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 and a general non-technical weather summary below, and when available (most days) a detailed technical meteorological discussion will follow. My email is [email protected]. This blog is for you, so I hope you enjoy it! -Matt Noyes
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Matt's Quick Weather Synopsis (New!): Areas of morning fog on Cape Cod and through Connecticut are evidence of increased moisture in the atmosphere, and while patchy black ice begins the day through most of New England, the icy spots will be a bit more widespread in these areas. The ice, fog and low-altitude clouds in these areas will all melt away quickly as Thursday brings another gorgeous and mostly sunny day. A weak cool front settled south across New England last night, and this will keep temperatures cooler than yesterday in most of northeastern New England, and even along the Southern New England coasts where a light seabreeze will develop. Farther inland, temperatures will rise well into the 50's, and a few lucky areas will make a run at 60 degrees. An approaching storm throws 3"-6" of snow across Northern Maine Thursday night while the remainder of New England stays mainly dry with winds kicking up after midnight. Expect this storm's associated strong cold front to march across New England on Friday, swinging a line of downpours and embedded thunder through New England Friday mid-morning through early-afternoon. Winds will blow at 20-40 mph with gusts over 65 mph Friday afternoon, and this will be enough wind for damage to tree limbs and power lines. Rain will change to afternoon snow across Northern New England, where a couple of inches will fall in the higher terrain. Cold air comes screaming into New England on these winds, with a bitter Friday night giving way to a windy and frigid Saturday, though winds are likely to be below damaging criteria over the weekend. Cold conditions continue through Sunday, and our next chance of snow comes late Monday and especially on Tuesday. -Matt
General Weather Summary: Any areas of black ice, fog and low altitude clouds across extreme Southern New England - and patchy black ice elsewhere, where melted snow refroze during the overnight - will melt away quickly today, leaving plenty of sunshine and just a few clouds for most areas. The morning surface weather analysis places an area of cold high pressure to our north, east of James Bay Canada, a center of warm high pressure to our south off the Carolina coastline, and a strong but temporarily stalled out stationary front sandwiched between these two airmasses, from Cleveland to Boston. This front represents the dividing line between the two sharply contrasting airmasses we've been watching together in these discussions over the past few days, and the temperature boundary that will become so important in our forecast the next 48 hours.
This front settled slowly southward overnight Wednesday night, and the weak drain of cool air behind it will allow for light onshore winds to develop through most of coastal New England today - and with ocean water temperatures running around 40 degrees, this will be a cooling effect to counteract the mild air that's in place. Farther inland, however, away from the effects of the ocean waters, temperatures will once again climb well into the 50's with a light wind and plenty of sunshine to go around. Those of us in Northern VT and NH will find thickening afternoon clouds as an area of rain and snow showers expands east out of Upstate New York, and will likely bring a few rain and snow showers to the mountains of far northern New England Thursday afternoon.
Expect mostly cloudy skies in many areas Thursday night as a storm center positioned over Oklahoma early Thursday morning ripples east along the stalled out frontal boundary, strengthening as it feeds off of the clashing airmasses to either side of its path. As moisture rides out well ahead of the circulation center, rain showers will continue periodically along and near the Canadian border, and snow will fall in Northern Aroostook County, ME, where 3"-6" will fall by Friday morning.
The counter-clockwise flow of air around this strengthening area of low pressure will draw more warm and relatively moist air northward into New England on Friday, forcing the same front that had been stalled across our area Thursday to push northward as a warm front in response to increasing southerly winds. No sooner does this front push through Northern Maine, changing Thursday night snows to Friday mid-morning rain showers, than the approaching storm center moves north of New England, dragging the opposite end of the fierce front southeast as a cold front. Although some breaks of sunshine are possible in Eastern New England early in the morning, skies will become mostly cloudy for all spots and a line of rapidly moving downpours with perhaps some emedded thunder will charge east across New England from mid-morning to early afternoon along and ahead of this approaching cold front. Expect winds to be gusty ahead of the front from the southwest, then shift to the west behind the front, sustained (steady) at 20-40 mph with gusts over 65 mph at times, strong enough to down tree limbs, trees and power lines. These winds howl as they carry cold air back into New England - you and I have been watching just how cold these -30 to -40 degree temperatures have been north of the border in these discussions, and though the air certainly will modify on its travel into New England, there is no question this will be a mighty cold airmass.
After a couple of inches of fresh snow Friday afternoon into Friday night across the mountains of Northern New England thanks to arctic cold air spilling in and squeezing moisture out of the atmosphere, winds will remain gusty into and through Saturday. Though the air will be dry enough for Saturday morning sunshine, and it will be plenty cold at the surface, the air aloft will be even more frigid, and this will make the atmosphere "unstable" - favorable for clouds and precipitation to develop. The result should be an increase in clouds through the day, and as an upper level disturbance at the jet stream level dives into New England, it will push a reinforcing shot of arctic chill southward at the surface. This second cold front will spawn Saturday afternoon snow squalls in Northern New England, and a few snow showers may sneak into Southern New England closer to Saturday evening. Winds will gust over 35 mph Saturday afternoon, and this wind combined with the brutally cold temperatures will bring wind chill values into the single digits in Southern New England and below zero across the north!
With the center of this cold high pressure cell still moving closer to us on Sunday, expect actual temperatures to be even colder! Winds will abate somewhat, however, (though still breezy) and this will help conditions to feel a *little* more bearable. Enough dry air will be in place - and no strong upper level disturbances are expected - that most areas can plan on a dry blend of sunshine and a few clouds.
The pattern for early next week is likely to turn more favorable for snow here in New England, as our cold airmass releases its grip a bit, allowing warmer and more moist air to move toward us, bringing a higher chance of snow. Additionally, as low level and surface winds come onshore, we will input Atlantic moisture to our arctic airmass, and this often is favorable to increase chances for snow. Finally, a storm center will be passing south of New England, and while the exact track of the low pressure center is still in question, there is a chance for at least the northern extent of this snow shield to reach into New England.
Item of note: Wednesday's high of 54 in Burlington, VT, was a record for the date.
Enjoy your Thursday!
Matt's Technical Meteorological Discussion: Updated Thursday, February 15 at 3:15 PM
Amazing cold air drainage display in Champlain Valley today created busted temps for yours truly but a wonderful spectacle of nature. It's funny that I can talk up how much we need to respect this awesome dome of dense cold air but then still overlook this, but it truly is evidence of just how massive this cold air is. Expect cold air to remain entrenched across the valleys of the far north (near the Canadian border, like BTV) to result in freezing rain showers to start the night before stronger gradient takes over and sweeps warmer air back in. Snow continues to fall over Northern ME where 3"-6" fall in NorthernAroostook County - probably on the higher side of that range by Fri AM.
Not much change to the Friday forecast - vort max swings thru midday so band of convective downpours will swing thru mid-morning to early afternoon from W to E. Mixing to 925 mb prefrontal with winds at 925 mb cranking to 70 kts, then mixing to 850 mb postfrontal with llvl jet around 65 kts, so damaging wind threat exists both ahead of and behind front, though to pinpoint times I'd say warm sector winds either side of 15Z and strongest period of cold advection around 21-00Z will be the times of greatest concern for damage. Ptype change in Northern New Eng Fri afternoon with 1-3" of fresh snow most mountains, and amounts exceeding 5" Northern Greens higher terrain. Rainfall amounts won't be significant, and enough drying due to wind speed/dry air advection occurs that we avoid flash freezing most areas as precip evaporates first.
Damaging wind threat subsides after 00Z, but wind continues to crank thru Sat with another arctic front dropping south Saturday midday. SUNYSB MM5 indicates squalls survive all the way into Northern MA with lake effect band input off Lake Ontario and I don't see why we shouldn't trust that, as sfc convergence and instability under cold pool could counteract downsloping flow at least to Route 2 corridor, though Boston area is less likely to find squalls making it in.
The models are warming the boundary layer on Sunday but I can't believe that given 850 temps still bottoming out, ridge axis still to our W and that means northwest flow continues. Those who read regularly know my respect for this cold air and therefore know why I've been at least 10 degrees under MOS. MOS guidance still hasn't caught up, but that's fine - teens both weekend days for most areas will cut it. Could top 20 south of the MA Turnpike but that'd be about it. Blustery wind esp Saturday keeps chills single digits and below zero north...bit better on Sun as gradient relaxes.
Next week's pattern features multiple storm threats. Of course, together in this discussion you and I have been watching a Tuesday storm threat. Ensembles have shifted flatter with this wave today, and operational models are also a bit flatter. But...that doesn't mean we should forget about it. Synoptically, high pressure shifts off the Eastern Seaboard and easterly to southeasterly flow sets up with arctic air still in place. This should hasten a northward ride of moisture up the coast later Monday as a shortwave rides south of NewEng, and I've introduced chance snow later Monday resultantly. Next shortwave is the one we've been watching and is much stronger than its predecessor. Though flow is progressive, there is clearly a surface trough bridging low over Southern Canada and frontal wave to our south, and I don't think we've heard the last of this shortwave. Given fast flow, models are having a bit of a difficult time wrapping around this thing, and while I've seen circumstances where you get strong signals for weeks leading up to an event and it all falls apart in the last few days, I'm not sold on that being the case here. The northern and southern stream shortwaves are located off the Pacific NW coast and east of Hawaii, respectively. These are both in data sparse areas and if the models were going to drop the ball it would be between now and Saturday morning, so I still think this is a storm threat that needs to be watched carefully, and while I will certainly acknowledge that none of us can get too overly excited about a solution that now is being indicated by literally none of the guidance, I also will be maintaining snow in the forecast for Tuesday for the time being, and I'm not going to give up on this until after Saturday 12Z model runs come back.
That's all for today...a short one but I wanted to get my thoughts out to you.
Have a great day.