Derecho

So just some stuff I found on the CET series. https://www.metoffice.gov.uk/hadobs/hadcet/releases/HadCET_v2_guidance_notes.pdf The above documentation confirms it is Rothamstad, Pershore College and Stonyhurst. Here is also the paper about the construction of the CET series https://www.metoffice.gov.uk/hadobs/hadcet/Parker_etalIJOC1992_dailyCET.pdf This bit does seem to confirm that the maxima and minima obs have been taken up to 9am since 1877. However what confuses me is that the max and min CET yesterday came out at 8.2C and -0.7C respectively. The minimums yesterday at Rothamstad, Pershore College and Stonyhurst were 1.7C, 2.6C and 3.8C respectively all recorded at 9am yesterday morning. So they are too mild but the minimums the earlier in the night at hourly points were -0.1C, -0.8C and -0.6C at these 3 sites. So it must be the minimum from the previous night up to 9am and the maximum on the day up to 9pm... that can be the only explanation...

Rheidolinflood It must have been Pershore college that was used because the 0900 to 0900 CET from yesterday according to the Meto was 4.8C. The minimum from this morning won't come into play for todays mean too much. It was already up to 2.6C by 9am this morning.

BlueSkies_do_I_see The morning of the 28th drags down the CET a bit with it turning increasingly milder as the day progresses, however with yesterday's mean coming in higher then expected I believe the record will go. I've got 5.8, 8.7 and 6.2 as the estimated means for the last 3 days. The 29th will hinge quite a bit on the timing of the cold front, just like on the 23rd. However that mean also came in higher then expected. It'd be interesting to see how exactly the Met Office record the CET, it seems to be 0900 to 0900 max+min / 2 but going by the weatherobs data there are still some differences. Annoyingly the EC tables on meteociel only have 6h increments, whilst the GFS pretty much always runs too cool anyway.

Summer Sun Thanks, a CET of 6.9C for the rest of the month is required to beat the record. EC00z has a mean of 6.9C for the last 3 days...

Metwatch I used to be a denier as well up until about 18 because I just found global warming too depressing and looked for arguments against the predictions. Uni sorted that out for me but ironically trying to find holes in the CC argument is one of the things that really got me into studying weather and climate as a whole.

BlueSkies_do_I_see It's still close, today should return another CET in the 3s though rather then the 6s because of the forecast minima for tonight. Based on 24 hour means from 0000 to 0000 I have the CET finishing at 7.87C. Based on the max/min from 0600 to 0600 I have 7.81C February 1779 had a CET OF 7.87C so it is very very close. 1779 wins it to 3 decimal places

WYorksWeather I agree totally but the fact I think we will resort to geoengineering sums up how bleak my view on climate change is. We are already geoengineering it to become warmer but I think out of desperation and an unwillingness to implement sufficient action, that's unfortunately what it will come to. We all know how much of a joke the Paris agreement was. I have no confidence in politicians ability to deal with the matter.

I think this is the biggest concern, positive feedback mechanisms which only serve to amplify the impacts we are having. Sadly I think geoengineering is going to become the last resort option we will exercise. Otherwise there will be mass migration out of areas that are too difficult to live in (rising sea levels, extreme heat, drought) and warfare over water and food shortages. I've looked at forum posts from around 15 years ago at times and they have aged so badly, there has definitely been an attitude shift. Numerous posts back then were hyping up a mini ice age or something along those lines.

Scorcher Agreed, I just like to follow things with close interest when there are potential records to be set! The analysis just a conclusion of what a model is showing but we know of course there are caveats - especially when it comes to cloud and overnight minima... working as a winter roads forecaster in the past makes me painfully aware of that It was similar to September last year when we were uncertain of whether the record would go or not.

Summer Sun A mean of 3.9C for yesterday suggests that Pershore College is indeed the site the Met Office use. If the 27th and 29th come in milder then there is still a chance we may only drop to 8.0C and set a new record but the odds are slim.

Daniel* Makes sense it is the more rural site. I had used Pershore college all this time as I thought that was the station. Ooops

Daniel* Is the Pershore station a different one to that on weatherobs? Your min obs for Rothamstad and Stonyhurst match the ones I had but the Pershore above looks like it dropped to around freezing? Edit: Ah yeah I stand corrected, the Pershore station just to the north was much colder so that brings down todays predicted mean to 3.5C

If we presume the 3.1C is the actual value for yesterday, the EC is going for: 25th: 3.9C (8.1C) 26th: 5.2C (8.0C) 27th: 3.3C (7.8C) - Pegged back significantly by a chilly night forecast 28th: 5.2C (7.7C) 29th: 7.2C (7.7C) - May rise if the chillier air from the west takes longer to arrive However it probably won't be enough, the mild weather from the 27th to 29th has been downgraded so 7.7-7.8C is likely the final figure. This is based off calculating the max and min temps on the EC from 0000 to 0000 and dividing by 2 which is probably the closest way to resemble the CET figures, I think I've read in the past it might be 0600 to 0600 though?

WYorksWeather Yesterday came in at 7.2C so quite a bit above the forecast I gave yesterday. 8.0C is definitely a possibility now, especially if the colder temps over the next 3 days have been overplayed.

Didn't realise I wrote this comment back before the Ukraine war started but it has unfortunately aged very well. We need more renewables! and the Ukraine war highlights it... the less we rely on the likes of Russia the better as it weakens their hand. It's a shame Trump will serve to strengthen it from next year.

WYorksWeather From the obs I can see, 5.9C is my best guess... but this is based off midnight to midnight obs.... Based on the EC 12z... 22nd: 5.9 (8.6) 23rd: 3.7 (8.4) 24th: 3.1 (8.2) 25th: 4.9 (8.0) 26th: 4.8 (7.9) 27th: 4.6 (7.8) 28th: 8.8 (7.8) 29th: 7.6 (7.8) So the 23rd and 24th look the only colder then average days now. 25th looking less cold as the low pressure is set to move across closer to the UK with air a little less cold. 27th is pegged back by the cold morning. The remaining days are set to have an average of 5.4C. If that mean comes in half a degree higher (5.9C) the record is gone.

Mean temps on the EC12z as close to possible to Stonyhurst, Pershore and Rothamstad on the 12z EC are as follows: 21st: 9.6C (8.7C) 22nd: 7.1C (8.7C) 23rd: 3.8C (8.4C) 24th: 3.2C (8.2C) 25th: 2.3C (8.0C) 26th: 2.7C (7.8C) 27th: 4.7C (7.7C) 28th: 8.7C (7.7C) 29th: 8.3C (7.7C) So the EC from the 23rd to 26th is a bit too chilly for us to beat the record. The minima on the morning of the 25th and 27th are pretty cold. Clear skies and slack winds being the culprit. If it is a bit cloudier then expected the daily means might hold up more but it'll still come in a bit short of 7.9C I reckon.

So looking at the 12z EC and trying to match the data to Rothamstad, Pershore and Stonyhurst as much as I can I get the following: Daily mean and monthly mean in brackets 20th: 8.7C (8.7C) 21st: 9.4C (8.7C) 22nd: 7.0C (8.6C) 23rd: 3.8C (8.4C) 24th: 2.9C (8.2C) 25th: 3.4C (8.0C) 26th: 3.5C (7.8C) 27th: 5.0C (7.7C) 28th: 8.1C (7.7C) 29th: 8.0C(7.7C) So just short of the 1779 record if the EC temperatures are right... we will see. This will at least be a useful litmus test to compare the EC point data to the observed temps. I think the minima may hold up a bit more then predicted on the back of this mild and wet spell but we will see. Personally I think we will just fall short of the 1779 record.

Daniel* Looks like this table is wrong then, strange it is that far out as in the summer it was pretty accurate.... Meteociel.fr - Tableaux ECMWF-ENS WWW.METEOCIEL.FR La météo en temps réel et prévisions météo pour la France, Observations météo, modèles numériques et logiciels météo (GFS, ECMWF, UKMO, GEM, AROME, ARPEGE, JMA) Looking at the WZ temps as well they tie in more with the figure you gave. The GFS data looks far more in line with the WZ anomalies so there is a problem with the EC tables generating on the website it seems, especially with the minimum temps. Based on the GFS 00z values a final figure of 7.4C is expected though that is cooler from Feb 27th-29th. Edit: Looking at the EC tables, unfortunately you can't get data directly from a point using this function anymore. The interpolation tab does some funny stuff. You can change it to point data... Meteociel.fr - Tableaux ECMWF-ENS WWW.METEOCIEL.FR La météo en temps réel et prévisions météo pour la France, Observations météo, modèles numériques et logiciels météo (GFS, ECMWF, UKMO, GEM, AROME, ARPEGE, JMA) But it says 'the grid point is 22.2 km from the selected point' at Rothamstad so it looks like it's just pulling data from nearby cities. Not a valid estimate anymore unfortunately.

Based on the EC 00z this morning with daily mean followed by rolling monthly mean in brackets: 20th: 9.7C (8.7C) 21st: 10.5C (8.8C) 22nd: 7.7C (8.7C) 23rd: 5.6C (8.6C) 24th: 5.4C (8.4C) 25th: 5.9C (8.3C) 26th: 5.7C (8.2C) 27th: 6.6C (8.2C) 28th: 9.1C (8.2C) 29th: 8.0C (8.2C) So even if the EC is cool biased it still breaks the record comfortably.

WYorksWeather A few days ago the EC had 8.6C to the 22nd whilst the GFS only had 8.0C from its forecast. Even the milder EC came in as an underestimate. If we end up as absurdly high as 8.8C then I think this mornings EC would be enough as the 27th-29th are mild. GFS cooler again but no surprise there.

I don't think you can really compare the El Nino's from any of those winters to this one. The January MEI values (which give a more comprehensive overview of ENSO state for those 4 winters and this one are as follows: 1973 - 2.02 1983 - 2.6 1998 - 2.2 2016 - 2 January 2024 only had an MEI index of 0.7... which makes it only the 32nd largest El Nino since 1871 (though the 3.4 region anomalies were a bit stronger). Indeed January 2010 had a value of 0.9. Jan 1969 and 1940-1942 also had higher or similar MEI values but those winters were very blocked. So I don't think ENSO is to blame for this winter, more a case of climate change and bad luck with the knock on effect of those crazy high SSTs to the SW of Spain leeching into Europe. Hopefully next winter will see a better roll of the dice. December 2022 was a decent effort for the first 20 days before the fine margins worked against us.

WYorksWeather Agreed, yesterday's CET is likely to have come in at around 9.9C according to the obs at Stonyhurst, Pershore and Rothamstad (though I calculated midnight to midnight mean). Both today, tomorrow and the 21st at least should see a daily CET in double figures (again). The 13.7C for Thursday was truly remarkable.

Looking at the output this morning from the 00z's, the GFS has the CET at a peak of 8.4C on the 21st whilst the EC has a CET of 8.6C. Oddly, even at short range the EC has milder minimums then the GFS. Is the GFS cool biased? After that it turns cooler but not for long on the EC and the CET holds out to 8.2C by the 29th. GFS has a longer run of average temperatures and the CET drops to 7.3C at the end of the month. So a record very much a possibility if the cooler maritime flow on the 23rd is only a blip.

WYorksWeather Stonyhurst is on Weatherobs and got to 13.96C a short time ago. Weatherobs WEATHEROBS.COM Global weather observations (METAR, SYNOP, BUOY, SHIP, TAF, CWOP) decoded to enable display of latest temperatures, weather, snow depths, precipitation, wind and wave conditions and more