Thursday, December 31, 2020

Ski Day Recap

It's been a very slow start to the East Coast ski season, with many resorts still struggling to open up terrain. I've become accustomed to these slow starts over the past few years, and in December I'm grateful and fortunate to get out and be on snow.

Yesterday I went to Ski Sundown with my brother and sister for my third day of the season, and I had so much fun, despite poor conditions.

To give some context on the status of snow in southern New England right now, the snowpack is virtually non-existent except for parts of the Berkshires in western Massachusetts. (In fact, Jiminy Peak did pick up 4" of natural snow the other day).

(NOAA/NOHRSC)

So any skiing in southern New England (apart from maybe the Berkshires) is being done entirely on man-made snow right now.

We arrived at 9:30 (90 mins after first-chair), booted up at the car, and headed over to the slopes. Like most ski areas in the world, Sundown is requiring reservations to ski, and despite the reservation system, the slopes felt a bit crowded even before 10:00 am. This was presumably due to not all terrain being open.


Compared to Mount Snow, where I skied after the major snowstorm two weeks ago, mask compliance at Sundown was much better, and people mostly took social distancing seriously.

Unfortunately, Gunbarrel was not open, though some piles of snow have been made on the trail. At Sundown, I think a good marker for a solid early-season is if Gunbarrel is open by Christmas Day. Clearly, that was not the case this year.


The day was mostly cloudy with some periods of sunshine, and temperatures were right around freezing. The snow surface was challenging, consisting of bullet-proof ice covered by sugary ice pellets of man made snow. Without sharp edges, yesterday would not be too fun. I had a super time, and we skied until about 2:30, probably getting about 25 runs in. Despite the curveballs that mother nature has thrown at ski resorts in southern New England this year, I give Sundown credit for getting its mountain up and running for the holiday week this year, something that is no longer a given.

As for the rest of New England, most mountains are facing similar early season difficulties to Sundown.

12/31 status of New England ski areas (OnTheSnow)

Okemo Mountain Resort, the area that hit the jackpot in the December 17 storm, currently has the most terrain open, followed by Killington and Sunday River. Signs are looking decent for some storminess after the new year, but for now, we must take what we have and make the most of it. 

Tuesday, December 29, 2020

Major Weather Events of 2020 Part 3

Here is the final part of my multi-part series covering major weather and climate related topics from 2020. For part 1, see this link, and for part 2, use this link.

8. Wild Weather Swing in Colorado

In early September of this year, Denver had an incredible week of weather, seeing everything from 100 °F heat to snow.

On September 5, the temperature reached in Denver 101 °F, setting a record high for the month of September there. And on the 6th, the temperature was 97 °F, setting a record high for that date. By September 8, the temperature had dropped to 31 °F as cold fronts moved through, setting a record low temperature for the 8th. And to top things off, early-season snow was recorded for many areas on September 9, with mountains areas seeing a foot in spots, and the plains recording about 6 inches.


(NWS Boulder/NOHRSC)

Snow in Colorado in September is certainly not unheard of - in fact, the earliest recorded snowfall in Boulder occurred on September 3 in 1961. What makes this year's event stand out to me is that just days prior the temperature was over 100 °F.

9. August 27 Severe Weather Day

August 27 stands out as a day with extreme weather here in southern New England. As a cold front moved into Connecticut, multiple tornadoes were produced with one EF-1 tornado that traveled 11.1 miles from Bethany, CT to New Haven, CT.

Here's what the sky looked like on that afternoon as storms moved south. It darkened quickly, and I made sure to stay inside as tornado warnings had been issued.



These were the Storm Prediction Center (SPC) Day 1 outlooks on August 27:

Aug 27 Categorical Outlook (NWS SPC)

Aug 27 Probabilistic Tornado Outlook (NWS SPC)

Aug 27 Probabilistic Damaging Wind Outlook (NWS SPC)

It is not frequent that Connecticut is in the 5% tornado probability category, so there was a good chance for tornadoes on that day. Additionally, there were very high probabilities of damaging winds, which I experienced at home.

Here is a radar loop from the event. I find it interesting to look at where tornado warnings popped up as the storm moved southwest towards New Haven.

Aug 27 radar reflectivity (Iowa Environmental Mesonet)

Many lost power, and the damage was impressive. Take a look at the before and after of the new turf field at East Haven High School, which was completely destroyed by the storm.


East Haven High School turf on Aug 27 before storms moved through (Brian O'Neill/Hera Sports Services LLC)

East Haven High School turf on Aug 28

10. Extreme Cold in Alaska

While it's no secret that 2020 was a year characterized by extreme warmth for much of the United States and the world, the impressive cool air that dominated in Alaska is worth noting.

In Fairbanks, AK, the average daily maximum temperature during January was -14.2 °F, with the average daily minimum being -21.4 °F. The daily mean temperature was -21.4 °F, which is 13.5 °F below the normal value, which is -7.9 °F. A similar trend held in there February, with the average maximum temperature beings 6.3 °F and the average minimum being -18.4 °F. The mean temperature departure from normal was -4.7 °F, so February it was also a colder than normal month in Fairbanks. 

January and February temperatures at Fairbanks, AK (NOAA Regional Climate Centers/xmACIS)

The above temperature chart shows daily temperature ranges for Jan and Feb in Fairbanks compared to normal values. Note how most days had below normal temperatures.

This temperature departure from normal map from the January 2020 NOAA Global Climate Report characterizes how cold it was in Alaska to start the year. Interestingly, despite the frigid weather there, much of Siberia had impressive warmth.

(NOAA)

I think that this January-February in Alaska is grounds for some interesting research surrounding climate variability. While the entire world is warming, the arctic is warming much faster than the rest of world, in a trend that is known as "Arctic Amplification." Although the arctic amplification effect was clearly present in northern Europe and Siberia this year, I'm curious about why Alaska was so much colder than normal this winter, as well as why it bucked typical warming and arctic amplification trends.


That's it for my 10 major weather and climate related events of 2020. Any thoughts on things I missed? Share your memories from 2020 in the comments.

Monday, December 28, 2020

Major Weather Events of 2020 Part 2

Here is part 2 of my recap of major weather or climate related events of 2020. For part 1, see this link.

4. Major Northeast Winter Storm on 12/16 to 12/17

As someone who loves winter weather, I simply had to include this storm in my top 10 weather events. 


The above NWS Eastern Region tweet shows the impressive snowfall totals from this storm. 4 states saw over 40" of snow, as shown in the above tweet. Additionally, pending approval form the National Weather Service and Vermont state climatologists, a 44.8" snowfall report from Peru, VT would set a new 24 hour snowfall record for the state.

The narrow band in the image of the above tweet shows where the heaviest band of snow formed. I found it particularly fascinating that a place like Ludlow in southern Vermont saw 40+ inches of snow, while just about 40 miles north less than five inches fell. If you watch the radar movie below carefully, you will notice the heavy band of snow in New York, southern VT and southern NH at around 5:00 AM EST. This heavy precipitation appears as the dark green and yellow colors on this radar loop.


Dec 16-17 winter storm radar (Iowa Environmental Mesonet)

Additionally, the timing of this storm was incredible. Snow started to pick up in Pennsylvania and western New York in the afternoon on December 16. By mid-day on the 17th, most of the storm had already departed New England. Heavy snowfall rates contributed to the impressive snowfall totals in such a short period of time.

5. Record Heat

While not one individual event, I'd be remiss to not discuss this year's extreme heat here in the Northeast, in the United States, and in the entire world. More so than past years, 2020 showed that global warming is happening and it is a problem that we must put our resources towards tackling.

Here in the Northeast, 2020 has been one of the hottest years on record for many locations. As the figure below shows, almost the entire Northeast had its yearly mean temperature in the 90th or greater percentile.

Year to date temperature percentiles (Southeast Regional Climate Center)

Focusing specifically on Hartford, CT, close to where I was based for much of the year, 2020 has been the second warmest year on record, following 2012.

(NOAA Regional Climate Centers/xmACIS)

The following 2020 temperature chart for the Hartford are shows that while we did have some cooler-than-normal days, temperatures this year were mostly above average, especially during the summer.


(NOAA Regional Climate Centers/xmACIS)

Shifting our focus to the country as a whole, the same trends that we saw here in the Northeast were experienced for much of the country. As the following map shows, most of the U.S. saw above normal temperatures, with this trend being especially evident in the Northeast and Southwest.
(High Plains Regional Climate Center)

And to focus on two specific location, Phenix had 156 consecutive days where the temperature was greater than 90 °F this year, and Las Vegas had 61 consecutive days where the temperature was greater than 1001 °F!

Globally, while the year has not yet ended, we are on track to have one of our hottest years on record, consistent with trends over the past 20 years.

Time series plot of global temperature anomalies (NOAA)

I could go on and on about how warm it has been this year, but for the sake of brevity, I'll stop here.

6. Midwest Derecho

Often misnamed "land hurricanes" derechos are meteorological phenomena consisting of severe thunderstorms, extreme straight-line winds, and heavy rains that can cause significant damage.

On August 10-11 this summer, a derecho struck Nebraska, South Dakota, Iowa, Illinois, Wisconsin, and Indiana, traveling 770 miles, causing multiple tornadoes, wind gusts estimated to be around 140 mph, hail 2 inches in diameter, and 4 fatalities. See radar reflectivity at one-hour time steps below. The derecho was especially potent in central Iowa, where locations lost power for up to ten days.

(NWS Chicago)

See this YouTube video from Evan Hindman, showing just how fast the straight-line winds from the derecho were.

 

According to a NWS Quad Cities report on the storm, a derecho of the intensity seen on August 10 is a "once-in-a-decade occurrence for [that] region." Extreme winds prevailed for 30-60 minutes, rather than a more typical 10-20 minutes, according to the NWS Quad Cities.

7. Bomb Cyclone Blizzard in Newfoundland

For most, this event would probably not stand out as a "top 10" weather or climate event for 2020, but for those that live in Newfoundland, Canada, it certainly does.

Far east of the United states in the Canadian province of Newfoundland and Labrador, the pressure dropped 54 mb (!) in 24 hours, forming what is known as "bombogenesis". In this blizzard, winds neared 100 mph, and the city of St. John set a 24 hour snowfall record of 30". Many lost power and a state of emergency was declared for the region. This storm particularly stuck out to be because of the incredible photos and videos from its aftermath. I'll let them speak for themselves:

(Andrew Vaughan/AP/Shutterstock)


That's all for part 2 of my top 10 weather and climate related events for 2020. I'll have the final 3 events at some point soon. 

Saturday, December 26, 2020

Major Weather Events of 2020 Part 1

What a year 2020 has been.

At the end of each year, I enjoy reflecting back on what we've learn, seen, experienced, etc. I thought I'd do that for this blog. This post will be the first in a multi-part series looking at 10 major weather events of the past year that stuck out to me. I will share the events (or collection of events) in no particular order. These will simply be weather or climate related topics that stuck out to me from the past year. Let's dive in, starting with the first 3.

1. The Atlantic Hurricane Season

This year's Atlantic hurricane season was record-breaking and relentless. There were 30 named storms, 13 hurricanes, and 6 major hurricanes. The 30 total named storms breaks the previous record for the most named storms (28 in 2005). Although the hurricane season officially begins on June 1, tropical storm Arthur became the first named storm on May 16.

 

I find the above video from NOAA particularly fascinating. It shoes GOES East satellite imagery for all named storms. Storms that particularly stood out to me in the satellite imagery are Cristobal (0:07 in the video), Isaias (0:26), Laura (0:34), Teddy (0:56), Epsilon (1:16), and Iota (1:27).

On September 14th, there were 5 named tropical storms in the Atlantic at the same time, and the NOAA satellite image below shows Sally, Paulette, Rene, Teddy, and Vicky in the ocean simultaneously.

(NOAA)

12 named storms made landfall on the United States, and Louisiana was particularly impacted, with 5 making landfall there, including Laura, which made landfall as a category 4 hurricane and caused 77 fatalities.

Iota, the last named storm, also happened to be the strongest one, with maximum winds of 160 mph and a low pressure of 917 mbar.

The storm of memory for me was Hurricane Isaias, which impacted New England as a tropical storm, causing nearly $5 billion in damage and power outages throughout the Eastern seaboard.

Here is a nice National Weather Service (NWS) infographic summarizing this Atlantic hurricane season.

(NOAA/NWS)

One final thought that I have on the 2020 Atlantic hurricane season is the impressive work that forecasters at the National Hurricane Center (NHC) did. These meteorologists have an extremely difficult and stressful job, and they really did an exceptional job forecasting this complex and protracted hurricane season.

2. Widespread Drought

It was an extremely dry year for much of the country, as evidenced by the map below, which shows the precipitation departure from normal through Christmas day.

(NOAA Regional Climate Centers)

The Northeast and much of the United States west of the Mississippi River saw below normal precipitation, with parts of Northern California being much below normal. 

This year's dearth of rain in much of the country created widespread drought conditions that inflicted many areas in the Southwest and Northeast. The following GIF shows the U.S. Drought Monitor for each week it was produced during the calendar year. If you take the time to watch, you can see how widespread drought conditions became, as well as the exceptional drought conditions that the Southwest continues to experience.

GIF of U.S. Drought Monitor for 2020 (National Drought Mitigation Center)

3. Western Wildfires

Scene in Oroville, California on September 9 (CNN/Josh Edelson/AFP/Getty Images)

Stemming in part from the aforementioned drought and lack of rain, wildfires ravaged the western United States this year. Nearly 14 million acres burned in the U.S. this year, which is the most burned in the past 30 years at least (there are not reliable records dating past 30 years). 

Here is satellite GOES WEST satellite imagery from September 9, showing widespread extend of the wildfires in the west.

September 9 GOES WEST (NOAA)

These fires had various causes, including the lack of precipitation and extreme heat in the west this year, lightning strikes, house fires, and campfires.

I took the following photo on September 16, when smoke associated with the western fires progressed eastward, causing hazy skies and a beautiful sunset at Middlebury College in Vermont.


This does not compare to the scene in the Bay Area in mid-September, when the sky appeared orange.

(VOX/AP/Eric Risberg)

While the wetter period of the year in the west has now arrived an many fires are now contained, there is still some wildfire activity. The Creek Fire in southern California is currently 65% contained. Use this app from the California Department of Forestry and Fire Protection to examine where there are still fires in California now. (You will need to click OK).


That's it for part 1 in this multi-part series of major weather and climate related events of 2020. I'll have part 2 within the next few days.

Friday, December 25, 2020

Storm musings

It's Christmas day. December 25th. These were the 6:00 am temperatures this morning in New England.

(NWS Burlington)

That is not typical. Areas as far north as Quebec should not be seeing temperatures in the 60s on December 25th. At Burlington, VT, the normal high temperature for Christmas day is 30 °F - the high temperature so far today there is 64 °F. That is a high 34 degrees above normal! Moreover, dew points this morning sit in the 50s for much of New England. As forecasted, winds from this storm were impressive, leaving many without power in the northeast.

The rain, high temperatures, and high dew points virtually washed away our snowpack overnight. Here is the current New England snowpack:

(NOAA/NOHRSC)

And this is what it was yesterday at the exact same time:

(NOAA/NOHRSC)

And to hammer the point home, here is a look at the Killington Superstar Webcam:

(Killington)

To put that image into perspective, Superstar (the trail you see on the left in the above photo) typically hosts the women's alpine ski world cup races each year during Thanksgiving weekend, and Killington is famous for making prodigious amounts of snow on the trail, forming what is known as the "Superstar Glacier" and enabling skiing past Memorial Day. On December 25th, that is not the Superstar webcam photo that you want to see.

Not all hope about this winter in New England needs to be lost though. On December 25th, 2014 in Boston, MA, the high temperature was 59 °F, when the normal high for that date in Boston is 38 °F.

(NOAA Regional Climate Centers/xmACIS)

What followed Christmas day 2014 in Boston was the city's snowiest Jan 1 to Mar 31 (winter 2015) period in history, with 107.7 inches of snow falling in that period.

Top 10 snowiest Jan 1 to Mar 31 at Boston (NOAA Regional Climate Centers/xmACIS)

Moreover, that period in 2015 was the third coldest Jan 1 to Mar 31 in Boston's history, with the mean average temperature being 26.3 °F.
Coldest Jan 1 to Mar 31 at Boston on record (NOAA Regional Climate Centers/xmACIS)

Similar trends held for much of New England during that winter. So while this Christmas day warmth and rain is unfortunate to see, past precedent tells us that an unusually warm Christmas could precede a cold and snowy winter, as it did for winter 2014-2015.

Wednesday, December 23, 2020

Nasty weather ahead

With high pressure building today, it will be a spectacular late December day, with abundant sunshine, light winds, and temperatures rising into the 30s. Here is a look at this morning's sunrise over I-84 in Middlebury, CT.



It'll be a perfect day to get out and enjoy the snowpack that we've built up from the storm last week. Right now, much of New England has roughly a 10 inch snow pack, with certain areas even deeper.


(NOAA/ NOHRSC)

In typical east coast fashion, that snow pack that we've built up will seemingly disappear overnight around Christmas.

NWS forecast map valid Thursday morning (NWS)

Low pressure moves eastward and by mid-day Thursday, we can expect temperatures to rise into the upper 40s with rain showers beginning to fall. Here is a look at NAM forecasted temperatures for at 1:00 p.m.

(Tropical Tidbits)

The main storm action takes place on Friday morning, Christmas day. This storm will have very strong winds that could lead to power outages, heavy rain which will contribute to snow melt, dense fog in spots, and high dew points that will further melt the snow pack.

Especially for coastal areas, winds will be extremely strong, and with the lack of leaves on the trees, it'll be very easy for power outages to occur.

(Tropical Tidbits)

Here is a look at forecasts surface winds for Hyannis, MA. Gusts could be greater than 60 mph!

(NWS Boston)

Temperatures will be unseasonably warm on Friday morning, with some areas seeing Christmas morning temperature readings above 60 °F.

(Tropical Tidbits)

Aside from the heavy rains, the warmth, and the winds, the dew points will be incredibly high with this system, causing a blow to our snowpack.

(Tropical Tidbits)

The front that will move through behind this storm can clearly be seen on all the maps I've shown. After that front moves through, temperatures will quickly plummet, and some freezing will occur. Enjoy the snowpack and the nice weather while we have it!

Monday, December 21, 2020

Winter solstice

Today is the shortest day of the year in the northern hemisphere, the first day of astronomical winter, and the winter solstice.

The solstice officially occurred at 5:02 a.m. eastern time this morning. At that time, the northern hemisphere of the earth had its maximal tilt away from the sun (see the image below).

(Encyclopaedia Britannica)

Conversely, the southern hemisphere had its maximal tilt towards the sun today, and the Tropic of Capricorn, located at a latitude of about 23.4 ° S, received direct sunlight.

All locations in the northern hemisphere had their least amount of daylight for the year today. Hartford, CT had 9 hours 8 minutes of daylight, while Burlington, VT had 8 hours 49 minutes. After 5:02 this morning, the northern hemisphere began tilting back towards the sun. That means that each day after today until the summer solstice, we will see more daylight!


Completely unrelated to the winter solstice, today is the day when Jupiter and Saturn will appear closest to each other, in what is being dubbed the 'Great Conjunction' of the planets. Over the past few weeks, Jupiter and Saturn have gradually appeared closer to each other each night, and that culminates tonight. I am not an astronomer, so for more on this neat phenomenon, I'll deflect to NASA.

Saturday, December 19, 2020

Inversion Morning

For me, one of the most fascinating weather phenomena is an inversion, and we had quite an inversion in New England this morning.

What is an inversion? Well, typically, as you increase in elevation or height above the surface of the earth, the air gets cooler. Typically, for every 1,000 ft. you rise in the atmosphere, the temperature drops by about 3 °C (~ 5 °F). In certain instances, though, the opposite is true, and the temperature rises as you get higher above the surface of the earth. That was the case this morning.

(NWS Burlington)

Take a look at the above image, which shows temperatures at various sites in Vermont at 7:00 AM this morning. Mt. Mansfield, which is the state's highest point at an elevation of 4,393 feet, had the highest temperature at 7:00 AM, a balmy 19 °F. Note that many other locations saw temperatures below zero.

(NWS Gray)

The same held true in New Hampshire. Mt. Washington, the highest point in New England (6,288 feet), had a morning temperature of 19 °F, which was warmer than the southern NH coastal town of Portsmouth, NH (11 °F).

Here is a look at the HRRR model sounding for this morning. In this image, the y-axis, which is pressure, can be thought of as height above the surface of the earth (pressure decreases as height increases). The x-axis is temperature in °C. The red line, which represents temperature, clearly shows a rapid increase in temperature as height increases, something that happens in an inversion.

(Tropical Tidbits)

What caused the inversion this morning? Last night was a very clear night, with virtually no clouds in the sky. The earth emits radiation (or heat) from its surface, and radiation can easily escape when there are no clouds. The emitted radiation cools the surface of the earth, and when lots can easily escape, the surface of the earth can cool to a greater extent than typical, thus causing an inversion. Additionally, cool, dense air from the higher elevations can easily "sink" into valleys on inversion nights, enhancing the inversion.

Today, you'll see the temperature inversion dwindle as the sun rises and the surface of the earth warms due to the suns radiation.

Thursday, December 17, 2020

What. A. Storm.

This storm was incredible, and it'll certainly be remembered for a long time. Some of my most vivid memories during my youth related to massive snowstorms (think Feb blizzard in 2013 and the Halloween snowstorm in 2011). These storms contributed to my love of weather, and helped grow my desire to become a meteorologist. I am sure that there are some kids that will want to become meteorologists after this storm. Let's unpack it.


The big winners for this storm were locations along an intense band of snowfall that extended from north central Pennsylvania, through the capital region of New York, and into southern Vermont and New Hampshire. As the above tweet from the NWS Eastern Region shows, 4 states (New York, Vermont, Pennsylvania, and New Hampshire) saw 40+ inch snowfall totals. It is difficult to put into perspective how much snow that actually is - I'll simply say it's incredible!



I find the above GOES East view of the storm pretty fascinating as well, and it shows just how potent it was. (Unfortunately the tweet of the satellite imagery is not embedding in the blog, but I encourage you to click the link and take a look).

Officially in Connecticut, we had 12.3" at Bradley International Airport in Windsor Locks and  9.4" at Bridgeport.

Vermont had a very interesting gradient of snowfall from north to south. In Burlington, only 2.5" of snow fell, while Ludlow, the town of Okemo Mountain Resort, had 44". This early season storm will certainly be a boon for the New England ski areas that were struggling to open terrain. If anything, 44" could be too much at one time for a ski area. I read that Okemo had to delay it's opening today as it worked on snow removal.

For me, the most impressive thing about this storm was how much snow it produced in such a short amount of time. I have read reports that some areas saw snowfall rates between 6 and 7 (!) inches per hour! That's incredible! In the 2013 blizzard (which is probably my favorite weather memory), we had 30+ inches of snow, but the storm lasted much longer. For this one, in less than 24 hours, sites saw 40+ inches.

Here are some scenes near my house in Middlebury, CT, where about 1 foot of snow fell. I spent much of the day enjoying the snow and shoveling in my neighborhood - unfortunately, I was so much fun that I forgot to stop and take more pictures. I absolutely love snow and will remember this storm for a long time.


Overlooking I-84 early this morning