Evening thunder

Groundhog day, i.e a cloudy morning brightening to hazy sunny spells, with temp maxing 21.5-22c. Though todays max could be a touch higher. Currently 21.1c with hazy sun, thin cloud just clearing from the north though cumulus starting to bubble up. Could do with an input of fresh air to clear this haze/pollution.

Cloudy once again. Yesterday the forecast I had seen said sunshine but it was cloudy all day. Today the Met Office say sunshine this afternoon, but the BBC forecast I saw about an hour ago looked like staying quite cloudy. The odd bit of hazy brightness and 18.5c, but on satellite a lot of cloud lingering here when it's clear blue skies west of Mid Devon. On the local forecast these are meant to be sunnier days before more cloud later in the week.

There must be a different phenomena in some parts but we never get 'smelly' mornings here, unless on a couple days a year a farmer has spread muck nearby, which tends to happen in Spring or Summer more. Looking outside, the trees look much the same as they did in August. Mainly green, the odd tint of colour perhaps, so nature still looks more summer than other things. Driving around you see some colour on a few trees, more than you might expect and the temp drop from July (mean 17.5c) to August (mean 14.9c) may have something to do with that, providing a temp drop more common for August-September where we would be at the start of October now instead. There are some aspects I like about this time of year, we can get shallow mists and fogs over the fields in the valley which can be beautiful in their own way, and I don't have to get up at quite such a silly time to see them (they occur in all seasons as do relatively cool nights here so aren't necessarily autumnal), or a sunrise. I like hints of Autumn colour amongst the green, in a way it adds something after a while being just green. Seasons are divided into neat 3 month blocks for record keeping and to provide some kind of definition, the truth is there is not a fixed sudden 'click' into Autumn or any season in nature and it's pretty similar to how it was in August still. Go tell my Gran it's Autumn now, she'll say it starts on 21st September. Some on here argue spring, summer starts around the 21st of the month. Hopefully none of them are now saying summer's over by the 1st because they want it to be Autumn or Winter instead. To me there really isn't a sudden boundary where 'now it's Autumn so I must change my attitude to everything'.

Much better than yesterday which was cloudy all day and I don't think there was any sun at all. Today has been pretty much sunny all day with generally just 1 octas small cumulus. Temp reached 21.1c, the highest since the 9th August (Though only just as it reached 21.0c 3 days ago)

There definitely seems to be an increasing concentration of quakes NE of Askja, starting to look similar in activity as the main dyke, but extends less deep. Shows both on the Icelandic Met pages e.g http://en.vedur.is/earthquakes-and-volcanism/earthquakes/vatnajokull/ and the 3D site (http://baering.github.io/) Maybe another intrusion, possibly allowed to occur in response to stress changes from the main dyke?

Bardarbunga 2 webcam zoomed in so can see more detail, seems to be coming from more than one crack or section along the same crack Aviation colour code upgraded to red http://en.vedur.is/earthquakes-and-volcanism/volcanic-eruptions/ Wasn't quite sure if it would be as it may not fulfil the 'significant ash emission into the atmosphere likely' part, but probably the eruption existing overrides that Need to go to bed but this is distracting, only checked by chance. Edit: beaten to it.

Well there we have it. Did notice a M3.1 quake only about 1-2km depth along with some other 2+ ones in the evening so maybe that was related. Edit: confirmed at the top of the Icelandic Met Office website: http://en.vedur.is/earthquakes-and-volcanism/articles/nr/2947

Was wondering if they would put Askja on yellow alert soon. This appears to show the cauldrons and certainly shows some rather interesting cracks in an old lava field north of the Glacier. http://ruv.is/frett/sprungur-i-holuhrauni-a-myndbandi The way they cross a streams/recent fluvial sediment deposits in the video and the preview image show they are new and caused by this event. Likely caused by stress changes due to the intruding dyke though not forming a continuous link to it yet as there is a lack of an eruption. If one was occurring/had occurred these flights should have discovered it.

Don't suppose it's possible that that these cracks/caldrons in the ice are the result of a eruption back when increased harmonic tremor led the Icelandic Met to suspect a small eruption was occurring, or do we know this tremor occurred in a different location?. I assume the area was flown over after then too so this is more recent? Have noticed perhaps a slight increase in small EQ's around the Bardarbunga caldera as well as the bigger ones we're seeing, and also near to Askja, though perhaps these are just aftershocks to the bigger quakes. However maybe the subsidence/ring faulting allowed a small amount of magma to be 'squeezed up' which caused the melt? As for fissure eruptions I could be wrong but doubt they tend to occur with the 'ground falling into a void', or being able to look down and see lava sat at the bottom at least before any eruption? If a connection to the surface opens up the magma is likely to be forced up and out by higher pressure below. So mainly just a crack opens and you get lava flowing/fountaining out, on a small scale if a crack split and re-joined maybe the small section of cutoff land could 'cave in'? ^ I think if a fissure eruption had been occurring for days the IMO or someone would know about it..

Also it probably relates to temperature and humidity to an extent, for example this morning lots of steam was present, later on as relative humidity had dropped due to higher temperatures, any steam was close to the vents, and now in the evening as it cools more steam is coming back. I noticed this morning that the 3D earthquakes page http://baering.github.io/ showed an additional M5.2 occurred at Askja as well as a M4.5 (not shown by default now as more than 16 hours ago, you'll need to change the timeframe), but the IMO page and their updates made no mention of it (just showing the 4.5 event as well as the 5.2 and 5.4 at Bardarbunga), so assume it must be an error.

Generally overcast and dull all day, with some drizzle and then light-moderate rain. Now the drizzle monster has well and truly set in with a soaking drizzle and fine rain falling at intensity of 4.4mm/hr just now. One of the worst days this month for summery weather/outdoor activities although the morning-early afternoon just had a bit of drizzle (Monday was wet most of the day but with some sunshine later). Yesterday was quite nice mainly and reached 20.4c. I'd say a couple recent Augusts were worse than this one here, such as August 2008.

Yes I posted in response to Buriedundersnow's post but saw yours afterwards as we both posted at the same time, Was just intrigued that estimates can vary that much, apparently a M5.7 earthquake releases 251 times more energy than a M4.1! according to this: http://earthquake.usgs.gov/learn/topics/calculator.php Interesting to have it upgraded to 5.7 on the Icelandic Met Office site, even that releases nearly 4 times as much energy than the 5.3's we've had. I wonder if it means anything or just continued subsidence as mentioned above, and also whether that 4.6 in the dyke or the 3.3 at about 30km (deeper than what we've seen) means anything much.

Had 6.2mm since midnight according to the manual rain gauges, bringing the monthly total to over 100mm. Hasn't felt especially wet this month though with quite a lot of dry/mostly dry days. Certainly not as wet as summer months in 2012 and some previous years.

The Met Office and BBC maps show the heaviest showers mainly from IOW westwards into Devon, though may be mainly north of here.

That's odd still shows as around 4.1 on here http://en.vedur.is/earthquakes-and-volcanism/earthquakes/vatnajokull/ (Edit: written before seeing Crepuscular Ray's post but still quite a difference)

Low of 3.8c here this morning, not quite as low as the 20th that reached 3.4c or my August record of 3.0c in 2010. Probably partly due to some cloud coming in late in the night. Some sunshine and brightness early but mainly cloudy thereafter, a max of 16.6c which is the coolest of this cool spell and the only sub-18c max here. In fact the coolest max since June the 4th. The next thing will be to see how much rain we get from this system.

The Met Office forecast for the SW tonight is quite interesting for August: 'A dry evening with some late sunshine. Temperatures falling sharply under the influence of clearing skies and light winds, leading to a grass frost in prone rural spots overnight. Cloud is likely to spread into western areas by dawn. Minimum Temperature 2 °C.' Although the forecast I use for a nearby town is actually a degree higher (7c verses 6c) than last week when we had 3.4c here. Not sure if we will get lower here or not. 3.0c in 2010 to beat to break my August record. Maxima of 18.6c today with sunny spells, quite sunny now. We haven't had any maxima below 18c during this spell and very little rain at all since the 14th. Not bad if you don't mind the cool temperatures really. Tomorrow looks like it may actually be the worst day of this spell here, with it forecast to cloud over limiting maxima to 15c.

A picture from the link The PIT posted in case some can't the webcam to work (I couldn't for a while). Looks like something happening, not very energetic/explosive though. Or perhaps steam, or even dust blowing in strong winds but looks a bit localised for that

Lol just saw the webcam on this page shake quite a lot for a few seconds.. unless someone is up there wobbling it. http://baering.github.io/ Hang on.. just saw there's a tick box called 'shake webcam on updates'.. doh wasn't properly paying attention to it.

Pretty consistent maxima for me over the last 5 days. Sun 17th: 18.7c Mon 18th: 18.4c Tue 19th: 18.1c Wed 20th: 18.4c Thu 21st: 18.4c No maxima below 18c so perhaps not too bad or as bad as some places. Minima more variable though, last 7 days graph:

Min of 3.8c last night.17.4c peak so far, then dropped back a little, but so far every day has managed to reach 18c and today might do later. That's back home, as I'm in Surrey for a couple days. Quite cloudy up here and ~17c

Down to 3.4c here last night in balmy Devon. Even a touch of frost on a flat felt type garage roof across the road. Now 8.2 with patchy cloud and some showers off to the west.

Certainly does feel rather different to earlier this summer! even felt a bit chilly indoors this morning due to being used to it being almost too warm in here.

Yes same here being in the Otter Valley. The only month I've not seen visible ground frost here before is July.

A min of 3.4c here... and a genuine touch of frost visible on a flat felt type garage roof opposite us. Gone now as the sun comes up and some cloud moves in. I have recorded colder in August once, on the 30th in 2010 at 3.0c when the same happened.