storm bertha Possible storm 'Bertha'

[Mokidugway]

Was gonna have a barbecue tomo.Better light it up today instead and put my Bergeron;-)

I'm still having a BBQ tomorrow ,not expecting much up here from Bertha !.......

[Summer Sun]

Updated warning from the met office, still great deal of uncertainty in the forecast at this late stage

 

Issued at: 1117 on Sat 9 Aug 2014

Valid from: 0015 on Sun 10 Aug 2014

Valid to: 2345 on Sun 10 Aug 2014

 

There is the potential for severe weather over much of the UK during Sunday as a depression tracks over, or close to, the UK. There continues to be a great deal of uncertainty in the forecast but the public should be aware of the risk of flooding due to heavy rain as well as very strong winds and large waves, particularly on the southern side of the depression. Given the unseasonable nature of the weather this could be sufficient to disrupt transport and make outdoor activities dangerous. This is a particularly volatile situation, and this alert is likely to be updated as the event approaches. The public are advised to keep up to date with the latest forecasts and alerts through the weekend.

 

Chief Forecaster's assessment

 

The remains of hurricane Bertha, west of the Bay of Biscay on Saturday morning, now possess the characteristics of a mid-latitude depression, albeit with very warm air wrapped up within it. This feature is expected to move towards the UK before deepening on Saturday night and Sunday morning. There is increasing confidence that this depression will affect the UK, though with very large uncertainty remaining over the track and intensity. There is the potential for rainfall totals of more than 50 mm in places and coastal gusts of over 60 mph, along with large waves. The locations affected are very dependent on the track of the low but the heaviest rainfall is thought most likely around and to the northwest of the low centre whilst the strongest winds are most likely around the southern flank of the low.

 

http://www.metoffice.gov.uk/public/weather/warnings/#?tab=warnings&map=Warnings&zoom=5&lon=-3.50&lat=55.50&fcTime=1407625200&regionName=uk

[Mapantz]

A squall line looks to be a feature going by various models, I'm not convinced of too much rain down here, that looks to be more for Wales and across the Midlands and up in to the northeast. The winds look to be the main feature for southern counties, while not a raging storm, it may cause a few disruption problems in some places.

I'm camping at a party tonight, the winds shouldn't cause a problem- they're not expected to pick up here until around 9am. It might be a bit wet for a time though.

[Flash bang flash bang etc]

As long as there is the possibility of lightning I'll be happy.

Oh and also as long as nobody gets hurt too!

Worried we'll hear the all-too-frequent story of someone being careless near the sea and getting into trouble. It always upsets me when people take risks that they don't need to

[Sean19]

Any chance of an estofex being issued later tonight?

[Zenarcher]

The exact track of Bertha seems to look better now than this time yesterday. Below I have made up another quick map that shows the track of it using the GFS, ECM and UKMO. They seem to agree on it passing over the same area and the deepness is expected to be around 990mb which most of the models show although some do have it a bit deeper.

 

 

Using the latest GFS 06z run here's what it says is meant to happen,

 

Sunday 12am to 6am - Bertha approaches the UK from the South West it makes land fall over the South West of England and Southern Wales. Wind gusts of 35 to 45mph are possible with exposed parts seeing gusts of 55mph or slightly more. Very heavy rain moves in as well over this area.

 

 

 

6am to 12pm - The low is now over the Midlands, gusts inland across England and Wales ranges from 30 to 40mph and exposed parts could see up to 50mph. The rain becomes more widespread covering Northern parts of England and the Eastern parts as well.

 

 

 

12pm to 6pm - The low passes over Northern England which brings strong winds there gusts around 40 to 50mph and on exposed parts along the Eastern coasts 60mph is possible. The rain over Wales and England starts to dry up but Northern England and Scotland see the rain at this time now.

 

 

[TonyH]

Showers ahead of it I should think although the satellite suggests they may be embedded yes.

Edited August 9, 2014 by TonyH

[Mapantz]

It looks like Bertha is now starting to show her hand in Cornwall. The satellite is also detecting some lightning in there, so there is a bit of convection there - maybe some embedded thunderstorms?

The NMM14 TT and K index certainly gives a good probability of a convective element, as well as decent SB and ML CAPE- quite significant around the east Midlands and the wash area during the afternoon.

[1976]

It looks like Bertha is now starting to show her hand in Cornwall. The satellite is also detecting some lightning in there, so there is a bit of convection there - maybe some embedded thunderstorms?

Hi, sitting out on hayle beach, sun / part cloud & warm - strangely quite considering, bit of a breeze picking up, small cumulus coming in from the west, no sign of lighting/cumulonimbus, if anything the sky looks clear out at see. Going to check radar.

[knocker]

Well I would differ slightly with that. Cs and Ci encroaching from the west. HE Modis just now. credit  "NERC Satellite Receiving Station, Dundee University, Scotland"  http://www.sat.dundee.ac.uk/

[Mapantz]

The IR imagery looks quite nice.

[johnholmes]

It will be interesting to see what the actual track and depth turns out to be. GFS has consistently taken it further north than either ECMWF or Met. Met have consistently shown it to take a track further south and ECMWF, from my recollections, has tended to be between the other two.

[1976]

Wonder if some of the thunderstorms will make it up to Manchester, we'll know tomorrow! But certainly, she's looking good for convection. Hi, what you describe seems really quite eerie! You'll have to keep us updated!

No storms here. I Can now see 3-4 big what looks like tops of cumulonimbus a long way out to sea across the seascape. Still small cumulus approximately 2 miles at sea developing what looks like a low level/thicker cirrus type cloud around them as I write?? Directly above is virtually clear, odd bit of cloud and warm sunshine. mild pleasant breeze.

[TonyH]

There are no thunderstorms as yet associated with Bertha, just a few sferics over Ireland in the showery airstream ahead.

[tinybill]

Bertha  can bee see now if your got rain alarm  can be see in the app to Irish sea

[William Grimsley]

Pretty sure this will whizz through quite quickly tomorrow especially in the south where rain soon clears to sun and showers, wetter further north as the low moves up there. Wind- wise slight chance of gales more especially towards the east coast pm, generally though probably nothing more than a rather windy day with gusts 30 to 40mph.

Ah, no it will be higher than 40 mph trust me.

[Sean19]

Netweather have forecast my location in Essex with thunderstorms tomorrow afterrnoon with heavy rain. But yet there are no mention of thunderstorms in any of the weather warnings I have read, why is this?

[knocker]

Warm and moist air moving in aloft.

Edited August 9, 2014 by knocker

[Skullzrulerz]

There is a live lightning strikes website if you need it.

 

http://www.blitzortung.org/Webpages/index.php?lang=en&page_0=12

 

Just looked on the met office and looking on St.austell the max gust of wind i am going to get is 40mph I was thinking it would be higher.

 

Can someone please answer this.

 

How bad do you think south Cornwall is going to get in terms of wind speeds and rain?

Edited August 9, 2014 by Skulltheruler

[William Grimsley]

There is a live lightning strikes website if you need it.

 

http://www.blitzortung.org/Webpages/index.php?lang=en&page_0=12

 

Just looked on the met office and looking on St.austell the max gust of wind i am going to get is 40mph I was thinking it would be higher.

 

Can someone please answer this.

 

How bad do you think south Cornwall is going to get in terms of wind speeds and rain?

The system intensifies as it moves NEward from Cornwall, that's why only 40 mph is shown.

[Chris K]

The system intensifies as it moves NEward from Cornwall, that's why only 40 mph is shown.

 

Yep, currently, most of the models suggest highest wind gusts will be seen along eastern coasts and eventually E & N Scotland. Gusts here could reach 50, maybe 60mph in exposed areas. 

 

SW areas looking more in the region of 30-40mph gusts (a bit higher perhaps on the coasts?). it will also depend how ex-Bertha continues to develop whilst crossing the UK.

[Skullzrulerz]

The system intensifies as it moves NEward from Cornwall, that's why only 40 mph is shown.

 

Oh well better luck next time.

Find out soon then.

[BornFromTheVoid]

Here she comes, courtesy of the MODIS on Terra.

 

 

http://lance-modis.eosdis.nasa.gov/imagery/subsets/?subset=Europe_2_01.2014221.terra.1km

 

Taken around 12:30 today

[BrickFielder]

  Still no real visible circulation to ex bertha, so the models are still likely to be up in the air. Looking at the current model outputs there are a few things to consider.

  First set of charts come  curtesy of lightning wizard based on GFS output.

 

This shows there is some residual moisture at the surface after the cold front has moved through.

 

NMM suggests a possibility of some  postal frontal storms.

 

Notice that the dry air does not really wrap into the system, probably meaning that the energy is not there for a bent back occlusion and a sting jet as the system crosses the UK.

 

This could be a bit of an unstable environment.

 

Looking at satellite pictures I think we are likely to get a significant warm sector shield, but there might be an oppotunity for some line convection on th back edge of the cold front.  We should also not ignore the triple point if it crosses the UK as this may have a wind field suitable for the formation of a mesocyclone.

 

One final chart which should be taken with a large pinch of salt.

 

Personally I am not sure the system is going to play ball the way models predict and there is a big risk it will all come to nothing. So its still way to early to predict.

 

Biggest risks are still from heavy rainfall and localised flooding. Depending on how things develop there is potential for a severe thunderstorm although tops look a little low, and cloud cover will play a part. Potential for some more covective activity in western areas late on as well.

 

[Mapantz]

Personally, I'm looking forward to the thundery element tomorrow morning with the potential of a squall line too.