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
Monday Podcast: Issued. Click link in upper left of page to subscribe to Daily_Weather_Synopsis.mp3
General Weather Summary:
A bundle of energy and moisture teamed together to bring intense bursts of Monday morning snow to much of Southern New England. A series of energetic disturbances will carry varying amounts of moisture eastward across New England for the next few days, launched east from a spiraling upper level storm lodged over the Upper Great Lakes.
In the meantime, snowfall rates of one to two inches per hour were observed across parts of Southern New England Sunday night into Monday morning, and total amounts ranged from a coating at the New Hampshire border to as much as localized four to five inches in Southeastern Massachusetts and the higher terrain of Northern Rhode Island. As the primary energy center responsible for this snow departs, it takes the heaviest snowfall rates with it, though lots of clouds will linger through the remainder of Monday with periodic light snow and flurries as numerous disturbances ride overhead and a frontal boundary wavers, nearly stationary, over New England. As temperatures climb above freezing in all spots that recorded snowfall, roads will improve dramatically late-morning to early afternoon regionwide. With light winds simultaneously as above-freezing temperatures, we're likely to find a rather mild feeling afternoon, even given the significant cloud cover!
Monday night, changes will once again move across New England. Yet another disturbance in the parade of energy centers will move overhead, and though it doesn't carry deep moisture with it, there's enough moisture in the lowest several thousand feet of the atmosphere to wring out a new area of accumulating snowfall. With temperatures in the middle and upper 20s across most of New England, and temperatures aloft running only about 20 degrees below freezing, snowflakes will once again be large and lovely, but that also means a bit less than ideal accumulating rates. Nonetheless, a fresh three inches is expected west, with a coating east: 
This fresh snow will make for some slippery spots again Tuesday morning, especially where an inch or more is forecasted to fall outside of Route 495 in Central MA and for many areas farther west. In Eastern areas forecasted to receive only a coating, it's actually possible that a few folks closest to the coastal plain don't even see amounts that high. Nonetheless, once again we'll find a break for most of the day Tuesday with lots of clouds and a few disorganized areas of light snow and flurries with some raindrops mixed in as temperatures climb over freezing once again, thereby allowing the roads to improve by late-morning once again in even the hardest hit areas.
This pattern of frequent disturbances but limited effects will continue into Wednesday, with perhaps another round of light rain and snow Tuesday night, then plenty of clouds but a mainly dry day Wednesday as temperatures climb about a degree or two each day, and stay about a degree or two milder, on average, each night. This gradual feed of milder and slightly more moist air comes as one large atmospheric storm churns counter-clockwise over the Northern Plains and Upper Great Lakes, ushering a broad west and southwest flow across the Ohio Valley and into the Northeast. Farther "upstream" (where the weather is coming from), this westerly flow is coming directly off the Pacific Ocean, with numerous disturbances and relatively mild energetic disturbances. In fact, it would be easy to flood the entire Northeast with mild air if not for another deep upper atmospheric storm over Eastern Canada. This, too, has a counter-clockwise flow of air, and therefore maintains a flow of cool Canadian air toward New England, colliding with the incoming warmth and moisture, and thereby continuing a somewhat unsettled pattern.
By Wednesday night, some clearing will take place with a break between disturbances and a temporary relaxation of the battle of incoming warmth and stubborn cold, and this clearing will allow for some sunshine Thursday morning. By later in the day, however, a stronger thrust of moisture-laden energy will rotate northeast as the Central U.S. storm deepens, and this will bring new clouds and new precipitation. Once again, we'll watch the battle of warm and cold to determine a rain/snow line that will likely progress from south to north, though Northern New
England, closest to the Canadian cold air, will likely stay as mostly snow.
This storm will wind up as it moves past New England, sending cool air surging southward. The initial surge of cool air will leave a front stalled just south of New England, and as a new disturbance moves along it on Sunday, there is at least the possibility of some snow again, though that is far less certain as I'm still unsure just how strong that next disturbance would be, and exactly where the front will stall, serving as a pathway for the new disturbance. Regardless, it seems likely that another shot of cold will follow the storm for several days into next week, meaning we extend some fantastic late-winter skiing across Northern New England.
I'll keep you posted!
Matt
Matt's Technical Meteorological Discussion: Updated Monday, February 26 at 1:20 PM
A fun morning for snow lovers with the one to two inch per hour burst that came thru parts of Srn NewEng. Those of you who checked in here Friday and again for the special update yesterday may have wondered why I was holding onto accums the way I was for this burst and the bottom line was the combo of decent warm advection with an energetic vort. As for model performance, many will say the models blew it but the Canadian Ensembles were consistent and correct since last Thursday, and the ECMWF did very well with 700 mb RH field forecast from that far out as well, so let's be sure to give credit to the foreign guidance that has performed superiorly in most events this year. The NMM was certainly amazingly consistent, but amazingly consistently wrong, as it's been in other events this year.
Nonetheless, we turn to what lay ahead and that's another disturbance tonight. This time around the setup is different with a much more strung out, channeled vort that is weaker with far weaker isentropic lift. The result will be a far less impressive scenario. Omega is negative in the lowest layers of the atmosphere where boundary layer will be sufficiently but not strongly below freezing, and the corridor of max ascent is fairly low in altitude - 900 to 800 mb - meaning we're looking at a thermal profile only favorable for about 10 to 1 ratio most areas. For as unimpressive as this vort is comparitively speaking, it's doing a good job of regenerating the snow shield over the Finger Lakes today and that does represent a band of at least some isentropic lift that will fall more gently than last night but for longer duration. The result will be highest amounts where most orographic help is available, and that's in Western Central/Srn NewEng, esp west of the CT river valley. Good agreement on close to .25" here, and this is where I placed 3" average amounts. Decrease in amounts farther E is due both to lack of orographic influence and lack of PVA as vort becomes less distinguishable.
Similar setup for both Tue and Wed with no major forcing mechanism but low level baroclinic zone nearby for plenty of clouds and weak vorts riding overhead to enhance these from time to time. By Thu, key player is the confluent flow on south side of upper low over Quebec, as it will be responsible for holding the cold. Looks as tho it can do that for all of NewEng on Thu, but deeper moisture doesn't arrive until Thu eve/night when confluent flow begins to pull northeast and sfc high moves SE of NewEng. This is never a good position for Srn NewEng to get prolonged wintry precip, tho an initial burst is still a good possibility, and Central/Northern NewEng don't look all that bad for prolonged snow or snow to sleet in the case of some Central NewEng areas. At this point, it's a matter of fine details on placement of warm layer, but this should be encouraging for skiers and snowmobilers who are looking to extend a late-starting season.
Farther down the line I'm interested to see what happens with the cold front that this end-of-week system will pull down, as indications from Ensemble members are that it doesn't make it much farther south than NJ, which makes sense given a ridge battling back over the SE US. The curiosity here is that the combo of a front stalled there and an incoming shortwave raises eyebrows for a possible Sunday low pressure wave, but that is a low-probability event at this point given uncertainty in placement of the front and evolution of the shortwave. Either way, deeper cold to the tune of 8 C below normal at 850 mb streams south to begin next week, so no warmup to end February and begin March. By the second week of March, signals are for warmer and even above normal air at 850 mb, but a series of bubble highs moving E across Srn Canada may keep a classic late-winter NewEng chill in the air.
Enjoy your Monday!
Matt
