kold weather

Already some decent gusts into W.Scotland and western portions of the island of Ireland at the moment, highest report is 64mph. Winds should ease a touch soon before the big pulse starts to move in tonight and we start to see the 70mph+ recordings begin.

People often underestimate just how strong winds are, even a solid 60-65mph gust can be intense, espeically if it occurs multiple of times and there is a wind shift associated with it, it will take trees down for sure. I'm not super far from the coast, so until the winds turn more westerly, suspect it might be a little rough. ECM showing 70mph gusts and quite sustained period of 60mph+ gusts. I'm fully expecting my fence to come down a 2nd time (the Jan storm took it down before) and I'm expecting my journey to work (along lots of country lanes) to be greatly extended due to trees coming down.

All I have done is take the temperatures aloft and then assume normal lapse rates for the middle of summer and gets to 42c. Likewise I have seen others use the skew-t from the day and have come to a pretty similar figure, therefore the theortical max for that was 42... However that is of course theortical, in practice your highly unlikely to get as high as local factors such as cloud cover comes into play. 40c I'm almost certain will happen in the next 20 years, probably sooner.

Just to note we were VERY close to seeing 42-43c in late June 2019. The airmass aloft was insane and normal lapse rates would have yielded 40c+ comfortably. Alas by pure luck the lowest 300m or so pulled in a cool ENE from the north sea rather than the super hot SE flow above. It meant in some places temperatures were cooler at the surface than at 850mbs. So at the moment, I'd say a theoretical max would be 42c.

When I went in 2014 there wasn't too much convergence of the sea breezes (I was in Orlando) and I think there was only 2-3 days that had storms, the rest were broadly just sunny days with low level cumulus. Most of the those storms came in the first 2 days (It was awesome seeing clouds just sit in one place and blow up in situ due to the convergence).

A 'warm' year compared to long term average, but not that impressive compared to some years in the 10s such as 2018, 2014, etc. Got to think some point soon we will get a year that will average 11c, we came relatively close in 2006 and 2014 (indeed 2006/2007 did have a period above 11c). This year seems to have been more comprised of reasonably short bursts of relatively extreme heat (Feb, July, end of August, even late December warmth in Scotland) rather than the sustained periods we have seen in some previous years.

I actually noted dr Cohen that the sample list was in a period of well known mild winters in W.Europe dominated by the Azores/SCEuro high when he put those maps out last winter.

Ultimately they are a function of high enough lapse rates to allow convection to drive the whole process. The combo of higher than average SST's and some very cold (relative) air aloft helps to really sharpen the lapse rates to the point where you'll get decent convection development and therefore drops the need for the temperatures at the surface to be as high as normal. Its a similar process to what we get in the med at times with these hybrid storms, very cold air aloft with what would appear too cold SSTs on the face of it, but lapse rates still high enough for decent convection.

Going to be a close run thing as to whether we can get to 150mm this month, the next 24hrs really do look very wet for some, but whether or not there is enough rain outside of the main zone is questionable. Still some areas today are going to get quite a large amount, 24hrs totals may well get north of 100mm in places from 08z to 08z tomorrow.

Interestingly it wasn't *that* wet further south, though the month was exceptionally wet in Scotland, N.Wales, N.Ireland and N.England, so much so that Dec 2015 was the wettest UK month on record... But for the south, rainfall totals were about average, a couple of spots were even a little below average in the far south, which meant in terms of the EWP, it did somewhat help to drag down the average to something a little less extreme.

I suspect the extent will still probably get close to where it has over the last 10 years or so but given a slow start you've got to wonder what sort of depth and quality of ice is going to develop in what may end up being a shorter than normal frozen season (especially further out from the ice rump left from the summer).

Given we still have a couple of hours of warming to go I suspect that 32.5c will be gone by the end of the day as well. Certainly been an interesting summer, short and sharp intense heat bursts interspread with fairly bland and fairly wet spells.

Yeah there are often differences. FWIW having done a few site comprasions between the average and the actual temps in central Africa that recorded below average according to that NCEP weatherbell chart (admittiedly not too many sites) but having looked at them for Congo and CAR and RoC but I'd guess the truth is in the middle but skewed more towards NOAA being correct, certainly Bangui was well above average, whilst the NCEP chart shows below average, which is 100% wrong for at least that site and therefore likely that section of the country. Still what I think is clear is July 2019 was well above normal on a global scale (0.3c above the 81-10 average is pretty impressive, especially as nearly none of that was ENSO induced and for it to be the warmest month ever or 2nd warmest, without ANY major El nino forcing is quite the eye opener to me!)

Yes 2nd place is looking increasingly likely now, but its still a very bad summer season up there no matter how it is looked at. It'll be interesting to see how the Russian/Alaskan section of the Arctic develops over the next 2-3 months, they've had an exceptionally warm summer up there and the SSTs are way above normal bar small little upwelling pockets here and there. Could be a late freeze in that part unless the weather gods are kind and a subsequent thinner ice sheet over the top that is prone to melting out quicker. 2013 was thankfully an ok year for the arctic so the basic recuperated some of its losses in 2012, lets hope 2020 is also as kind, otherwise we may have yet another step down as we saw from 07 onwards.

The danger for Greenland is once you start to get temperatures that can reach above 0c even at highest points you begin a slowelting process that in a warming world will be tough to switch. Reason being your going to be losing height across the sheet, meaning that by itself will lead to warming temperatures regardless if surrounding dynamics (as lower heights generally relate to higher maxes, at least in summer) and it starts to become a feedback loop. Of course such a situation on its own would likely take a very long time...but we keep on increasing temperatures by 0.5c every 25 years (imo probably the best case scenario) and that will enhance melting, especially at the fringes of the sheet which will naturally be thinner anyway.

The clue is in the maps. The weatherbell is taking the 1981-2010 average 30 year average which should be much lower than the NOAA, which is using the 1900-2000 average (to show the difference in the longer term to what it has previously been). Both show an above average world, but what is REALLY clear is how much warmer it has been this July compared to the very long term average globally. To be 1c above the long term average is quite shocking actually, especially given the distinct lack of any strong El Nino forcings in play.

There were a lot of PWS showing 101-102f in the region. I see no reason why it wouldn't be realistic. If it is, we have broken the record!

Amazingly after the cloud has passed here, we are back close to the peak, just 0.3c cooler than the peak an hour ago, but more cloud coming in so will drop away again soon.

Suspect we will be struggling to find a higher temperature now. Pretty close to the record though despite fairly considerable cloud cover at times and showery outbreaks, impressive effort for sure and we did manage to get that 100f for just the 2nd time!

No.2 and by some distance as well. Certainly a very hot day, got to think we will be getting more days like these as global temperatures elevate over the next decade or two.

Cor this is getting VERY close indeed, over 100f now but still a little short. I'd say the period between 3.30-4.15pm is key, if we are to break it it is going to fall over the next 45 minutes. Unfortunately there are weak showers moving in towards SW london however. Will be interesting to see what Writtle/Cambridge are showing, plus other stations in the surrounds.

Finally got some decent cloud cover moving in again, good spell of sunshine pushed my local area back upto 35c again but given radar presentation and time of day, I suspect I may finally have peaked. Great day though, 35c is the hottest day of the year and 2nd hottest I've ever had in this country (obviously August 10th won that one, we were at a similar temp to Gravesend, though being the opposite side of the estuary was just a smidgen lower.)

Regardless its not the record, as the record would be a 39c due to it being rounded up from 38.6c, so no great issue really either way.

Well to be fair he said rounded, didn't say up or down unless I missed it, could just as easily be 38.2c for example?

Yeah, Heathrow also has a decent clearence now for the next hour with only probably 2/8th cloud cover feeding in. I'm an hour downstream and still only around 2/8th's cover (well somewhere between 2 and 3/8ths) so Heathrow has a solid hour of that to work with at least before temps naturally start to slip away a little into the late afternoon and early evening.