Saturday PM Update

3:17PM

No big changes here, just a few minor adjustments. Another update later!

Forecast for southeastern New England…

REMAINDER OF AFTERNOON: Mostly cloudy with snow showers mainly RI and southeastern MA with minor accumulation. Highs 33-38. Wind NW to N 5-15 MPH.

TONIGHT: Overcast. Snow developing from south to north mainly after 10PM, may be moderate to heavy for a while before tapering off toward dawn. Snow accumulation 1-4 inches except 4-8 inches eastern Cape Ann and coastal Plymouth County MA southeastward through Cape Cod and the Islands. Some blowing and drifting snow. Lows 15-20. Wind NW 10-20 MPH inland and 20-30 MPH along the coast with higher gusts in all areas.

SUNDAY: Cloudy with lingering snow showers especially coastal locations, with another fluffy inch or two possible on Outer Cape Cod, then some breaking clouds from the west later. Highs struggle to reach the upper 20s. Wind N to NW 15-25 MPH with gusts 35-45 MPH. Additional blowing snow.

MONDAY – PRESIDENTS DAY: Sunny & windy. Low 10. High 30.

TUESDAY: Increasing clouds. Snow/mix midday to mix/rain showers later. Low 20. High 40.

WEDNESDAY: Partly cloudy & windy. Scattered snow showers. Low 14. High 31.

THURSDAY: Partly cloudy & breezy. Isolated snow showers. Low 13. High 33.

FRIDAY: Increasing clouds. Chance of snow late. Low 12. High 32.

Model Battle

5:17PM

Let’s cut to the chase. The stupid computer models have been all over the place with this one. Why can’t it all be easy like the blizzard? Well it doesn’t work that way. The complexities of the atmosphere often overwhelm our man-made weather predictors. It’s just the nature of it. So when you have one model predicting traces to an inch or 2 of snow, another predicting a foot, and most of the others somewhere in between, what do you do? Throw darts? Roll dice? Guess? … You apply meteorology and hope for the best. That’s what I have done in thinking about what to forecast for this weekend’s weather.

After a mild Friday, a hint of the coming of Spring to some, a cold front will amble west to east across the region overnight and early Saturday, bringing a band of snow and rain showers to the region. The best chance of snow taking place will be over inland areas where it will cool sufficiently tonight before the clouds grow too thick. A slower temperature drop closer to the coast may leave the air marginal for supporting snow for a while. Either way, I’m only expecting minor snow accumulations where snow does occur from the first of this 2-part event. It’s the second part, Saturday night and early Sunday, that has many meteorologists in a tizzy, but a cooler head is going to prevail at WHW. Calmly forecasting the second part, in the form of a developing low pressure area, to explode over the water into a beast, but JUST too far east to give much of the area a huge snowstorm. And it will become cold enough for snow in all areas very quickly as it draws much colder air down from the north as it intensifies. There will likely be accumulating snow in all areas of eastern MA, RI, and southern NH, but for now all of the snow amounts in this forecast will be underneath double-digits. With such a close pass expected, there is virtually no margin for error and a slight jog either direction can potentially have drastic impact on snow amounts. So please stay tuned…

After the madness ends, late Sunday will just be plain windy and very cold, Monday (Presidents Day) will continue more of the same, but Tuesday will see rapid moderation in temperature and a chance of a minor precipitation event later in the day into the night, followed by a mostly dry but windy and colder middle of next week, based on current expected timing of weather systems.

Updated forecast for southeastern New England (southern NH, eastern MA, and RI)…

TONIGHT: Clouds increase. Chance of snow and rain showers. Lows drop to the upper 20s inland and lower 30s coast. Wind SW around 10 MPH decreasing to calm for a while then NW up to 10 MPH toward dawn.

SATURDAY: Mostly cloudy with snow and rain showers becoming mostly snow showers during the morning, accumulating anywhere from a coating to 1 inch. Partial sunshine possible around midday before clouds thicken again in the afternoon. Highs 33-38. Wind NW to N 5-15 MPH.

SATURDAY NIGHT: Overcast. Snow developing early, may be moderate to heavy for a while before tapering off toward dawn. Snow accumulation 2-5 inches except 5-9 inches eastern Cape Ann and coastal Plymouth County MA southeastward through Cape Cod and the Islands. Some blowing and drifting snow. Lows 15-20. Wind NW 10-20 MPH inland and 20-30 MPH along the coast with higher gusts in all areas.

SUNDAY: Lots of clouds to start with lingering snow showers especially coastal locations, then some increasing sun from west to east during the afternoon. Highs struggle to reach the upper 20s. Wind N to NW 15-25 MPH with gusts 35-45 MPH. Additional blowing snow.

MONDAY – PRESIDENTS DAY: Sunny & windy. Low 10. High 30.

TUESDAY: Increasing clouds. Chance of mix/rain showers late. Low 20. High 40.

WEDNESDAY: Partly cloudy & windy. Scattered snow showers. Low 14. High 31.

THURSDAY: Partly cloudy & breezy. Isolated snow showers. Low 13. High 33.

FRIDAY: Increasing clouds. Chance of snow late. Low 12. High 32.

Quick Update

7:25AM

Hi everybody! Sorry for the short discussion & forecast following this. Bigger update later today… Leaning toward more of a miss than a hit for Saturday at this point. Some lighter snow during the day. Bigger punch of precip. stays offshore at night (if it comes further west we’ll have much more snow but leaning away from this at the moment).

TODAY: Partly sunny. Highs around 50. Wind S 5-15 MPH.

TONIGHT: Partly cloudy. Lows 25-30. Wind W to NW 5-15 MPH.

SATURDAY: Cloudy. Periods of snow and rain with up to a couple inches accumulation of snow mainly away from the coast. Highs 33-38. Wind NW to N 10-15 MPH.

SUNDAY: Partly cloudy and windy. Low 18. High 28.

MONDAY – PRESIDENTS DAY: Mostly sunny. Low 14. High 34.

TUESDAY: Partly sunny. PM rain showers. Low 29. High 44.

WEDNESDAY: Variably cloudy. AM snow showers. Low 28. High 38.

THURSDAY: Mostly sunny. Low 18. High 33.

Snow Threat Or No Threat?

7:25AM

A cold front approaches Friday which will be a milder day but not as bright as Thursday. Colder air starts to move in Saturday at the same time complex low pressure develops along and off the East Coast. It looks like one of these low centers will move north northeastward near the coast to just offshore and should be enough to bring a period of precipitation to the southeastern New England areas. With cold air just starting to become established, it’s unclear if it will snow in all areas – may be warm enough for mix or rain in some. Still working out the details on this. By Sunday, we’re all windy and much colder behind departing low pressure. A bright and cold Presidents Day is expected, followed by a moderating trend.

Forecast for southeastern New England…

TODAY: Mostly sunny. Highs around 40. Wind light variable.

TONIGHT: Partly cloudy. Lows around 30. Wind light S.

FRIDAY: Partly sunny. Highs around 50. Wind S 5-15 MPH.

SATURDAY: Mostly cloudy. Snow or rain possible. Low 28. High 38.

SUNDAY: Partly cloudy and windy. Low 18. High 28.

MONDAY – PRESIDENTS DAY: Mostly sunny. Low 14. High 34.

TUESDAY: Partly sunny. PM rain showers. Low 29. High 44.

WEDNESDAY: Variably cloudy. AM snow showers. Low 28. High 38.

Midweek Side Swipe, Weekend Watcher

10:01PM

Tuesday brought a gusty wind and held cloudiness than I had forecast, but still fairly mild air allowing for more snow-melt. Next up is a wave of low pressure passing south of the area Wednesday night and early Thursday, but close enough for some light snow in parts of the region. The adjustment from the last forecast is to push this area slightly further south. After a break Thursday into Friday, we’ll be watching for the potential for storm development over the weekend. It still remains unclear how much of an impact a trough and storm development will have on southeastern New England, so a simple forecast will remain in place for now.

Forecast for southeastern New England from southern New Hampshire to RI and the MA South Coast…

TONIGHT: Clouds go bye-byes. Watch for black ice on untreated surfaces, especially walk ways where melting snow re-freezes. Lows upper 20s to lower 30s.  Wind W 10-20 MPH and gusty early, relaxing overnight.

WEDNESDAY: Sunshine, brightest in the morning, becoming filtered during the afternoon. Highs around 40. Wind W under 10 MPH shifting to N.

WEDNESDAY NIGHT: Clouds thicken. A period of mainly light to briefly moderate snow around and south of the Mass Pike, steadiest over the South Coast, mainly after 9PM. Accumulations ranging from nothing or a dusting near the Pike to an inch or two along the South Coast. Lows 25-30. Wind light N.

THURSDAY: Clouds retreat, sun becomes dominant. Highs around 40. Wind NW 5-15 MPH.

FRIDAY: Partly sunny. Low 22. High 46.

SATURDAY: Mostly cloudy. Early snow showers. Snow developing at night. Low 24. High 35.

SUNDAY: Cloudy with early snow then clearing late. Low 20. High 30.

MONDAY – PRESIDENTS DAY: Sunny. Low 17. High 40.

TUESDAY: Partly cloudy. Low 31. High 50.

Activity Increase

9:54PM

The pattern is becoming more active, or more correctly stated, it already has. We had Blizzard 2013, and then the mix to rain event Monday. Next comes a wave of low pressure throwing a small snowfall into southeastern New England Wednesday night and early Thursday. Following that is a weekend storm threat and down the road additional storms in the pipeline.

More immediately, areas of dense fog over the snowcover will begin to dissipate as drier air starts to flow in from the west overnight. This will lead to a nicer day Tuesday though a gusty westerly wind will be blowing as a broad low pressure area slides across southeastern Canada.

The wave of low pressure responsible for the Wednesday night and early Thursday snow threat will be an open wave disturbance moving rapidly east northeastward and passing just south of New England.

A larger scale trough will dig into the eastern US as the weekend arrives and will ignite a significant storm. The track and development of this system is a little uncertain but there remains a significant storm threat for that period.

Forecast for southeastern New England…

TONIGHT: Showers end, fog dissipates, clouds linger. Lows 32-37. Wind W up to 10 MPH.

TUESDAY: Mostly sunny. Highs 40-45. Wind W 10-20 MPH with higher gusts.

TUESDAY NIGHT: Clear. Lows from near 15 inland valleys to the lower 20s most areas. Wind W 5-15 MPH.

WEDNESDAY: Bright sun morning, filtered sun as high clouds advance in the afternoon. Highs around 40. Wind W up to 10 MPH.

WEDNESDAY NIGHT: Thickening overcast. A period of snow especially southern and eastern locations. Lows around 20. Wind light variable.

THURSDAY: Snow ends early after accumulating  from a coating to 2 inches in northwestern areas to 2-4 inches in southeastern areas (Mass Pike as a general line between the 2 areas). Increasing sunshine. Highs 35-40. Wind N to NW 10-20 MPH.

FRIDAY: Sun & clouds. Low 18. High 36.

SATURDAY: Storm threat – snow or mix develops. Low 25. High 35.

SUNDAY: Storm threat – mix or snow tapers off. Low 28. High 38.

MONDAY – PRESIDENTS DAY: Mostly sunny. Low 10. High 26.

The Week Ahead

8:06PM

After an eventful week weather-wise, it’s time for a break right? Well not really. The new week starts with a threat of some icing inland, the midweek is a watch period for a storm passing to the south, and next weekend carries the potential for another winter storm.

The first system will be a low pressure area cutting through the Great Lakes Monday and early Tuesday, redeveloping over northern New England and heading into eastern Canada. Enough cold air will be around for some snow/sleet/freezing rain well north and west of Boston to start out around mid morning to midday Monday, but eventually these areas will transition to rain. Mainly rain will fall elsewhere. Melted precipitation amounts will be limited to generally under 1/2 inch so that problems with roofs should be limited, since wind blew much of the snow off of them except in areas where snow was wetter (southeastern MA). Some street flooding will occur due to blocked drains. Drivers should use caution anyway as there will still be some very large snow banks and narrow streets. A gusty west wind is expected Tuesday with drier weather as broad low pressure moves through eastern Canada and exerts its influence down across the northeastern USA. At midweek, later Wednesday into Thursday, developing low pressure in the Southeast will move off the Mid Atlantic Coast. It appears this system will be too far south to impact New England but will be watched in case. Later in the week, especially next weekend, a larger scale trough is expected to move into the East and ignite storm development near the East Coast. It’s too early to tell how it will play out but there is some potential for a winter storm at that time.

Forecast for southeastern New England…

TONIGHT: Clouds increase. Lows 15-25 northwest to southeast by midnight then rising. Winds light variable through midnight then  becoming S up to 10 MPH overnight.

MONDAY: Cloudy. A period of rain late morning through afternoon except starting as snow to sleet and freezing rain in the I-495 belt especially from the Mass Pike northward. Highs 40-45. Wind S 5-15 MPH.

MONDAY NIGHT: Partly cloudy. Lows 32-37. Wind W 5-15 MPH gusting to 20 MPH.

TUESDAY: Partly cloudy. Highs 40-45. Wind W 15-25 MPH gusting over 30 MPH.

WEDNESDAY: Sun gives way to clouds late. Low 25. High 40.

THURSDAY: Clouds give way to sun late. Low 25. High 40.

FRIDAY: Mostly sunny. Low 20. High 37.

WEEKEND: Winter storm possible.

Beyond The Storm

7:34PM

As the region continues to recover from Blizzard 2013, it’s time to do a couple of things on the blog.

First and foremost, I want to again thank all of those who read and to those who add comments as well! I very much appreciate you all being here and trusting the information you get here.

Next it’s time to post links to the wind and snow reports. If these links don’t work for you, or if they seem like they are leading to the wrong page, let me know. Sometimes the NWS changes things and suddenly the address isn’t quite right.

(See the comments section below for links to snow & wind reports!)

Finally, it’s time to look ahead to the coming days beyond the storm…

As the storm pulls away and the gusty winds behind it continue to blow the newly fallen snow around, the sky is clearing and the stars will sparkle in it above the deep snowcover, but conditions like this also lead to very cold air, and this will indeed be the case overnight as some locations head toward zero. Recovery comes on Sunday, back to the 30s, under bright sun. A nice day to continue and hopefully finish digging out and cleaning up. The nice weather won’t last though, as another low pressure system will approach and pass north of the region on Monday, bringing a variety of precipitation but no major storm to the region. Another low pressure area will try to make a run at us around midweek, but this one looks as if it will pass to the south. If it should come further north, a snow threat will exist sometime in the late Wednesday to Thursday time frame. Not going for this right now.

Fair weather is expected Friday followed by the threat of a winter weather event next weekend. It is too early to get specific about this threat, but just pointing out that the ingredients for an event are showing up on a reliable forecast model (the one that predicted the blizzard many days ahead of time). So I’ll keep an eye on it.

Updated forecast for southeastern New England…

TONIGHT: Clear & starry. Lows 0-10 inland to coast. Wind NW 10-20 MPH gusting around 30 MPH. Wind chills as low as -10. Additional blowing snow.

SUNDAY: Sunny. Highs 33-38. Wind W 5-15 MPH.

SUNDAY NIGHT: Clouds move in. Lows around 30. Wind SW 5-15 MPH.

MONDAY: Cloudy. Afternoon snow/mix transitioning to rain. Highs around 40. Wind SE 5-15 MPH early shifting to S and increasing to 15-25 MPH by the end of the day.

TUESDAY: Partly sunny. Low 30. High 44.

WEDNESDAY: Partly sunny. Watching storm to south. Low 25. High 40.

THURSDAY: Partly sunny. Watching storm to south. Low 23. High 38.

FRIDAY: Mostly sunny. Low 18. High 38.

SATURDAY: Mostly cloudy. Chance of snow. Low 16. High 35.

Storm Update (Saturday Morning)

11:44AM

A little later on I’ll post some links for storm totals and other information. Of course  many of my readers do that for me in the comments section and I want to thank all of them and EVERYBODY for reading and commenting here!

Just a short update here on what has happened (expand on this later) and then a look ahead to the next several says.

SNOW: Winding down. Another 1-3 inches MA South Shore to Cape Cod which should bring the snow totals into the predicted range there. Big amounts many areas, 18-30+ inches fell and with a difficult storm to measure and all the reports still coming in, we’ll look at a full list when it becomes available. Another snow band to the west should weaken as it comes eastward but may produce a little more across the area before falling apart.

WIND: Still NW 15-35 MPH and gusty with blowing & drifting snow through the afternoon.

COASTAL FLOODING: The worst is passing, but hard hit areas including Hull, Scituate, Sandwich, among a few others. Will try to get more info on this as well. Despite a few areas seeing serious flooding, this is not even remotely close to the scope of what happened in 1978!

POWER OUTAGES: The heavy wet snow for the first part of the storm resulted in big time power outages especially on the South Shore of MA. Hoping that everybody gets the power back as soon as possible!

What’s coming up?

This storm is about to depart and in its wake we can expect a very cold night tonight with the deep snowcover. Sunday will be a glorious sunny day and will feel “warmer” compared to today as there will be less wind along with the higher mid February sun angle. Much of the dig-out should be able to be completed during Sunday. Please use caution if you are shoveling!

Early Week… Frontal system swings through Monday with a minor precipitation event.

Mid Week… Watching a storm threat but for NOW going to lean toward it being out to sea.

Late Week / Weekend… A brief break then a storm threat for the weekend. Too far away to even venture into any detail. We’ll just leave it at saying there is a possible storm to deal with at that time.

Updated forecast for southeastern New England…

THIS AFTERNOON: Snow winds down but lingers over the South Shore of MA for a while and Cape Cod & Nantucket longer where another 1-3 inches will fall. Sun may peak out. Temperatures holding in the upper teens and 20s. Wind NW 15-35 MPH with higher gusts, causing additional blowing and drifting snow.

TONIGHT: Clearing. Stars will shine above a deep snow cover. Lows drop to near 0 remote suburbs to near 10 most areas. Diminishing NW wind.

SUNDAY: Sunny. Highs in the 30s. Wind W up to 20 MPH early then diminishing.

MONDAY: Clouding over. PM mix to rain showers. Low 20. High 40.

TUESDAY: Partly cloudy. Low 30. High 45.

WEDNESDAY: Partly cloudy. Watching storm to south. Low 20. High 40.

THURSDAY: Partly sunny. Watching storm to south. Low 20. High 40.

FRIDAY: Mostly sunny. Low 15. High 35.

Storm Update (Friday Evening)

4:51PM

There is not a whole lot to say about this storm, now underway, that hasn’t already been said. All valid info from the previous post is still the same. One thing I would like to stress though is the coastal flooding issue, which will be worst at high tide times tonight and Saturday morning. No, we won’t see as widespread and major flooding as what occurred in 1978, HOWEVER, some areas, especially around Scituate and Sandwich and any north-facing coastal areas and especially bays, will be vulnerable to some major flooding problems. Property damage is very likely there and those areas should be evacuated.

The previous comments on timing, snow intensity and amounts, accumulations, and lightning/thunder chances remain the same. The one change I am making to the accumulations is this: Up the totals a little on the outer Cape Cod region and Nantucket to 6-12 inches with locally heavier (these areas may see a few additional inches at the end of the storm due to ocean-effect snow as well, even after the main storm snow has departed later Saturday.

Starting to feel that the jackpot of 24-30+ inches may occur along a band somewhere in the I-95 belt to I-495 belt northwest of Boston. Another such area may take place from the southwestern suburbs of Boston to northern Rhode Island. This will be updated as needed.  Bottom line: Major snow accumulation and major snow drifting during the next 24 hours.

Updated forecast for southeastern New England…

THROUGH SATURDAY: Any mix to snow Cape Cod/Islands, snow elsewhere, moderate to heavy, at times very heavy, with white-out conditions, peaking during the nighttime and early morning hours, tapering off and ending from west to east during the day Saturday. Accumulations (inches) of 6-12+ Nantucket to Outer Cape Cod ranging to 18-30+ most other areas as mentioned previously. Lightning and thunder possible. Temperatures hanging in the middle to upper 10s interior MA into southern NH, falling from the lower 30s into the 20s in southeastern areas. Wind NE shifting more to the N with time, 25-35 MPH gusting 45-65 MPH inland, 35-45 MPH gusting 55-75 MPH higher elevations and coastal areas. Isolated higher wind gusts possible.

SATURDAY NIGHT: Clearing. Lows around 10. Wind NW 15-25 MPH. Wind chill around zero.

SUNDAY: Sunny. High 32-37. Wind W 5-15 MPH.

MONDAY: Clouding over. PM snow to mix ending as rain. Low 20. High 40.

TUESDAY: Mostly cloudy. Low 30. High 40.

WEDNESDAY: Partly sunny. Low 27. High 42.

THURSDAY: Partly sunny. Low 25. High 40.

FRIDAY: Mostly sunny. Low 22. High 42.

Storm Update (Friday Morning)

7:27AM

This is the first of several updates to come throughout the storm. This one is only an update for time period and shows no changes to the discussion or forecast. The next will be posted this afternoon. Everybody stay safe!

Blizzard Warning through 1PM Saturday for most areas except portions of north central MA and Nantucket Island. Winter Storm Warning for these locations.

A blizzard is defined as winds of 35 MPH winds or greater and visibility under 1/4 mile due to heavy falling and/or blowing snow for a period of 3 hours or more. These conditions will take place over a large portion of the region Friday night into Saturday.

Storm track: Northeastward from the waters south of New England to the waters east of New England between Friday morning and Saturday night, possibly stalling for a time.

Mixing: Yes some mixing with rain is still possible over the immediate coast and especially Cape Cod and the Islands, hence the slightly lower projected totals there. But even there by mid storm it will be all snow.

Wet or dry snow? Wetter where mixing occurs and on the immediate shoreline to start, dry and fluffy elsewhere, then becoming drier and fluffy all other areas during the storm.

Start time: Ocean-effect snow showers may reach eastern MA around or after midnight or in the early hours of Friday morning. Storm’s snow will start light during Friday morning then grow steadier and more moderate into the afternoon and moderate to heavy by late afternoon.

Peak time: All of Friday night and well into Saturday morning when snowfall rates of up to 2 and even 3 inches per hour may occur.

End time: It may take all day Saturday to taper off but all snow should be done by early evening except lingering ocean-effect snow showers possible over parts of Cape Cod.

Accumulation (inches): 4-8 Nantucket through Outer Cape, 8-16 Mid Cape & Martha’s Vineyard, 10-18 Upper Cape, 18-30 elsewhere with a few 30+ amounts possible.  IMPORTANT not to focus on the top number in the range. The large range is to cover the fact that much of the snow will be dry and fluffy and there can be great variability due to local effects (elevation, ocean-enhancement, etc.). Also, blowing and drifting will be considerable and will assure that very few areas end up with level snowcover when this is over anyway.

Coastal flooding: 2 to 3 feet of storm surge flooding is possible especially on north-facing and east-facing shorelines at high tide times Friday night and Saturday morning. Some property and shore road damage is possible.

Wind: Starting out east to northeast and increasing to 10-30 MPH during the day Friday, shifting more northerly with time, 25-45 MPH inland and 35-55 MPH higher elevations and coast with gusts 45-55+ MPH inland and 55-75+ MPH higher elevations and coast.

Power outages: Isolated to scattered. Not expecting widespread ones because much of the snow will be dry and not stick to the trees and power lines. This may be less the case on parts of Cape Cod and the Islands which may have wetter snow longer. Leafless trees also lessen the chance of trees coming down.

Lightning & thunder: Not out of the question that some occurs during this storm. It can be fairly common with intense winter storms.

Updated forecast for southeastern New England…

TONIGHT:  Becoming cloudy. Ocean-effect snow showers possible east coastal areas around or after midnight. Lows 15-25 northwest to southeast. Wind E 5-15 MPH.

FRIDAY: Overcast. Snow develops, light and spotty then light and steady morning, growing moderate to eventually heavier at times during the afternoon. Mix/rain possible immediate coast especially south of Boston and Cape Cod/Islands. Highs 25-35 northwest to southeast. Wind E to NE 10-30 MPH, strongest near the coast.

FRIDAY NIGHT: Stormy. Moderate to often heavy snow except mix/rain parts of Nantucket and Outer Cape eventually changing to snow. Blizzard/white-out conditions often occurring. Rapid snow accumulations except in mix/rain areas. Lows 15-25 northwest to southeast. Wind NE to N increasing to 25-35 MPH with gusts 45-55 MPH inland and 35-45 MPH with gusts 55-75 MPH coastal and higher elevation areas. Isolated higher wind gusts are possible in all areas.

SATURDAY: Overcast. Blizzard conditions including heavy falling, blowing, and drifting snow to start the day, with gradual lessening of this during the day. Additional significant snow accumulation (see above for numbers). Temperatures steady 15-25 northwest to southeast. Wind N to NW 25-35 MPH inland and 35-50 MPH coast with higher gusts in the morning, diminishing slightly in the afternoon.

SATURDAY NIGHT:  Lingering snow showers Cape Cod otherwise clearing. Lows around 10. Wind NW 15-35 MPH diminishing overnight. Additional blowing and drifting snow.

SUNDAY: Sunny. Highs 30-35. Wind W 5-15 MPH.

MONDAY: Clouding over. PM light snow/mix/rain. Low 20. High 40.

TUESDAY: Partly sunny. Low 28. High 42.

WEDNESDAY: Partly sunny. PM rain showers. Low 33. High 44.

THURSDAY: Variably cloudy. Chance of snow showers. Low 23. High 37.

Making The Hit List

5:42PM

We are on Mother Nature’s hit list with a storm that may make the top 10 or even top 5 “hit list”. Southeastern New England is going to be dealt a serious blow with this major winter storm that is just about to get its act together.

For the purposes of keeping this discussion on the shorter side, there is not much to add and I will just detail the major points of the upcoming storm and skip the discussion about the days after, just covering those in the updated forecast that will follow.

I will attempt a shortened post on the 35th  Anniversary of the Blizzard of 1978 later this evening.

Just the facts…

Blizzard Warning 6AM Friday through 1PM Saturday for most areas except portions of north central MA and Nantucket Island. Winter Storm Warning for these locations.

A blizzard is defined as winds of 35 MPH winds or greater and visibility under 1/4 mile due to heavy falling and/or blowing snow for a period of 3 hours or more. These conditions will take place over a large portion of the region Friday night into Saturday.

Storm track: Northeastward from the waters south of New England to the waters east of New England between Friday morning and Saturday night, possibly stalling for a time.

Mixing: Yes some mixing with rain is still possible over the immediate coast and especially Cape Cod and the Islands, hence the slightly lower projected totals there. But even there by mid storm it will be all snow.

Wet or dry snow? Wetter where mixing occurs and on the immediate shoreline to start, dry and fluffy elsewhere, then becoming drier and fluffy all other areas during the storm.

Start time: Ocean-effect snow showers may reach eastern MA around or after midnight or in the early hours of Friday morning. Storm’s snow will start light during Friday morning then grow steadier and more moderate into the afternoon and moderate to heavy by late afternoon.

Peak time: All of Friday night and well into Saturday morning when snowfall rates of up to 2 and even 3 inches per hour may occur.

End time: It may take all day Saturday to taper off but all snow should be done by early evening except lingering ocean-effect snow showers possible over parts of Cape Cod.

Accumulation (inches): 4-8 Nantucket through Outer Cape, 8-16 Mid Cape & Martha’s Vineyard, 10-18 Upper Cape, 18-30 elsewhere with a few 30+ amounts possible.  IMPORTANT not to focus on the top number in the range. The large range is to cover the fact that much of the snow will be dry and fluffy and there can be great variability due to local effects (elevation, ocean-enhancement, etc.). Also, blowing and drifting will be considerable and will assure that very few areas end up with level snowcover when this is over anyway.

Coastal flooding: 2 to 3 feet of storm surge flooding is possible especially on north-facing and east-facing shorelines at high tide times Friday night and Saturday morning. Some property and shore road damage is possible.

Wind: Starting out east to northeast and increasing to 10-30 MPH during the day Friday, shifting more northerly with time, 25-45 MPH inland and 35-55 MPH higher elevations and coast with gusts 45-55+ MPH inland and 55-75+ MPH higher elevations and coast.

Power outages: Isolated to scattered. Not expecting widespread ones because much of the snow will be dry and not stick to the trees and power lines. This may be less the case on parts of Cape Cod and the Islands which may have wetter snow longer. Leafless trees also lessen the chance of trees coming down.

Lightning & thunder: Not out of the question that some occurs during this storm. It can be fairly common with intense winter storms.

Updated forecast for southeastern New England…

TONIGHT:  Becoming cloudy. Ocean-effect snow showers possible east coastal areas around or after midnight. Lows 15-25 northwest to southeast. Wind E 5-15 MPH.

FRIDAY: Overcast. Snow develops, light and spotty then light and steady morning, growing moderate to eventually heavier at times during the afternoon. Mix/rain possible immediate coast especially south of Boston and Cape Cod/Islands. Highs 25-35 northwest to southeast. Wind E to NE 10-30 MPH, strongest near the coast.

FRIDAY NIGHT: Stormy. Moderate to often heavy snow except mix/rain parts of Nantucket and Outer Cape eventually changing to snow. Blizzard/white-out conditions often occurring. Rapid snow accumulations except in mix/rain areas. Lows 15-25 northwest to southeast. Wind NE to N increasing to 25-35 MPH with gusts 45-55 MPH inland and 35-45 MPH with gusts 55-75 MPH coastal and higher elevation areas. Isolated higher wind gusts are possible in all areas.

SATURDAY: Overcast. Blizzard conditions including heavy falling, blowing, and drifting snow to start the day, with gradual lessening of this during the day. Additional significant snow accumulation (see above for numbers). Temperatures steady 15-25 northwest to southeast. Wind N to NW 25-35 MPH inland and 35-50 MPH coast with higher gusts in the morning, diminishing slightly in the afternoon.

SATURDAY NIGHT:  Lingering snow showers Cape Cod otherwise clearing. Lows around 10. Wind NW 15-35 MPH diminishing overnight. Additional blowing and drifting snow.

SUNDAY: Sunny. Highs 30-35. Wind W 5-15 MPH.

MONDAY: Clouding over. PM light snow/mix/rain. Low 20. High 40.

TUESDAY: Partly sunny. Low 28. High 42.

WEDNESDAY: Partly sunny. PM rain showers. Low 33. High 44.

THURSDAY: Variably cloudy. Chance of snow showers. Low 23. High 37.

The Calm Before, Or Finding “Nemo”

6:21PM

Might as well say it right away: The “Nemo” thing is just a joke about The Weather Channel’s name for the storm upcoming. I’ll refrain from comment on this practice for now. Also, sometime in the next 24 hours I will write a special blog about the 35th anniversary of the Blizzard of 1978, which is today/tomorrow (February 6-7).

With still over a day to go before this major event arrives, don’t lose sight of the fact there could still be some revisions to the forecast about to be posted. That said, here is my best guess for how the major winter storm, which has now prompted a blizzard watch for much of the I-95 corridor and a winter storm watch for the remainder of southeastern New England into Saturday, will play out. And then we will look beyond that into next week.

The makings of this winter storm are coming from 2 places, a disturbance in the northern jet stream moving through the Upper Midwest into the Great Lakes then diving southeastward, meeting up with a developing storm in the southern branch of the jet stream over the southeastern USA. Think of the northern stream system as a source of energy and the southern stream system as a source of moisture. And then the 2 systems get together along the East Coast, a process called phasing (when the 2 jet streams link up).  This results in a new storm that often intensifies rapidly, and then moves east or north, either out to sea or up the coast. In this case, pretty much all signs point to the intensifying storm moving northeastward, passing near latitude 40N and longitude 70W, which is southeast of Cape Cod. 40/70 is viewed as “the benchmark” by meteorologists when trying to forecast significant  winter storms. This track, and the size of the storm, means that a major impact will take place, including heavy snow, big snow amounts, and high winds. But there are some factors which will come into play to determine final snow amounts. They include:

* Ocean water temperatures which are running a few degrees above normal may prompt some mixing along the immediate coastline and especially over Cape Cod and the Islands.

* Final storm track. Any shifting one way or another even by 10 to 20 miles can impact amounts. I don’t expect this to change too much.

* Banding. With many storms that are deepening as they pass, often bands of very heavy snow will set up especially north and west of the center. In between these can be lighter areas. This can result in a fairly wide variability over a relatively short distance. This will be covered by a large range of snowfall in the forecast.

* Dry air wrapping into the circulation. When this happens, snow can become much lighter or even stop in an area it was expected to be heavy. I don’t expect this to become a major factor at this time either but will watch it.

* Storm speed. If this storm was moving right along, even though its impact is major, amounts would be a little less. However this storm may slow or even appear to stall as it does a tiny loop just east of New England (as the low pressure organizes itself between different levels of the atmosphere). Any slowing of the storm will prolong the snowfall and therefore increase the amounts. This will be factored into the forecast amounts.

Here is the time line and snow amounts…

Start time: Friday morning, from west to east but light snow for several hours. There may be a couple ocean-effect snow bands that move in from east to west across eastern MA and NH. These would be responsible for some minor accumulations but could cause slippery going on untreated surfaces.

When does it get serious? Timing can always shift a little, but I expect the steadiest moderate to eventually heavy snow to begin any time from 2PM on. If there is much of a Friday afternoon commute, conditions will be deteriorating rapidly.

Peak: The heaviest snow and strongest winds are likely from 10PM Friday through 6AM Saturday, give or take a couple hours depending on location.

End time for snow: Lower confidence on this, but the steadiest snow should be done by the middle of Saturday afternoon and other than some lingering snow showers near Cape Cod the entire event should be a done deal by about sunset or early evening Saturday.

Snow amounts: POTENTIAL snowfall, and this will be updated based on details as they change. 12 to 20 inches with locally higher amounts, except 6-12 inches in far southeastern MA especially the Cape Cod region (pending the mixing situation), and 3-6 inches Nantucket where it may mix much longer.

Forecast details for southeastern New England…

TONIGHT: Clear. Lows 12-17. Wind NW 10-20 MPH and gusty, diminishing overnight.

THURSDAY: Increasing cloudiness. High 22-27. Wind N 5-15 MPH.

THURSDAY NIGHT: Thickening overcast. Lows 15-20. Wind light NE.

FRIDAY: Overcast. Snow developing in the morning, growing steadier/heavier afternoon. Mixed snow/rain possible along the South Shore & South Coast of MA/RI including Cape Cod & the Islands. Highs 25-30 except 30-35 coastal areas. Wind E increasing to 10-20 MPH shifting to NE with higher gusts around 30 MPH or higher by the end of the day.

FRIDAY NIGHT: Winter storm with moderate to heavy snow and blowing snow, still some mixing possible far southeastern areas especially early. Heavy snow accumulations (see above). Lows 15-20 except 20-25 by morning in far southeastern areas. Wind NE to N 15-30 MPH with gusts 40-55 MPH. Blizzard conditions possible especially from Providence to Boston and westward.

SATURDAY: Overcast. Snow, still moderate to heavy at times through midday then diminishing and tapering off from west to east during the afternoon. Additional significant accumulation (see above). Blowing and drifting snow. Highs 20-25. Wind N to NW 15-35 MPH with higher gusts.

SUNDAY: Sunny. Low 9. High 33.

MONDAY: Cloudy. Chance of rain/sleet/snow showers. Low 20. High 40.

TUESDAY: Mostly cloudy. Low 30. High 44.

WEDNESDAY: Mostly cloudy. Low 31. High 40.

Don’t Open Your Gifts Early!

6:50PM

You may stand in one of many places about the thought of a big winter storm. Perhaps you love snow, perhaps you hate it, perhaps you wish for it to change to rain, or go out to sea, or maybe just dust the ground gently before moving on to dump upon the maritime provinces of Canada (“They deserve it up there! All they talk about is hockey and curling!”)

As much as I’d love to go into great detail about what I think is going to happen with that potential storm at the end of the week and why, I’m going to be brief about it here, and then work backward to more immediate happenings that I am more confident about.

There are so many computer models to digest, or ignore if you choose, as a meteorologist. I’ll admit I ignore many of them, and at least glance at my favorites, and linger longer on my absolute favorites. But I always look at enough data to at least feel like I’m informed enough to make the best educated guess I can make about any given situation. And this will be no different. But the truth is, even though I realize there is a fairly significant potential for a moderate to major, or perhaps even blockbuster, winter/snow storm on Friday to early Saturday, I just don’t have enough confidence to go into any detail yet. I’ll start to try to work that out tomorrow. Perhaps we’ll be starting to hint at snow accumulations, maybe big numbers, maybe not so big as the potential indicates can happen as of now. Too much can change. These are computers making forecasts. They’re not perfect. They are for use as guidance, and looking at them long enough over a period of years teaches you (and hopefully you remember) not to take anything they say too seriously until you are confident, based largely on experience, that they are painting an accurate picture. Even though one very reliable model has been showing “big storm” for about 3 days now, and did a stellar job forecasting the track of Sandy about a week or more in advance, I am not ready to bite its bait yet. So for this update, the wording will remain general for that period, but keep in mind there is a whole lot of potential with this, and we’ll be sorting that out in the next couple days…

A quiet Thursday will precede whatever event unfolds at week’s end, but before that, we have a complex but weak disturbance moving through the region tonight and Wednesday morning, and it will deposit a small amount of snow across southeastern New England. See below for accumulations.

A peek beyond all the madness into the future indicates a quiet end to the weekend and a warm-up at the start of next week.

For now, here is my latest thinking for southeastern New England’s weather…

TONIGHT: Cloudy. Periods of snow, mainly on the light side, but may be briefly moderate at times especially near the South Coast. Accumulations generally under 1 inch, but a few 1 to 2 inch amounts are possible especially south of Boston and over the South Coast and Cape Cod. Lows 22-27. Wind NE up to but mostly under 10 MPH.

WEDNESDAY: Mostly cloudy eastern and southern areas through late morning with any lingering snow or snow showers ending, otherwise partly to mostly sunny north and west with more sun south and east in the afternoon. Highs 35-40. Wind N up to 10 MPH in the morning shifting to W and increasing to 10-20 MPH with higher gusts in the afternoon.

WEDNESDAY NIGHT: Mostly clear. Lows from 10 inland valleys to near 20 immediate coast. Wind NW 10-15 MPH gusting 20-25 MPH through midnight then diminishing.

THURSDAY: Sunshine followed by increasing clouds. Highs 23-28. Wind N 5-15 MPH.

FRIDAY: Cloudy. Snow develops, except possible mix/rain coast & Cape Cod. Potential for significant winter storm conditions developing late day and night. Lows in the 10s. Highs from the 20s northwest to 30s southeast.

SATURDAY: Clearing. Low 20. High 30.

SUNDAY: Sunny. Low 10. High 35.

MONDAY: Mostly cloudy. PM rain showers. Low 30. High 45.

TUESDAY: Partly sunny. Low 35. High 48.

To Phase Or Not To Phase?

4:55PM

Several low pressure systems coming at the East Coast this week will be measured by their ability to phase, or the ability for energy in the northern and southern jet streams (a split flow pattern) to link up. When this happens, larger storms result.

The first 2 systems are easy: One passing just south of New England Tuesday morning and another coming through the region during the day Wednesday, moving mainly west to east, not linking up with energy further to the south. These systems will produce light snow on the South Coast and scattered snow showers, respectively, with minor accumulations at best.  A system being eyed for Friday is less certain, not only because it is further out in time, but because computer guidance varies from a nearly harmless non-phased couplet moving west to east with the northern one giving some light snow or snow showers to the region, similar to Wednesday, to a phased system that brings a major coastal storm with wind/rain/snow. The dilemma in terms of being a forecaster is that the computer model giving the “big hit” is one that is often fairly accurate and one of the first to pick out the track of a storm. My meteorological sense tells me not to ignore this, but my gut feeling is telling me that the Friday system will have trouble phasing due to speed differences in the northern vs southern jet stream energy. For now, it will just be something to keep an eye on, and keep the forecast wording fairly generic.

Updated forecast for southeastern New England…

TONIGHT: Partly cloudy to mostly clear 1st half of night, clouds return west to east later. Lows from 10 outlying areas to 15-20 urban centers & Cape Cod. Wind W 10-20 MPH gusting to 30 MPH 1st half of night diminishing to 5-10 MPH overnight.

TUESDAY: Mostly cloudy through midday with heaviest clouds south of the Mass Pike, including a period of snow of up to but mostly less than 1 inch near the South Coast. Increasing sun especially north and west of Boston during the remainder of the afternoon. Highs from the upper 20s to middle 30s northwest to southeast. Wind light variable.

TUESDAY NIGHT: Clouds increase again. Snow showers possible before dawn especially west of Boston. Lows around 20. Wind light variable.

WEDNESDAY: Mostly cloudy. Occasional snow showers , accumulations under 1/2 inch. Highs from the lower to middle 30s. Wind light variable.

THURSDAY: Sunshine giving way to clouds. Low 17. High 37.

FRIDAY: Cloudy. Chance of snow/mix/rain. Low 28. High 38.

SATURDAY: Mostly sunny. Low 19. High 39.

SUNDAY: Partly cloudy. Low 27. High 44.

MONDAY: Variably cloudy. Low 31. High 46.