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:
A slow moving front will sag across New England on Wednesday, and will waver across the six-state region through the end of the week, bringing varying amounts of cloud cover and ensuring no quick transitions to deep Canadian cold, nor to milder air south of the region. Overall, this leaves most of us in a "no man's land," so to speak, though occasionally strong storms can develop along frontal boundaries if a strong enough disturbance encounters the airmass clash. With no strong disturbances in sight for New England, however, we will instead see an extended period of clouds, sun, and light showers of rain and snow.
That pattern takes hold today, with morning rain and snow showers exiting Eastern areas early with the passage of an upper level disturbance, and another disturbance moving east out of New York State, depositing continued showers of snow on Western New England. Elsewhere, a northwest wind will slope down off the mountains and hills of New England - resulting in a "downsloping" wind for most of New England, which serves to dry the atmosphere. This will help to squash most snow showers that try to escape east across New England, and will help to break up cloud cover and bring some sunshine out for most locales. Last to see emerging sun will be Cape Cod, while Northern and Western mountains will see at least scattered snow showers by later Wednesday afternoon.
Most mountain snow showers will end Wednesday night as drier air moves into New England from Southern Canada, and many communities will find partly cloudy and cool conditions during the overnight. With the aforementioned front lingering over New England on Thursday, expect similarly breezy and cool conditions to prevail, and a late-day disturbance aloft should develop a wave of low pressure at ground level, serving as the focus for Northern New England and especially mountain snow showers Thursday afternoon and evening, while Southern areas are likely to remain dry. While this pattern certainly isn't as helpful as a series of snowstorms for ski areas, the bright side about all of this is that it brings a fantastic pattern for making snow, with most nighttime AND daytime temperatures cold enough in the Northern Mountains. Farther south in New England, ski areas will rely on overnight snow production to boost conditions, but cold nights should ensure that conditions continue to improve where snowmaking takes place.
By late in the week, this cool fair weather cell will merge with another, larger bubble of high pressure moving over the Mid-Atlantic coastline, and this will mean a possible slight moderation in temperatures for Friday, though a cool northwest wind flow is still likely to persist and therefore little noticeable change is likely to evolve. By next weekend, another energetic upper level disturbance will be ejecting east after churning across the Rockies and Plains, resulting in another swath of moisture pluming out of the Gulf of Mexico and thereby bringing another likelihood of rain - perhaps mountain snow if cool air can hold on long enough and especially in the mountains of the North - though not until after what is likely to be a dry day Saturday as a slow-moving ridge of high pressure begrudgingly lets go of the Northeast.
Though the overall pattern will feature above normal temperatures for most of Canada for the next couple of weeks, and there is no screaming signature of a major snowstorm for the Northeastern U.S., it's important to understand that while no deep cold can penetrate a pattern like this over the average for the time period, high pressure over Central Canada can allow surface and low-level cold air to sneak southward into Eastern Canada, making it available to New England when the right storm comes along. Therefore, while I certainly can make no case for deep arctic chill, each storm will bring great interest in the coming weeks.
Matt
Matt's Technical Meteorological Discussion: Updated Wednesday, December 27 at 1:55 PM
Clouds continue to blossom with passage of shortwave trof and weak windex event as lingering low level moisture and instability are focused with combo of sluggish sfc cold front and well defined upper level shortwave. The available upper level diffluence has been sufficient to prompt snow and rain showers where frontal forcing and orographic forcing intersect, tho lots of virga in those radar returns owing to moderate dewpoint depression in sfc obs. Expect activity to wane south as available moisture decreases tho Nrn Mountains may find new snow showers developing afternoon and eve with vort max passage as evidenced on water vapor imagery.
Not bone-chilling cold Wed ngt but Tds in the teens and 20s will support similar overnight lows as winds gradually subside and clouds gradually diminish with loss of low level instability as diurnal effects wane. Another disturbance slated for Thu afternoon aloft will focus snow showers near frontal boundary, which is fcstd to waver N and therefore best focus for snow showers and perhaps a few squalls will be Nrn NewEng and esp where upslope flow is favored. Elsewhere, mixing will result in another breezy day with temps near Wed levels.
Sat there was little support of precip in 00Z guidance but noticing 12Z guidance coming around which makes sense and fits the forecast I have going, so hopefully the trend continues. Just makes sense to crank out at least light precip (rain/snow likely mostly snow with cool low levels) given steady weak warm and moist advection and weak vort aloft. Main precip from Central US storm will still be SW of area until late Sat Ngt or perhaps even Sun. The trick here is how quickly the ridge crests over NewEng and the trend on that has been slower, but last time we saw the operational guidance trend slow while the Ensembles stayed on course and the Ensemble guidance from both GFS and Canadian say bring the rain in late Sat night/Sun as ridge axis passes, so will hold steady on that for now. As for ptype, logic would dictate that in a similar longwave pattern, if a high of equal or greater strength (this one greater than last) settles to similar position (this time a bit farther south over Southern NewEng) later into the cold season, expect cold to penetrate a bit farther. Tho guidance is a bit spread on baroclinicity, the mean seems to agree with this line of thinking and this shud mean another mountain snow with a rain/accumulating snow line a bit farther south than the last time around for Sun. Thereafter, the first half of next week will bring occluded air, not a shot of cold, and in fact air behind an occluded front often can be mild as the cyclone blocks the southward progression of cold.
The question is, would there be any cold available anyway? The GFS Ensemble mean 850 temp anomaly shows some +16-+18 C anomaly over Central Canada, and while that would typically lead one to believe there's no available cold, keep in mind that warmer average temp in a column is associated with a ridge, and a sfc/llvl ridge centered over Central Canada keeps a shallow flow of cold air from the North Pole to Eastern Canada. This is reflected in guidance progs of -20 C and colder at 850 over Eastern Canada, and in fact, this low level cold is partly what helps out the North Country with this upcoming weekend storm, because while the flow goes SE, any ageostrophic flow would bleed intense shallow cold southward. Farther out, though we're blocked from the cold by the mature cyclone spinning over the Northeast and Southern Canada, the persistent sfc ridge over Central Canada continues to load cold into Eastern Canada and this will mean a steady drain of cold air that will be readily available when the right synoptic situation comes along.
Enjoy your day.
Matt
