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


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Posted
  • Location: Ludgershall, Wiltshire
  • Location: Ludgershall, Wiltshire
    3 hours ago, Man Without Beard said:

    Who's waiting to see if the traditional end of month heatwave will materialise? Anyone who forecasted CET over 9C is out of the game - I can't see us averaging over 12C in the second half. 8C to 8.5C, though, is well within range.

    I am (only to save my CET guess)!  😉

    Whilst I see what you mean about those (myself included) forecasting a CET over 9C being out of the game, I think it's too early to call that at this stage, as we know how quickly the models can flip!  Remember, February looked primed to be a cold or very cold month but ended up somewhat milder than average.

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    I think the headline should include "exceptional frosty". We've had sunny and very dry Aprils in the past but rarely has an April has been this frosty.

    Excel April 21 CET.xlsx PDF (Summary)April 2021 Summary.pdf The cold April caught everyone out this month, in February we also had the weather models predicting a cold start to the month and

    My mean temp is currently running at 5.7C (-3.0C) to the 29th. In records back to 1980, the coldest was April 1986 with 5.8C. This month will beat that if tomorrow averages 7.1C or below. For ref

    Posted Images

    Posted
  • Location: Irlam
  • Location: Irlam
    3 hours ago, Man Without Beard said:

    Who's waiting to see if the traditional end of month heatwave will materialise? 

    One peculiarity about April is that the highest maxima ever recorded during April are not to be found in the last few days  of the month. For instance 25.6C for March was recorded on the 29th in 1968, also 25.0C was recorded on that date in 1929 and 1965.

    The highest maximum ever recorded during  the last 5 days of April is only 26.1C (only 0.5C higher than the March all time record) on the 30th in 1952.   26.0C was recorded on 10th of April last year. 

     

     

    Edited by Weather-history
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    Posted
  • Location: Newcastle Upon Tyne (Spital Tongues)
  • Weather Preferences: Cold, Snow, Windstorms and Thunderstorms
  • Location: Newcastle Upon Tyne (Spital Tongues)
    3 minutes ago, Weather-history said:

    One peculiarity about April is that the highest maxima ever recorded during April are not to be found in the last few days  of the month. For instance 25.6C for March was recorded on the 29th in 1968, also 25.0C was recorded on that date in 1929 and 1965.

    The highest maximum ever recorded during  the last 5 days of April is only 26.1C on the 30th in 1952.   26.0C was recorded on 10th of April last year. 

    Similar with the CET maxima. The record high maxima on the 3rd, 23.5C (in 1946), is the 4th highest for the whole month. It's also warmer than any of the record maxima in the last 9 days of April.

    I guess it highlights the potential for maxima in the mid 20s throughout April

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    Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

    Sunny Sheffield down to 5.5C -1.8C below average, Rainfall 2.8mm 5% of normal.

    Is this going to be yet another month with a cold first half followed by a warmer 2nd half?

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    Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl
    On 09/04/2021 at 21:22, LetItSnow! said:

    2012 is the last (7.2 vs 8.3)

    1990 before then (8.0 vs 8.3)

    then 1989 (6.6 vs 7.5)

    interestingly, 1991 almost did the same (both 7.9).  March, 1991 was a bizarre month in that it was well-above average in a general very cool period. IIRC the blocking that led to exceptional cold in February slid further south over Europe/Russia which ended up bringing a lot of very mild southerlies instead. Then the cold pattern resumed in April. 

     

     

    Thanks, yes not surprised 2012 did it after the exceptional March, April was a shocker!

    Vague recollections of March 91 being quite a good month, don't remember April 91 much. The cold theme broke in July, following a very chill June. The Sept 90 to June 91 period overall was quite cold in a generally very mild period that commenced Dec 88 lasting through until Summer 92... we then had a variable period until Summer 97 with intermittent cold and very mild periods, cold such as autumn 92, summer and autumn 93, winter 95-96, spring 96 and late 96. Warm such as summers 91, 94, 95, winters 92-93, 94-95, spring 97..

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    Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

    5.8c to the 10th

    0.8c below the 61 to 90 average
    1.8c below the 81 to 10 average

    ___________________________

    Current high this month 8.8c on the 1st
    Current low this month 5.8c on the 7th & 10th

    Edited by Summer Sun
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    Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl
    1 hour ago, Summer Sun said:

    5.8c to the 10th

    0.8c below the 61 to 90 average
    1.8c below the 81 to 10 average

    ___________________________

    Current high this month 8.8c on the 1st
    Current low this month 5.8c on the 7th & 10th

    Is this the low point? Probably tomorrow, then a slow rise.

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    Posted
  • Location: Rotherhithe, 5.8M ASL
  • Location: Rotherhithe, 5.8M ASL
    22 hours ago, Don said:

    I am (only to save my CET guess)!  😉

    Whilst I see what you mean about those (myself included) forecasting a CET over 9C being out of the game, I think it's too early to call that at this stage, as we know how quickly the models can flip!  Remember, February looked primed to be a cold or very cold month but ended up somewhat milder than average.

    Can we all collectively say no chance?

    A86B3CEA-B503-4DE0-8680-DD4BE7624C82.thumb.gif.f5bb03ec586ca5ca8bab348652174e3a.gif

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    Posted
  • Location: Ludgershall, Wiltshire
  • Location: Ludgershall, Wiltshire
    2 hours ago, Daniel* said:

    Can we all collectively say no chance?

    A86B3CEA-B503-4DE0-8680-DD4BE7624C82.thumb.gif.f5bb03ec586ca5ca8bab348652174e3a.gif

    No, not yet.  It's only the 11th of the month.

    Edited by Don
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    Posted
  • Location: Rotherhithe, 5.8M ASL
  • Location: Rotherhithe, 5.8M ASL
    8 minutes ago, Don said:

    No, not yet.  It's only the 11th of the month.

    Yeah and well it’s looking nothing but average at very best to 20th. It would take some heatwave....

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    Posted
  • Location: Ludgershall, Wiltshire
  • Location: Ludgershall, Wiltshire
    54 minutes ago, Daniel* said:

    Yeah and well it’s looking nothing but average at very best to 20th. It would take some heatwave....

    We will have a better idea in 10 days time.

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    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada
    Posted (edited)

    Something unusual that is in play now would be a CET below all forecasts. Godber1 and daniel* have 6.8, no guarantee we make it even that high looking at recent GFS runs. This next week has slightly less direct cold feed but it hardly warms up at all, according to guidance, staying 2 to 3 below average. The CET daily maxima only go back to 1878 (unlike the mean daily which go back to 1772) -- I would think 1837 has some unknown record low maxima around now to go with the daily records. There are reconstructed maps now for 1837 and the pattern looks rather similar to this coming week. The month only warmed from 2.9 on 15th to a tied record low of 4.7 by the 30th.

    Edited by Roger J Smith
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    Posted
  • Location: Irlam
  • Location: Irlam
    5 hours ago, Roger J Smith said:

     I would think 1837 has some unknown record low maxima around now to go with the daily records. There are reconstructed maps now for 1837 and the pattern looks rather similar to this coming week. The month only warmed from 2.9 on 15th to a tied record low of 4.7 by the 30th.

    These readings were recorded by Orlando Whistlecraft at Thwaite in Suffolk during April 1837

     Minima, maxima

    -1.1, 8.3

    -2.2, 8.9

    2.2, 7.8

    -0.6, 7.8

    0.6, 6.1

    -0.6, 7.2

    -1.7, 5.6

    0.6, 6.1

    -1.1, 3.9

    -2.2, 5.0

    -2.3, 7.8

    -2.8, 5.6

    0.6, 6.7

    1.1, 10.6

    -0.6, 10.6

    0.6, 6.7

    1.1, 5.6

    3.3, 8.9

    4.4, 10.6

    2.2, 13.9

    0.6, 11.7

    3.3, 11.7

    2.2, 7.8

    5.0, 14.4

    2.2, 15.0

    7.2, 15.6

    4.4, 14.4

    4.4, 16.1

    4.4, 13.9

    8.3, 14.4

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    Posted
  • Location: Rotherhithe, 5.8M ASL
  • Location: Rotherhithe, 5.8M ASL

    Puts into perspective how cold these nights have been up north the last 3 days all colder than prior 2013 record low in Shap, Cumbria.

    DCF52403-D9E5-4F44-9140-CBAF3DB55196.thumb.png.81d791b97b35175572b6534ee4d9f2c3.png

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    Posted
  • Location: Newcastle Upon Tyne (Spital Tongues)
  • Weather Preferences: Cold, Snow, Windstorms and Thunderstorms
  • Location: Newcastle Upon Tyne (Spital Tongues)

    Latest projections

    AprilProj12.thumb.png.db7952483ed9e77405053aa3c7d5791b.png AprilProb12.thumb.png.70c6107972d4fbe9428ed1bb92871397.png

    The chances of finishing:
    Close to average (8.5C to 9.5C) is 🔻to 1.6% (2 days ago 3.6%)
    Above average (>9.5C) remains at 0.0% (2 days ago 0.0%)
    Below average (<8.5C) is 🔺to 98.4% (2 days ago 96.4%)

    The period of the 12th to the 17th is forecast to average 4.5C, which is 3.2C below the 91-20 average.
    The absolute highest outcome now is 8.7C, so it's safe to rule out anything above 9C.

    Edited by BornFromTheVoid
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    Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

    5.7c to the 11th

    1.0c 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 5.7c on the 11th

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    Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

    Sunny Sheffield down to 5.3C -1.9C below normal. Rainfall a measly 3.3mm 5.9% of the monthly rainfall. A good chance of it finishing in the top ten driest at the moment it's in second place.

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    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada

    EWP only about 4 mm so far, 3 on the tracker to 10th, maybe another 1 mm Sunday, then GFS estimate only 7-10 mm for ten days and I don't see much in the outlook days 11-16, possibly 5-10 mm more ... gets us very close to end of the month with a mere 16-24 mm estimate range. 

    The 06z GFS run once again rather cold with a few more moderate days but signs of a late month cold spell too, might have trouble getting out of the 6-7 range if this run is anywhere near accurate. It may take most of this coming week to get past 6.0 and of course that's before the end of month revisions so this could be one of the colder Aprils of modern times unless there's a stronger reversal than the models have detected so far. 

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    Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

    5.6c to the 12th

    1.2c 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

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    Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

    Sunny Sheffield at 5.2C -2.3C below average. Rainfall unchanged.

    Looks like the weather is getting ready to switch over to a mild 2nd half which it has been doing for a while now.

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    Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl

    The low point, perhaps another nudge down tomorrow given how cold last night was.. then allow rise.. but nothing overly mild on the horizon. High odds for a below average end return I think.. unless there is an exceptional warm spell in the last third, which I cannot see.

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    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada

    So far any signs of warming are rather faint and not very sustained before yet another cool spell sets in towards end of the month. On the 12z GFS output would say 6.7 about as high as it might stumble. Just looking back, in reverse chronological order these are the only years that were colder than our current 5.5 (allowing a slight adjustment) after 12 days, and how each of them finished the month. I included any at 5.6 and 5.7 also (italics)

    COLDER THAN 2021 (to 12th)

    reverse chronological order, to fill space the more recent cases are in the left hand column.

    YEAR ___ CET (12) _ CET (30) ___ May CET _______ YEAR __ CET (12) _ CET (30) ___ May CET

    2013 ____ 4.3 ______ 7.5 ________ 10.4 ___________ 1881 ____ 5.5 ______ 7.3 ________ 11.8

    2000 _____ 5.7 _______ 7.8 _________ 12.1 _____________ 1858 ____ 4.9 ______ 7.7 ________ 10.8

    1994 _____ 5.7 _______ 8.1 _________ 10.7 _____________ 1842 ____ 5.3 ______ 7.8 ________ 11.4

    1986 ____ 4.0 ______ 5.8 ________ 11.1 ____________ 1841 _____ 5.6 _______ 7.8 _________ 12.7

    1984 ____ 5.1 ______ 8.1 _________ 9.9 ____________ 1839 ____ 3.1 ______ 6.4 ________ 10.2

    1983 ____ 5.1 ______ 6.8 ________ 10.3 ____________ 1837 ____ 2.7 ______ 4.7 _________ 9.9

    1978 _____ 5.7 ______ 6.5 _________ 11.7 _____________ 1824 ____ 4.3 ______ 7.4 ________ 10.7

    1975 ____ 4.5 ______ 8.3 _________ 9.9 _____________ 1816 ____ 4.4 ______ 6.6 _________ 9.9

    1973 _____ 5.7 _______ 7.0 _________ 11.4 ______________ 1809 ____ 4.1 ______ 5.2 ________ 13.1

    1970 ____ 4.0 ______ 6.7 ________ 13.0 _____________ 1806 _____ 5.6 _______ 6.8 _________ 12.1

    1968 ____ 4.2 ______ 8.1 _________ 9.8 _____________ 1804 ____ 5.2 ______ 6.9 ________ 13.3

    1958 ____ 4.0 ______ 7.4 ________ 11.1 _____________ 1799 ____ 3.9 ______ 5.4 _________ 9.6

    1941 ____ 4.9 ______ 6.4 _________ 9.4 _____________ 1797 ____ 5.4 ______ 7.4 ________ 11.3

    1924 ____ 4.2 ______ 6.9 ________ 11.6 _____________ 1795 _____ 5.6 _______ 7.7 _________ 10.9

    1922 ____ 3.7 ______ 5.5 ________ 12.7 _____________ 1793 ____ 4.9 ______ 6.2 ________ 10.9

    1917 ____ 2.3 ______ 5.4 ________ 12.8 _____________ 1790 ____ 4.9 ______ 6.1 ________ 11.9

    1911 ____ 4.5 ______ 7.5 ________ 12.9 _____________ 1789 _____ 5.6 _______ 7.4 _________ 12.5 

    1902 ____ 5.2 ______ 7.5 _________ 8.9 _____________ 1786 ____ 5.1 ______ 8.1 ________ 11.2

    1897 ____ 4.8 ______ 7.1 ________ 10.0 _____________ 1785 ____ 5.5 ______ 8.4 ________ 12.3

    1891 ____ 5.3 ______ 6.2 _________ 9.5 _____________ 1784 ____ 3.6 ______ 5.7 ________ 13.5

    1888 ____ 3.6 ______ 6.2 ________ 10.7 _____________ 1782 ____ 4.9 ______ 5.2 _________ 9.0

    1887 _____ 5.7 _______ 6.2 __________ 9.4 _____________ 1780 ____ 4.0 ______ 6.3 ________ 12.8

    1885 ____ 5.2 ______ 7.7 _________ 8.9 _____________

    ________________________________________________________________

    45 previous years in this set, 10 of which were 0.1-0.2 warmer, so 35 this cold or colder (14%).

    The average warming to end of month was 2.1 C, and few warmed past 7.5 C. None got any colder

    but 1782 only added 0.3, the smallest increase from a cold start. 

    The mid-way point for cases was in the 1880s, so a slight bias towards the first half of the data.

    Twenty cases had occurred by 1842 (a frequency of 32% for 1780-1842).

    Decades with frequent cases of cold starts to April include the 1780s, 1880s and 1980s oddly enough.

    This April has started off colder than all but eight since 1950, with another four close behind. 

    ... Mays that follow seem to group into three sets, both very warm and very cool are over-represented

    compared to average distributions, and the middle set appear wet, so some form of blocking likely 

    continues from April into May.

    One encouraging feature is that quite a few good summers follow, for example 1911, 1975, 1983, 2013.

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    Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

    Sunny Sheffield still at 5.2C -2.3C below normal. Rainfall unchanged.

    I'm expecting a slow rise in the next few days. Next week it may speed up somewhat.

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    Posted
  • Location: Newcastle Upon Tyne (Spital Tongues)
  • Weather Preferences: Cold, Snow, Windstorms and Thunderstorms
  • Location: Newcastle Upon Tyne (Spital Tongues)

    Latest projections.

    AprilProj14.thumb.png.5f44741cf2f9606a71ec8260e1a1de26.png AprilProb14.thumb.png.eed8c0777a2eaa8232ef2794b92081fc.png

    The chances of finishing:
    Close to average (8.5C to 9.5C) is 🔺to 2.4% (2 days ago 1.6%)
    Above average (>9.5C) remains at 0.0% (2 days ago 0.0%)
    Below average (<8.5C) is 🔻to 97.6% (2 days ago 98.4%)

    The period of the 14th to the 19th is forecast to average 7.0C, which is 1.7C below the 91-20 average.

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    Posted
  • Location: Skirlaugh, East Yorkshire
  • Location: Skirlaugh, East Yorkshire

    We're running at 4.7C (-3.4C) to the 14th. Its going to be the coldest first half of April here since 1986. That had a mean of 4.3C for the first half.

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