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My storm chasing friend Dave Carroll from Blacksburg ventured up to Salt Pond Mountain today (the one Mountain Lake is on). He saw a little light snow blowing around and shot some photos of a wintry mountaintop with an autumn background. My favorite, small at the left and a larger version linked here, showns rime ice on tree branches above 4,100 feet at Bald Knob. Riming is caused by winds blowing water droplets in clouds against surfaces that are below freezing. He also shot a picture of a wee bit of snow accumulation on some of the many ferns found on the mountain. Just a hint of winter today at the area's highest elevations.

Some more snow showers are possible overnight at elevations generally above 3,000 feet (possibly creeping lower into the New River Valley after midnight) as another disturbance swings through. The bigger issue will be the potential for a growing season-ending freeze tonight and again Sunday night over most of Southwest Virginia west and north of Roanoke. Freeze warnings and watches have been issued.

A late week snow set records for earliest on record in some states to our northeast.

This taste of winter won't last long, as gradually warming temperatures are expected through the coming week.

The storm that formed over Vinton and eastern Roanoke County on Wednesday was fairly impressive. It appeared to develop a rounded base and some lowerings for a short time, as this photo I took looking north from Buck Mountain Road in south Roanoke County shows (lowered cloud bases are hanging over the ridgeline). There may have been some weak rotation in the storm for a time, and I have got at least one report of wind gusts that would have been near severe level (58 mph and higher). The storm spread westward and southwestward dumping heavy rain on much of the Roanoke Valley, with a flash flood warning posted for Roanoke city for a time. While the Roanoke Regional Airport only received .33 inch of rain, a couple of automatic gauges in eastern parts of the Roanoke Valley quickly gathered rainfall near or over an inch. I was out in some of that, with water ponding on the roads along Franklin Road and into downtown. Other parts of Southwest Virginia, from the New River Valley west and south, also saw some locally heavy downpours on Wednesday.

With east and northeast winds pushing low level moisture against the mountains today -- a "wedge" effect -- we're likely to stay too cloudy and cool (low 70s for highs, at best in Roanoke) for much in the way of big storms today. Scattered light showers and some patches of drizzle will be more the mode today. If skies clear tonight, it could be rather chilly with an air mass pushed in from the northeast, as lows in the upper 40s to mid 50s would be widespread.

On Tuesday I posted a non-tornado photo from just east of Roanoke near Explore Park -- scud clouds being pushed along a ridgetop by outflow winds. Danny Vinson e-mailed me a photo of something similar today at Blacksburg, taken by his-co-worker Ross Spoon. This, too, has a tornado-ish appearance, but is really steamy scud clouds lifting upward toward a somewhat lowered cloud base. No rotation, just sort of a "funnel."

While no tornadoes have been reported in today's storms, there has been some wind damage and street flooding in Franklin County, which experienced a strong thunderstorm this afternoon.  With tropical moisture firmly in place, daytime heating and some upper-level disturbances preceding a rather strong cold front on Friday, additional thunderstorms will be likely intermittently over the next 48 hours. Locally flooding rain will be the biggest threat, but some high winds can't be ruled out.

From an overlook just off the Blue Ridge Parkway near Explore Park east of Vinton, I watched a storm go across the Roanoke Valley this afternoon, and shot several frames (click here and here for examples) that show a funnel-like extension reaching a ridgetop. It has wider base near the surface similar to a debris cloud that could be spun up by a funnel. So was it a tornado?

NO!  it was not in any way, shape or form a tornado, but rather scud clouds being pushed along by the outflow boundary of a thunderstorm. There was no rotation, and what's more, the wider piece along the ridgetop actually formed independently before the clouds above connected to it. It was one of those foggy kind of low clouds that form in the mountains from evaporation of rain, and eventually the lowering at the front of the outflow connected with it as they both blew along in front of the storm.

It was a picturesque storm that produced some photogenic scenes as it brought heavy rain and briefly gusty winds to the valley this afternoon. But it wasn't a severe storm, and it certainly didn't spawn any tornadoes.

Click here for a Weather Journal column about why this storm may have developed rotation

Right place, right time. I was watching the storm build east of downtown Roanoke, and noting some rotation in it, even before the tornado warning was issued once National Weather Service Doppler radar began picking up tight rotation within the storm just before 4 p.m. This photo (bigger version here), taken from the roof of the Roanoke Times building, captures the counterclockwise circulation I observed, with the arm of clouds coming in from the left wrapping toward the center of the circulation back behind the Wachoiva tower. Some hail up to an inch in diameter was reported in Vinton, very indicative of a storm with rotation lifting water droplets higher in the atmosphere for a more sustained time.

Here is one clue as to why this storm might have exhibited rotation for a period of time: A midafternoon chart from the Storm Prediction Center shows a small pocket of 40 knots of wind shear up to 8 kilometers high located over the region where the storm developed. We typically look for 40 knots of shear (wind changing speed and direction with height) up to 6 kilometers high as the baseline for likely supercell development.  This storm may not have had rotation long enough to be a supercell, but it certainly started out with a supercelluar-type structure. Another possibility I am wondering about is some kind of atmospheric boundary produced by the storm cluster over central Virginia last night. An outflow of cooler air from previous storms can produce horizontal rotation where it bumps into a different air mass  or a terrain feature (the Blue Ridge?), and that rotation can be pulled into a storm's updraft, producing vertical rotation. That is just conjecture on my part at this point.

Click here and here for additional photos I took of the storm organizing just before the tornado warning was issued.

Ron Bailey of Vinton sent in several photos from the storm as it passed overhead. The lowered cloud structure on pics 6 and 7 definitely has the appearance of a possible wall cloud, or lowering with circulation that has the potential to drop a tornado (though it appears that no tornadoes actually touched down.)

David Gray sent this photo of rotating storm clouds over his backyard in Vinton.

A reader only identified as Kelly sent in this photo from over Cardinal Glass in Vinton.

A small photo of hail accumulation in Vinton from Karenna Glover, who works in marketing at the Roanoke Times.

I sometimes get asked "Why don't you storm chasers just chase the storms that happen around here?" I have a multi-part answer to that question that includes references to this area's terrain and tree cover, and the atmospheric patterns that typically yield much more powerful and photogenic storms in the central U.S. But the first part of the answer is "We DO chase storms around here." A day back from the 2-week Virginia Tech storm chase trip to the Plains states, severe storms were popping all around Southwest Virginia today. Most of these were pulse-type storms that went up and down quickly, meaning any effort to track one down would lead to getting there only as it collapsed and died. But late in the afternoon, a short bow-segment type storm with a little more longevity moved out of the Blacksburg area toward the Roanoke Valley, and I was able to get to a higher location off Electric Road in Southwest Roanoke County to get some structure shots of a stacked shelf cloud and what may have been a brief wall cloud near the southwestern flank of the storm. The bulk of this storm shifted into the northern Roanoke Valley and gradually dissipated.

Today's pop-up severe weather has yielded a cluster of severe weather reports in Southwest Virginia, including one report of a large tree blocking a road in Salem.

This snowy field in Floyd County (for bigger version, click here) isn't a snowy field at all. No, that's hail, two hours after it had fallen at Indian Valley ... so there was even more before this shot was taken by occasional Weather Journal blog commenter "Indian Valley John." If you look closely, you can even see some hail fog at ground level ... moisture condensing in air cooled by the fallen and melting hail. A slow-moving storm combined with a low freezing level (just below 11,000 feet) caused large amounts of mostly small hail to be dumped on a portion of Floyd County Wednesday afternoon. Up to 5 inches of hail accumulated at some spots near Willis and Indian Valley.

So, while some of you didn't even see rain in your back yard (most of the Roanoke Valley), others not far away had quite a stormy show. That will be the pattern the next few days, as spotty showers and storms occur with a flip-flopping front waving across the area and a series of disturbances. More organized action may occur by the weekend.

Click here for a few more photos from Indian Valley John, all taken about 2 hours after the hail storm:

Ankle-deep hail

Hail piled up along a highway

Another roadside hail pile

A visit to the Roanoke Times roof garden earlier this evening resulted in an unexpected treat. The late-day sun, out of view to my left, was refracting through high ice-crystal clouds known as cirrus, creating a phenomenon known as a sun dog. A sun dog almost looks like a second sun, with a slight rainbow effect as light rays are scattered by ice crystals.  So the photo at left may look like the sun itself somewhat obscured by clouds near the horizon, but fact, it is the sun's light some distance north of the setting sun. (full-size version of photo linked here)

Jennifer Pfister-Santoroski sent me an e-mail the other day noting her family's disappointment with Roanoke's bizarre snow drought, particularly that of her son, Mark. But Jennifer's parents in Giles County got 2 inches of snow last week, so she hauled a little bit of it back for Mark (left)  and his friend Thomas Latham to play in. (Full photo here)  "... I grabbed all five of our coolers and headed for the countryside. I packed in as much snow as I could and then headed back to Roanoke ..." Jennifer wrote. "It was a very small patch yet it did provide one-hour worth of fun of snowball fights and itty-bitty snowmen. We received many double-takes from people driving down the street, and the boys took on snowball fights with the UPS guy, mail carrier and flower delivery man. ... With our first snow taken care of, the boys can’t stop talking about it all! It was well-worth the 3-hour round trip, and we are now a little less snow-envious. We still are hoping for a real snow right here in Roanoke yet if it snows around us once again – this time I’ll just drive the boys to the snow."

UPDATE 6:10 PM: The winter storm warning has expanded southward to include Bedford County and the Lynchburg area, where ice has accumulated much of the day. Temperatures are dropping in the Roanoke Valley and patchy ice has developed on trees and exposed objects in some areas. Spotty ice may become more widespread as slightly colder temperatures work in for a time overnight. END UPDATE

You don't have to go too far off the floor of the Roanoke Valley to find some light ice accumulation. I drove up to Happy Hollow Gardens, a park not far from Valhalla Vineyards on Mount Pleasant Road in southern Roanoke County, and found a winter wonderland of ice-tinged trees and fence railings. (Click here to see two more photos on the SwoCo blog) Temperatures have been hovering 33-34 along the floor of the valley but have dropped to 31-32 in some of the higher elevation areas just outside the valley. I noticed the ice line was about 1,600 feet, though that's variable, and it's spotty up to about 2,000 feet.  The ice isn't thick enough to cause problems with tree damage or power lines, at least not yet, and I found no ice at all on any roads.

The National Weather Service in Blacksburg isn't giving up on the ice just yet ... in fact, the same advisories and warnings remain in effect with just a few western counties like Pulaski sliced out. If you've followed the temperatures today, you may have noticed that places like Dublin and Bluefield, W.Va., have shot into the 40s while it remains near or slightly above freezing at Roanoke and Lynchburg. Two different forces are at work this afternoon and evening. One is warm air advection being pulled primarily to our west by the developing low pressure system much farther west. The second is a slight tendency for high pressure to wedge in cold air to our east. We're caught between those forces today. The weather service is actually hinting that temperatures may drop a few degrees from Roanoke eastward and northeastward because of the wedge. If that is the case, we might still have some ice to deal with overnight in many spots before the warmer air eventually wins the battle.