Severe Weather Question

[hhawks18]

Hi, I am working on a meteorology project and am focusing on the severe weather of Washington. Aside from the various statistics, would someone be able to explain the importance of the three converging weather systems? and why does Mount Washington receive the brunt of these systems?
I wasn't able to find anything specifically on this on the website, but if I'm missing it or should look somewhere else, I'd appreciate any information.
Thanks

[WuzzyG]

Would also be interested in reply.I was in Siberia two years ago and wonder why Mount Washington is so extreme given its longitude and latitude compared to northwest Siberia.

[kpmg77]

Very interesting question. I wish I had the answer for it. Can anybody answer this question for us?

Thanks

[HelenGolds]

Sorry I can't help you, but am interested in your fascinating question.

[ladaga]

It is probably due to its geographic location, there are many areas like this dotted around the World where they can receive uncommon weather patterns.

[Brad]

On the summit in the Weather Room they have a map of the US with the major storm tracks over some period of time. Can't remember whether it is xx number of storms or a specific number of years. But, almost all either went over or close to or had some influence on the summit's weather. So, it gets slammed by storms more often than a normal location.

Two or the three major directions (west and northwest) are the predominate paths. The way the Presidential range is located storms get funneled by the outlying parts of the range so the weather gets pushed to the center of the funnel - Mt Washington. Then when the weather and wind goes up and over Mt Washington itself the wind is squeezed like putting your thumb over the end of a garden hose - the water (wind) goes faster. From what I understand (and I am not a weather guy) it is a combination of factors - more storms - stronger due to the shape of the range - and higher winds. It all adds up to very tough conditions.

Okay, weather folks - how was that for an explanation?

[BlueDog]

From the FAQ page on this very site...

1. Does Mount Washington really have the world's worst weather?

It is the combination of extreme cold, wet, high winds, icing conditions and low visibility consistently found atop Mount Washington which earn it the title "Home of the World's Worst Weather". As William L. Putnam states in The Worst Weather on Earth, "There may be worse weather, from time to time, at some forbidding place on Planet Earth, but it has yet to be reliably recorded." Despite its relatively low elevation (6,288') Mount Washington is located at the confluence of three major storm tracks, and being the highest point in New England, it generally takes the brunt of passing storms. The steepness of the slopes, combined with the north/south orientation of the range, cause the winds to accelerate dramatically as they rise up from the valleys.

[Breeze]

Consider the October Blizzard of 2005. The extratropical remains of Hurricane Wilma were traveling up the Connecticut River Valley loaded with moisture, from a southwesterly direction. An Arctic Cold Front was approaching from the North northwest, and another extratropical ( the remains of the last storm before Wilma) off the coast of Labrador was wrapping NE ( retrograde flow) around into northern New England, conspiring to keep both Wilma's last gasp and the Cold front on a collision course, well inland.

The warm, wet, southerly flow, a DEEP low pressure system, couldn't move east. The cold front barrelling in ( a strong HIGH pressure) system created a big pressure gradient, with resulting strong winds and a lot of mixing of cold dry air with warm wet air. It couldn't move in quickly and got stalled out . The spine of the Northern Presidentials itself causes airmasses to RISE to get over the ridgeline, so you are bound, no matter how you look at it, to have a significant weather event when weather systems conspire in one location.

So go back and retrace ( visualize) what was happening in terms of "storm tracks", factor in the topography, and there is a good case study.

The retrograde flow over the last few days brought lots of snow to the Green Mountains of VT, and blessed Cannon, Loon, and Bretton Woods with a good dump. Attitash and Wildcat saw flurries.

It's a fascinating place.

Breeze

[Bill O]

The idea that storms are constantly converging over Mount Washington is really silly and the "three storm tracks" idea should be downplayed as it currently stands.

The main take away should be that Mount Washington and New England lie at the convergence of the major storm tracks that effect the eastern United States. It's not that storms are literally converging / merging with each other (but that does happen). It's that you get a lot of storms because they cross your region. Please somebody correct me, but the major tracks are generally considred to be:

Nor'easters - forming off the NC, DE, NJ, NY coasts
Alberta Clippers - forming in the Canadian Plains
Great Lakes Lows (maybe)

[Knapper]

Like Bill O mentioned, it isn't that three storm systems are “converging” on the summits nor are their three tracks converging on the summit at the same time (usually). I think a lot of people picture the movie/book “the Perfect Storm” in which they made it appear that the storms were all converging at once against impossible odds. This is partially true but Lows merge and combine often (look at 12-12-10 for a good example at that).

A storms track can play into the strength of the winds we get but the concept of the three storm tracks (not systems) explains the frequency of the high winds we get on the summit. On average there are three common directions that storms come from and they all typically follow water ways of sorts. The first is the Great Lakes lows that travel up the St Lawrence River. The second are lows from the Ohio River Valley that usually form in the Gulf or Mexico region and the third being up the Atlantic coast line. There are several other directions that they come from but these on average are the three most common ones. A good paper to look at is a paper by Van Cleef published in the 1908 Monthly Weather Review (citation number 36:56-58 as well as Chart XII on page XXXVI-38 and Chart XIII on page XXXVI-39). This will help explain storm tracks across the US. There are other ones to review and a simple google search or library search will find them but this is the paper behind the map we show tourists up here on tours. I would recommend a physical copy for a clearer picture but you can read it online here: http://books.google.com/books?id=zjh...201908&f=false. It is the frequency of passing lows that has earned New England the nickname “the Tailpipe of the US” because most lows that form somewhere in the lower 48 will usually make their way towards us (see the averaged low map to see what I mean). And it is this frequency of passing lows that allows the summit (on average) in the “winter” (Oct to May) to see a hurricane force gust (73+ mph) every other day and a century gust (100+ mph) one out of every four days.

There are several factors that go into the winds we (and others) get: a storms track and proximity, the pressure gradient between incoming and exiting highs/lows, a lows/highs vertical stacking at various levels in the atmosphere, wind direction at each level, sheering or veering, jet streaking, temperature gradients horizontally and vertically, the air density horizontally and vertically, how a low fills-in, how a low deepens, friction on the surface, color of the terrain and vegetation, type of terrain (water vs land), the elevation of the terrain and the shape of the terrain (Brad touched upon both of these a bit), as well as location of measuring it all. I’m not sure of your meteorological background so the three to focus on for us are pressure gradients, the shape of the land, and the height of the land. Those are the ones that we use on tours and are the easiest for most people to “get”.

Hope this helps get you steered in the right direction and if anything else, feel free to ask and I will try to respond timely. If all else fails, a private message works to get my attention since it is linked to my email.