Leaves, flakes and hurricanes
If you noticed that some trees, which may have started out with bright colors, suddenly dulled a bit, with some leaves even going rather quickly to a rust color, you have those cold September mornings to blame.
On some mornings we saw widespread readings in the lower 20s, and there was even one morning with a 17, just north of Caribou. As I explained recently, the dry summer would not have caused any dulling of color. Dry summers can be followed by a spectacular display due to a higher concentration of sugars in the leaves. Instead, it’s the sub-25-degree nights that are problematic.
That said, every fall foliage season is a treat (at least to me), and I have certainly seen some incredible trees and vistas so far this season.
Meanwhile, I was looking up some snow stats the other day, and came across something rather notable. The last two winters, 2018-19 and 2019-20, were the snowiest of any two consecutive winters combined, as measured at NWS Caribou, with a total of 317.3 inches (26.4 feet). In addition, the last two winters are the only two consecutive winters on record to have at least 150 inches of snow each. Records at Caribou date back to 1939. The average snowfall at Caribou, based on 30-year climatological norms, 1981-2010, is 108.7 inches. So if each of the past two years had been exactly average, Caribou is almost exactly 100 inches above normal over the past two winters combined.
Now where I grew up (just south of D.C.), we only average 16 inches of snow per year. And that’s what made the President’s Day storm of 1979 one I’ll remember for all of my days. Why? Because it buried our picnic table. Completely. Couldn’t see any of it, just a mound. At the tail end of the storm in the early morning hours, snowfall rates were four inches per hour. The huge flakes appeared to be stacking up like tea plates. I was so astonished that I awakened my parents. I said, “Trust me, you have to get up right now to see this. It’s nothing bad.” (By the way, I still have a habit of “dragging” people outside to see wondrous things.)
Speaking of snow, it looks like a La Nina winter in shaping up. In terms of systems which bring accumulating snow to The County, La Nina years often feature storms which move through the Ohio Valley or Great Lakes, and then sometimes intensify when they hit the coast and draw in some of that Atlantic moisture. In some cases, all along the storm track, prior to getting to the Atlantic, the accumulations are nothing to write home about, but then, when they hit the water and tap into some extra moisture, heavier snowfall rates and higher totals can occur.
Years ago when I was living in Bangor, one of the heaviest snowfalls I experienced in my several years there, 16 inches, came from one of those types of storms.
By the way, the record snow season of 2007-08 in The County was a La Nina year. La Nina features significant cooling of the central and eastern equatorial Pacific. This, as well as its opposite, El Nino, which features a warming of that same region, influences weather patterns on a broad scale.
On another note, there have been many named tropical systems this hurricane season. By another metric, known as accumulated cyclone energy, or ACE, the season has not been anywhere near the top of the list. The last big ACE year was 2017. The top two ACE years are 1933 and 2005, respectively, with 1933 featuring the infamous Chesapeake-Potomac hurricane, which came ashore on North Carolina’s Outer Banks and drove a tremendous storm surge up Chesapeake Bay and the rivers that empty into it, like the Potomac, where the storm surge caused significant flooding in Washington, D.C. In 2005, there was Hurricane Katrina, with its unimaginable 28-foot storm surge along the Mississippi Gulf Coast.
It’s important to remember that some named storms may have remained weak and never come close to land, but they are counted in the total count for that season. “Weak” refers to wind speed. “Weak” tropical storms or tropical depressions are capable of producing life-threatening flash flooding if they are close to or over land, so one must still be mindful of them.
Sometimes, the way storms are defined can cause public confusion, and a prime example just happened with Hurricane Teddy, which lashed Nova Scotia. After having been tracked for days and referred to as “Hurricane Teddy,” it was no longer a hurricane as it approached Nova Scotia. It had undergone a meteorological transition, such that it was no longer a textbook hurricane; however, its impacts were unchanged.
With the word “hurricane” not being used, the average person might have a tendency to let their guard down. I am in favor of continuing to call a storm of tropical origin a tropical storm or hurricane (depending on which it is) until its potential impact to life and property has ended.
Just before landfall, Hurricane Teddy was called Post-Tropical Cyclone Teddy. I’m thinking that’s not resonating with a lot of folks.
The same issue arose during Hurricane Sandy in 2012. The advisories stopped calling it a hurricane just before its New Jersey landfall, because it did not meet the meteorological definition of a hurricane. That storm, as you may recall, flooded the subways in lower Manhattan. If you’ve never seen those photos, they are astounding and easy to find. Just google “Sandy flooded subways.”
Ted Shapiro holds the Broadcast Seal of Approval from both the American Meteorological Society and the National Weather Association. An Alexandria, Va. native, he has been chief meteorologist at WAGM-TV since 2006. Email him at firstname.lastname@example.org.