRESENT WEATHER PATTERN IS CHANGING FOR THE BETTER
Since October, I have been calling for some of a dismal start to winter in New England; although officially winter does not begin for another ten days or so. Storm tracks have been incredibly consistent finding their way inland from the Ohio Valley or Mid-Atlantic states and inland across the Adirondacks. This has resulted in very unusual wet weather for many souther/central New England ski resorts--putting a den and delay in the early ski season, with a mixture of snow, sleet and rain for us in three consecutive storms. The storm Friday and Saturday will be no exception with several inches of snow across most of Vermont and the Adirondacks, New Hampshire and Maine before a "possible" changeover to some freezing rain, sleet and or rain on Saturday in southern and central sections and maybe as far north as Stowe, Whiteface, Bretton woods with icing.
The big news comes later Sunday night through Tuesday a.m. when a foot should fall here by then with a "major weather" pattern change that may persist well into the end of the month. We have some short term changes in the pattern since a few days over Thanksgiving as we have had some snow, but this change will bring a more needed shot in the arm for us, perhaps for the rest of the month. It is possible that parts of Quebec could see all snow from the storm Saturday with 6-12" many areas and then get another 3-6" or more Monday-Tuesday which should really improve things in Canada. I think that Sugarloaf and Sunday River could get at least 3-6" and possibly a foot of snow from the storm Saturday and then more next week--We will watch this. There may be great conditions there.
Our winter weather pattern will be controlled by El Nino, and various meteorological parameters such as the Northern Atlantic Oscillation Index (difference between atmospheric pressures over Greenland and the Azores). I also need to look at historical cycles of very wet summers (wettest on record some areas this last summer) and the active hurricane season in Florida and for other reasons. Just based on wet summers, El Nino and hurricanes alone, I have been calling for a so-so early start to winter, warmer than people expect and then perhaps a great late winter.
Few meteorologists discuss "Rossby Waves"-- also known as/planetary waves/. These waves owe their origin to the shape and rotation of the earth, and are one of the most intriguing natural phenomena. They are easily observed in the atmosphere (i.e. as large-scale-long term meanders of the mid-latitude jet stream), but their existence begins in the oceans, and first theorized by Carl-Gustav Rossby-- a Swedish Oceanographer who studies at MIT and who developed some of the most important theories in thermodynamics and in ocean meteorology in the 1930s.
Rossby waves travel very slowly from west to east creating generally long-term weather patterns that can last for weeks or even months at a time. For example, even though the weather was not always cloudy and rainy in the east this summer, and some storms tracked in different ways, the overall pattern was for record northeast summer rainfall over a 2-3 month period. It was the set up of Rossby waves that caused this. Short waves travel within this long-Rossby waves and are responsible for the day to day changes in weather.
(insert map--RW
What makes these waves most interesting is that they are invisible and not apparent on computer models to meteorologists. One might think that these almost invisible waves are uninfluential - this is wrong! They have major effects on the large-scale ocean circulation, and thus on weather and climate.
Perhaps the most important effect of these waves is on western boundary currents, such as the Gulf Stream. Rossby waves can intensify the currents, as well as push them off their usual course. If we keep in mind that those currents transport huge quantities of heat, we can easily understand that even a minor shift in the position of the current can dramatically affect weather over large areas of the globe. In the North Pacific, for instance, a Rossby wave, after the 10 years or so that it takes to cross the basin, can push the Kuroshio Current northwards and affect weather on the North America continent. This might have happened already in 1993, the culprit Rossby wave being an effect of the 1982-83 El Niño
Finally, North America's weather pattern has been quite consistent the last few weeks with east coast storms generally migrating up across the N. Adirondacks into Quebec and western storms diving into S. California, Arizona and ultimately Colorado from the Pacific. This weather scenario has brought big snows to parts of the west, while southern New England has been drenched with rain and northern areas a combination of both rain and snow.
This map shows the change in the weather pattern for next week. The big circle over western British Columbia represents unusually warm air out west and much drier. The "480" in central Canada represents well below normal temperatures and snow. The bow shaped trough (U) in the east suggests storminess and pieces of this colder weather being forced down from eastern Canada early next week and again around the 19th or so.
Insert map (Thursday 1).
This map would also suggest that by the 18th or so, much drier weather for British Columbia, Alberta, the Pacific Northwest and the Tahoe to Utah region and possibly Colorado. This weather scnearion is what we discussed several days ago and that the west may begin to dry out some...However, after the great snows the last couple days and some areas receiving snow on Monday (Jackson and Colorado)--conditions will be great until this possible pattern change about 7-10 days from now when it is possible things will dry out for a while.
We will have a quick update on the weekend and early week storms early this afternoon or certainly tomorrow.
Roemer
