Welcome to the weather blog - a regular Monday through Friday discussion of the weather! While the discussions usually will only come on days I'm working, I'll issue special updates when the weather warrants. I will always post to let you know when no discussion is expected if I'm away on vacation, etc. - if no update is here and no info is available, that likely means the server has temporarily gone on the fritz and I will update as soon as technically possible. You'll find a quick weather synopsis linked to the daily forecast at the top of the page, a general non-technical weather summary below, and when available (most days) a detailed technical meteorological discussion will follow by mid-afternoon. My email is contact@mattnoyes.net. This blog is for you, so I hope you enjoy it! -Matt Noyes
General Weather Summary:
An active weather pattern will continue for the next several days into the weekend, and will bring another strong storm by Friday night. In the meantime, a large storm in the upper levels continues to churn over New England and will pivot a new spoke of energy over the six-state region Tuesday night.
In the meantime, a steady northwest wind has kept cool air in place across the region with plenty of clouds helping to ensure temperatures will have to struggle just to break the 50 degree mark in a lot of communities Tuesday afternoon. These clouds come as a result of cold air aloft - often found with an upper level storm - and the difference between those very cold temperatures and the relatively warmer temperatures near the ground. This, combined with moisture in the lower few thousand feet of the atmosphere, allows the clouds to continue bubbling up over New England through Tuesday. While Southern New England is somewhat removed from the core of cold air aloft and will find only a few clouds growing tall enough to drop a sprinkle or shower Tuesday afternoon, Northern New England lay under the belly of the high-altitude storm, and that's where clouds will continue to grow tall enough to deposit pockets of rain and snow to the North Country, with some bursts rather heavy in intermittent spells.
With the approach of the next spoke of energy rotating around the storm, bands of rain and snow showers have already developed over Southern Quebec and have been rotating southward toward Northern New England, with scattered showers of rain and snow developing in the Northern Mountains ahead of the more organized activity. Overnight Tuesday night, that organized precipitation will enter New England, falling as snow showers and heavier squalls in the higher terrain. The Tuesday night snow will be somewhat of an elevation dependent snow, with areas below 1000 feet needing to see a heavy burst of snow to get much accumulation. Nonetheless, I've carried the chance for a dusting as far south as Manchester, NH, for a push of rain and snow showers that will move through in the pre-dawn hours of Wednesday, moving south out of the mountains. While the actual cities of Concord and Manchester may not see more than a few flakes mixed in, higher terrain around those areas may see enough to coat roadways in the early morning hours, and that will result in a few slick spots. Farther north, overnight snows will accumulate into Wednesday morning, with as much as 6"-8" possible around Jay Peak, and several inches possible in the higher terrain of the Northern White Mountains and Mountains of Northwest Maine as well, especially above 1500 feet.
Though snow showers will start the day in some spots Wednesday morning, the passage of the upper level disturbance and an associated wind shift at the surface will bring increased wind gusts, continued chilly air, but mostly dry conditions to most of New England. Though some snow showers and heavier squalls may linger for a time in the mountains, the remainder of New England should find more sunshine than was seen on Tuesday, though the effect on the daily high temperature will be minimal. After a chilly night Wednesday night with winds subsiding, Thursday will bring sunshine and moderating temperatures - a break in the action before our weather turns stormy once again.
This end-of-week storm comes with a history, as two key weather systems will come together in its formation. The first is Hurricane Paul, heading for Baja and packing winds of 80 mph as of this writing, but forecasted to weaken before making landfall. Nonetheless, Paul still will represent a large mass of moisture, heat and energy as he crosses Texas en route to the southeastern United States, carried by the subtropical jet stream. To the north, a strong energetic disturbance is moving southeast down the Western Canada coastline, caught in the polar jet stream that carries energy centers and cold air from the north. This storm, too, will dive toward the Southeastern U.S., where it will meet with the remnants of Paul late in the week. The result will be a strengthening storm to the southwest of New England on Thursday, and this storm will launch a slug of meaningful warmth and moisture toward New England on Friday. With cool air in place already, and clouds on the increase, temperatures will remain cool. Additionally, a new fair weather cell packed with cool Canadian air will be settling into Southern Canada during the period, and this will provide a supply of cold air to New England. The result will be a stubborness of the cold air to let go from Northern New England as moisture comes streaming in, and this likely will crank out snow across Northern New England when precipitation moves into New England later Friday or Friday night into Saturday, and if all works out as it currently appears, plowable snow would occur on a more widespread scale than the past day or two have brought. Farther south, it's more likely that air will be warm enough for liquid to fall Friday night into Saturday.
For most areas, Saturday showers of rain and snow would taper and give way to gradual clearing, though clouds may linger across the north. It's worth noting that - contrary to what we see in most storms - this storm would be unlikely to deliver a shot of hearty cold air behind it, and actually would likely bring warmer days after its passage, given its tropical origins and absence of cold air behind the storm circulation.
Have a great Tuesday.
Matt
Matt's Technical Meteorological Discussion: Updated Tuesday, October 24 at 1:10 PM
No techie update yesterday thanks to server failure at provider - apologies, especially considering I'm off to a public appearance today so limited time to share my thoughts. Let me get them out as quickly as possible:
Well defined vort max to swing southeast across VT/NH/ME overnight and into early Wed AM. The cyclonic vorticity advection (CVA) ahead of this vort is fairly well distributed - largely normal to the flow - and that will provide extra impetus to generate convective precip overnight. Couple this with cold air aloft providing instability and upslope flow in Nrn mountains and you have a fairly favorable setup for accumulating snow even though sfc winds may not be the ideal NW direction I'd like to see. Nonetheless, 925 mb temps fall steadily late this afternoon thru Tue Ngt and this shud ensure elevated areas are cold enuf for snow. To take thermal fcst profiles literally, no snow will fall below 1500 feet, but I'd expect the convective nature of the precip in the CVA ahead of the vort max to overcome this inhibiting factor and lower the snow level considerably. Elevated terrain will benefit from the combo of cold profile, abundant moisture, good snow crystal growth and upslope flow to crank out amounts as high as 6"-8" in favored locales like Jay Peak and perhaps Sugarloaf, as well. Enuf warm air in the valleys that locales below 500-600 feet will probably have trouble getting snow to stick well as sfc temps stay above freezing. Still, vort max passage doesn't occur until Wed AM in Srn NH and near coastal plain of ME where some snowflakes certainly may mix in, and wouldn't want this to be a shock to the awakening public in the AM so have adlibbed this possibility accordingly. Have carried D-1" rather far south, as well, but am stressing elevation dependence - bottom line here is that I'm untrusting of the pattern with the combo of instability and vorticity, I'm untrusting of the low-level wind flow that is not only non-ideal upslope north, but more importantly to this point is non-ideal downslope south, and I'm untrusting of moist low levels. Nonetheless, anything that does survive the trip would die or ship out quickly Wed as a final mix of mostly raindrops and some snowflakes, tho upslope flow will strengthen on Wed in the Nrn mountains where snow showers will continue. Let's also not forget the connection from Lake Ontario, which has dropped light rain showers in SW CT earlier today and tho it has broken up with diurnal htg and assoc mixing, should redevelop overnight tho will be warm enuf for rain in these areas.
Moisture mixes out a bit better on Wed but cold pool is slow to decay and while I expect more sunshine, more mixing, greater wind speeds than Tue, clouds will still bubble aplenty during the afternoon beneath the cool pool. Thu is a decent break in the action, and the trend has been for slower progression of Fri system which makes sense for at least a little while as Pacific energy and Tropical Storm Paul merge in the trof over the SE US. This significant amplification will slow the progression, but once Paul's remnants are absorbed into the circulation, this will enhance the thrust of warm and moist advection ahead of the storm, and precip should develop later Fri from SW to NE. 1020 mb bubble of high pressure over Ern Canada bridges to high pressure over MidAtl while col (area of light wind) sets up between these two anticyclones and the cyclones to the southwest and northeast of NewEng. At Cornell University, one of my meteorology professors, Dr. Colucci always would say "always beware the col". As the low level flow becomes weakly convergent in this coll, it serves as a magnet for secondary storm development and/or track, and the GFS is close to this line of thinking. A track from the MidAtl coast to the col for a secondary low would allow cool air to hold into Nrn NewEng enuf for a significant accumulating snow event Fri Ngt into Sat and am carrying that in fcst for now, with liquid much more likely ptype in Srn NewEng.
Enjoy your day.
Matt
