This year is as twisted a time in history as possible, so of course it makes sense that on a single day we had at least one fire tornado in California and a rare funnel cloud in Vermont's Northeast Kingdom.
We'll get into the California tornado first, then the Vermont funnel.
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| Rare fire tornado in California on Saturday |
And things kept going this morning, with a rare lightning barrage in San Francisco. We're using that word "rare" in this post a LOT! It's 2020 after all.
FIRE TORNADO
The western United States is enduring a record heat wave and a drought. The inevitable result of that is wildfires. It's so dry and winds are so erratic that we're getting extreme fire behavior out there
Large wildfires sometimes create something called pyrocumulonimbus clouds. (Say that five times fast!) The heat generated by the wildfires create strong updrafts which create tall, sometimes violent smoky thunderstorms.
Such was the case in northeastern California on Saturday.
As Washington Post Meteorologist Matthew Cappucci engagingly explains, that strong pyrocumulonimbus cloud was in an area of wind shear - the wind was changing direction with height. That created a spin. Plus, the atmosphere was primed for updrafts even without the fire.
The updrafts and the changing wind direction with height helped the pyrocumulonimbus cloud to rotate. At times, parts of the rotation tightened and you had tornadoes.
This was a true tornado, not a fire whirl in which the flames get caught in a tight rotation just near the ground. This tornado lowered from the smoky cloud. It touched down in a fairly remote area, so the actual tornado didn't cause a lot of damage. The wildfire did, of course.
Fire tornadoes have happened before, but they are not observed often at all. If you want a notable example other than yesterday's an area near Redding, California had a massive fire tornado in 2018.
Yesterday's fire tornado in northeastern California is the first known in the United States to prompt a National Weather Service office to issue a tornado warning.
VERMONT FUNNEL
While all this was going on, Vermont's Northeast Kingdom had it's own twisty excitement. In this case, it wasn't particularly dangerous, but not something you see in Green Mountain State, that's for sure.
Like in the fire tornado above, wind shear played a large role in creating the Northeast Kingdom funnel cloud. Winds were coming from the east at elevations below 10,000 feet, and from the west at elevations above 10,000 feet or so.
The air flow also tended to converge in the area where the funnel formed, which encouraged its development.
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| Funnel cloud near Newport, Vermont Saturday. Photo by Bob Minnie |
There was enough instability in the air to create some showers and thunderstorms, as a pocket of cold air aloft helped clouds billow upward into storms.
That chilly air aloft and the spin created what is known as a "cold air funnel" that caused that stir around Newport and Lake Willoughby Saturday evening.
There were no tornado or severe storm warnings as the parent storm that spawned the funnel wasn't severe. Plus, cold air funnels don't usually make it all the way to the ground. On some occasions they do and can cause damage, but in this case, the funnel stayed aloft.
SAN FRANCISCO'S TURN
Cool, stable air created by the chilly waters of the Pacific Ocean tend to help squelch thunderstorms around the San Francisco Bay Area, so they don't see many summer lightning storms.
But the extreme heat in California, and I think warmer than normal Pacific Ocean water temperatures, helped create a lightning barrage early this morning in the Bay Area.
Here's that word again: Rare.
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| Storms that created funnel clouds over Vermont's Northeast Kingdom weakened as they moved westward, causing this fiery sunset in St. Albans, Vermont |
Rare severe thunderstorm warnings were issued for much of the central coast of California this morning because of gusty winds associated with the storms.
The storms didn't contain much rain, so the lightning was particularly dangerous because it could set off more wildfires. The strong, gusty winds associated with the storms didn't help.
This was just happening as I wrote this, so I'm unsure yet if these storms sparked any wildfires.
Like I said, if you wanted a bizarre year, 2020 is it, for sure!
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