Storm Recap

This storm was a bit of an over performer, bringing close over 20 inches of snow to parts of Vermont, with upslope flow and additional moisture set to provide additional snow showers to the northern mountains for the rest of the day.

Take a look at snowfall totals from the storm:

Thank you for all of your reports! We were able to come up with a storm total snow map through 2 PM this afternoon. Additional accumulations will be possible across northern Vermont this afternoon. Visit https://t.co/bWrAqA6WUF for more info. #nywx #vtwx pic.twitter.com/2tZ1FVLdGx

— NWS Burlington (@NWSBurlington) January 17, 2021

As you can see in the map (and as was well-forecasted), the snow was very elevation-dependent, with areas in the valleys seeing close to no snow while mountainous regions saw close to two feet.

The snow provided a much-needed boost for ski areas, and here are what some are reporting for the past 24 hours:

Stratton - 18"

Sugarbush - 15"

Bolton Valley - 10"

On the back end of this storm cold air will filter in, preserving the snow pack that has now built up in northern New England. This GIF shows surface temperatures from the GFS from Monday through Thursday night. It will be chilly!

(Tropical Tidbits)

It's tough for me to write about all the snow that the East has received, especially after coming out to Colorado, where I'll be for the next few weeks doing remote school. The mountains here are absolutely gorgeous, and it's fun to be able to do lots of skiing, but I'm ready for a true western cold-smoke powder day. Here is a photo from my skin up Beaver Creek this morning:

Stunning scenery and a nice sunrise, though I do think those trees would look better with a coat of white on them - hopefully the East can share some snow!

Storm Update

The picture for this weekend's storm is beginning to become more clear, and it's looking like a very latitude and elevation dependent one.

(NWS)

A winter weather advisory has been issued for much of northern Vermont and New Hampshire and New York, with winter storm watches in place in other areas. If you live in northern areas at elevation, expect to wake up to some snowfall tomorrow that will likely remain snow all day. This is a warmer event, so areas in the valleys will likely see a changeover to rain mid-day (see sounding for Champlain Valley below).

(Tropical Tidbits)

Due to the warmer nature of this storm, snow-to-liquid ratios will be low, causing a heavy, wet snowfall that is climatologically uncharacteristic of mid-January. For ski areas, this will be helpful to build up a base that is still fairly thin.

The elevation-dependence makes snowfall totals difficult to predict. Here's what the National Weather Service is thinking.

(NWS Burlington)

Precipitation leaves the region by late-Saturday, though we may see some lingering snow-showers in the mountains into Sunday.

Enjoy the weekend!

Weekend storm

I haven't posted in the pat few days because there simply hasn't been much to talk about weather-wise in New England.

Yesterday's NWS forecast chart (NWS)

As shown in yesterday's National Weather Service forecast map, high pressure dominated for much of the country. The weather remains quiet until the weekend, as a cold front and low pressure system will bring some rain to southern New England with some mixing and snow to interior, mountainous areas.

Saturday Forecast Map (NWS)

There will be considerable moisture in the atmosphere, which will bring significant precipitation to some areas.

The storm track is still uncertain this far out and will become more clear as we approach the weekend. The GFS has the low tracking further to the east than most other models I have seen. If this track verifies, we could see less rainfall, and the mountains might not pick up too much snow.

Sat-Mon GFS (Tropical Tidbits)

For southern New England, this storm is looking like an all-rain event, as temperatures will simply be too warm to support any mixing.

(Tropical Tidbits)

In northern VT, NH, and western ME, however, there will be enough cold air to support accumulating snowfall.

While the details of this storm are still somewhat unclear, it's nice to have some more active weather to look at.

Winter Report Card So Far

To put it simply, the weather over the next week will be quite boring. There are signs that changes will be coming in the medium to long term due to a phenomenon called a sudden stratospheric warming (SSW), but over the next week or so, will see fairly seasonable weather with sunny skies.

With not much to talk about in the immediate future, I figured I'd give a winter report card through today (Jan 9).

Walking outside to get the newspaper at my house in CT this morning, the scene does not look very wintery.

Much of New England has a moderate snow depth, but nothing too significant, with maximum depths no greater than about 15 inches.

(NOAA/ Northeast River Forecast Center)

(NWS Burlington)

The Mount Mansfield snow stake currently has a snow depth of 15 inches, well below its January 9 normal value of approximately 40 inches.

Mount Mansfield snow depth time series (SkiVt-L/UVM)

But statistically, how has winter been in New England so far? Using data from various NWS forecast offices throughout the northeast, I put together this table, showing snowfall since December 1 for different sites in New England.

Seasonal snowfall through Jan 9 (Data from NWS)

These are major cities in New England, and we can see that the big winner so far is Concord, NH, which has seen 14.3 more inches of snow than normal this year. That is largely due to the major storm on December 17, which southern New Hampshire did very well in. Areas further north, like Burlington, VT or Bangor, ME, have struggled so far this year, seeing less than their normal snowfall.

To see how ski resorts are doing for snowfall, I recommend the site bestsnow.net.

As for temperatures, it's been a fairly warm winter in New England. The following image shows the percentiles for mean temperatures from Dec 1 through Jan 1. BTV's winter is in the 96th percentile, meaning it's having one of the warmest winters to date on record. 

(Southeast Regional Climate Center)

We can see that the further north in New England you go, the warmer it has been relative to normal.

To sum, I'd call this winter a fairly average or slightly below average one in New England so far. While it's unfortunate to see the ground bare on January 9, we have seen one major nor'easter and no extreme warm spells. For many areas, snow-to-date is above normal, though northerly areas that are accustomed to abundant snow have seen less than normal snowfall. Over the next few days, look for no chances for new snow but seasonal temperatures.

If you are looking for snow, Spain is one place to look. Here is a video that my host family from my semester abroad in Madrid sent me. Madrid, where snowfall is a rarity, is seeing its largest winter storm in 50 years.

BDL December Recap

Just like I've previously done for Burlington International Airport (BTV), here is my recap of this past December's weather at Bradley International Airport (BDL) in Windsor Locks, CT - close to where I was for all of the month.

Temperatures

The mean daily average temperature for the month at BDL was 33.7 °F, warmer than the normal value of 31.6 °F by 2.1 °F. The month's average maximum and minimum temperatures were 42.2 °F and 25.3 °F, respectively - both are values roughly 2 °F above normal.

The temperature graph below shows the slightly warmer-than-normal temperature trend for BDL this December, with the only true cold spell occurring after our major winter storm on Dec 17, and a few warm periods at the start of the month, the middle of the month, and on Christmas day, when the temperature reached 63 °F.

(NOAA Regional Climate Centers/xmACIS)

The Hartford area set one record high temperature this December, when we reached 61 °F on December 13, surpassing the previous Dec 13 record of 60 °F set in 1946.

The month's low of 1 °F was reached on December 19.

Precipitation

Straying from the trend of dry weather that BDL grew accustomed to over 2020, December 2020 was a wetter-than-normal month. A total of 5.30 inches of precipitation fell, which surpasses the normal monthly value of 3.44 in. by 1.86 inches.

(NOAA Regional Climate Centers/xmACIS)

As shown in the above precipitation chart, much of our precipitation fell in 3 separate events events: a small snowstorm with heavy, wet snow and some rain on December 5, our major snowstorm on December 16-17, and the large rain event on Christmas Day. On December 25, the Hartford area saw 2.12 inches of rain, breaking the old Dec 25 record of 1.39 inches set in 1979.

Snowfall

BDL had 13.3 inches of snow in December 2020, when a normal December would have 7.4 inches. There where seven days when at least a trace of snow fell. The bulk the snow fell during the Dec 16-17 storm,  when BDL received 12.3 inches over the course of those two days. The 7.8 inches of snow that fell on the 17th set a record for that date, breaking the previous record of 6.5 inches set in 2016.

While the warm 2020 trend continued at BDL, it was nice to see a wetter month with one major nor'easter. Let's hope for more major snowfalls in 2021!

BTV December Recap

As I like to do at the end of each month, here is my recap of the weather at Burlington International Airport (BTV) in South Burlington, VT for December 2020. In a future post, I'll take a look at Bradley International Airport's December weather.

Temperatures

We started the month on a warm note, with the temperature reaching 66 °F at BTV on December 1. While setting a Dec 1 record, that temperature reading fell 2 degrees shy of the record December high temperature at BTV, which is 68 °F set in 2015. 

As a whole, December was a warm month at BTV. The mean monthly temperature was 31.3 °F, when the normal value is 25.8 °F, giving a mean temperature departure from normal of 5.5 °F for the month. We only had 8 days where the maximum temperature was less than or equal to 32 °F, and in an "average" month, we would have seen 13.3 of those days. Also of note, there were no days when the temperature dropped below 0 this December.

This temperature graph gives a good sense of the warm temperatures that BTV experienced this year, with an especially warm period around the start of the month and around Christmas day. In fact, BTV set a record high Christmas day temperature of 65 °F, surpassing the previous record of 62 °F set in 1964.

(NOAA Regional Climate Centers/xmACIS)

December 2020 was the 9th warmest December on record, falling far behind December 2015, which had a mean temperature of 39.2 °F.

Burlington Area mean Dec temperatures since 1900 (NOAA Regional Climate Centers/xmACIS)

Precipitation

It was a drier than normal month for the Burlington area, with 1.27 inches of total precipitation falling, when the normal value is 2.38 in. 

(NOAA Regional Climate Centers/xmACIS)

Christmas Day was the wettest day of the month, with 0.40 in. of rain falling.

While much of the Northeast is no longer experiencing drought conditions, abnormally dry conditions persist at BTV.

(National Drought Mitigation Center)

Snowfall

BTV saw 8.2 inches of snow this December, when a formal December would have 17.9 inches, giving a departure from normal of -9.7 inches.

The greatest snowfall at BTV was on December 17th, when a large Nor'easter pummeled parts of Vermont with over 40 inches of snow. Burlington was a bit too far north to get in on the action, though the airport did record 2.5 inches of snow that day.

Overall, the last month of 2020 was an uneventful one at BTV, characterized by warmth and a few extremely warm days that set records. BTV has seen less than 50% of its normal snowfall at this point in the season, so lets hope that changes as we move into the new year.

Where things stand with climate

While the calendar has flipped and many are rejoicing that 2020 is behind us, the climate system knows nothing about the Gregorian calendar, and our climate is still in a dire state.

Atmospheric Carbon Dioxide

Despite a global shut-down mid-year, the monthly averaged carbon dioxide level at NOAA's Mauna Loa Observatory still reached its highest level ever, at 417.07 ppm in May. NOAA data also de-seasonalize carbon dioxide values (they tend to be highest in summer), and November 2020 (the most recent month with available data) had the highest de-seasonalized value ever, at 414.90 ppm. Observations of carbon dioxide at the observatory have steadily climbed since they began in 1958.

Carbon dioxide abundance in ppm over time at Mauna Loa Observatory (NOAA)

Arctic Sea Ice

The Arctic sea ice extent this year was much lower than the 1981-2010 median, and at times, it was the lowest ever.

(National Snow and Ice Data Center)

The blue line in the above graph shows 2020 Arctic sea ice extent through December 1. When we compare to the 1981 to 2010 climate normals (the grey median line in the above graph), 2020 and the past several years have had much lower sea ice extent than normal. The new climate normals for 1991 to 2020 will be released at some point soon, and it appears that the new median line and the interquartile range will be much lower than where it currently is.

To further show this pattern, here is a graph of sea ice anomalies in the Northern Hemisphere over time in January:

(National Snow and Ice Data Center)

The National Snow and Ice Data Center has lots more interesting data for other months and good visualizations, so I recommend looking at the center's website.

Temperature

For many spots in the world, 2020 was the warmest year on record. I like looking at NOAA's Global Climate Reports, which are released monthly. December's report has not yet been released, but the November report paints a clear picture that 2020 was an extremely warm year. According to the report, the Jan-Nov 2020 global temperature was 1.80 °F above average, which is the second warmest Jan-Nov period after 2016.

(NOAA)

Globally, it was certainly a warm year, but what happened locally?

As we end 2020, here's a calendar year summary of temperature, precipitation, and snowfall, suggesting a warm and dry year relative to normal. All values are based on data at the Burlington International Airport (BTV) and compared to the 1981-2010 normals. pic.twitter.com/wkwlKWOSTo

— NWS Burlington (@NWSBurlington) January 1, 2021

In Burlington, VT, it was the second warmest year on record after 2012, and we had the most days with high temperatures above 90 °F since 1988 and the fewest days with low temperatures below 32 °F since 1941, as shown in the NWS tweet above. You could pick many sites throughout the northeast and U.S., and similar trends would arise:

(NOAA/HPRCC)

Lastly, as I previously mentioned, new climate normals for the period from 1991-2020 will be released at some point in this year. 

With one month to go in 2020, the new 1991-2020 climate normal period is almost set. How is it looking compared to the previous (1981-2010) period? Not good. Only a few stations will have a cooler climate period. pic.twitter.com/cobhxNexYM

— Brian Brettschneider (@Climatologist49) December 4, 2020

Climatologist Brian Brettschneider has done some really neat work to show how the climate normals will change from what they were. In virtually every site in the world, the new climate normals will be warmer than they were for 1981-2010 and the trend is especially pronounced in Europe.

I apologize for painting a grim picture of where things stand with climate, but its what the data show. Hopefully 2021 will usher in a renewed focus on tackling climate change.