Top 10?

7:00 PM

In order for this storm to make it into the top 10 for Boston, we will have to surpass 18.2″. And I think that is very likely to happen. Here is a image provided by the National Weather Service of a few other city’s top 10 snowfalls.

The only update I will make to the forecast is the snowfall totals for Boston. Any mixing that may happen will be very temporary and will not affect the snow totals. Although at the beginning of the storm, we will have an east wind, which will produce a wetter snow that doesn’t accumulate too well. We will eventually switch over to a drier snow that will accumulate 1-3″ per hour. This will occur overnight Friday and into Saturday, until around noon. Thunder-snow is possible. The winds will be another story, as gusts may approach 70 MPH, helping to create blizzard conditions.

When this is all over with, I expect final snowfall totals to range from 18-24″, with possibly high amounts if we get under heavier bands. Snow drifts may approach 5 feet in some areas.

The Snow Is A Go!

2:00 PM

I am sitting in my dorm room, looking out the window as a few flurries fly by. These are associated with an arctic front, which is a major ingredient for a snowstorm. The other ingredients are moisture and energy. The energy from the northern stream will merge with the southern stream, just off the east coast. The southern stream has most of the moisture. This will result in a rapidly deepening storm track near the benchmark, which is typically the sweet spot for a New England nor’easter.

Here are a few graphics to get an idea of how I am coming up with this forecast, and all are free to view.

The image above shows the mean snowfall from a whole bunch of different models.

The image above shows the probability for 12 inches of snow. Over 70% for the Boston area.

There are two bits of uncertainty that will impact amounts. The first one is mixing issues at the start of the storm as we will have easterly winds, coming off a mild ocean. This will also have an impact on the snow to liquid ratio’s. At the early stages, the ratios will be below 10:1(10 inches of snow per 1 inch of rain). As winds shift, the ratios will shoot up, resulting in a fluffier snow that will accumulate much quicker. The second one is where the heaviest axis of snow ends up. This will result in a rather large range in forecast accumulations for the area.

Lyndon State College will be on the northern edge of the storm, but snow to liquid ratio’s will be around 20:1, and most models are showing at least .5″ of liquid precipitation. Confidence is a bit lower here.

Timing: (For the Boston area)

Light snow or mix will begin Friday morning, and will increase in intensity through the afternoon. The height of the storm will be overnight Friday through Saturday morning, which will fall as snow as winds will have shifted more northerly. During this time, snowfall rates of 2-4″ per hour are possible. Snow will taper by the afternoon on Saturday.

Accumulations: (For the Boston area)

Right now I am expecting 12-20″, with the possibility of 2 feet if we escape major mixing issues, and we get under the heaviest bands.

Accumulations: (For Lyndon State College)

I am expecting 8-12″ of snow for the college.(May change)

A More Active Pattern

10:00 PM

This rather long introduction will serve as a slight in depth discussion as to how I came up with my forecast.

So far this month, it has not seemed like we are in meteorological winter as temperatures have been above average for the most part. There has also been a lack of snow so far this month, especially in Southern New England(Not entirely uncommon). Central and Northern New England have been also lacking snow, along with above average temperatures.

The pattern that we have been in for the past two weeks is about to undergo drastic changes. Changes that will likely bring colder temperatures, and an increased possibility of snow. This is all in response to blocking upstream moving into a favorable position, or what is known as a west-based negative North Atlantic Oscillation(NAO) in the meteorological world.

A west-based NAO is known to increase storminess and cold along the east coast. The combination of moisture and cold air leads to snow. However, the depth and intensity of the cold determines how long precipitation can stay in the form of snow, especially along the coast line as ocean temperatures are quite mild. There is also the common question of how much moisture is available. All of these variables are greatly influenced by the track of a low pressure system, which is one of the most crucial parts of a forecast.

You might ask how we can determine a storm track several days out, as well as the amount of cold air and moisture available. The simple answer is computer models simulate future weather, and there are many different models out there. The problem with models is that their solutions aren’t always perfect, and the solutions can vary greatly from different models. These solutions can also change day to day, especially when the event or events are several days out.

The models aren’t the only tool out there for meteorologists, which is why I brought up the NAO earlier. There are other global indices that can affect our pattern, which I won’t get further into as you might get put to sleep if your not interested. If you are interested in a good read, feel free to check out this link. http://www.nc-climate.ncsu.edu/climate/patterns/NAO.html

Now onto what the short term future may bring, which will extend out to next week.

For the Boston area…

The first batch of precipitation comes through Sunday afternoon and ends Monday morning. It will likely start off as snow showers, then transition over to sleet, then over to all rain overnight Sunday. Snow accumulations of a coating to an inch is expected for this batch.

The second storm looks to be much stronger than the one coming through Sunday night. At this point it looks like to impact this region Wednesday and Thursday. Since we are quite far out, and since model guidance is all over the place in terms of a solution(Where does the storm track)(snow vs rain), I will revisit this storm on Monday.

For the Northeast Kingdom of Vermont…

The first batch comes through Sunday night, and lasts till about noon on Monday. Enough cold air will be around to support all snow. The models are currently trending toward higher precipitation amounts as we get closer, which lowers my confidence. The reason my confidence lowers is because whenever a model or several models trend one way or another, it is necessary to keep a close eye encase the model decides to trend back. In this case, the model may trend back to less precipitation amounts. At this point I believe Several inches of snow are possible.

The second storm impacts this region Wednesday and Thursday. It should be mostly snow again with this storm. The question again is where the storm tracks will determine how much snow we receive.

The ski resorts of Northern New England should fare well with these two systems, so there will be plenty of snow over winter break.

Be sure to check back for future updates.

Synopisis on Sandy 10-27

4:00PM

Hurricane Sandy is currently moving northeast, and will start to move back to the coast Monday morning. Sustained winds of 75 MPH with a minimum pressure of 961 mb.

Here is the current satellite of Sandy.

This is a very large storm covering a large area. This is important because even though it will make landfall south of New England, we will still feel major impacts.
Here is the current forecast cone of where Sandy will make landfall.

This is showing that Sandy could make landfall anywhere from Virginia beach, all the way to New York City. The center of that is Delaware, which may shift north or south during the next day or so.

The Rain

The rain should move in Monday morning, and will be with us right through Wednesday. The rain will be varying in intensity, with the heaviest falling Monday afternoon through Tuesday.

Rainfall amounts of 1-3″ are expected.
The Winds

The winds by far will be the biggest impact from this storm, which will be with us from Sunday night till Wednesday. The strongest winds will be from Monday afternoon and into Tuesday morning.

Sustained winds of 30-50 MPH with Gusts 65-80 MPH.

Those winds WILL knock out power, so be prepared with flashlights, back up generators if you have them, and emergency kits.

Coastal Flooding

Minor to moderate coastal flooding with midday tide on Monday, with moderate to major flooding with the tide Monday night.
Check back for updates tomorrow.

If you have any questions, feel free to post them below in the comments section.

Update on Hurricane Sandy-10/25

10:40PM
Hurricane Sandy is currently centered over the Bahamas at a category 2 with sustained winds of 100 MPH.
Sandy is moving northward and will soon interact with cooler water, which will start the post-tropical transition. Sandy will also interact with a powerful cold front, and phase with it. The question becomes when the phasing takes place, and the result of that will determine where Sandy, or the remnants of Sandy, makes landfall. Current model guidance such as the ECMWF is suggesting a quicker phase, which will allow Sandy to make landfall around the Delaware area. While this would be a better solution for the Boston area, we would still feel the effects due to the very large wind field. This model may be over-amplifying things at this point, so we may see that model trend northward, closer to New Jersey and Long Island, or even Connecticut. A further north solution would obviously cause more impact for the area.
We are still several days from this storm, but some likely effects from it are coastal flooding and beach erosion, wide spread wind damage with power outages, and flash flooding.
Right now it is uncertain to the magnitude of those impacts, but my early estimate is that the winds will be the biggest issue, while the rainfall may not be too significant due to a possible dry slot forming in eastern Mass. Coastal flooding will also be a very large impact due to the astronomical high tide cycle.
Stay tuned for more updates as we get closer to the storm.

Here is the current forecast cone from the NHC.

The Week Ahead

9:30PM

An area of showers will be with us tonight, but will be out of the region for majority of Monday.

The showers will return for Tuesday, and will be with us for most of the day. A bit of a warm up for Wednesday, but there will be lots of clouds around with a chance of a shower.

Thursday is looking like the best day this week as the sun will be prevalent and temperatures should max out at around 60 degrees.

Friday will be a day that starts off mild and ends cool as a batch of cold air moves in aloft.

Forecast details for the Boston area and surrounding suburbs…

Monday: Partly sunny. High 58. Wind NW around 5 MPH.

Tuesday: Cloudy with showers. High 56. Wind NE 5-10 MPH.

Wednesday: Mostly cloudy with a chance of a few showers. High 64.

Thursday: Mostly sunny. High 60.

Friday: Mostly cloudy. A slight chance of a shower. High 55.

The First Five Days of Fall

8:15PM

A dry and seasonal forecast in in the offering for the first 5 days of fall.

Friday will be a cool day as we will still have an onshore breeze to contend with.

The wind shifts south for Saturday, which will bring up some milder air from the south, so expect temperatures in the middle 70s.

A cold front with little moisture will pass through early Sunday, meaning clouds to start and sun to finish. A quick shower may be in store for very early Sunday.

Early next week is looking great with plenty of sunshine and seasonal temperatures.

Forecast details for the Boston area and surrounding suburbs.

Friday: Mostly sunny. High 66. Wind NE 5-10 MPH.

Saturday: Partly cloudy. High 74. Wind S 5-15 MPH.

Sunday: Partly sunny and brisk. A slight chance of a morning shower. High 70. Wind W 10-15 MPH.

Monday: Mostly sunny. High 65.

Tuesday: Mostly sunny. High 70.

A Fresh Update

8:15PM

Ample moisture to the south, which is feeding on energy to the north that is a cold front, will provide a batch of heavy showers along with gusty winds. That is expected to arrive to our region Tuesday and into the first part of Wednesday. This is a fast moving system, and the cold front should pass through early Wednesday, so Wednesday afternoon will dry out and some sun may be around.

Beyond Wednesday is a stretch of dry and rather cool weather as winds will be onshore for the remaining part of the week.

Forecast Details for the Boston area and surrounding suburbs…

Tuesday: Mostly cloudy with a few showers possible. High 72. Wind SSE 10-20 MPH.

Wednesday: Cloudy in the morning, then becoming mostly sunny in the afternoon. Rain likely in the morning. High 68. Wind NW 5-10 MPH.

Thursday: Partly cloudy. High 64. Wind NE 5-10 MPH.

Friday: Mostly sunny. High 66.

Saturday: Partly sunny. High 65.

So there is a cold front coming…

10:15 PM

This warmth and humidity will not go away quietly, but when it does, a hint of fall will be in the air.

Saturday will start off as a decent day, although it will be quite humid. There may be a pop up shower in the afternoon due to the air being very unstable.

The cold front passes through Saturday night, and there will be a squall line ahead of it. Since the squall line passes through after dark, and with the possibility of showers during the day, instability will be limited. However there will still be a period of showers and downpours, along with a period of gusty winds, possibly up to 40 miles per hour. I don’t expect these storms to become severe in our area.

Sunday will start the improvement, however there still may be enough instability for a quick shower during the day. It will be noticeably less humid.

The first half of next week is looking splendid, and may even feel like fall, especially on Tuesday where highs may not get out of the upper 60s.

Forecast details for the Boston area and surrounding suburbs…

Saturday: Partly sunny with showers and thunderstorms possible in the afternoon. Humid. High 82. Wind S 10-20 MPH.

Saturday night: Showers and thunderstorms likely. Some storms may produce strong winds and heavy rainfall. Low 62. Wind S 5-15 MPH, shifting to NW.

Sunday: Partly sunny with an isolated shower possible. Much Less humid. High 75. Wind NW 5-10 MPH.

Monday: Mostly sunny. High 72. Wind N 5-10 MPH.

Tuesday: Sunny. High 68.

Wednesday: Sunny. High 73.

Warm and Humid

9:45 PM

The next 5 days will feature warm and very humid conditions as tropical moisture will be in place, which will also bring shower chances.

Wednesday will feature a good deal of tropical showers and downpours. It will be very humid as dew points will be in the low 70’s.

Thursday will remain humid, although not as obsessive as Wednesday. We should stay rain free at least.

Friday is going to be a warm day, and remaining humid. High temperatures will reach the low 80s. An afternoon shower is possible.

The weekend will be still be warm and humid, a chance of showers for Sunday.

Forecast details for the Boston area and surrounding suburbs.

Wednesday: Cloudy with showers. Humid. High 77. Wind SW 5-10 MPH.

Thursday: Mostly cloudy. Humid. High 75. Winds light and variable, becoming SE at around 5 MPH.

Friday: Partly sunny with an isolated shower. Humid. High 82. Wind SW 5-10 MPH.

Saturday: Partly cloudy. Humid. High 80.

Sunday: Mostly cloudy with a chance of showers. Humid. High 78.