Blessed Weather

July 2023 The July stats confirm a disappointing month, especially with the below average sunshine levels and above average rainfall made even more noticeable following an exceptionally dry, warm and sunny June. A few observations: whilst the rainfall amounts averaged across the Region were above average, within that a patchy picture with some areas pretty much on the long-term average. Wrt sunshine amounts, it looks like the extreme coastal strip of N Suffolk/S Norfolk received around the average amount of sunshine. And is that Cambridge that looks to be an 'island' of average sunshine too? Here's the national anomaly charts versus the 1991-2020 long-term average (mean temp, rainfall and sunshine): Source: https://www.metoffice.gov.uk/research/climate/maps-and-data/uk-actual-and-anomaly-maps Focusing in on East Anglia stats, courtesy of Dan Holley, Weatherquest, reveals: Near-average temperatures (-0.2°C) Wettest July since 2015 (149%) Dullest July since 2012 (84%) Highest number of July rain days since 2012 This was the first July to not reach or exceed 30°C in this region since 2012. Source: Twitter @danholley_ Final thought. I'm not a big fan of the Met Office habit of updating the reference period against which monthly results are compared as it seems to me to mask the variation versus the longer term, i.e. it compares against the recent last 30 years, which is too short a period in time imho. Here's an example using July 2023 temperature anomaly compared with the two reference periods available. First, against the 1991-2020 period and this shows temps were 'average'. But compared against the older 1961-1990 period it shows temps were actually warmer. So with climate change and ever rising temperatures, by continually moving (updating) the reference period 'goalposts' are we giving a false impression when we compare monthly results with the so-called long-term average?

Not long to wait for the official stats Pete. It'll be interesting to see what the July rainfall anomaly for the East turns out to be. It may turn out above average for E Anglia thanks to Storm Poly (named by the German Met Service) which rattled through the EA/SE Region on the 4th - 5th July and (for example) deposited 55mm of rain in just six hours at Lowestoft on the Suffolk Coast. The average for July in the East is 56mm. But it wouldn't surprise me if parts of the SE corner come in slightly below average. Rain totals 4th 5th Source: Netweather Extra Hi-Res rainfall calculations. ITV covered the Storm Poly story: A months worth of rainfall recorded in six hours in the East after the hottest June on record

Just breaking in the media is this statement from the Met Office regarding the Nature article on the AMOC. I can't locate the official/original Met Office statement. Anyone got a link please? “As far as we're concerned in the Met Office, the paper is far too simplistic,” said Richard Betts, the Head of the Climate Impacts at the Met Office Hadley Centre. He added: “There's still no evidence that we're kind of past the point of no return in terms of devastating impacts."

Whilst the previous collapse of the AMOC was likely caused by a huge outflow from a glacial lake, I believe the concerns this time around are based on the magnitude of the ongoing sea ice loss as global air and SST temperatures continue their upward trajectory. There are known tipping points for many climate related aspects of our planet, for instance the melting of northern hemisphere permafrost e.g. in Siberia, has caused a 37% increase in small lakes (from the melting ice within the tundra) and this is causing ever more greenhouse gas emissions which will melt even more permafrost: "As the permafrost thaws, microbes and fungi get to work and digest dead plants and other organic matter in the previously frozen soil. The process produces carbon dioxide, methane (CH4), nitrous oxide and other gases. This is a normal process. ‘Many lakes “burp” methane naturally,’ says Walter Anthony. In the normal scheme of things, the majority of bubbles in larger lakes would dissolve in the water column before reaching the surface. However, thanks to the speed of thawing and the morphology of the new lakes, the release of gases is happening at an unprecedented scale." Source: https://geographical.co.uk/climate-change/the-big-thaw-melting-permafrost-is-causing-a-global-problem Back to the AMOC and what we don't fully understand is the tipping point of this current by (a) the rise in SSTs and (b) the ongoing release of large quantities of fresh water into the oceans. Here are some indisputable facts: NASA reports the Greenland icesheet mass has been falling by 271 billion metric tons per year since 2002 Source: https://climate.nasa.gov/vital-signs/ice-sheets/ Copernicus Ocean State report 2022 reports Arctic sea ice loss 1979 to 2021 was an area of 2.14 million km2. About 6 times the area of Germany. They note that consequent changes to water salinity and temperature could impact the strength and flow of ocean currents. Source: https://issuu.com/copernicusmarine_service/docs/2022.09.27_cosr_6_summary_single_page My 'take' is that whilst there may indeed remain many unknowns, it's hard to argue against the evidence that we humans are conducting a very large experiment with earth's climate system.

Sorry, I don't understand what 2 articles you are referring to. Do you mean the AMOC report and the above July temps report. If so I can't see any contradiction as it will be the rapidly warming global temperatures that impact the AMOC by, for instance, higher temps melting the ice sheets and introducing fresh water into the North Atlantic.

Apologies if this news report from the World Meteorological Organisation has already been posted elsewhere. My take - it's the rapid speed at which the world climate is heating up that is very worrying. Previous fluctuations in global temperatures have been on a scale measured in thousands of years. Just look at the average first 23 days of July temperature chart (below) showing the trend in just the last 90 years. Here's the report intro: July 2023 is set to be the hottest month on record Bonn and Geneva, 27/07/2023 (Copernicus and WMO) - According to ERA5 data from the EU-funded Copernicus Climate Change Service (C3S), the first three weeks of July have been the warmest three-week period on record and the month is on track to be the hottest July and the hottest month on record. These temperatures have been related to heatwaves in large parts of North America, Asia and Europe, which along with wildfires in countries including Canada and Greece, have had major impacts on people’s health, the environment and economies. "We don’t have to wait for the end of the month to know this. Short of a mini-Ice Age over the next days, July 2023 will shatter records across the board" said United Nations Secretary-General António Guterres. Chart: Average global air temps 1 - 23 July from 1940 to date: And the full report is here: https://public.wmo.int/en/media/press-release/july-2023-set-be-hottest-month-record

Thanks. Very interesting to read the views of fellow scientists. The vast majority of comments seem positive/supportive about the paper's methodology and overall conclusions, but as you say above it's not a settled science and the big uncertainty centres around timing (of tipping point) and impact. The authors were honest enough to acknowledge the uncertainties in the 'discussions' section but I thought made a very good point with the accompanying statement that "......given the importance of the AMOC for the climate system, we ought not to ignore such clear indicators of an imminent collapse."

New research published in Nature Communications yesterday, 25th July 2023: Warning of a forthcoming collapse of the Atlantic meridional overturning circulation Abstract: The Atlantic meridional overturning circulation (AMOC) is a major tipping element in the climate system and a future collapse would have severe impacts on the climate in the North Atlantic region. In recent years weakening in circulation has been reported, but assessments by the Intergovernmental Panel on Climate Change (IPCC), based on the Climate Model Intercomparison Project (CMIP) model simulations suggest that a full collapse is unlikely within the 21st century. Tipping to an undesired state in the climate is, however, a growing concern with increasing greenhouse gas concentrations. Predictions based on observations rely on detecting early-warning signals, primarily an increase in variance (loss of resilience) and increased autocorrelation (critical slowing down), which have recently been reported for the AMOC. Here we provide statistical significance and data-driven estimators for the time of tipping. We estimate a collapse of the AMOC to occur around mid-century under the current scenario of future emissions. The full paper is available in Nature Communications. You can also find other research papers and articles on the AMOC in the Netweather Learning & Research section here.

You know what? Even a rubbish day (certainly for July) can provide some weather interest. How's about this threatening sky over the local allotments in Hadleigh this afternoon?

A really nice afternoon here. One brief light shower at lunchtime but overall plenty of sunny spells with the local Met Office station at Wattisham showing the temp got up to 23C for a couple of hours this afternoon. Cumulus melting away now so sat in the garden enjoying the evening sunshine.

Two distinct lines of light showers crossing the Region this afternoon and a quick check back of the Arpege wind chart for this afternoon shows the two areas of wind convergence caused by the topography of (1) the West Country Moors and (2) the Preseli Hills of Pembrokeshire as the winds veer around them but then convergence in their lee.

Well this afternoon turned out thoroughly wet, the saving grace was being sat inside the cricket club pavilion watching the England team on the telly, pint in hand, as the rain lashed down outside. From the radar it's looking like even heavier rain to move thru later on.

And the soggy Saturday turns into windy Sunday. The low pressure centre just off the south of the Isle of Man gives SW'ly coastal gales in the morning and as it swings out into the North Sea later Sunday giving a N'ly back-hander for Norfolk. Dreadful for late July. 03.00 23.00

So a thoroughly wet weekend on the cards, but where will the most rain fall? Here's the forecast of rainfall accumulation up to midnight Sunday from 3 models. Certainly looking like north of the Region wettest with around an inch (25mm) of rain, but much less further south with folk in the SE corner possibly left wondering what the 'wet weekend' fuss was all about: Arpege: ICON: GFS:

Yes, thanks Damian. I was editing my post with a correction as you were posting.

Thanks. I can't for the life of me remember the exact description the weather presenter used to describe his chart (for interest I might try and find the replay on itvX) but whatever, I can't argue with your chart.

I know July so far has felt very poor for many after an excellent June, but it's interesting to see that the CET up to the 17th July 2023 is currently running 0.3C above the July average and that rainfall for all Regions bar N Ireland is running below average. EDIT: My apologies. Rainfall is actually running above average. I misinterpreted the chart from ITV reproduced below; it is actually showing the rainfall up to the 17th as a percentage of the normal monthly rainfall in the whole of an average July, so at 90% the UK is heading for a way above average month. CET: Source: https://www.metoffice.gov.uk/hadobs/hadcet/cet_info_mean.html Rainfall to 16th July: Source: ITV National Weather

No, not necessarily a disliking of the post. The Oxford dictionary gives the meaning of disagree as "have a different opinion", so I'd prefer to think that it's being used to express a differing opinion to the poster.

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Could we stick to discussing Model Output in here please folks. If your post has disappeared it's been moved over to the Summer Chat thread. Thank you.

I've been to the Hadleigh Cricket Club game this pm and whilst there was plenty of sunshine to enjoy the wind was extremely gusty. Me and friends were constantly having to grab glasses to stop them being blown off the table! Even empty chairs kept sliding across the terrace when the occupants went to the bar. Here's the wind gusts situation at 18.00 today courtesy of Starlings Roost Weather . Current top of leaderboard is Weybourne, Norfolk, at 54 mph:

Yes, some decent rain over the last couple of hours. It'll be interesting to check actuals tomorrow, but I suspect the Arpege rainfall forecast I posted could be a bust.

Please folks. This is the Summer 2023 chat thread and not the place to discuss other subjects. So could we please get the discussions back on topic or I'm afraid they will start disappearing. Thank you.