Thunderstorm/Convective Watch - Spring/Summer 2012

Hammer Archer

Damn my heavy sleeping.

cotton

I'm the other side of Bray Head & it was quite spectacular. The thunder woke us up with a bolt, it looked amazing over the sea, the sky was black & the sea was something else. Lots of tunder hail too. Very pleasant surprise this morning.:)

Iancar29

jd wrote: »

Here ya go..

OMG!!!!!! I CANNOT BELIEVE I MISSED ALL THIS!!!!!!!!!!!

Did Trogdor get this!?!

Omg i cannot believe this!! .... :mad::mad::mad::mad::mad:





AMAZING VIDEO ! I cannot i missed this all happening !

But i must say ... its a WATER SPOUT .... NOT .. an Tornado.

A waterspout is an intense columnar vortex (usually appearing as a funnel-shaped cloud) that occurs over a body of water and is connected to a cumuliform cloud. In the common form, it is a non-supercell tornado over water.[While it is often weaker than most of its land counterparts, stronger versions spawned by mesocyclones do occur. Waterspouts do not suck up water; the water seen in the main funnel cloud is actually water droplets formed by condensation.[4] While many waterspouts form in the tropics, locations at higher latitude within temperate zones also report waterspouts.

Mc4pc

Another video here!

http://www.youtube.com/watch?v=f0hecJea_38&feature=youtube_gdata_player

Iancar29

The following are 4 radar screen grabs from the storm this morning. :cool:



https://us.v-cdn.net/6034073/uploads/attachments/207463/200407.png

https://us.v-cdn.net/6034073/uploads/attachments/207463/200405.png

https://us.v-cdn.net/6034073/uploads/attachments/207463/200408.png

weisses

Iancar29 wrote: »

OMG!!!!!! I CANNOT BELIEVE I MISSED ALL THIS!!!!!!!!!!!

Did Trogdor get this!?!

Omg i cannot believe this!! .... :mad::mad::mad::mad::mad:

A waterspout is an intense columnar vortex (usually appearing as a funnel-shaped cloud) that occurs over a body of water and is connected to a cumuliform cloud. In the common form, it is a non-supercell tornado over water.[While it is often weaker than most of its land counterparts, stronger versions spawned by mesocyclones do occur. Waterspouts do not suck up water; the water seen in the main funnel cloud is actually water droplets formed by condensation.[4] While many waterspouts form in the tropics, locations at higher latitude within temperate zones also report waterspouts.

Totally agree with you there However this happened in The Netherlands

Waterspout>Tornado 1972 August 11 and 1992 August 17, Ameland
Waterspouts are a regular occurrence in Dutch coastal areas in the late summer and autumn and are estimated to occur roughly 10 times a year on average . Usually the entire life-cycle of these waterspouts takes place over water, although every now and again a waterspout comes onshore and becomes a tornado. Such a thing happened in 1972 when seven people were killed and 90 were injured at a campsite on the northern Dutch island of Ameland when a tornado passed over the site . During this tornado, caravans - some of them occupied at the time - were lifted up by the force of the tornado. A fraction over 20 years later, in 1992, a similar thing happened at another campsite on the same island . This time one person was killed which, at the time of writing, was the last time a tornado killed anyone in the Netherlands.

Full article

http://www.dandantheweatherman.com/Bereklauw/dutchtns.htm

Su Campu

Waterspouts and tornados are exactly the same thing - the only difference is where they occur. A waterspout can become a tornado, and vice versa, if it moves from one surface to another. It looks like this one could have hit land briefly before dissipating, as many waterspouts do when they hit land.

BEASTERLY

Iancar29 wrote: »

But i must say ... its a WATER SPOUT .... NOT .. an Tornado.

A waterspout is an intense columnar vortex (usually appearing as a funnel-shaped cloud) that occurs over a body of water and is connected to a cumuliform cloud. In the common form, it is a non-supercell tornado over water.[While it is often weaker than most of its land counterparts, stronger versions spawned by mesocyclones do occur. Waterspouts do not suck up water; the water seen in the main funnel cloud is actually water droplets formed by condensation.[4] While many waterspouts form in the tropics, locations at higher latitude within temperate zones also report waterspouts.

Further research suggests that most waterspouts are not tornadoes. But these waterspouts rarely come from thunderstorms. If a waterspout was born from an actual thunderstorm it most likely is a tornado just over a body of water. Considering the conditions in Bray this morning with large hail and thunder and lightning, a very definite strong thunderstorm. My guess would be that this waterspout was in fact a Tornado.

BEASTERLY

Su Campu wrote: »

Waterspouts and tornados are exactly the same thing - the only difference is where they occur. A waterspout can become a tornado, and vice versa, if it moves from one surface to another. It looks like this one could have hit land briefly before dissipating, as many waterspouts do when they hit land.

Not true most of the time it seems http://www.dtmag.com/Stories/Dive%20Weather/09-99-weather&waves.htm

But I do think it is wrong to be telling people that this was not a tornado. As in this case it could well have been.

Iancar29

Su Campu wrote: »

Waterspouts and tornados are exactly the same thing - the only difference is where they occur. A waterspout can become a tornado, and vice versa, if it moves from one surface to another. It looks like this one could have hit land briefly before dissipating, as many waterspouts do when they hit land.

Theres 2 different types.NOn- Tornadic and tornadic.

This event was a Non-Tornadic event, forming form some towering cumulus rather that the updraft of a tornadic supercell. Other-wise known as fair weather water spouts....

They usually only have a EF0 maybe EF1 rating.

BEASTERLY

Iancar29 wrote: »

Theres 2 different types.NOn- Tornadic and tornadic.

This event was a Non-Tornadic event, forming form some towering cumulus rather that the updraft of a tornadic supercell. Other-wise known as fair weather water spouts....

They usually only have a EF0 maybe EF1 rating.

So are all twisters that form outside supercells over land technically called ''landspouts''?

Wild Bill

Wild Bill wrote: »

I'd estimate contact with the water to be about 100 - 200m diameter. Anyone any idea of the likely wind speed involved at the surface?

- hard to tell from the video but it looks like it might have passed across the DART line (which is literally on the shore at that point).

Common - someone tell me :rolleyes:!

Iancar29

BEASTERLY wrote: »

So are all twisters that form outside supercells over land technically called ''landspouts''?

Nope landspouts are such called when a water spout originating over water moves onto land. So this would be a landspout for a short time before it dissipated too im sure.


I hope they have Met Eireann sort all this commotion out later on.... if im wrong im wrong ha... but thats what i learnt in college...

weisses

Waterspouts

By Bruce B. Smith, Meteorologist
Science and Operations Officer, NWS Gaylord

1. What is a Waterspout?

Persons living in northern Michigan are well aware that the Great Lakes have a profound impact on local weather patterns. Examples include heavy lake effect snows in winter, and cooling lake breezes in summer. As the end of the summer season approaches, another type of unique Great Lakes weather phenomena is possible -- the waterspout. The following waterspout photo was taken over Lake Huron in the fall of 1999.

Waterspouts on Lake Huron

Dr. Joseph Golden, a distinguished waterspout authority with the National Oceanic and Atmospheric Administration (NOAA), defines the waterspout as a "funnel which contains an intense vortex, sometimes destructive, of small horizontal extent and which occurs over a body of water." The belief that a waterspout is nothing more than a tornado over water is only partially true. The fact is, depending on how they form, waterspouts come in two types: tornadic and fair weather.

Tornadic waterspouts generally begin as true tornadoes over land in association with a thunderstorm, and then move out over the water. They can be large and are capable of considerable destruction. Fair weather waterspouts, on the other hand, form only over open water. They develop at the surface of the water and climb skyward in association with warm water temperatures and high humidity in the lowest several thousand feet of the atmosphere. They are usually small, relatively brief, and less dangerous. The fair weather variety of waterspout is much more common than the tornadic.

Waterspouts occur most frequently in northern Michigan during the months of August, September, and October, when the waters of the Great Lakes are near their warmest levels of the year. Waterspout formation typically occurs when cold air moves across the Great Lakes and results in large temperature differences between the warm water and the overriding cold air. They tend to last from about two to twenty minutes, and move along at speeds of 10 to 15 knots.

Dr. Joseph Golden distinguishes five stages of waterspout formation:

Dark spot. A prominent circular, light-colored disk appears on the surface of the water, surrounded by a larger dark area of indeterminate shape and with diffused edges.
Spiral pattern. A pattern of light and dark-colored surface bands spiraling out from the dark spot which develops on the water surface.
Spray ring. A dense swirling annulus (ring) of sea spray, called a cascade, appears around the dark spot with what appears to be an eye similar to that seen in hurricanes.
Mature vortex. The waterspout, now visible from water surface to the overhead cloud mass, achieves maximum organization and intensity. Its funnel often appears hollow, with a surrounding shell of turbulent condensate. The spray vortex can rise to a height of several hundred feet or more and often creates a visible wake and an associated wave train as it moves.
Decay. The funnel and spray vortex begin to dissipate as the inflow of warm air into the vortex weakens.

2. How does the National Weather Service forecast waterspouts?

National Weather Service (NWS) meteorologists consider forecasting waterspouts during the late summer and fall whenever large, cool air masses overspread the waters of the Great Lakes. Water temperature, air temperature, moisture, and wind speed in the lowest several thousand feet of the atmosphere are among the parameters forecasters assess when determining the likelihood of waterspouts. Waterspouts become favorable when water temperatures are warm, the air is cold and moist, and wind speeds are relatively light.

3. What forecasts and warnings are issued by the National Weather Service to warn of waterspouts?

Once the NWS has determined that waterspouts are possible, the threat is outlined in the Nearshore Marine Forecast and Hazardous Weather Outlook. The NWS strives to provide this information to the public 12 to 24 hours prior to waterspout occurrence.

When waterspouts have been detected by Doppler Radar or reported by local law enforcement or spotters, the NWS issues a Special Marine Warning. Since it is not uncommon for numerous waterspouts to occur simultaneously over a large area, these warnings tend to cover larger geographic areas than land-based tornado warnings which generally cover a single county.

In most cases, waterspouts which make landfall are much weaker than tornadoes, produce little or no damage, and dissipate quickly. Once on land, they tend not to be a great threat to life and property. In these instances, the NWS issues a Severe Weather Statement. In rare cases, stronger waterspouts may produce significant damage when making landfall. These waterspouts can be a significant threat to life and property. In these cases, the NWS will generally issue a Tornado Warning.

4. What should you do?

Take waterspouts seriously. If you are a boater or a person living along the coast of the Great Lakes you should be aware of their destructive potential. When warnings are issued for waterspouts, be prepared to quickly seek safe harbor, or to find shelter out of the path of the waterspout.

Your best source for waterspout forecast information is NOAA Weather Radio (NWR). These continuous broadcasts from transmitters scattered around the Great Lakes provide forecasts and warnings 24 hours a day.

Iancar29

Wild Bill wrote: »

Common - someone tell me :rolleyes:!

between 75 and 110 mph

blackius

On a related weather note croghan mtn in south Wicklow has snow on it from this mornings showers.
Lugnaquilla is also majestically white from head to toe now viewable from Arklow.

Iancar29

blackius wrote: »

On a related weather note croghan mtn in south Wicklow has snow on it from this mornings showers.
Lugnaquilla is also majestically white from head to toe now viewable from Arklow.

Sure its not hail?

blackius

Iancar29 wrote: »

blackius wrote: »

On a related weather note croghan mtn in south Wicklow has snow on it from this mornings showers.
Lugnaquilla is also majestically white from head to toe now viewable from Arklow.

Sure its not hail?

pretty certain as I was up at croghan and lug would be over a 1000ft higher

Trogdor

Can't believe i missed this, literally just a few minutes away from my house but i wasn't at home last night

Iancar29

Some more cells popping up teasingly just near the IOM ... *FINGERS CROSSED! *

DOCARCH

Iancar29 wrote: »

Some more cells popping up teasingly just near the IOM ... *FINGERS CROSSED! *

Just saw those on radar! Hopefully they don't all go south like this mornings 'episode'. I put a lot of time and effort into monitoring this morning developing storm!

Iancar29

DOCARCH wrote: »

Just saw those on radar! Hopefully they don't all go south like this mornings 'episode'. I put a lot of time and effort into monitoring this morning developing storm!

It seems to be going southwards ... * GETS ON BICYCLE AND CYCLES LIKE LANCE ARMSTRONG TO BRAY!! * ha :rolleyes:

arctictree

Power is back here but all my internet equipment has been fried. (On mobile now). That's the second time in 4 years my house has been struck by lightening. It seems the strike comes down from the wireless panel on the roof and blows anything on that circuit. I was in the kitchen this morning and it was like an explosion inside the house.

Note to self, unplug the router and panel during a thunderstorm!

Su Campu

arctictree wrote: »

Power is back here but all my internet equipment has been fried. (On mobile now). That's the second time in 4 years my house has been struck by lightening. It seems the strike comes down from the wireless panel on the roof and blows anything on that circuit. I was in the kitchen this morning and it was like an explosion inside the house.

Note to self, unplug the router and panel during a thunderstorm!

Sorry to hear that, it's a right pain

ThisRegard

Iancar29 wrote: »

Sure its not hail?

Was in Roundwood at 7am and there was a mix of hail, sleet and definitely big wet snow flakes, and lots of it.

And I have pics from the N11 of the spout, it looked quiet cool but the pics didn't do it justice, taken with a phone at motorway speed. Lots of thunder and lightning too, alongside the big smoke plume from the fire in the pub.

DOCARCH

Iancar29 wrote: »

It seems to be going southwards ... * GETS ON BICYCLE AND CYCLES LIKE LANCE ARMSTRONG TO BRAY!! * ha :rolleyes:

I think those showers in the Irish Sea will take the same track as this mornings - missing here - but making landfall in south Co. Dublin and north Wicklow.

Trogdor

Hailstones pelting down here at the moment

cotton

Trogdor wrote: »

Hailstones pelting down here at the moment

Sun's just gone in here, sky gone black, they must be heading our way.

BEASTERLY

Iancar29 wrote: »

Nope landspouts are such called when a water spout originating over water moves onto land. So this would be a landspout for a short time before it dissipated too im sure.


I hope they have Met Eireann sort all this commotion out later on.... if im wrong im wrong ha... but thats what i learnt in college...

I'm sure you're right it's just a bit confusing. So there is different qualifications for a vortex to be tonadic over land and sea. If it's over sea it has to be from a supercell. Overland they are all tornadic? Seems strange.

Iancar29

BEASTERLY wrote: »

I'm sure you're right it's just a bit confusing. So there is different qualifications for a vortex to be tonadic over land and sea. If it's over sea it has to be from a supercell. Overland they are all tornadic? Seems strange.

Its basically what it comes from , severe storm , low eleveated clouds , that would be a tornadic one.

But todays seemed to be the "fair weather " one.

Over land u can have Gustnadoes ..... then fair weather tornadoes that seem to form from high elevated clouds too just like today.

Its confusing at the start but ye most people seeing one over sea would call it a tornado but then the type of that tornado is later decided by the type of storm / clouds in which it was produced .

You can also have a snow spout too! ha