Thundersnow. It May Be The Most Misunderstood Weather Phenomena In The World Today,

[Jane Louise]

Has anybody ever experienced this weather Phenomena at all.? I know I haven't had the pleasure, maybe one day eh!

Thundersnow, also known as a winter thunderstorm or a thunder snowstorm, is a relatively rare kind of thunderstorm with snow falling as the primary precipitation instead of rain. It typically falls in regions of strong upward motion within the cold sector of an extratropical cyclone. Thermodynamically, it is not different from any other type of thunderstorms but the top of the cumulonimbus are usually quite low.

http://en.wikipedia.org/wiki/Thundersnow

Typically, a thundersnow event occurs with the majority meteorological recipe coming from a thunderstorm forming over a body of water. When the colder air from a normal winter front collides with the warmer air over the water--you're likely to get heavy snow and thunder clapping concurrently. But it isn't just that cut and dry and harmless. All the variations involved in thundersnow make it frequently dangerous if you're caught out outdoors when it happens.

Some of the examples of what thundersnow can do based on recorded bizarre weather events in history:

When thundersnow happened, strangely, in New Mexico once during the late 90's--a ski lift at a ski resort was hit by lightning and heavily damaged. In one of the interesting variations--snow fell as ice pellets. These ice pellets are frequently are larger than typical hail...hence causing more injury if you happen to be outdoors with no undercover areas within sight.

Buffalo, NY (during one of their massive snowstorms in 2006) reported a heavy thundersnow event that went on for hours. It's said that it's one of the longest reported thundersnow events in weather-recording history. People reported heavy snow falling with heavy claps of thunder and lightning strikes all through the night and day. This seems to give the indication that thundersnow can turn into a circular and prolonged storm if the conditions are just right.

Please discuss:

[Snowstorm1]

Yes Ive had this many times here in the Northeast we get this quite often if Im honest and love it!

[Andy_]

Yes Ive had this many times here in the Northeast we get this quite often if Im honest and love it!

Yeah I've had it at least a couple times in the last few years, nearly jumped out of my skin the first time it happened in my GCSE English Class. It's amazing the convection you get of the north sea in a north easterly air-stream

[Stormyking]

Oh yes I have witnessed these babies a few times, I remember March 2007 we had some of the most amazing looking lightning and loud thunder going off for about and hour under heavy snow, I was in shock as this was the first time Ive ever seen it and was like OMG I love this, my new favourite Weather type.

Happened again on the evening of April 6th 2008 as a heavy snow shower developed and produce a flash of Lightning and a loud crack of thunder.

February 3rd 2009 we had some very heavy snow in early morning leaving about 2 inches, however come around midday West wight experienced very very heavy snow and a very close flash of lightning with an almighty crack of thunder, there was about 7 inches of snow after.

Last Winter there was line of heavy snow just in the channel but narrowly missing us, my mate text me to say he kept seeing lightning and lots of it, I went to the sea front to see if I could see anything and the sky lit out some absolute beasts of multiple strikes at once, one produce 4 strikes in one, but because there was so much snow in the clouds it selt the lightning was like orange and almost red!!!

[AderynCoch]

22nd December 2009 was a good 'un. My idea of thundersnow had always been that it would be rather tame in comparison to a summer thunderstorm, but this was proper thunder and lightning for about half an hour. I was working in the library when the moderate snow that morning was suddenly punctuated by a brilliant pink flash which caught everyone's attention, followed very quickly by an almighty bang. It must have been pretty close.

It even made the local paper: http://www.wirralglobe.co.uk/news/4816212.Rare_thundersnow_storm_sweeps_up_the_Mersey/

[Coast]

Never seen it myself unfortunately. Here is an explanation from the National Geographic site:

Thundersnow—when thunder and lighting occur during a snowstorm—most often appears in late winter or early spring, experts say. That's because the ingredients for thundersnow—a mass of cold air on top of warm, plus moist air closer to the ground—often come together during that time.

What Causes Thundersnow

Thundersnow starts out like a summer thunderstorm, Market said. The sun heats the ground and pushes masses of warm, moist air upward, creating unstable air columns. As it rises, the moisture condenses to form clouds, which are jostled by internal turbulence. The "tricky part" for making thundersnow, Market said, is creating that atmospheric instability in the wintertime. For thundersnow to occur, the air layer closer to the ground has to be warmer than the layers above, but still cold enough to create snow—a very precise circumstance.

In the recent southern U.S. thundersnow storms, for instance, the atmosphere became unstable enough that thunderstorms with rain developed. Those storms then moved north where the air was below freezing, said Howard Silverman, a National Weather Service senior forecaster in Sterling, Virginia. The thundersnow events were also coupled with "pretty decent snowfall rates," at the rapid clip of more than two inches (five centimeters) an hour, Silverman said. Heavier snowfall is usually linked to thundersnow, both experts agreed

How to See Thundersnow

Experiencing thundersnow requires being in the right place at the right time, said University of Missouri atmospheric scientist Patrick Market, who has received funding from the National Geographic Society's Expeditions Council. (The National Geographic Society owns National Geographic News.) Even then, he said, you probably won't see anything but white. "In a really nice thundersnow event, the sky [simply] gets bright. You don't see a lightning bolt. There's nothing for a second or two, and then you hear a rumble of thunder." The best spots for catching thundersnow in person are Wolf Creek Pass, Colorado, and the eastern shores of Lake Ontario, Market said—two hot spots that he has pinpointed in his research. Thundersnow can also occur along coasts, experts say, because that's where moisture from warm water can easily evaporate into the colder, drier air above.

Thundersnow to Aid Weather Forecasts?

Market and colleagues track thundersnow storms in the field. After the researchers identify a winter storm, they release weather balloons, which are meant to reveal how the atmosphere becomes unstable. By collecting data on pressure, temperature, humidity, and wind speed and direction—the five key factors meteorologists use to make predictions—Market and colleagues hope their thundersnow studies can help make future weather forecasts more accurate.

Interactive animation here:

http://ngm.nationalg...multimedia.html

http://www.youtube.com/watch?v=qJt4nV6hM1Y

[Nick F]

28th January 2004 always sticks in my mind for witnessing thundersnow. In fact I remember across the breadth of the UK reports of thunder that afternoon/evening on the old BBC snowatch message board - as a very active 'ana' cold front, with sub zero air behind, moved south across the UK undercutting and forcing relatively milder air ahead of the front upwards in cumulonimbus clouds.

Otherwise, away from these less than common frontal thundersmow events, IMO thundersnow is fairly common towards the coasts of the British Isles in cold set-ups in winter, particularly early on in winter - thanks to the contrast in sea temperatures and much colder air above it. Remember thundersnow being reported fairly often near the North Sea coast back in last November/December's bitterly cold spell - with the winds coming from a NE'rly or E'rly direction.

[peterf]

we had it here last year.

[Flipflop]

I never realised you could get thundersnow until last year when someone from here (lewis!) said that we may get some, so i left the the webcam on record

and got this.

The bloke next door looked like he got a bit of a fright and quickly went in

Hope we get some more this winter

Edited September 27, 2011 by Del Trott

[knocker]

Otherwise, away from these less than common frontal thundersmow events, IMO thundersnow is fairly common towards the coasts of the British Isles in cold set-ups in winter, particularly early on in winter - thanks to the contrast in sea temperatures and much colder air above it. Remember thundersnow being reported fairly often near the North Sea coast back in last November/December's bitterly cold spell - with the winds coming from a NE'rly or E'rly direction.

We had thundersnow in Camborne during the same spell in early December. Cold northerly and the western approaches. I can't say it's very common in these parts.

[Stormyking]

Actually 28th January 2004, i think was my first time witnessing it, we was eating dinner and I knwo snow was forecast for the evening but because it was taking so long I was getting impatient, then all of a sudden we was at the table my mum put her finger and was like hold on a second, she opened the back door and we was greeted to blizzard type conditions and right out of the blue a bright blue flash of lightning followed by a crack of thunder. Yes I remember this now as I remember saying to my mum how the hell did you know it was snowing haha.

[4wd]

Fairly common here when beefy showers run down the coast and hit the high ground.

Typically you just get one or two discharges then they move on.

The snowfall can be almost chokingly intense and would give several inches per hour were it not usually a quite short-lived shower.

[Wynn D Woo]

I can only recall one instance, way back in February 1991, I looked out of my bedroom window and thought wow, probably didnt last much longer than 5-10 mins though but did add a nice top up to the snow cover we already had.

[The watcher]

This fanastic nightime one in December last year...never seen it before in Bangor. The precipitation was a mix of snow and pea sized hail which dropped 4-6 inches in about an hour. In total I counted about 13 strikes of lightning.

Edited September 27, 2011 by The watcher

[WinterSnow]

I have seen i quite a few times, i remember first seeing it about 7-8 years ago. Lit the whole street up at night with the snow falling it was pretty magical

[Isolated Frost]

November 29/30 last year I think - brilliant, intense snow.

[chionomaniac]

I have only witnessed it twice, once the 28th Jan 2004 event and the other at night between Christmas and New Year a few years prior to that. I remember the night time episode as I had been sleeping with one eye open hoping for snow from a cold front travelling in from the NW. I was really disappointed to find out that when it arrived it was pouring with rain, so I went back to bed. Within five minutes I heard a large crash of thunder and immediately got up. I knew that the most vigorous section of the cold front had arrived and therefore there was a good possibility that the rain would turn to snow. And sure enough when I looked out we had whiteout conditions. Reward for my patience.

[Nick L]

Seen it once before, really is bizarre but awesome at the same time. Was in January about 7 or 8 years ago.

Edited September 27, 2011 by Nick L

[Coopsy]

Yup in the UK on Jan 28th, 2004 but I dont think I've had it here in Canada though - maybe something to do with dry air in winter and being 1000 miles away from the sea

[I remember Atlantic 252]

seen it once 19th March 07, but because of time of year snow didnt lie

Edited September 27, 2011 by snow? norfolk n chance

[Supercell]

Another thundersnow report from the 28th Jan 2004 event. The most intense period of snowfall I have been in. Walking home from school I thought I saw a flash of lightning, but it wasn't until the thunder boomed that I knew what was happening. Memorable.

[Thundery wintry showers]

I've seen it quite a few times. In Cleadon I had it at 4:50am on the 29th December 2000, woken up by a loud clap of thunder during heavy east-coast snow showers. On the 22nd December 2003, I got woken up by thunder and lightning associated with a cumulonimbus just off the North Sea coast (about half a dozen flashes and rumbles), just after a snow shower had passed through Cleadon and deposited a couple of centimetres of snow cover. Finally, on the 31st December 2009, there were a couple of lightning flashes and one distant rumble accompanying a mix of snow and graupel. I've also had some instances of a hail/sleet mix accompanied by thunder and lightning- three in Cleadon (17th November 1995, 14th/15th December 1999, 8th November 2001) and one occurrence in Norwich on the evening of the 21st November 2008.

I'm aware that Cleadon had thundersnow last winter too- a very close strike on the evening of the 28th accompanying a snowstorm, and then a more significant thunderstorm with snow and hail on the morning of the 29th- but I was away in Norwich on that occasion.

Newcastle seems to be the biggest thundersnow hotspot in the North East, and must surely be a contender for "thundersnow capital of Britain". For instance, there was thundersnow reported quite widely there on the 21st February 1994 and more recently on the 3rd January 2008 and 2nd February 2009, as well as the various occurrences in the last two winters.

[Weather-history]

Never seen it myself unfortunately.

Same here, never seen it.

[Jane Louise]

Thanks for sharing all.

Almost every Winter here in Gloucestershire we have snow but nothing as spectacular as thunder and lightning with it. Something to keep an eye on this winter I guess, but even a normal thunderstorm is a rareity here, but who knows lol .

[Trugoy]

I remember seeing this once about 10 years ago on the south coast, while i'd be lying if i said i remember the month i remember it seemed a little earlier in the year for snow, we got a huge blizzard (huge blizzard by southern Englands standards ) , some lighting and thunder while it was intense and the snow settled although it turned into a sleat storm and was all melted within a few hours..