What Is This

[JRMcLeod]

Hey Everyone...

Just a quick question! What is the cloud formation in the Yellow Circle?? Anyone got any ideas?? Is it a High Pressure or what? Picture is the latest image from Metoffice

[Nick F]

Look like scattered convective cumulus cells in the polar maritime air giving showers across the North Atlantic

[JRMcLeod]

Whay are they all the same shape?? Would that bring settled weather over the UK if it were above us?? Is it cold air or would it pull warmer air in?? Sorry about all the questions but it will benefit me when looking the next time...

[johnholmes]

hi

the shapes correctly described by Nick are the typical shapes seen on a sat picc for cumulus, fairly shallow type. The cells become 'more blobby' as the convection increases. As to the weather then just a few light showers might come from these as they develop coming south over warmer seas. A similar effect to what happens over land when the temperature rises.

Much more complex than that but its ok for a first idea.

John

[JRMcLeod]

So is this going to head towards the UK?? If so, as it tracks South East will the clouds produce anything in the way of Storms??

[Nick F]

So is this going to head towards the UK?? If so, as it tracks South East will the clouds produce anything in the way of Storms??

I shouldn't think so, as John says, it's fairly shallow cumulus - so light showers at best. Anyway, a ridge of high pressure is expected to build from SW during tomorrow which will suppress most convective activity in the West, before the next Atlantic low arrives from the NW bringing cloud and rain to the NW during Tuesday.

[JRMcLeod]

Hummfff!!! So thunder looks like it aint gonna happen then?? Slightly off topic but is there any signs of anything dramatic weather wise in the next month?? Like Thunder etc...or more extreme heat?? I'm useless at finding decent long range forcasts! Allbeit they aint all that accurate.

Someone posted the lightning strikes that have been in the UK in July from the Metoffice website! Does anyone know if that is updated daily or if it is published monthly??

[Nick F]

Wednesday to Friday this week could see heavy showers with hail and thunder according to GFS spreading South, as winds back NW'erly to N'erly with low pressure close by and colder air arrives aloft steeepning lapse rates.

Weds 18z: http://www2.wetter3.de/Animation_06_UTC/84_20.gif

Thurs 18z: http://www2.wetter3.de/Animation_06_UTC/108_20.gif

Friday 12z: http://www2.wetter3.de/Animation_06_UTC/126_20.gif

It's always usefull to look at GFS Cape and Lifted Index charts to see if there's any potential for storms, anything above 100 j/kg of CAPE and LI <0 gives a good indication that there might be storms. Not really any CAPE and -ve LI until Wednesday in Northern Scotland:

http://www.wetterzentrale.de/pics/Rtavn8411.png

Anyway, keep an eye on the Storms and Extreme weather threads for updates

Re: MO lightning maps, they are only updated once a month, usually 7 days after the each last month's ended.

Edited August 6, 2006 by Nick F

[JRMcLeod]

Cheers Nick...much appreciated...really need to find some sites that can give me details on extreme weather forcasting