Wednesday 25 November storm

[SmartD]

Hi all-

Global model output suggests this front on a convergent trough with a

pre-frontal low-level jet (~30 m/s) will form into a sharp ana-cold

front. Expected is a core/gap morphology with Line Echo Wave Pattern

characteristics. UKMO invent output (presumably processed 1.5 km var)

is predicting such-

http://www.metoffice...ent/weathermap/

There is a risk of localised damaging winds and brief tornadoes.

I would be grateful if reports of damage and unusual AWS readings

could be amended here. It is important that AWS users switch to high

frequency logging. 5 min logging is insufficient to record the frontal

passage.

Time frame is 18Z 24th to 06Z 25th all of England and Wales as the

front progresses eastwards,

thanks,

David

davidDOTwaghornATgmailDOTcom

I am still interested in seeing high-resolution (1 min) AWS records of this front eg with pressure kicks of =>2 hPa, strong wind gusts (>25 m/s, ~50 kt) and veer at frontal passage,

thanks,

David

davidDOTwaghornATgmailDOTcom

[johnholmes]

sorry unable to help David-very subdued when it went through here so my AWS does not show anything like you request.

An interesting front mind you-I don't recall seeing what with quite such good characteristics-enjoyed reading the paper of yours with Keith Browning and I did understand most of it!

[Zenarcher]

Gusting around 55mph here with heavy hail showers passing over.

[stormforce 10]

very stormy here overnight, was woke up about at 03:00am the wind was ferocious.

still very windy here with passing heavy showers. some impressive shower clouds around.

[SmartD]

sorry unable to help David-very subdued when it went through here so my AWS does not show anything like you request.

An interesting front mind you-I don't recall seeing what with quite such good characteristics-enjoyed reading the paper of yours with Keith Browning and I did understand most of it!

Cheers John,

it looks like the tendency last night was for the rain cores to be tilted down (the system-relative) wind., with less upright updraughts and a weaker gravity current flow compared to 24 sept 2007.

David

[johnholmes]

I suspect that you could very quickly lose me David-as an ex senior forecaster reading output from Keith and listening to an occasional lecture from him was about my limit, although his work into frontal activity, especially his early work around the Scilly Isles-Project Scilly I think led to an increasing awareness of conveyor belt fronts. That said I find it extremely interesting and your work certainly highlights the number of occasions when this type of frontal activity associated with the Ana cold front can and does occur.

For myself I had never noticed so vividly the radar effects which last night showed-it seemed a classic to me but I'm just an interested onlooker really. So your views will be avidly read on here David.

[Guest North Sea Snow Convection]

Yet another very windy night, which was sleep preventing (again) in terms of having a bedroom window facing towards the weather direction, but that apart, there was literally a minute or so of very blustery rain around 4.30am and that was it. Was waiting for something else to happen, but to my grateful surprise it didn't and sleep finally arrived as the wind suddenly faded out.

[coldfingers]

I'm shocked to see no warnings out from metoffice gusting to 62mph here.

I also thought that this morning around 2:00am to 3:00am as the wind then was 41.2kn/47.4mph/F9 and gusting to 52.6kn/60.5mph/F10. However for the coast here that is really just an Autumn storm so perhaps why the METO seems to be just concentrating on giving warnings for the rain.

I assume that was a cold front passing through as the temperature has gone down from 14C at 2:00am to 9.8 now.

This soft southerner is feeling chilly. :lol:

Edited November 25, 2009 by coldfingers

[sammie]

=O I'm shocked to see no weather warning out for here, were gusting up at 21 meters a second now!

[glasgow-guy]

=O I'm shocked to see no weather warning out for here, were gusting up at 21 meters a second now!

dunno what the meto is playing at today but its blowing a gale here really shocked also that there is no warning. yet yesterdays warning was not needed for the Strathclyde area

[sammie]

dunno what the meto is playing at today but its blowing a gale here really shocked also that there is no warning. yet yesterdays warning was not needed for the Strathclyde area

I'm starting to get really nervous now, the wind here is dangerous security are discussing if its safe to keep campus open or if they are going to have to shut it. The library is shaking.

[glasgow-guy]

I'm starting to get really nervous now, the wind here is dangerous security are discussing if its safe to keep campus open or if they are going to have to shut it. The library is shaking.

my nearest weather station is reporting gusts of up to 38mph its further inland than where i am so i reckon perhaps gusts are maybe around 55mph where i am

structural damage will occur at 65-70mph so i wouldn't worry at the moment

[sammie]

my nearest weather station is reporting gusts of up to 38mph its further inland than where i am so i reckon perhaps gusts are maybe around 55mph where i am

structural damage will occur at 65-70mph so i wouldn't worry at the moment

you have not seen how badly built this building is...does any one know when this is meant to dye down ?

[grab my graupel]

Rather blustery here, but nothing significant, with gusts of around 45mph.

Quite similar to what I experienced at the weekend, so far.

[glasgow-guy]

you have not seen how badly built this building is...does any one know when this is meant to dye down ?

i think the warning is out till 18:00 hrs well on this site at least...

[sammie]

i think the warning is out till 18:00 hrs well on this site at least...

hopefully it will clear through by then my best friends coming up from London on the train and I'm worried about her getting in on time with this weather. And I don't want to have to go back out in it to pick her up.

My hair is ruined and my brolly torn to shreds.

[SmartD]

I suspect that you could very quickly lose me David-as an ex senior forecaster reading output from Keith and listening to an occasional lecture from him was about my limit, although his work into frontal activity, especially his early work around the Scilly Isles-Project Scilly I think led to an increasing awareness of conveyor belt fronts. That said I find it extremely interesting and your work certainly highlights the number of occasions when this type of frontal activity associated with the Ana cold front can and does occur.

For myself I had never noticed so vividly the radar effects which last night showed-it seemed a classic to me but I'm just an interested onlooker really. So your views will be avidly read on here David.

It is a rather specialised subject and there is not that much recent work from the UK to put it in context. Much of the recent research originates in the States. I think UKMO and other forecasters/nowcasters will have to think more about it though as Doppler becomes more available and the grid spacing of operational models goes to ~1km.

I am happy to answer any questions (as best i can!) about the paper if people are interested,

best,

David

[glasgow-guy]

slight improvement barometer rising 975.4mb 1.9mb/hr looking brighter also so perhaps the worst is over for now

[sammie]

Hopefully. The roof of the comp library I'm sitting in just got damaged, security are clearing out the building now and closing down the surrounding area.

Lovely I have to go back in to the wild now.

[sunny scunny]

Rather breezy, with the average wind speed at 30mph, with the strongest gust so far at 44mph.

[West Sussex Kate]

Saw a few trees down in the area

[johnholmes]

some of you were suggesting that the Met O should have had warnings out for the wind-perhaps you are not aware of the criteria they use

this is it

Severe gales

Repeated gusts of 70 m.p.h. or more over inland areas.

now, it may be me, but I have not seen anything even approaching that for the Forth-Clyde area?

There has been a warning out since early morning for more northern areas.

[Callie]

Very heavy and squally rain and then a very close lightning strike here in Eastbourne.

[Mondy]

Never even bothered to check for warnings. Knew myself what was coming. Gusty and more rain. Some damaging gusts I hear. Just gotta get on with it. We're used to it up here ;-)