December 20, 2001
It seems like just a few weeks ago, many were poised to throw in the towel on this winter season. With the above normal temperatures for much of the fall, I can see why folks could have been lured into this style of thinking. But as you know, weather changes rapidly, and the weather pattern that is evolving looks to be anything but quiet and tame across much of the nation. In the short range, we have a secondary storm system developing off the Northeast coast which will bring another round
of windy and snowy conditions to parts of Northern New England. Maine looks to get hit hard again with upwards of 6" falling across part of the state thru the day on Friday. Parts of upstate NH, VT and NY should also see some snow during the day on Thursday and Thursday night before the Lake Effect snows begin for the favored areas later on Friday.
In the medium range, simply stated, the piece of energy currently positioned off the West Coast (Java Satellite) will provide enough theatrics to keep your stepdaughter busy at a Ted Nugent concert! Guidance has been somewhat erratic with powerful storm off the West Coast and it's 500mb energy once it hits the Rockies during the day on Friday. As pointed out in the model diagnostic discussion put out by NCEP for the 0Z suite of models, "INTERESTINGLY...CURRENT SATELLITE IMAGERY SUGGESTS THIS SYS
IS DROPPING SEWD...NONE OF THE MODELS SUGGESTED THIS MOTION DURING THE
FIRST 3 HRS OF THE FCST CYCLE....AM CONCERNED THAT ALL MODELS MAY BE TRACKING THE SYS TOO FAR NORTH
BASED ON CURRENT SATELLITE TRENDS." Clearly based on satellite, that is the case at this time. In a nutshell, this particular storm is the one that has made headlines recently as being a possible candidate for giving parts of the Eastern US a White Christmas. However, it will not be that easy. Certain things need to happen in order for a snowstorm to affect the East Coast in time for Christmas. For one, we would need things in the Northen Stream to speed up quite a bit to allow a Northen piece of energy to pass through while a second piece in the North is allowed to phase with the the Southern energy farther East. That is one scenario that seems unlikely at this time. Most guidance (save the NGM) show a phase between streams ocurring late Saturday over the Plains. That spells trouble if you want snow in the Mid Atlantic for the holiday. At the surface, a vigorous storm system will be tracking from the Colorado area through the Great Lakes between Saturday and Monday. Blizzard conditions will be common across parts of the Plains with strong to severe weather likely in parts of the Tennessee and Mississippi Valleys on Sunday. Quite a dynamic system!!
By the time Christmas Eve rolls around, the system, now located in the Lakes will try to redevelop a low somewhere along the East Coast as has been common with the few prior systems we have seen (including the current one) this year. At this time, it looks like rain along the plain before the system winds up in coastal New England.
And even farther down the road, there is so much energy emerging from the Pacific, there is the good possibiliy that if the first system (Xmas) turns out to be nothing more than a period of rain, a piece of energy left behind will round he base of the well-established East Coast trough to prove yet another chance for wintry weather in the Northeast later in the week.
So in short, some snow tomorrow for parts of Northern New England. LES kicks in Friday and Saturday. Major system emerges from Colorado Sunday with blizzard conditions in the Plains and strong to severe weather in the Tennessee and Mississippi Valleys Sunday. Low forms a triple point or transfers energy to the coastal plain on Christmas Eve with what looks to be a period of rain and showers for the major East Coast cities. Cross polar flow gets established mid to late week with another shot for wintry weather in the Northeast possible. With it being a busy travel period, a holiday, and still 4-5 days away, please check back in the next few days as this system develops. Guidance is having a tough time handling the abundance of Pacific energy off the NW coast, so I am hesitant to make a final verdict just yet as the where the new low will develop or how strong it will be etc. It will be interesting to see what happens with the H5 vorticity once it emerges from the Rockies. Anyhow, that is how I see things at the current time. There will be another update by the weekend.
S.B.
