June 2021 C.E.T. and EWP forecast contests

[The PIT]

Sunny Sheffield down to 16.6C +2.8C above normal. Rainfall 14.8mm 19.2% of the monthly average.

Possibly the low point of the month with slight increase possible from now once again before levelling of again.

[summer blizzard]

So we did end up with the warmest opening third since 1982, the warmest first half since 2004 and the warmest first two thirds since 1970.

Current models would suggest a steady drop though towards an unremarkable figure.

[Roger J Smith]

EWP now around 38 mm (33 to Sunday, +5 est Monday) ... GFS now goes on a rampage over Yorkshire later this month, not sure if it's that consistent with other guidance so large uncertainty on the 40-50 grid average to 30th that gets us to 78-88 mm but I'll take it after writing off anything much over 60 most of the last week or two. ... CET looks rather cool to end, probably will leak a bit and end up in the mid to high 15s. 

It is exceptionally warm in my part of the world this month (expecting a +4 C anomaly), looking back at other very warm Junes here, I see a general correlation with cool/wet outcomes in Europe. Not totally in that direction though. Also the GFS guidance for early July is currently a mixture of fair to very poor for summer weather. The early June warmth in Britain was also a "contra-indication" for generally sustained summer warmth. Let's hope 2021 bucks all these signals but if I had to bet money, summer in late August and early September. 

 

[Roger J Smith]

So already the GFS has ripped up the plan for a new one, now the heavier rain is reserved for the southern counties of England, and parts of next week look a bit warmer again. That would change my outlooks from yesterday to something like 70 mm total EWP and 16.0 outcome for the CET. Minor differences in terms of contest scoring but major differences in terms of weather forecasts for regions. We can't seem to avoid the impending killer heat wave in store for us here however, forecasts are basically scaring people with numbers equalling all-time highs recorded in this part of the world (and it normally gets quite hot here every summer). Canada's highest temperature (from 1937) was 45 C and British Columbia's highest is 44 C which I believe has been shared by several locations in different years, none of them all that recent. I don't recall a reading over 42 C in western Canada in my fairly extensive time of tracking weather. But I think we may see some very high readings here this weekend, we have a 582 dm thickness in the forecast models. 

It was just about a week ago that Palm Springs CA hit 50.6 C to equal their all-time record high, and that heat dome sort of fell apart without totally disappearing and now it's apparently going to give a second performance up near us. 

[The PIT]

Sunny Sheffield down to 16.5C +2.6C above normal. Rainfall 14.8mm 19.2% of the monthly average.

Models struggling at the moment with large changes from run to run. FI probably starting around T48.

Edited June 23, 2021 by The PIT

[Summer Sun]

15.9c to the 22nd

2.0c above the 61 to 90 average
1.8c above the 81 to 10 average

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Current high this month 17.7c on the 2nd
Current low this month 15.9c on the 22nd

[Stu_London]

Perhaps a small fall over the next couple of days, with a small rise in the last couple of days of the month.

With adjustments probably mid 15s - so above average but not particularly noteworthy. 

Borderline exceptional warmth for the first half of the month, particularly in the south east, which wont be fully recognised in the CET figures.

 

[The PIT]

Sunny Sheffield still at 16.5C +2.5C above normal. Rainfall unchanged.

[Summer Sun]

15.8c to the 23rd

1.8c above the 61 to 90 average
1.6c above the 81 to 10 average

___________________________

Current high this month 17.7c on the 2nd
Current low this month 15.8c on the 23rd

[summer blizzard]

A warm but mediocre month minima aside so glad to see the CET will reflect that.

[snowray]

5 hours ago, The PIT said:

Sunny Sheffield still at 16.5C +2.5C above normal. Rainfall unchanged.

Is Sheffield usually that much milder than the CET zone.? O.7c higher seems quite a lot.

[Roger J Smith]

EWP has reached 37 mm (est 1 mm for yesterday), rest of month estimate from GFS is around 25-30 mm. For a provisional outcome similar to our consensus (which was 63 mm between two forecasts of 61 mm, 65 mm) the scoring would show last month's first and second annual leaders extending their margins over the chase pack as Feb91Blizzard (61 mm) and snowray (58 mm) had relatively high scores and some of the group from 3rd to 10th last month were further from the mark. Others were also close and move up a few spots (Don 60 mm (now 3rd), Bobd29 61 mm (now 4th), Federico 60 mm (now 5th), Relativistic 60 mm (now 7th) would all move a spot or two higher, Reef (52 mm) down to 6th and virtualsphere (46 mm) down to 11th lose some ground. Davehsug (67 mm) is up to 9th and Midlands Ice Age (59 mm) is now 10th in the provisional scoring. If the outcome is a bit higher I think the two leaders still remain comfortably in front but some of the details change. Only Godber1 and myself of the top ten last month have forecasts above 80 mm. PIT (70 mm) holds on to 8th but Godber1 (88 mm) goes from 9th to 17th, and I would go from 10th to 18th (89.6 mm), but if the outcome is above 70 mm we would possibly be closer to 14th-15th.

Will revisit this at end of month with a scoring summary and file posted then. 

In my arbitrary designation of 63.1 mm for an outcome, Ed Stone (65 mm) finishes top for the month (any value 63.0 to 66.0 will do for Ed Stone who would move up to 14th from 26th) with bobd29 (61 mm), feb91blizzard (61 mm) second and third, B87 (60 mm) fourth and three other entries from top ten listed above at 60 mm 5th to 7th places. 

Given the uncertainty on the rainfall there is probably some chance of a much higher outcome (some parts of southern England are definitely going to end the month well above 100 mm), so none of this is carved in (ed) stone. 

CET might oscillate a bit from here to end, would think 15.6 is about the current over-under for a finish. 

Edited June 24, 2021 by Roger J Smith

[Roger J Smith]

7 hours ago, summer blizzard said:

A warm but mediocre month minima aside so glad to see the CET will reflect that.

Yet another June with a warm first half unable to sustain that value to the end, apparently (can't see it getting back to where it was on 15th even if it does warm up a bit next week). I've noticed also that a lot of these warm-start Junes only got into warmth at very end of May so from that we can deduce that 10-day to two-week warm spells are the norm for early summer weather patterns, more prolonged warmth is more typical of July-August spells. If there is any explanation, it may be that warmth in early June provokes a confrontation with still-quite-cold regimes further north which then are drawn into the circulation. Later on perhaps they aren't as robust and the warmth may be more anchored by a semi-permanent high further east in the Atlantic than statistically normal. However this may be an explanation lifted out of an automatic assumption (what is known as auto-correlation). 

Taking my earlier table of decreases first half to second half June, the July and August CET values that follow the full list of significant drops would be as follows, the lists are the values in the same order as the table to make any trends for size of decrease evident ... note that the drop is roughly double the difference between h1 and end of month CET value (which is the average of h1 and h2). 

___ July and August CET values following Junes that cool from h1 to h2 (by 1.0 or more) ... listed in order of size of decrease in June ... the gap separates decreases greater than 2.0 (left) from those 2.0 or smaller (right) ... years shown below the two values.

JUL __ 16.7,16.4,15.8,15.0,15.9,17.8,15.2,14.7,16.5,16.8,15.1__14.5,14.8,13.7,16.1,15.0,15.6,15.2,15.2,16.7,15.4,15.5,17.3,15.4,15.5,15.9,14.2,17.2,14.1,14.6

AUG _ 18.9,16.9,17.6,14.5,15.7,17.6,14.3,15.9,15.7,15.4,15.6__17.1,15.8,13.6,16.9,14.7,15.2,16.0,15.4,15.8,16.2,16.2,15.5,16.1,16.4,15.6,14.3,16.3,14.3,15.3

(year) _ 1997_1835_2004_1813_1927_1933_1963_1980_1982_1925_1940___1842_1858_1922_1937_1966_1822_1970_2007_1775_1806_1981_1869_1918_1939_1950_1812_1825_1907_1915

The averages are 16.0 and 15.4 for the two halves of data for July (blended mean 15.6).

and for August they are 16.2 and 15.6 (blended mean 15.8)

Two tendencies emerge ... one is not relevant to this year, if a June is generally cool and loses ground, then the summer is often a shocker in general, but if June is fairly warm and loses ground, there's a tendency for the recovery to take two months and August is then warmer than July as is the case in 17 of 30 cases above (which is a bit more than expected at random, note the first three in the list with the biggest losses in June have a strong August warmth signal). Also in overall terms, July is 1.0 warmer than August in only two cases (three more at 0.9) but August is 1.0 warmer than July in five cases (one more at 0.9). So all things considered there is a slight overall tendency for this sort of June to be followed by a late second warm spell. There is no signal for any unusual warmth and anomalous cold shows up more often than you would want to see in any analogue set. 

[The PIT]

Sunny Sheffield down to 16.4C  -2.3C below average. Rainfall 18.5mm 24.1% of the monthly average

[The PIT]

16 hours ago, snowray said:

Is Sheffield usually that much milder than the CET zone.? O.7c higher seems quite a lot.

Nope normally not at all. In winter it's generally 0.8C below the CET zone. In summer this closes to around 0.4C so I'm surprised it's that much higher.

[Stu_London]

The usually north west / south east split was perhaps more west / east at the start of the month. Perhaps Sheffield found itself favourably positioned compared to some of the more western CET stations - only explanation I can think of. 

[Summer Sun]

15.8c to the 24th

1.8c above the 61 to 90 average
1.6c above the 81 to 10 average

___________________________

Current high this month 17.7c on the 2nd
Current low this month 15.8c on the 23rd & 24th

[damianslaw]

Not expecting much change between now and the end of the month. Much of the CET zone fairly close to the late June average if not a little below, but northern parts unusually may be warmer than southern. 

[Stargazer]

For comparison, Reading University, our nearest official station, is currently at 16.6 (+1.2), so as expected a smaller positive anomaly here in the south. Long term averages here are around CET + 0.8 degrees.

A rather larger positive rainfall anomaly looks certain for this month in our area.

Edited June 25, 2021 by Stargazer

[Dancerwithwings]

10 minutes ago, Stargazer said:

For comparison, Reading University, our nearest official station, is currently at 16.6 (+1.2), so as expected a smaller positive anomaly here in the south. Long term averages here are around CET + 0.8 degrees.

A rather larger positive rainfall anomaly looks certain for this month in our area.

Big differences, almost a 6c lower here in the heart of England

11.2c in my back yard and most stations here in the Midlands, must be all the rain we are having atm

[Summer Sun]

15.8c to the 25th

1.7c above the 61 to 90 average
1.6c above the 81 to 10 average

___________________________

Current high this month 17.7c on the 2nd
Current low this month 15.8c on the 23rd, 24th & 25th

[The PIT]

Slight correction just noticed I forgot to save the spreadsheets so one day was missing. Sunny Sheffield on 16.2C +2C above normal. Rainfall 20.6mm 26.8% of the monthly average.

[The PIT]

Sunny Sheffield still on 16.2C +1.9C above normal. Rainfall unchanged.

The month does look like it's going to be in the top ten of warmest June's' on records and could still make the top ten driest although any showers would likely move it outside.

Edited June 27, 2021 by The PIT

[damianslaw]

2 hours ago, The PIT said:

Sunny Sheffield still on 16.2C +1.9C above normal. Rainfall unchanged.

The month does look like it's going to be in the top ten of warmest June's' on records and could still make the top ten driest although any showers would likely move it outside.

Yes expecting it to go down as a Top 10 driest June. Temperature wise, its been consistently warm with nothing particularly cool at any stage, though Friday was cold.. so whilst it may go down as a Top 10 warmest June, because of lack of any notable heat, nothing above 23 degrees here, it won't go down in the memory of many. Many a cool June has brought temps above 25 degrees, indeed some have brought 2-3 day heatwaves. Hoping July can bring a least one spell of what I class very warm temps, 25-28 degrees range.

 

 

[Summer Sun]

15.7c to the 26th

1.7c above the 61 to 90 average
1.4c above the 81 to 10 average

___________________________

Current high this month 17.7c on the 2nd
Current low this month 15.7c on the 26th