14:11 Thu Mar 05, 2015
The Winds of March
After the long brutal winter New England has been seeing so
far this year, we are all looking for a slight break. Like Tom mentioned yesterday, that break
seems to be likely in coming days. This made me think about the old saying “In
like a lion, out like a lamb.” I then asked myself, “How accurate is its
meaning is for the summit of Mount Washington? Does that saying even apply up
To get a quick and simple answer to these questions, I looked through our weather records. Particularly the hourly wind speeds and daily peak wind gusts for the month of March from 1935-2014. Then, I split the month into two halves (March 1st-15th, and March 16th-31st), and calculated the average hourly wind speeds and the average daily peak wind gusts for each half. See the chart below
Michael Kyle, Weather Observer/IT Specialist
As you can see there is a slight drop in both the average hourly wind speeds and average daily peak wind gusts in the second half of the month. With just a quick look at just our wind records it does seem like the old wives tale does slightly stand true here on the summit. Though, I wouldn’t quite say out like a lamb is accurate, unless it is a very angry lamb.
20:45 Wed Mar 04, 2015
Signs of Spring on the Horizon?
After a very cold and snowy February across New England, we may be seeing signs of changes ahead for the month of March. After a chilly next few days with arctic air locked over the region as it has been for much of the winter, temperatures look to be in the 30s and even lower 40s by the end of the weekend across all of New Hampshire. What’s responsible for this expected warm up? The main driving force is a major change in the jet stream. The jet stream is a narrow current of strong winds existing roughly around 30,000 feet above the earth that circles the planet and serves as a focus for most of the weather we see in our part of the world.
For much of this past winter, the jet stream has been riding north all the way up into Alaska before diving south to the east of the Rocky Mountains and back up again along the east coast. Storm systems for our area often developed or strengthened just offshore, dumping heavy snow over New England. This is a somewhat typical pattern for winter in North America, although this winter the pattern was especially stubborn, with very little changes to allow any warmer air to work its way into the Northeast.
Looking ahead, the jet stream will be flattening out over the Northeast U.S. by this weekend, keeping the arctic air bottled up to our north in Canada and allowing for more seasonable temperatures for New Hampshire. While this may only be a fleeting warm up, it is a sign that spring is just around the corner, much to the joy of many of the snow-weary residents of New England!
Tom Padham, Weather Observer/Meteorologist
14:09 Tue Mar 03, 2015
Second Coldest February on Record for the Summit
A project that has been ongoing since I arrived here back in December of 2005 is the digitizing of our weather records into a database. If you are a long-time follower of the Observer Comments (i.e. this blog), you know some of the difficulties our interns/full-time staff have encountered in this process, first in entering the data but also regarding quality control of the data. Year by year we have chipped away at entering our data and are (hopefully) nearing the light at the end of the tunnel as we approach the records for the start of the Observatory back in 1932. Data for 1935 to present is complete which allowed Michael Kyle to list the “Top 4 Coldest Months on Record For Mount Washington (1935-Current)” in a comment last month. In case you missed that comment, they were:
Top 4 Coldest Months on Record For Mount Washington (1935-Current)
For several locations around New England and Eastern Canada, February 2015 has been posted as being one of the coldest if not the coldest February on their records. Mount Washington had an average temperature of -5.1F for the month of February 2015, which certainly lands on the list above. While it didn’t wind up being the coldest month ever it was certainly colder than the February 1936 average. But was it the coldest February on record with a few years still remaining to be digitized? In the past few days, I have been doing a quick sweep of the temperatures for the years remaining in our data entry (1932-1934) and inputting them temporarily into a spreadsheet. After entering the data and reviewing the numbers twice, another month/year floated up onto the list of coldest months. The month was February, the year was 1934, and the monthly temperature average was -5.3F. So, after this quick evaluation, 2015 ended up being the second coldest February on record. As for where 2015 and 1934 land on the coldest ever list, (pending further review) the list will be reshuffled to:
Top 5 Coldest Months on Record For Mount Washington (1932-Current)
Ryan Knapp, Weather Observer/Staff Meteorologist
20:01 Mon Mar 02, 2015
Profiling More Precipitation
You have probably noticed that we have gotten quite a bit of snow this winter, and if you have been paying attention to the forecasts, you know that there’s more en route to New England tomorrow night. However, this storm system will be a little different from those experienced in the past month. It will begin as a typical “Alberta Clipper” with low pressure forming over northwestern Canada. This time, instead of moving towards New England, upper air patterns will keep the low pressure center far to our North. This will have a few different implications on New England weather…
With the bulk of the cyclone largely to our North, it will be a notably warmer storm than those of the past few months as warm air gets cycled in from the southwest.
This storm is expected to develop a significant occluded front as it moves east. The actual occlusion (think sharp spike in temperature) should stay to our north, but its vicinity means that we will experience a very brief warm sector because the cold front and warm front will be so close to each other.
With most of our snow affiliated with these developing fronts, their proximity means that the swift snowfall will be accompanied by a fleeting temperature spike. This will make for a wet heavy snow that we have rarely seen this winter.
Because of these factors, we are likely to see a much different spread of precipitation across New England throughout the storm’s passage. Ahead of the warm front on Tuesday night, New England looks like it should receive consistent snowfall throughout the region, but as things warm up Wednesday morning, the chances of mixed precipitation look increasingly likely for southern New Hampshire.
Let’s take a look at some different models for the time period in question:
Here we can see the NCEP (National Centers for Environmental Prediction) GFS model output displaying precipitation types for 1:00 am EST early Wednesday morning. Shades of green represent rain, blues display snow, pink is ice pellets, red is freezing rain, and yellows show mixed precipitation.
Nate Iannuccillo, Summit Intern
The GFS shows New Hampshire pretty safe from the mixed precipitation territory.
Here is the same time period displayed by the CMC (Canadian Meteorological Centre) GEM model.
The Canadian model shows a wider berth of mixed precipitation, extending into southern NH.
And lastly, we’ll look at NCEP’s NAM model.
The NAM shows a wide spread of mixed precipitation and freezing drizzle scattered over the northeast. If the NAM turns out correctly things could be a little damper than expected.
The fringe areas are more difficult to forecast for, but I would expect southern NH on down to get a little mixed precipitation Wednesday morning, whereas in the North Country, I think most of our snow should be on the ground before temperatures rise high enough for any notable mixed precipitation.
Things will begin to cool down again on Wednesday night, maintaining some nice conditions for later in the week.
21:41 Sun Mar 01, 2015
Wanted: Summer Interns!
Every summer, fall, and winter, the Observatory searches for interns who are interested in learning about extreme weather while assisting with the daily tasks required to run a mountaintop weather station. We are currently seeking enthusiastic students, recent graduates, and qualified weather enthusiasts who are looking for an adventure this summer! The last day to submit applications is this Thursday, March 5, 2015. To find out more information about this exciting opportunity, and to apply, please see our Internship page
Kaitlyn O'Brien, Weather Observer/Education Specialist