This photo of snow is from last January in southern Roanoke County, but shows the kind of heavy, wet snow sagging tree limbs that parts of Southwest Virginia west of Interstate 77 experienced with Superstorm Sandy 10 years ago in late October. Photo by Kevin Myatt.

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The day Superstorm Sandy came ashore 10 years ago – Oct. 29, 2012 – plays second-fiddle in Virginia weather to the 29th day of another month in the same year.

That, of course, would be June 29, 2012, the day of the destructive and deadly derecho that rolled across most of the state. Ironically, the part of the state least affected by the derecho, the extreme Southwest corner of the state, can claim the most memorable impacts from Sandy, and diametrically opposite ones to the sweltering heat of derecho day.

Nationally, though, Superstorm Sandy was the biggest weather story of 2012, affecting 24 states and causing an estimated $65 billion in damage, with economic and political shock waves lasting many years, perhaps not entirely settled out yet.

As the 10th anniversary of Superstorm Sandy is recalled this week, it will be remembered as a monstrous pre-Halloween ‘Frankenstorm’ that transformed from powerful hurricane to sprawling, pinwheeling extratropical low-pressure system, devastating the Jersey Shore and carrying inland impacts as far west as Lake Michigan.

Sandy wasn’t really Virginia’s storm, but it did churn up some waves on the coast as it passed by offshore in the last stages of its hurricane phase and, once inland, spun through some roaring, chilly winds that knocked out power to a few thousand mainly in the mountains of the western side of the state.

Sandy’s principal legacy in Virginia, however, was heavy wet snowfall focused on a few counties in the Southwest part of the state west of Interstate 77, amounts regionally unprecedented for October, an extension of similar snowfall that clocked much of West Virginia.

This map shows snowfall totals following Superstorm Sandy. West Virginia had by far the widest distribution of heavy snow, but some isolated heavier amounts occurred in Southwest Virginia also. Note also the light shades of light snow accumulation along the Blue Ridge farther east. Source: National Weather Service.

Some of the highest elevations of Wise and Dickenson counties near 3,000 feet of elevation reported more than 2 feet of snowfall, with 6-12 inches not uncommon even down to about 1,600 feet before dropping off to minor amounts below that.

(Climate researcher Wayne Browning has an extensive analysis of Sandy and its snowfall in Southwest Virginia on his High Knob Landform blog, linked here:

Coming as it did on northwest winds wrapping around Sandy’s circulation center to the north, the snow tended to dry out crossing the Appalachians, as is often the case.

Light accumulations made it as far as east as the New River Valley – Blacksburg tallied 0.6 inch, its first measurable October snow in 50 years – and the higher elevations of the Blue Ridge. Flurries flew on winds gusting up to 60 mph even into the Roanoke Valley.

There is no actual official meteorological moniker “superstorm,” but the term has been applied by the media and popular usage to a couple of storms with extraordinary intensity and unorthodox synoptic evolution.

The first “superstorm” is what many Virginians call “the Blizzard of 1993,” a powerful low-pressure system that formed from the fusion of energy in three different branches of the jet stream over the Gulf of Mexico. The storm then rode up the East Coast, delivering storm surge to coastlines, tornadoes in its warm sector over Florida, and a greater volume of snowfall than has been dumped by any U.S. storm over a wide swath east of the Mississippi River.

Sandy became a “superstorm” when a deep southward dive of the jet stream, or polar trough, captured what had once been a Category 3 hurricane, pulling it west-northwest inland as the circulation broadened but maintained a good deal of its intensity.

This movement dealt an unusual perpendicular crash into New Jersey’s shoreline, whereas most hurricanes and nor’easters glance by just offshore, leading to widespread damage from storm surge and winds gusting over 80 mph at times.

Sandy’s impact thrust much focus at the time on the role of human-influenced climate change. The general consensus scientific view on Sandy a decade later is that its core causes were rooted in natural variation, but warmer oceans, higher sea levels and perhaps displaced atmospheric features linked to climate change made it more intense than it otherwise would have been.

Sandy wasn’t the first or last time that a hurricane or hurricane remnants were absorbed by a polar trough. In fact, it happened just four weeks ago.

Hurricane Ian’s remnant circulation became embedded with an upper-level trough, leading to the development of a nor’easter low that piled up some high surf along the coast in the Tidewater area, the Eastern Shore and Chesapeake Bay.

The handoff between Ian as a tropical entity and the son-of-Ian nor’easter was not particularly smooth, which was a great break for inland Virginia.

Ian’s tropical spin and rain shield quickly diminished and the barely discernible circulation center meandered over the Old Dominion a couple of days, mostly bringing drizzly weather and sporadic showers. Only then did the trough absorb what was left of Ian’s spin for a potent storm offshore, but not destructive winds or floods over the inland areas.

A much smoother transition between major hurricane and powerful extratropical low happened 58 years before Sandy with Hurricane Hazel.

Hazel would have likely been dubbed a “superstorm” in modern parlance. In October 1954, Hazel made a destructive Category 3 swat on many of the beaches Virginians frequent today on either side of the North Carolina-South Carolina border, as it was already in the process of transitioning from a hurricane to a powerful extratropical low, captured by a polar trough much like Sandy.

Hazel’s extratropical manifestation carried hurricane-force wind gusts, sometimes topping 100 mph, across Virginia and throughout much of the Mid-Atlantic, Northeast and into southeastern Canada.

Weather maps of the November 1950 Appalachian Storm (left) and 2012 Superstorm Sandy reveal obvious similarities, with the Appalachian Storm positioned farther west, in Ohio, than Sandy’s circulation center in Pennsylvania. Southwest and Southside Virginia are circled. Source: National Weather Service.

Sandy’s evolution also bears some resemblance to the Great Appalachian Storm, which dropped gargantuan amounts of snow on parts of the Ohio Valley and Appalachians (hence the name) on Thanksgiving weekend of 1950.

In that case, a deep diving trough with bitterly cold Arctic air captured a developing surface low on the coast of the Carolinas and pulled it northwestward across Virginia, eventually stalling and spinning over Ohio.

In Virginia, heavy snow penetrated eastward all the way to the Blue Ridge, with Roanoke getting as much as 8 inches on a very white Black Friday (long before it was ever called Black Friday).  Just about everywhere to the west in Virginia had a foot or more. The snow cut off sharply just east, however, as Lynchburg and Danville both had only a trace to a few tenths of an inch.

Like with Sandy 62 years later, the 1950 Appalachian Storm became so wrapped up that cold air was working around its back side into Virginia while warmer air was pulled around its east and north side into New England and southeast Canada.

We can be thankful that there is nothing similar to Sandy around this year sending Halloween decorations airborne.

Humpback Bridge near Covington with some recent fall foliage. Reader Suzanne Vail of Roanoke recently made the trip to the covered bridge to enjoy fall colors. Courtesy of Suzanne Vail.

Weather stats of the week

So many places in Southwest and Southside Virginia reached freezing or below last week, but one major climate station did not: Roanoke.

Roanoke dropped to 34 on Friday and Saturday mornings, and was 35 to 37 Tuesday, Wednesday, Thursday and Sunday mornings. But no 32. No official freeze.

Your part of Roanoke or nearby in the Roanoke Valley may have made the freezing mark, but it didn’t do so at the official weather station at the Roanoke-Blacksburg Regional Airport.

And it doesn’t appear it will reach freezing the rest of October, which will mean it will be the fourth year in a row that Roanoke has not had its first fall freeze until (at least) November. That will be a record streak of post-October first fall freezes, going back to 1912.

A colorful maple tree in Roanoke. Foliage is near peak in the Roanoke Valley, along the Blue Ridge and in the western Piedmont. Courtesy of Suzanne Vail.

Weather ahead

What you really want to know about is what the weather will be doing at trick-or-treat time on Halloween.

Monday evening is still five days away, so definitely some wiggle room still.

That’s a good thing, because right now, it looks like a cool, damp pattern developing Sunday for sure and possibly extending into Monday as well

High pressure to the northeast will wedge southward against the mountains – it’s lacking any Arctic air now, so no freezing/frozen stuff to worry about. But moisture from the south will be overrunning the cooler air mass, so showers with temperatures in the 40s and 50s looks to be on tap come Sunday into Monday.

If we’re lucky, Monday night will be on the backside of all this for some improvement and not quite as damp. But just be thinking about how to keep your little ghosts and goblins dry if it’s drizzly or showery.

Journalist Kevin Myatt has been writing about weather for 19 years. His weekly column is sponsored by Oakey’s, a family-run, locally-owned funeral home with locations throughout the Roanoke Valley.

Kevin Myatt has written about Southwest and Southside Virginia weather for the past two decades, previously...