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

[Shillitocettwo]

My 10.6.C has utterly had it lol! It’s like last April without the warmth.....

[Daniel*]

 

[Freeze]

3 hours ago, Shillitocettwo said:

My 10.6.C has utterly had it lol! It’s like last April without the warmth.....

It's like last April without the warmth, and without the sunshine... So it's actually nothing like last April then lol

[damianslaw]

30 minutes ago, Freeze said:

It's like last April without the warmth, and without the sunshine... So it's actually nothing like last April then lol

Sunshine levels have been variable. Western parts are doing well, especially here, compared to eastern districts, indicative of the airflow bring predominantly northerly and easterly as is common for April.

[The PIT]

Plenty of sunshine here anyways

Sunny Sheffield up 5.5C -2.3C below normal. Rainfall 3.3mm 5.9% of the monthly average.

[Summer Sun]

5.7c to the 17th

1.5c below the 61 to 90 average
2.1c below the 81 to 10 average

___________________________

Current high this month 8.8c on the 1st
Current low this month 5.6c on the 12th, 13th, 15th & 16th

[Roger J Smith]

EWP still has not reached the minimum value of 8 mm (1938) and is at 5 mm now. The next ten days look quite dry apart from some moderate rainfalls expected to hit the southwest, so the grid average by 28th will be just a bit higher at 8-10 mm. The last two days of the month may see the blocking highs retreating and frontal bands of rain, but seems unlikely to produce enough to get past our first forecast of 36.1 mm (Polar Gael). Will post some provisional scores soon, and open the May contest overnight for tomorrow morning UK time. 

[damianslaw]

Slow rise in CET over next few days perhaps a 0.1 degree day by day.. no major warm up on the cards.

[Roger J Smith]

As mentioned it seems likely that the EWP will begin to accumulate a bit of a balance but may end up short of our driest forecast which was 36.1 mm (Polar Gael). Anything under 40 mm is going to give Polar Gael the win for April, we have Weather26 at 44 mm then myself at 48.2 mm, a few at 50 mm. There's an outside chance of those taking the lead, but for now, would say these preliminary scores can only change marginally. The scoring was updated from 25 mm -- any changes below 40 mm can only alter a few ranks in average error but not in points. This is a summary of top scores for the month and annually. Will revise these when or if necessary. 

Ranking for average error now requires a minimum of 3/5 contests so we have dropped a few high ranked leaders after the last version when  they were 2/4 but failed to enter April. 

Average errors for any forecasters who have entered five contests will all drop at the same rate if we exceed 25 mm, every 5 mm will drop your average by 1.0 ... until you reach your forecast amount. For those at 4/5 the drop will be faster (every 4 mm extra will drop your average by 1.0). This could lead to minor changes in rankings for average error but the only change in points would be very minor from the percentage differential (a range of about .03 point increases available to those around 50-60 mm).

For now just the top twenty scores, excel file will be made available closer to the final results.

 

TOP SCORES for APRIL _________________________ ANNUAL SCORING (Dec to Apr)

Rank _ Forecaster ___ fcst _______ err _____ score _______ Rank _ Forecaster ______ Total pts ___ avg err (rank)

_01 __ Polar Gael ____ 36.1 mm ___ +11.1 __ 10.00 ______ 01 ___ virtualsphere ________ 38.34 ____ 30.92 (2)

_02 __ Weather26 ___ 44.0 mm ___ +19.0 ___ 9.77 ______ 02 ___ Feb91Blizzard ________ 37.82 ____ 33.84 (5)

_03 __ Roger J Smith _ 48.2 mm ___ +23.2 ___9.56 ______ 03 ___ Bobd29 _______________ 35.99 ____ 36.84 (10)

_04 __ Federico ______ 50.0 mm ___ +25.0 ___9.35 ______ 04 ___ Federico ______________ 35.93 ____ 33.72 (4)

_05 __ Reef __________ 51.0 mm ___ +26.0 ___ 8.96 ______ 05 ___ snowray ______________ 35.87 ____ 33.96 (6)

_06 __ Blast/Past _(2, 1d) 50 mm __ +25.0 ___ 8.93 ______ 06 ___ The Pit ________________ 35.53 ____ 35.60 (9) 

_07 __ B87 ___________ 55.0 mm ___+30.0 ___ 8.76 _______ 07 ___ Relativistic ____________ 34.15 ____ 32.00 (3)

_08 __ Feb91Blizzard(2) 55.0 mm__ +30.0 ___ 8.64 ______ 08 ___ Reef ___________________ 32.48 ____ 34.04 (7)

_09 __ syed2878 ___ (3) 55.0 mm __ +30.0 ___ 8.52 ______ 09 ___ Blast from the Past ____ 30.23 ____ 42.64 (T19)

_10 __ DiagonalRedLine (4) 55 mm _+30.0 ___8.40 ______ 10 ___ Don ___________________ 28.67 ____ 39.36 (13)

_11 __ Mr Maunder (5) __55.0 mm __+30.0 ___8.28 ______ 11 ___ JeffC ___________________28.29 ____ 39.84 (14)

_12 __ General Cluster (6) 55.0 mm _+30.0 ___8.16 ______ 12 ___ Godber1 _______________ 28.08 ____ 41.44 (16)

_13 __ Mulzy ________ (7) 55.0 mm __ +30.0 ___8.04 ______ 13 ___ Polar Gael ______________ 27.94 ____ 30.80 (1)

_14 __ virtualsphere ___ 56.0 mm ___+31.0 ___7.38 ______ 14 ___ Midlands Ice Age _______ 27.84 ____ 39.14 (12)

_15 __ Norrance ___ (2)  56.0 mm ___ +31.0 ___7.26 ______ 15 ___ noname_weather ______ 25.92 ____ 44.60 (27)

_16 __ WxEnthusiast91 _57.0 mm ___+32.0 ___ 6.99 _____ 16 ___ February1978 __________ 25.75 ____ 44.16 (24)

_17 __ Jonboy _________ 59.0 mm ___ +34.0 ___ 6.79 ______ 17 ___ Roger J Smith __________ 25.34 ____ 45.10 (29)

_18 __ summer blizzard 60.0 mm ___ +35.0 ___ 6.59 ______18 ___ davehsug ______________ 24.87 ____ 42.56 (18)

_19 __ sundog ____ (2) _ 60.0 mm ___ +35.0 ___ 6.47 ______ 19 ___ seaside60 ______________24.86 ____ 43.76 (22)

_20 __ J10 ______________ 61.0 mm ___ +36.0 ___ 6.20 ______ 20 ___ Jonboy _________________24.64 ____ 42.36 (17)

__________________________________________________________

note: 5th place Reef scored from 6th scoring interval, goes to 5th due to late penalty for Blast from the Past.

Other top ranked average error values include Joneseye (8th, 34.53, 54th in points after 3 contests entered),

Frigid (15th, 41.10, 4 contests and 38th in points), moffat (11th, 37.03, 3 contests, 43rd in points and will be

unranked if no further entries), The top 20 points and error ranks are now converging with the occasionals

dropping out, the only other missing top 20 error rank is T19 42.64 mm for General Cluster who ranks 23rd

for points behind Leo97t (21st) and Stewfox (22nd). The rest of the top 30 are SteveB (24th), J10 (25th), 

Stationary Front (26th), Kirkcaldy Weather (27th), Mulzy (28th), Summer Blizzard (29th) and Norrance (30th).

These are all quite close behind 18th to 20th in total points, even 30th is only down to 23.40, and Weather26

jumped up to 31st (23.25) with second place this month (from 48th). 

All other scoring details will be posted at final stages. 

 

 

[The PIT]

Sunny Sheffield up to 5.6C -2.3C below average. Rainfall unchanged

[BornFromTheVoid]

Latest projections

 
The chances of finishing:
Close to average (8.5C to 9.5C) is  to 0.0% (3 days ago 0.4%)
Above average (>9.5C) remains at 0.0% (3 days ago 0.0%)
Below average (<8.5C) is  to 100% (3 days ago 99.6%)

The period of the 19th to the 24th is forecast to average 8.7C, which is 1.2C below the 91-20 average.

Edited April 19, 2021 by BornFromTheVoid

[Roger J Smith]

EWP projections are now even drier than previously with the southwest not likely to get any rain from the Atlantic disturbance well out to the southwest, the only projected rainfall now comes from a trough dropping south on 29th-30th that gives perhaps 10 mm to the grid, possibly less. At 5 mm so far which is still below the driest April total of 7.1 (1938). Whether it's a good or bad thing, we could be passing all of the bottom ten on the last day of this month, but if not 2021 will end up somewhere in this list:

1. _ 1938 (7.1) ___ 6. 1785 (10.1) ____t-11. 1842 (14.3)

2. _ 1817 (7.9) ___ 7. 2007 (10.4) ____t-11. 1974 (14.3)

3. _ 1912 (9.0) ___ 8. 1984 (10.8) ____ 13. 1783 (15.2)

4. _ 1957 (9.7) ___ 9. 2011 (11.6) ____ 14. 1954 (16.1)

5. _ 1893 (9.9) __ 10. 1854 (14.1) ____ 15.1844 (16.6)

[Summer Sun]

5.8c to the 18th

1.5c below the 61 to 90 average
2.0c below the 81 to 10 average

___________________________

Current high this month 8.8c on the 1st
Current low this month 5.6c on the 12th, 13th, 15th & 16th

[Roger J Smith]

Back around the 12th I produced a list of Aprils that were colder or similar to that point. Assuming we are at 6.0 or lower by the 20th, this is the revised list and we have moved from around 35th coldest on the 12th to around 30th on the 20th if then at 5.9 (after adjustments). My current estimate for the finishing value is 6.8. 

The original list was reverse chronological but this one is ordered by temperatures. Colder values on the left in the first column.

Years with an asterisk were not in the list on the 12th so have moved from a value above 5.7 to where they are now. A list of nineteen members of the 12th listing that have drifted above 6.0 now can be seen below this table.

 

Rank __ Year __CET 20th__final CET____ Rank __ Year __CET 20th__final CET

_ 01 ___ 1837 ___ 3.3 _____ 4.7 __________ 18 ___ 1936*___5.4 _____ 6.3 

_ 02 ___ 1917 ___ 3.6 _____ 5.4 __________t19 ___ 1804 ___ 5.5 ____ 6.9 

_t03 ___ 1784 ___ 4.5 _____ 5.7 __________t19 ___ 1924 ___ 5.5 ____ 6.9 

_t03 ___ 1816 ___ 4.5 _____ 6.6 __________t19 ___ 1966 ___ 5.5 ____ 7.2 

_t05 ___ 1790 ___ 4.6 _____ 6.1 __________t22 ___ 1891 ___ 5.6 ____ 6.2

_t05 ___ 1809 ___ 4.6 _____ 5.2 __________t22 ___ 1849*___5.6 ____ 6.4  

_ 07 ___ 1780 ___ 4.7 _____ 6.3 __________t22 ___ 1958 ___ 5.6 ____ 7.4 

_t08 ___ 1782 ___ 4.8 _____ 5.2 __________t22 ___ 1983 ___ 5.6 ____ 6.8

_t08 ___ 1793 ___ 4.8 _____ 6.2 __________ 26 ___ 1807*___5.7 ____ 7.7

_t08 ___ 1986 ___ 4.8 _____ 5.8 __________t27 ___ 1842 ___ 5.8 ____ 7.8 

_ 11 ___ 1799 ___ 5.0 _____ 5.4 __________t27 ___ 1918*___5.8 ____ 6.7 

_t12 ___ 1839 ___ 5.1 _____ 6.4 __________t27 ___ 1978 ___ 5.8 ____ 6.5

_ 01 ___ 1917 ___ 4.5 _____ 5.2 __________t30 ___ 1806 ___ 5.9 ____ 6.8  

_t12 ___ 1879 ___ 5.1 _____ 5.7 __________t30 ___ 1847*___5.9 ____ 6.6 

_t12 ___ 1922 ___ 5.1 _____ 5.5 __________t30 ___ 1860*___5.9 ____ 5.9 

_t15 ___ 1812*___5.2 _____ 5.5 __________t30 ___ 1887 ___ 5.9 ____ 6.2 

_t15 ___ 1824 ___ 5.2 _____ 7.4 __________t30 ___ 1888 ___ 5.9 ____ 6.2

________________________________________ t35 ___ 1772*___6.0 ____ 6.4 

________________________________________ t35 ___ 1818*___6.0 ____ 6.9 

________________________________________ t35 ___ 1903*___6.0 ____ 6.4 

________________________________________ t35 ___ 1970 ___ 6.0 ____ 6.7

_____________________________________________________

These years were colder than (or close to) 2021 on the 12th April listing and have dropped off the list above ... and this is how they fared from 20th to end of the month.

1785 (7.3 --> 8.4) .. 1786 (7.1 --> 8.1) .. 1789 (6.5 --> 7.4) .. 1795 (7.0 --> 7.7) .. 1797 (6.3 --> 7.4) .. 1841 (6.4 --> 7.8)

1858 (6.6 --> 7.7) .. 1881 (6.8 --> 7.3) .. 1885 (6.2 --> 6.7) .. 1897 (6.2 --> 7.1) ..1902 (6.5 --> 7.5) ..  1911 (6.4 --> 7.5)

1941 (6.4 --> 6.4) .. 1968 (6.6 --> 8.1) .. 1973 (6.7 --> 7.0) .. 1984 (6.4 --> 8.1) ..  1994 (6.1 --> 8.1) .. 2000 (6.3 --> 7.8)

2013 (6.8 --> 7.5) 

____________________________________________________________________________

So if the 20th CET (after adjustments) is 6.0 or below, we will have passed most of those 19 Aprils (about three or four

were in the close or within 0.1 of 2021 grouping on the 12th, to be determined) while meanwhile ten new ones have

joined the list, only five of which are likely to be ahead of 2021, so a net gain of about nine places towards the cold

end of the list. 

The average end of April CET of the 5.8 to 6.0 group above is 6.6. 

[The PIT]

Sunny Sheffield up to 5.8C -2.2C below normal. Rainfall 3.3mm 5.9% of the monthly average.

[Summer Sun]

5.9c to the 19th

1.4c below the 61 to 90 average
1.9c below the 81 to 10 average

___________________________

Current high this month 8.8c on the 1st
Current low this month 5.6c on the 12th, 13th, 15th & 16th

[damianslaw]

As anticipated a 0.1 degree rise day on day expected, even though nights look cooler.. maxima look near or just above average for next few days at least. Perhaps something cooler towards months end, stunting the rate of rise. Good chance will end up below 7 degrees.. or only just in the low 7s. I'll stick my neck out and go with high 6s taking account downward corrections.

Edited April 20, 2021 by damianslaw

[Frigid]

Good chance we come under March's CET of 7.2c. Something not seen very often these days

[BornFromTheVoid]

Latest projections

 

The chances of finishing:
Close to average (8.5C to 9.5C) remains at to 0% (2 days ago 0%)
Above average (>9.5C) remains at 0% (2 days ago 0%)
Below average (<8.5C) remains at 100% (2 days ago 100%)

The period of the 21st to the 26th is forecast to average 9.0C, which is 1.3C below the 91-20 average.

Also, we're currently at 8 sub 0C minima for the month, which is the joint 4th most on record. Two days, the 10th and 11th, were barely above 0C, so might drop below after corrections, and the minimum tonight could also get close to freezing, taking the total to 11 days, the 2nd most on record (after 1917 with 12).

[Summer Sun]

6.1c to the 20th

1.2c below the 61 to 90 average
1.7c below the 81 to 10 average

___________________________

Current high this month 8.8c on the 1st
Current low this month 5.6c on the 12th, 13th, 15th & 16th

[The PIT]

Sunny Sheffield up to 6C -2.1C below average. Rainfall Unchanged.

[Relativistic]

The last time a month outside of the November-March period finished 1C below the 1961-90 mean was in October 2012 (September 2015 and August 2014 came very close). We could be looking to end that run.

[Weather-history]

Coldest, driest April is 1855, I think with a CET: 7.1C and 19.9mm

[The PIT]

Sunny Sheffield having a pause for thought at 6C -2.2C below normal. Rainfall unchanged

[Summer Sun]

6.3c to the 21st

1.1c below the 61 to 90 average
1.6c below the 81 to 10 average

___________________________

Current high this month 8.8c on the 1st
Current low this month 5.6c on the 12th, 13th, 15th & 16th