Roger J Smith

18.0 C and 45.4 mm.

Meanwhile, the highest temperatures today are in the 37-38 range in southern France and also in northeast Spain but the largest anomalies are further north near the crest of the 576 dm thickness in the Netherlands where one station was reporting 35 C. Also of note for UK forecasts, dew points have soared to low 20s in parts of central France. The modelling suggests that the heat approaching the UK will be a second push north as this first push subsides a little into Germany tomorrow. We'll just have to see whether the Netweather guru model has a surprise last minute win over the realist camp. The 06z GFS appears to be perhaps 1 dm lower in its thickness projections for Friday-Saturday but that's not much, all depends on how much sunshine gets through ... a good sign to me that temperatures have recovered reasonably well on the south coast today despite the morning cloud and remnant showers from the Channel storms. Hopefully skies will clear out considerably for Wednesday and get the ground heated a little for days to come. I also feel that the largely dry cold front scenario for Saturday is going to see changes closer to the time due to the moist conditions being encountered by this heat.

Today's highest readings of 36 were in the lower Rhone valley but it's 34 as close to Paris as Auxerre about 100 kms southeast. The 576 dm thickness contour continues to show up in southern England by Friday and Saturday on the latest two GFS runs. The model output may be overdoing the North Sea regional cooling effect, it's fairly weak today with the highest readings in England at Southend and Wattisham (25 C). By the core of the heat wave the flow into southern England is more south than east so any North Sea cooling that takes place mid-week should be extinct by then. I like Saturday for extreme heat because the flow turns more westerly at lower levels and this will waft the heat from the Thames valley towards the urbanized southeast. For the contest we have going, 123 Netweather gurus predict a median high of 35.4 C. 90% go higher than 33. The models have all but abandoned any localized thunderstorm potential except for Friday to early Saturday in Ireland into north Wales and northern England when the cold front activates there. If the models are right about the heat being mainly dry, that would also argue for less cloud or convective debris to interfere with temperature rises in the early part of the daytime heating cycle.

Okay, well my table has 121 entries, so the median value is 35.2 C. If we counted the two with the wrong Sunday date, which are both above that, the totals are 123 and the median is 35.4 C ... 41 (plus the 2 excluded) said Heathrow, 20 said some other location in London or suburbs, excluding the 17 who said Gravesend (one other said just Kent). Those total 79 (or 81) of the 121 entries. Of the rest, Cheltenham is picked by six, then two others are close in saying Worcs and Warwick. This leaves 34 scattered around various parts of the country, about half a dozen are in East Anglia and Cambridge, a similar number in the Thames valley to Somerset, and also Wales and Scotland get mentions. (about 10% failed to pick a location at all). Then as to dates chosen, it goes 9 for Thursday, 44 for Friday and 56 for Saturday (and 2 for Sunday) with the rest not picking any date.

Paul, what's the status of the two forecasts that mentioned Sunday 30th? Are they still playing their temperatures and locations? If so, I can edit that part into the table of entries. Also, somebody commented that the forecast for their location was only 26 C. I didn't count that as an entry.

This is now a list of forecasts to 11:59 pm Sunday. Please check for accuracy (I will also do a final sweep for quality control and the list remains unofficial just for contest interest). Note, if no date is shown, your entry lacks a date and you could add that either by edit or separate post. One entry also lacks a location as well as a date, and one other has a date but no location. I have left out one entry of 14 deg (B'ham Tues), one of 5 (in my fridge) and one of -8 with snow. ... Also, I have shown two forecasts that mention Sunday 30th as the date after the table of entries. Status of those would be up to Paul (hope this might save you some work, you could cross-check it if you have your own list already). The entries for same temperature are in the order submitted. Entries in this table have been checked for accuracy (0050h Mon 24th). Table of forecasts for maximum temperature in late June 2019 hot spell FORECASTER __________ Temp ___ location ______________ date Thundershine ____________42.8 ___ Heathrow _____________ Fri 28 Richard David McCarthy ___ 40.8 ___ Norwich ______________ Sat 29 Crepuscular Ray __________39.8 ___ Gravesend ___________ Stationary Front __________ 39.4 ___ Cheltenham ___________Sat 29 Bartlett High _____________ 39.3 ___ none ________________ Fri 28 BlackburnChris ___________39.2 ___ Gravesend ____________ Fri 28 MattStoke _______________ 39.1 ___ Northolt ______________ Sat 29 Connor Bailey Degnan _____ 39.1 ___ Faversham ___________ Man with Beard ___________ 39.0 ___ Porthmadog __________ Fri 28 Steve Murr _______________39.0 ___ Gravesend ___________ Sat 29 Sweatyman ______________ 38.9 ___ Heathrow _____________Sat 29 sarafandjak ______________ 38.8 ___ London _______________Sat 29 SW Saltire _______________ 38.3 ___ Heathrow _____________Sat 29 AWD ___________________ 38.3 ___ Pershore _____________ Sat 29 Broughty ________________ 38.3 ___ Gravesend ___________ Sat 29 I Remember Atlantic 252 ____ 38.1 ___ N. London ____________ Sat 29 Kirkcaldy Weather _________ 37.8 ___ Banbury ______________ Fri 28 Smartie __________________37.8 ___ Heathrow _____________ Fri 28 Leo97t ___________________37.8 ___ Heathrow _____________ Essex Easterly ____________37.7 ___ Heathrow _____________ Sat 29 Ross Andrew Hemphill _____ 37.7 ___ North London __________ Sat 29 Don ____________________ 37.7 ___ Gravesend ____________ mizzle __________________ 37.4 ___ Hampshire ____________ Fri 28 Bob G __________________ 37.4 ___ Wattisham ____________ Fri 28 CheesepuffScott __________ 37.3 ___ Farnborough ___________Fri 28 matt111 _________________ 37.3 ___ Hampshire ____________ Sat 29 mikeofmacc ______________ 37.2 ___ London _______________Sat 29 MR EXTREMES ___________37.2 Adam C _________________ 37.1 ___ Heathrow _____________Fri 28 summer blizzard ___________37.1 ___ Cheltenham __________ Sat 29 parrotting fantasist _________37.1 ___ Heathrow _____________Fri 28 Roger J Smith ____________ 37.0 ___ Heathrow ____________ Sat 29 MrBartlettazores __________ 36.9 ___ Gosport ______________ Fri 28 Mike Poole _______________36.9 ___ Gravesend ___________ Summer Sun _____________ 36.9 ___ Kew Gardens _________ Fri 28 Bobafet __________________36.9 ___ Hampshire ___________ Fri 28 Ed Stone ________________ 36.8 ___ Gravesend ___________ Sat 29 Barbmac _________________36.8 ___ Heathrow ____________ Sat 29 mattwolves _______________36.7 ___ Faversham ____________Fri 28 alderc ___________________ 36.6 ___ Cheltenham __________ Sat 29 snowsummer _____________ 36.5 ___ Heathrow ____________ Sat 29 Emmett Garland ___________ 36.5 ___ Gravesend ___________Sat 29 LightningLover ____________ 36.4 ___ Heathrow _____________Thu 27 South coaster _____________36.4 ___ Heathrow _____________Thu 27 danm ____________________36.2 ___ Heathrow _____________Fri 28 SouthLondonCold __________36.2 ___ Heathrow _____________Fri 28 Lewesdon ________________ 36.2 ___ Cheltenham ___________Fri 28 Super_Uwe _______________ 36.1 ___ Taunton ______________Sat 29 Quicksilver1989 ____________36.0 ___ Heathrow _____________Sat 29 95 Degrees _______________ 35.9 ___ Staverton (Bristol) ______Fri 28 mb018538 ________________ 35.9 ___ Heathrow ____________ Fri 28 ChezWeather _____________ 35.8 ___ Heathrow _____________Fri 28 Onding __________________ 35.8 ___ Heathrow _____________Sat 29 (1537) Northwest snow ___________ 35.8 ___ Heathrow _____________Fri 28 MKN ____________________ 35.7 ___ Heathrow _____________ Sat 29 virtualsphere _____________ 35.6 ___ near Aberystwyth _______ Thu 27 markwells ________________35.6 ___ Prestatyn _____________ Sat 29 Psychedelic Tony __________35.6 ___ Northolt ______________ Sat 29 Geordie Snow ____________ 35.4 ___ Cheltenham ___________ Fri 28 Bullseye _________________35.4 ___ Heathrow _____________ Sat 29 Tom W __________________ 35.2 ___ Kew Gardens __________Fri 28 Kentspur ________________ 35.2 ___ Heathrow _____________ Sat 29 Diagonal Red Line _________35.2 ___ Bettws, Bridgend S Wales _Fri 28 Froze were the Days _______ 35.1 ___ Heathrow _____________ Northwest NI _____________ 35.1 ___ Oxford _______________ Fri 28 SilverWolf ________________35.0 ___ Cheltenham ___________ Fri 28 Norrance ________________ 34.9 ___ Gravesend ____________ AppleUK 123 _____________ 34.9 ___ Heathrow _____________ Fri 28 The BEAST from the East ___ 34.9 ___ Gravesend ____________Sat 29 SunnyDazee ______________34.8 ___ Heathrow _____________Sat 29 pinball wizard _____________ 34.7 ___ Kent ________________ Fri 28 seabreeze 86 _____________ 34.7 ___ Cheltenham ___________Sat 29 January Snowstorm _________34.7 ___ Heathrow ____________ Sat 29 philglossop _______________ 34.6 ___ Newbury _____________ Fri 28 Sir Mim __________________34.5 ___ Gravesend ____________Sat 29 Snow Queen One __________34.5 ___ Heathrow _____________Sat 29 Dean E __________________ 34.5 ___ Gosport Fleetlands _____Thu 27 snowrye _________________ 34.5 ___ Gravesend ____________ Stargazer ________________ 34.4 ___ Wisley _______________ Fri 28 Mark Wheeler _____________34.4 ___ Northolt ______________ Sat 29 tesaro ___________________ 34.4 ___ Cambridge Cambs _____ Sat 29 Feb1991Blizzard __________ 34.4 ___ Richmond (Gr Lon) _____ Sat 29 nn2013 __________________34.3 ___ Heathrow _____________ Fri 28 mike5900 ________________ 34.3 ___ Dorset _______________ Thu 27 cheshire snow ____________ 34.2 ___ Stoke on Trent _________ Sat 29 Ben Sainsbury ____________ 34.1 ___ Heathrow _____________ Sat 29 shuggee _________________ 34.0 ___ Cambs _______________ bazooka bob ______________33.9 ___ Wiltshire ______________ Fri 28 bybo 1999 ________________33.9 ___ Gravesend ____________ Sat 29 zmstorm _________________ 33.7 ___ Gravesend ____________Sat 29 nicknacknoo ______________ 33.7 mother nature rocks ________ 33.7 ___ Heathrow _____________Fri 28 stainesbloke ______________ 33.6 ___ Heathrow _____________Sat 29 spurskevin _______________ 33.6 ___ Gravesend ____________ Sat 29 Another Kent clipper ________33.5 ___ Bury St Edmunds _______Fri (30) -- assume means 28th Andrew R ________________ 33.4 ___ West Sussex __________ Fri 28 Mercury Rising ____________ 33.3 ___ London _______________ Stuie W __________________ 33.3 ___ Cambridge ___________ Thu 27 Luke Best ________________ 33.1 ___ Kew Gardens _________ Sat 29 Congleton Heat ____________33.0 ___ Bristol _______________ Fri 28 sunnijim __________________32.9 ___ Northolt ______________Sat 29 Dami ____________________ 32.8 ___ Heathrow ____________ Thu 27 jet streak _________________ 32.8 ___ Warwick _____________ Sat 29 seaside 60 _______________ 32.8 ___ Heathrow _____________ Sat 29 BeazleyBlizzard ___________ 32.8 ___ Heathrow _____________ Sat 29 Runcible Spoon ___________ 32.7 ___ Heathrow _____________ Fri 28 Calneee _________________ 32.7 ___ Trowbridge ____________ Fri 28 Mesoscale _______________ 32.7 ___ Northolt _______________Thu 27 Canadian Coops ___________32.7 ___ Wiltshire ______________Sat 29 h2005__uk__ _____________ 32.6 ___ Heathrow _____________Sat 29 Mr Frost _________________ 32.4 ___ Aviemore _____________ Fri 28 Downpour ________________ 32.2 ___ Heathrow _____________ Fri 28 Harry ____________________32.1 ___ Heathrow _____________ Sat 29 Alex _____________________31.8 ___ West London __________ Sat 29 Aleman __________________ 31.6 ___ Worcs ________________Thu 27 badgers01 ________________31.4 ___ Saunton Sands ________ Sat 29 Andy from Donny ___________31.4 ___ Kew Gardens _________ Fri 28 sainsbo __________________ 31.1 ___ Salisbury _____________ Fri 28 DaveL ___________________ 30.6 ___ London ______________ Sat 29 Summer of 95 _____________ 30.5 ___ Glasgow _____________ Fri 28 clark3r ___________________30.3 ___ Heathrow _____________ Sat 29 _____________________________________________________________ (Sunday 30th forecasts) Northumberland snowman ____ 38.2 ___ Heathrow ____________ Sun 30 (1423) Captain Shortwave __________ 37.5 ___ Heathrow ____________ Sun 30 ___ (said otherwise 35, North Wales)

About half the forecasts mention Heathrow, mostly Friday or Saturday. Other frequent choices are Gravesend (which may not exist as a location any more), Cheltenham, various London area stations not specifically Heathrow, and a scattering in the Thames valley, Wales, Cambs, and Scotland. The table of entries has migrated to end of the forecasts.

I have the hunch that models will begin to show a more southerly component for the core of the heat Friday-Saturday and this will allow the higher readings to occur in southern England as in France. Meanwhile, the heat is on the move north. Today's hot spot in Spain is Zaragoza in the northeast at 37 C. Readings in southern France have come up a bit today also, 32 fairly common between Bordeaux and Marseilles. High 20s into Paris region now. The 576 dm thickness was shown a bit further north also, across west-central Spain. Its further progress appears to be a gradual push north into central and eastern France. (would agree a lot of things need to fall into line to get to my high reading of 38.7, the real over-under from all guidance appears to be 33 or 34).

Also, to avoid confusion, this is not the official contest thread for top temperatures, in case anyone enters a forecast here thinking they are in that thread, nope, it is in another thread, look for an orange-brown header above the text on your screen and click on that to get to the right place. But that said, I think the top reading will be 38.7 somewhere in greater London.

I have returned the word "severe" to the thread title after upgrades to guidance earlier today. Tracking the heat, beginning to show up now in southern Spain, highest reading I can see earlier today was 35 C at Andujar, the 576 dm thickness (which will reach central England) is hovering near the south coast of Spain. To give some perspective, in North America the 576 dm thickness today was situated in northern Missouri, despite a lot of cloud and wet ground from recent heavy rains, temperatures reached 30 C. I notice that the ECM is pushing the core of the heat significantly further west than the GFS or GEM by Friday. The frontal storms on Saturday are now looking like a potentially severe outbreak for west-central England and south Wales into Midlands. Unlike 2015 I don't think this will be the only hot spell of the summer, but with these parameters it may be the most severe.

The guidance has been upgrading so I am going for 37.0 at Heathrow Saturday. took 1.7 off the first entry but first in at 37.0 as of Sunday 8:30 pm.

With the slight downgrades in some model guidance, I opted to edit the title of the thread and removed the word "severe" from heat wave, although have not edited any of the wording in the original post otherwise. We're still seeing 570 dm thicknesses into southern England and 576 dm almost into the southeast, so not a huge change, also each run seems to be angled a bit differently and holding back the breakdown a bit further. Some parts of Wales may be in for locally excessive thunderstorm rainfalls and that may be one of the bigger impacts of this event.

Possibly their forecast is based on guidance with lower values for 850 mb temp, or they believe an easterly flow will persist to the extent that North Sea cooling effects will reach that far inland. The latest GFS 06z guidance appears to have downgraded slightly and is also more gradual with its northward push of the very warm air mid-week, on the other hand the breakdown is now pushed back to around Sunday 30th.

Looks to me like there should be a discussion thread open for the impending severe heat wave that will begin to set up on Monday 24th and reach full intensity from Tuesday to Friday of next week, gradually ending from west to east on Saturday 29th on current guidance. (edit, later guidance shows a late Saturday breakdown for the southeast) Upper parameters are near their limits for southern England, the 576 dm thickness contour is shown moving north as far as the Midlands and south Yorkshire, and various model runs depict 850 temps of 22 to 24 C. These values with any long intervals of sunshine would argue for mid-30s temperatures away from moderating influences of coastal seas, probably in just about all of southern and central England and some distance further north at times. With those temperatures will come rather high levels of humidity, in part because the month has been quite wet (twice normal rainfall so far) and this will give a source of low-level evaporation into the air mass even if it has lower dew points in its source region of France (where by the way temperatures could be as high as 38-40 C). Nights will not cool off much especially in larger urban areas. Some lows of 20 to 23 C are possible in greater London, 17 to 19 C in less urbanized settings. There will be zones of frontal contrast over the far southwest, Wales, Ireland, northwest England and southwest Scotland at times, both with the warm fronts moving up ahead of the heat wave Sunday night into Monday, and then when the heat wave is established, along quasi-stationary fronts oriented from Ulster southeast to south Wales and Devon. Outbreaks of heavy thundery rain seem likely with those. When the heat wave begins to break down late Thursday into Friday, slow-moving cold fronts will push further east raising the possibility of severe thunderstorms into the Thames valley, west Midlands and south central England. A final phase (according to 18z GFS) may be frontal intensification by Saturday 29th as pressure falls sharply over the Irish Sea, leading to more widespread heavy thundery rainfalls from northwest England to the Midlands and southeast England. This will be a complete changeover from the rather cool conditions so far in June (although those have been moderating recently). At one point recently, the CET for June was only 12.9 C (normal by end of June is 14.5). But some of these heat wave days may be threatening the all-time June record of 23.0 (average of max and min) set on 3 June, 1947. In a similar set-up of shorter duration, the daily CET on 1st July 2015 reached a record 24.6 C (the all-time July record is 25.2 from 1948, and for August, 24.9 in 1995). In the impending heat wave, daily records may be falling in many areas. Top maximum temperatures in England could reach as high as 35 or 36 C. Readings of 32 C or higher could be widespread. In the western regions closer to frontal zones, 25-28 C may be the top values.

EWP tracker had reached 100 mm after 18th, likely around 103 mm now. The ten day GFS precip forecast map shows an average of 25 mm more by 06z June 30th, with potential for perhaps 5 mm the rest of that day, so most likely outcome is now around 133 mm. Compared to the provisional scoring for 120 mm, the only change would be LG moving up to 4.2 points and tied 26th out of 44 (same error as 66 mm), while all who had been 28th to T42nd would move down one rank and lose 0.2 or 0.3 points. (former 27th now 28th but same points as calculated from second entry at 66 mm). Those changes and a scoring line for the "what if" for Stewfox's late entry (line 335) are shown in this updated version of scoring. Further slight changes would occur depending on how far up or down the result is -- LG would move past all the other forecasts this month if we reached the June record of 160 mm. EWP20182019Jun.xlsx

The 06z GFS continues to be more aggressive with the heat 25th-26th than the 12z which just rolled out, but either way, it would likely return to normal values by 29th-30th, so the outcome is beginning to converge on a narrow range of about 14.4 to 15.0 before adjustments. From the 12z GFS I am seeing 14.66 ((3x13.1 +2x17)/5)=(73.3/5) while from the 06z it would be 15.0. Would estimate 0.2 as correction so 14.4 to 14.8 there for final value. If heavy rainfalls accompany the warmth we might be looking at a top ten or even top five outcome for EWP.

(a) CET Temperature forecast contest -- averages and extremes ... all years since 1981 are shown for comparison ... 25.2 ... 29th, 1948, warmest daily mean 19.7 ... 2006 (warmest July) 19.5 ... 1983 (2nd warmest) 19.1 ... 2018 (3rd warmest) 18.8 ... 1783 (4th warmest) 18.7 ... 1852, 1976 (tied 5th warmest) 18.6 ... 1995 (7th warmest) 18.3 ... 2013 18.2 ... 1989 18.0 ... 1994 17.7 ... 1999, 2014 17.6 ... 2003 17.3 ... 1991 17.2 ... 2001 17.1 ... 2010 16.9 ... 1984, 1990, 2005, 2016 ... average for 1989-2018 (16.85) (highest 30-year average) 16.8 ... 2017 ... average for 1991-2018 (emerging 1991-2020 normal) and 2001-2018 16.7 ... 1997 ... average for 1981-2010 16.5 ... 1982, 1996 ... average for 1971-2000 16.2 ... 1985, 1992, 2008 16.1 ... 2009 ... average for 1961-1990, also for 1901-2000 and 1701-1800 16.0 ... 2002 ... average for all years 1659-2018 15.9 ... 1986, 1987, 2015 15.8 ... 2004 ... average for 1801-1900 15.6 ... average for 1659-1700 15.5 ... 1981, 1998, 2000, 2012 and lowest 30-year average 1671-1700 (15.47) 15.2 ... 1993, 2007, 2011 mean and coldest since 1988 (14.7) 14.7 ... 1988 (tied with 1980 as coldest since 1965, and with four other years as tied 35th coldest) 14.0 ... 1965 CET (tied 11th coldest with 1674, 1685, 1713) 13.9 ... 1919 (10th coldest) 13.8 ... 1725, 1840, 1841 (tied 7th coldest) 13.7 ... 1888, 1922 (tied 5th coldest) 13.6 ... 1879 (4th coldest) 13.5 ... 1695,1802 (tied 2nd coldest) 13.4 ... 1816 (coldest July) 8.7 ... 20th (1836) coldest daily mean ____________________________________________________________________________________________ Enter your July forecast by end of the day Sunday 30th June without penalty, or during the first three days of July with increasing time penalties. ================================================================================= (b) Optional EWP contest Predict the England and Wales mean precipitation in mm for July 2019. The contest uses the Hadley EWP version which runs from 1766 to 2019. Here are some averages and extremes as a guide: 182.6 __ wettest (1828) 140.7 __ wettest since 1981 (2009) _93.9 __ highest 30-year running average (1773-1802 and 1775-1804) _69.8 __ average for 1989-2018 _67.3 __ average for 1981-2010 _57.4 __ lowest 30-year running average (1971-2000) _26.3 __ driest since 1981 (1999) _15.8 __ driest since 1825 (1911) __8.2 __ driest (1825) __ second driest was 1800 (9.1 mm) _____________________________________________________________________________________ Enter your forecast with your CET forecast, same deadlines. Maximum score 10.0, late penalties 0.2 per day.

The 12z GFS backed away from the extreme warmth scenario and all guidance seems to converge now on a solution where the continental heat stays just the other side of the Channel but fires up an active frontal wave around Tuesday into Wednesday of next week, that might produce some vigorous thunderstorms in southeast England and Midlands. Some of the warmer days might approach 20 for average CET from a 23/17 sort of max/min but I think any chance of record warmth would be across the far southeast if it gets onto land anywhere in the UK. Still, guidance could wobble back to the extreme warmth option again before this is settled. From a climatological standpoint the wet spell would suggest caution with any sharp warming trends, they are going to be under pressure to overcome a tendency for warmer air to become cloud laden and therefore not as warm as it could be potentially had there been a dry run up to the signals. Hadley EWP tracker was at 96 mm after 16th, is now very likely above 100 mm and there's a solid 20-30 mm more indicated on the charts to 30th, with potential for 40-50, so outcome now seems almost assured to be above all but the one or two forecasts.

By the way, worth mentioning that the upper parameters shown on the GFS are extreme values for southern England (around 26th-27th), 850 mb temperatures as high as 24 C and 576 thickness contour into Midlands suggesting 578-579 for southeast England. That's almost desert heat. You could imagine readings of 36 to 38 (and 40 in parts of France) with these parameters. Given how wet it has been any fronts would have a lot of moisture available too. The air mass might be trying to dessicate but with that surface moisture dew points would be sure to get close to 20 C, making it a very oppressive heat. I would not be the least bit surprised if this output proves overcooked because otherwise it will be many of the readers of this thread being overcooked. The full heat would not spread into Wales or Ireland or most of Scotland, it would get warm (23-27 C) but not that hot. Remarkable maps anyway, whether true or false (perhaps the summer version of some of the 10-day maps we had last January).

Warmest June day on record is 23.0 on 3rd (1947) which is low-hanging fruit for this climate, almost everywhere else with a temperate climate would expect to set its all-time June record near the end of the month adjacent to July. Normal values are certainly higher at end of June than start of the month. In a way it was surprising that June 1976 didn't manage to dislodge the early June mark from 1947, there was a full week of heat wave conditions at end of June and values above 24 were recorded by early July. It would be a bit of a laugher if this month managed to set the all-time record, but it matches what happened at end of July 1948 which was otherwise quite a cool month. Even a four-day heat wave at end failed to move it past 16 C.

June is the only month whose highest running 30-year CET was not in the recent past (it was 1822 to 1851). We were within striking distance after last June but this one will prolong the inevitable to about 2021 when cool June 1991 is out of the interval. If June 2020 and 2021 are just average, the 30-year running mean will likely reach the same value as its maximum back in the 1822-51 interval (which was 14.72). December's highest 30-year mean goes back a bit to 1971-2000, otherwise all other months max out in some very recent 30-year interval. I have been number crunching the historical EWP values too, and there was a marked rise in June EWP about the same time, the 30-year running average reached a peak value of 79 mm for 1828 to 1857. It then dropped off gradually to values below 60 mm and the minimum was 52 mm (1913-42) but has recently been increasing again, peaking recently at 69 mm (1987 to 2016) and last seen at 67 mm for 1989 to 2018. That will be back up again for 1990 to 2019 perhaps to 69 mm as 1989 was a little under the average (the mean will change by 1/30 the difference of 2019 minus 1989).

I wonder if that map compares mean temperature to date with all of June average temperature, that would push it down a couple of degrees. For example, the CET is currently 1.6 below the 1981-2010 June normal. But it's much closer to the running mean 1st to 15th. Also, if they have stats for daytime anomalies, those are probably running lower than the overall anomalies. Or if it refers to the past ten days instead of all of June, the mean without 1st and 2nd must be close to 2 deg below normal. Another competing theory is, it's just plain wrong. Can I say that?

I would say looking at the 06z GFS output, the second half would average about 15.5 which combined with first half of 12.9 produces a value of 14.2. There's still plenty of rain left to come on that run also, especially in the last week of June. Looking at my files of running CET, the warmest June CET following any start below 13 (to 15th) was 15.1 in 1941 which recovered from 12.2, so the second half there averaged 18.0. Another outcome of 15.1 in 1817 came from a lower start than all but 1941 (12.4) which required a second half average of 17.8 C. Also 1878 went from 12.9 to 15.1 (second half there was 17.4). And 1935 recovered from 12.8 to 15.1 (second half of 17.3). June 1782 went from 12.9 to 14.9 (second half average 16.8). June 1986 went from 12.7 to 14.8 (second half average 16.8). A similar rise to June 1941 occurred in June 1936 which went from 11.8 to 14.7 (second half of 17.7). June 1891 went from 12.9 to 14.7 (second half 16.6). 1989 went from 12.9 on 15th to an outcome of 14.6 (second half was 16.2). 2005 had reached only 13.2 by 15th en route to 15.5 (second half was therefore 17.8).

Yes, I was over on a visit in June 1972 and it was remarkably unpleasant, can remember one afternoon in the Midlands with a temperature of about 8 C and a raw wind with drizzle along with it. The whole month was basically not much better than that. It appears not to have added up to a large rainfall total but it was a fairly persistent light rain together with very raw temperatures.

This month has been a strong case for the superiority of astronomical season dates over climatological month-based seasons. I guess there was a reason why that convention was ever adopted in the first place. Mind you, winter seems to have evaded detection by either system this past year.