Damaging Wind Event Unfolding for New England Friday...Bitter Wintry Weekend In Store
Quiet Pattern Continues through Midweek...Periodic Light Snow in the Mountains

Quiet and Cool Winter Weather to Start the Week

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:  After a blustery but bright weekend across New England, winds will subside on Presidents' Day with abundant sunshine giving way to a few late-day high-altitude clouds, and a wonderful day for many folks to enjoy a well-deserved day off.  The trend over the next several days will be for energetic disturbances to move over New England aloft - at the jet stream level - but for deep atmospheric moisture to stay south of us.  If the energy and the moisture were to join, a larger storm would be in the making, so we'll continue to watch this pattern carefully, but for now it looks most likely that each disturbance will slide through with periods of increased clouds and a chance of spurts of flurries or light snow, but no blockbusters appear to be in the cards given the inability to team energy AND moisture together.  So, at this point the rest of the week breaks down this way:  Tuesday starts with sunshine, then clouds thicken with an approaching disturbance and some flurries or light snow are possible with little or no accumulation.  Wednesday will be a similar blend of sun and clouds, with another chance of flurries or light snow late and at night.  With another energetic disturbance and the return of somewhat milder air Thursday, there may be a bit more in the way of clouds, especially early when a few flurries or some light snow is possible.  A cold front pushes through later Thursday and leaves cooler Friday temperatures wtih billowing afternoon clouds and a few snow showers.  Have a great Monday!

General Weather Summary:  Quick Update:  I just finished with the noon show and realized something I've been mentioning on-air in my NECN broadcasts and neglected to mention in this discussion:  If you're up early enough, check out the south sky around 5:30 in the morning Tuesday.  This morning's display was brilliant - looking south about one hour before sunrise, Jupiter was bright and clear just up and to the right of the moon...it should be visible again around 5:30 AM Tuesday and - provided clouds don't interfere - Wednesday, as well.

Previous Weather Discussion:  A quiet Presidents' Day lay in store for New England, as the damaging winds of the past weekend have quieted and arctic air begins to release its grasp.  The overall weather pattern this week features a steady train of moisture-loaded systems scooting east across the Southern Tier of the United States, and a steady train of energetic but moisture starved systems racing across the Northern Tier - including New England.  If the supply of moisture and energy were to team up, a large storm would be the result - but it looks as though this merger of northern and southern stream systems will occur far enough east to avoid major storm development along the Eastern Seaboard for the next few days.

The result, therefore, will be periods of increased clouds and chances for light snow and flurries with these passing energy centers, all of which should amount to very little through most of New England, with possible exceptions in the mountainous terrain, where precipitation from incoming Canadian disturbances can often be enhanced.

After a mostly sunny start to Presidents' Day for most of New England with clouds and flurries lingering in the mountains of the North Country, most of New England will enjoy sunshine through our Monday, and this sun will help to boost temperatures to around 30 in many locales.  Late Monday, high-altitude clouds will increase in association with one of these active northern stream energy centers, though without much moisture, these clouds will do little more than mix with the sunshine to end the day, and these will maintain scattered cloud cover overnight Monday night.  Still, most areas will drop into the single digits and teens with light winds.

Tuesday will be a similar setup for New England, with an energetic disturbance dropping overhead later in the day.  The subtle difference on Tuesday will be that the moist southern stream will inch ever-so-slightly closer, and this may provide just enough moisture on its northern periphery to provide a period of flurries or very light snow later Tuesday into Tuesday evening.  Little or no accumulation would result, except for the mountains which may see a fluffy inch or two.

It's likely that this similar pattern will continue for the next few days - allowing southern moisture and northern energy to get only close enough to enhance one another a bit, before phasing just far enough east of the coastline to spare us from any hearty storm development.  The result will be increased cloud cover and periodic flurries or very light snow again later Wednesday and Wednesday night.  By Thursday, the merger of northern energy and southern moisture will occur close enough to New England, that we'll be keeping a close eye on how the pattern unfolds, as it's possible this development will be close enough to enhance the period of snow just a bit for at least some of New England - especially the farther northeast one is.  Regardless, by Friday I expect a stronger push of northern energy to send a cold front through New England, reinforcing cold air and bringing yet another chance for snow showers, before a threat for merging energy and moisture brings an possible storm threat next weekend.

Enjoy the tranquil start to the week!

Matt

Matt's Technical Meteorological Discussion:  Updated Monday, February 20 at 1:15 PM

Quiet pattern prevails in the short term with regard to sensible weather, tho the pattern is quite active aloft.  Separation of northern and southern streams prevents phasing and therefore mitigates a storm threat that last week I expected would be looming my the middle of this week.  Instead, northern and southern stream flow remain separate just long enough to keep secondary low pressure development far enough to our southeast to keep most of NewEng out of organized precip, at least in the short term, tho there is plenty to remain on-guard for by the middle and end of this week.

First, shortwave riding overhead later today brings increasing high altitude clouds but otherwise dry low level air squashes out lingering mountain flurries in the North.  Expect dry conditions overnight with overcast deck of cirrus in Northern NewEng, otherwise scattered cirrus and cold temps that are kept just above the dewpoint in most areas thanks to a light wind, though sheltered valleys are likely to decouple and areas of freezing fog are possible in the deepest valleys.

The shortwave squeeze is on for Tuesday with one vorticity maximum strung out in confluent flow passing immediately south of NewEng, and the other a strong and more consolidated vort max dropping southeast through Ontario and into NewEng Tue afternoon.  While the southern stream vort is devoid of much moisture, there may be just enough moisture input to enhance the approaching northern stream vort and crank out flurries and perhaps even periods of light snow Tue afternoon/evening producing little or no accumulation in most of Central/Southern NewEng (it will take a lot of factors coming together just to produce this light snow/flurry activity) but likely to deposit a couple of fluffy inches from the Northern Berkshires through the Greens and Whites and into the mountains of Maine Tue Ngt.

A similar pattern continues through Wednesday when another southern stream wave misses south while the northern stream partner rides overhead, wringing out another couple of fluffy inches for the mountains Wednesday eve and night, while the rest of NewEng sees another period of increased clouds and periods of light snow or flurries.  There are some indications of weak troffing setting up over Central and Southern NewEng, and it's possible that the snow would gain enough life for some measurable QPF depositing a dusting of Wednesday night snow - but at this point that's all that looks reasonable.

Thursday and Thursday night we pay closer attention to this weather pattern as a much stronger vort max drops across NewEng and amplifies shortwave troffing just off our coastline.  The result will be for a deepening area of low pressure east of NewEng, but troffing will extend NW across the St. Lawrence River Valley.  The result at the surface is for a surface trough reflection - a well defined and extensive Norlun trough that sets up under a cold pool of air at 500 mb approaching temps of -40 C!  The GFS is doing a remarkable job of picking up on precip associated with this trough Thu Ngt into Fri, and while the 84 hr NAM runs out to Thu eve, it's clearly picking up on the precip potential with the strong northern stream vort.  So, this certainly gives most of NewEng something to watch very carefully, and means you won't hear my hum-drumming the forecast beyond Wednesday, as I'd rather not be caught surprised if this trough lights up.  There is good low level convergence with this feature and a jet streak wrapping into the SW side of the developing mid and upper level circulation, which places the streak over Wrn NY/PA/Nrn NJ, increasing diffluence over NewEng.  So, more plentiful bursts of snow are in my forecast for late Thu into Fri, and at least some accumulation is possible.

I have to be quite honest that I do not trust this pattern at all.  The flow to our west is flat and fast, and this means lots of shortwaves embedded in the flow, streaking in from the north, streaking in off the Pacific and through the Pacific NW, and then an active subtropical jet streaking shortwaves in from the south, laden with moisture.  These shortwaves all are coming from low observation density areas, and meteorologists need to step cautiously having this understanding.  It appears as though Thursday into Friday will be the first of this careful stepping, and this weekend will represent the next.

Have a great Presidents' Day.

Matt