New England enjoys a breather on Friday before our next storm Friday night...though much of the weekend is looking quiet, too, as energy and moisture converge to our south and west and take a bit longer than the ongoing parade of disturbances typically has to reach New England. A shot of cold air is expected by the middle of next week and the start of the New Year, before bulging warmth invades New England for the middle of January.
Thursday afternoon and evening's snow verified a bit farther north than I'd expected, but the net result turned out quite similar for most spots - a coating of snow that froze to ice for slick spots that lingered into Friday morning for many communities throughout the six-state region, but especially for Massachusetts points north. Increasing sunshine and an active but certainly not overbearing breeze sends the signal that Friday will bring a break in the action for the Northeast. Though the weather pattern is expected to remain active for quite some time to come, today's weather is the first in what will be a few breaks between systems in the next several days. The overall driving force of the weather pattern nationwide continues to be a fast jet stream wind, roaring in off the Pacific Ocean with a parade of disturbances, and dipping southward as a jet stream "trough" or dip in the Western United States. This pattern resulted in a dandy of a snowstorm for the foothills of the Rockies of Colorado on Thursday, and the same storm is winding through the nation's midsection on Friday, delivering heavy snow to Chicago, heavy rain to Indianapolis, and widespread heavy rain and thunder to the Tennessee Valley. All of these spots are likely to find flight delays, and you can check for yourself with the links under the Travel Interests section on the left side of this page. Meanwhile, ahead of the deep jet stream trough, a "ridge," or bump, continues to hold across the Eastern United States. Along with a ridge comes warmth, and that warm air contributed to the near-record temperature of 80 in Orlando, Florida, yesterday - the old record was 82 from 1990. As a constant reminder that weather - even extreme weather - works in cycles, the record cold temperature of -23 degrees F in Alamosa, Colorado, on Thursday also broke a record from the very same date in what year? You guessed it...1990. If it's older records you're more impressed with, Waco, Texas, delivered with a temperature of 24 degrees, tying the old record from way back in 1938.
This clash of cold and warm air provides a battleground ripe for storm development, and between the two airmasses a corridor of southerly winds carry moisture in from the Pacific and out of the Gulf of Mexico. Though New England has been between disturbances on Friday with sunshine, clouds will thicken late in the day ahead of the incoming energetic jet stream disturbance, and its surface storm reflection moving east through the Ohio Valley. The deep tropical moisture this storm has tapped will continue to push northeast toward New England, and will make great progress as it collides with only weak lingering cool air in the Northeast. In fact, to produce snow Friday night, deep cold would have to be in place when considering the thrust of tropical air moving northward, and as Friday afternoon highs climb into the 40s and there's no surging cold out of Canada, this should be a sure sign, especially with a developing southeast wind, that the cold won't be deep enough in either Southern or Central New England to hold, meaning rain will be the predominant type of precipitation as it moves in after midnight. Farther north, across Central Vermont and New Hampshire, and most of Maine, enough cold air will be in place for snow Friday night when precipitation begins after midnight, but warmth carried northward several thousand feet off the ground will likely result in a change to sleet and freezing rain for all but the North Country as the night wears on. In Northern New England communities that remain mostly snow, a solid half foot is certainly a possibility, while much greater precipitation totals will be recorded in the plain rain swath, where over an inch of precipitation may result in hydroplaning concerns and some urban and poor drainage flooding in Northern Massachusetts and Southern New Hampshire, where snowmelt will continue.
By Saturday, precipitation will be over for most spots by early to mid-morning from west to east, and the storm center will be winding up north of New England. Interestingly enough, Friday night's storm will have developed along an area where cold air and warm air have mixed - called an "occlusion" in the world of meteorology, and the product of a mature storm that has mixed the cold and warm air that originally prompted its development. The result should be for lots of clouds and temperatures near 40 in Northern New England, but some breaks of sun and temperatures well into the 40s farther south with an active southwest wind. It's not impossible that some far southern areas may even approach or exceed 50 Saturday afternoon as sunshine breaks out for much of Central and Southern New England. Saturday evening in the Meadowlands for the Pats looks awesome for breaking all the records - dry, partly cloudy, temps in the 40s. There will be a 15-20 mph wind to contend with, but that'll be about the only negative factor.
Thereafter, the combination of energy digging back into the Western U.S. trough and the departing strong storm from New England will leave New England in another break between systems for a time, quiet Saturday night and into Sunday. By Sunday night, however, the next energetic disturbance looks to be in line, ejecting northeast out of the nation's midsection once again. This disturbance seems less likely to be loaded with Gulf moisture, but still will bring some Pacific moisture with it and won't have nearly as strong of a warm surge of air, meaning after clouds thicken later Sunday, any precipitation that makes it into New England should fall as snow Sunday night.
Beyond that, there are still questions as to how the following energetic disturbances will interact on Monday, but it looks right now like another break in the action with perhaps plenty of clouds lingering and temperatures rather neutral in the 30s. This would bode well for New Year's Eve, keeping any bone-chilling cold out of New England and hopefully maintaining just the right temperature to enjoy, but maintain, the First Night ice sculptures in so many New England cities! More energy will follow later Monday night and Tuesday, at least by the way the timing looks this far out, and that would favor another round of wintry mix, but uncertainty increases rather substantially later Monday through midweek.
The overall pattern, however, looks a bit more defined, and that would be to bring a shot of more significant cold into the Northeast for the middle of next week into the start of 2008, with intense warmth riding northward through the Western and Central United States in a highly amplified pattern of deep cold east and deep warmth west. At this juncture, it appears as though that deep warmth should move east across the Northeast through the first half of January, and if it comes in as strong as it looks right now, it could spell record warmth. We'll see.
Enjoy a wonderful weekend.