Possible HP Supercell & 3 Tornadoes 30122006

[Paul Sherman]

Hi Guys, I am starting this thread with regards to Saturday Afternoon and the Storms that moved from the South West into Central Southern England, and Would appreciate any more Info from the affected Areas

Synopsis & Evolution

At about 2pm on Saturday afternoon a pretty strong Cell came ashore in South East Devon, this cell tracked towards Dorset in a East North East direction. By 3pm this Cell was looking very decent on radar imagery and had Supercellular radar characteristics. **If Anyone has the radar saved I would appreciate them posted on here** The 1st Characteristic from this cell was a right Split, where part of the cell broke off and moved North North-Westward towards Gloucester, the right moving split then moved into a VERY Favourable environment (More Associated within the Plains of the USA) A Dry Air Intrusion ahead of the cell was becoming stronger than previously predicted on the model and CAPE Was effectively Doubled in the Moisture Tongue this cell was now riding along. The 850Mb jet was also showing incredible surface shear. IMO This cell was now a bonafide HP Supercell.

Further Synopsis

By 315pm a Warm Front was strectched from South Wales to the Wash with a Cold Front from South Wales to Dorset. A secondry surge of Moisture behind another Warm Front from Sussex to Avon and ANOTHER Cold Front from Avon to South Dorset further Complicated matters and gave us this Unique Situation.

As the Cell moved towards the east of Reading a Possible Tornado touched down near a Place called Winnersh (Berks) Torro members have done site investigations on this, the cell then Bowed out to the South West of London and moved North Easterly towards West Essex, Suffolk and Norfolk, where a Severe Squall line was now apparant, Watfords Premiership match was abandoned due to the intensity of the rainfall, as the line moved through 2 more possible Tornadoes were reported in (1) Haverhill in Suffolk and (2) Ludham in Norfolk.

If any members have anything eg pictures or local reports from any of these places please post them here.

Many Thanks

Paul Sherman

[Paul Sherman]

So I take it no-one has any Info from local reports then :o

Thinking about this more this afternoon the More I am certain this WAS A Supercell.

1. The Radar Signatures were Indicitive of Supercellular Storm

2. The Cell went through at least 1 Splitting Motion (Right Mover)

3. Winds fields were favourable with South West, South East and North East winds just before Tornado Reports

4. Supercell in its Mature Stage then evolved into Bowing Squall Line.

Regards

Paul Sherman

[Nick F]

Hi Paul,

Fortunately I saved the radar image (15.45hrs) around the time the HP Supercell was indicated to have developed Saturday afternoon - just West of London in the Berks/Surrey area:

Wind chart for 15.41 showed strong veering of surface winds over Central Southern England - which possibly caused strong helicity and rotating updrafts in any supercell which formed:

Here is the actual T+00 18z FAX chart that evening, and indicates possible triple point that may have moved over the area a few hours earlier

... though also a main reason was probably a dry air intrusion aloft from the jet streak causing strong convection and also the very strong deep layer of upto 80kts shear due the jet streak aloft (shown below) - which would indicate supercells were possible. Also strong Low-level shear was indicated below - suggesting tornadoes were possible.

T+18 lightning wizard wind shear for 18z Saturday 30th Dec:

[Paul Sherman]

Many Many Thanks Nick, All of this further consolidates that i am nearly 100% certain this was a Rare HP Supercell, what a year 2006 was for Storms. Also worth pointing out the Mammatus field was visible from Central Wales for this Storm and a VERY Pronounced USA Style Mammatus field was visible from the Worcester area.

Paul Sherman

[Nick F]

Certainly looked like a HP supercell, both on the radar looking at ppn rates and shape, the dry air intrusion causing strong convection, and also looking at the wind fields - with strong speed shear aloft with a low level jet, and also surface winds backed from the strong upper flow above it which would allow updrafts to rotate with help of strong veering of surface winds also present.

Interesting that areas West and SW had a good view of the possible supercell's cloud structure, due to clearer, drier air and less low cloud than East and SE of the storm system where the moisture was.

[Mammatus]

Hi everyone, pictures taken Sunday morning after the freak tornado that ripped through Haverhill through to Great Yeldom. This Hotel is two minutes drive from my house, I live 1 mile away (if that). I didn't bother taking pictures of fences/trees down etc as we've all seen that before, these are far more impressive!!

One night I won't forget in a hurry for sure, winds reminded me of October 1987. The description my family/friends gave (all live in Haverhill) 'Sounded like a Train'. I can still picture the moment it happened, scared the s*** out of me, my wife and my house! :lol: Thought our roof was going to go any minute.

These pictures I've taken are of The Hotel Inn on the Bypass in Haverhill. Whilst I were taking these pictures, News24 were doing a live report (roughly 12.25pm, I recognised the reporter too) I'm also sure I saw Sky News there, but can't confirm. Anglia News were also there.

Pictures below - some of Hotel Roof Off, windows blown out and parts of the metal roof wrapped around a tree!! Now you all know why I was ssssssoooooooo excited. Enjoy!!!!!!!!!!!!

[fine wine]

Although I have the radar image saved, I can't upload it as it fails each time. I was in our roof space at the time and it sounded like a train coming. i ran downstairs to see the door blown of the conservatory as well as some of the roof. What followed was 5 - 8 minutes of heavy rain and extremely strong winds. For about a minute or so the winds were the strongest I have ever seen. It was alomst dark when it struck, but as the very strongest winds hit, you could see clear blue sky to the NW and streaks of rain falling. The back of the storm towered high into the atmosphere.

I am located about 5 miles south of Haverhill

[pottyprof]

Sorry I missed this thread earlier Paul..

Hope these help..

[Dazza]

Hi everyone, pictures taken Sunday morning after the freak tornado that ripped through Haverhill through to Great Yeldom. This Hotel is two minutes drive from my house, I live 1 mile away (if that). I didn't bother taking pictures of fences/trees down etc as we've all seen that before, these are far more impressive!!

One night I won't forget in a hurry for sure, winds reminded me of October 1987. The description my family/friends gave (all live in Haverhill) 'Sounded like a Train'. I can still picture the moment it happened, scared the s*** out of me, my wife and my house! Thought our roof was going to go any minute.

These pictures I've taken are of The Hotel Inn on the Bypass in Haverhill. Whilst I were taking these pictures, News24 were doing a live report (roughly 12.25pm, I recognised the reporter too) I'm also sure I saw Sky News there, but can't confirm. Anglia News were also there.

Pictures below - some of Hotel Roof Off, windows blown out and parts of the metal roof wrapped around a tree!! Now you all know why I was ssssssoooooooo excited. Enjoy!!!!!!!!!!!!

Great Captures Mammatus, saw the above on SKY News :lol:

[*Stormforce~beka*]

Well I know I said that because I was going up north that the south would have lots of thunder and all the exciting weather BUT ... I never thought it would really happen!!! Gits! :lol: LOL.

Any cloud pictures from anyone? Paul can you post a picture of this HP Supercell (or what one looks like) please.

[Joneseye]

Hi Paul,

very interesting thread! Haven't got much to add other than the fact that it was some of the most intense rainfall I have ever experienced. A few friends described it as tropical..

I live about 18 miles to the west of Winnersh, but unfortunately haven't got any decent equipment to have captured it.

Ian

[LeeKay]

Here's a Sat. image showing the trough:

[Paul Sherman]

Well I know I said that because I was going up north that the south would have lots of thunder and all the exciting weather BUT ... I never thought it would really happen!!! :lol: Gits! LOL.

Any cloud pictures from anyone? Paul can you post a picture of this HP Supercell (or what one looks like) please.

Beka

Here are 2 diagrams showing HP Supercell formations etc and a Picture of what one of these look like, contrast would have been poor on Saturday but as Nick F Says a clear slot to the West and South West would have given someone a perfect camera opportunity.

Paul (Potty) Thanks for those radar grabs, shows how the cell developed and moved between 2pm and 4pm

[*Stormforce~beka*]

Interesting thanks Paul Jelous as hell am I!!

[Noctilucid]

I know this is not to do with saturdays event but its a pic of a possible HP Supercell that hit The Thanet area back in July :lol:

Joe

[SnowAngel]

I know this is not to do with saturdays event but its a pic of a possible HP Supercell that hit The Thanet area back in July :lol:

Joe

Wow! That is one awesome image! I had a bad storm experience on Saturday. It was afternoon, raining lightly and I was down in our barn getting the horses stables ready for the night, as we were expecting that big storm. Suddenly, there was a cloud burst so intense , it created a flash flood down our fields, like a raging river. Something that has never happened before, even in heavy rain. I hurridly caught my mares and foals in and began to desperately dig a trench to stop our barn and workshop being flooded. Then there was the most terrifyingly bright flash of lightning and deafening clap of thunder. I dropped my metal shovel and bolted into the barn to calm my very frightened girls. It was the only flash of lightning but the flash flood got worse . Luckily my husband and some wonderful neighbours rushed down and diverted the river. I had a snow hurricane last year, that was exciting too!

[Mammatus]

Wow! That is one awesome image! I had a bad storm experience on Saturday. It was afternoon, raining lightly and I was down in our barn getting the horses stables ready for the night, as we were expecting that big storm. Suddenly, there was a cloud burst so intense , it created a flash flood down our fields, like a raging river. Something that has never happened before, even in heavy rain. I hurridly caught my mares and foals in and began to desperately dig a trench to stop our barn and workshop being flooded. Then there was the most terrifyingly bright flash of lightning and deafening clap of thunder. I dropped my metal shovel and bolted into the barn to calm my very frightened girls. It was the only flash of lightning but the flash flood got worse . Luckily my husband and some wonderful neighbours rushed down and diverted the river. I had a snow hurricane last year, that was exciting too!

Thanks for your post.

Would love to experience a snow hurricane, although I must say there quite rare in Suffolk. :lol:

Mammatus

[Mad Murdoch]

I know this is not to do with saturdays event but its a pic of a possible HP Supercell that hit The Thanet area back in July :lol:

Joe

dont know if this is important, but at about 3.pm i saw a cloud just like this, out of the window. i remeeber it well cause it was very pink and i pointed out to my husband.

[Paul Sherman]

Kelly yes it is very important, have you got a picture, at about 3pm you would have been in the perfect position just South of the Supercell with the setting sun coming in from the west. Please post the piccie if you have it.

Paul Sherman

[*Stormforce~beka*]

Thanks for your post.

Would love to experience a snow hurricane, although I must say there quite rare in Suffolk. :lol:

Mammatus

Whats a snow hurricane?!

Kelly yes it is very important, have you got a picture, at about 3pm you would have been in the perfect position just South of the Supercell with the setting sun coming in from the west. Please post the piccie if you have it.

Paul Sherman

We will kill you if you don't ... Paul has taught us all well. DONT GO ANYWHERE WITHOUT THAT CAMERA!!!!!!!!!!!!

[Mad Murdoch]

Whats a snow hurricane?! :lol:

We will kill you if you don't ... Paul has taught us all well. DONT GO ANYWHERE WITHOUT THAT CAMERA!!!!!!!!!!!!

you guys are going to kill me

i was in the middle of moving my bedroom funture, so no i didnt, i did say to my hubbie i would get the camera, but i couldnt get out the room,

i must say it look amazing

sorry u lot

kelly

[*Stormforce~beka*]

This is my response: *Big Tears* *Wail* *Wail* I'm on the next ferry I know where you live :lol:

[Paul Sherman]

Paul S

[*Stormforce~beka*]

Paul S

Two sets of big tears Care to join me on the next boat Paul ... LOL

[Mad Murdoch]

Paul S