May 2019 C.E.T. and EWP forecast contests

[Roger J Smith]

The 12z GFS run would suggest a CET rising gradually next week to perhaps 10.5-11.0 by Friday 17th, then sliding back down into the 9's before the end of the run on 25th.

Not saying that later part is very reliable at 10-15 days, but it would certainly bring a very cold average into play. If that backs off to something more ordinary, chances are the month will hover in the 10.5-11.0 range for most of the second half. That would still be colder than most of our forecasts. 

[The PIT]

Sunny Sheffield down to 8.2C -1.0C below normal. Rainfall 26.3mm 45.6% of the monthly average.

[Roger J Smith]

This table shows the rank of the coldest months of each name in past 50 years (1969 to 2018) and it shows that May 1996 was about middle of the pack in terms of ranking or differential from coldest. Extending the period back to 1940 only nets five colder months including the most recent coldest month, Feb 1947. 

 

MONTH __ Coldest __ min since 1969 __ rank __ differential __ colder 1940-68

JAN ______ -3.1 1795 __ -0.4 1979 ____ 17th ___ 2.7 _______ -2.1 1963 (5th)

FEB ______ -1.9 1947 __ -1.1 1986 _____ 5th ___ 0.8 _______ coldest was 1947

MAR ______ 1.0 1674 ___ 2,7 2013 ____t12th ___ 1.7 _______ none

APR ______ 4.7 1701,1837 _5.8 1986 ____t18th ___ 1.1 _______ none

MAY ______ 8.5 1698 ___ 9.1 1996 ____ t13th ___ 0.6 _______ none

JUN ______11.5 1675 __ 11.8 1972 _____ t2nd ___ 0.3 _______ none

JUL ______ 13.4 1816 __14.7 1980,88 __ t35th ___ 1.3 _______ 14.0 1965 (t 11th)

AUG ______12,9 1912 __13.7 1986 ____ t16th ___ 0.8 _______ 13.5 1956 (t 5th)

SEP ______ 10.5 1807*__11.3 1986 ____ t14th ___ 0.8 _______ 10.7 1952 (6th)

OCT _______ 5.3 1740 ___ 7.8 1974,92__t26th ___ 2.5 _______ none

NOV _______ 2.3 1782 ___ 4.1 1985 ___ t28th ___ 1.8 _______ none

DEC _______-0.8 1890 ___-0.7 2010 ____ 2nd ___ 0.1 _______ none

median ________ 1789 ______ 1986 ____ 15th ___ 0.95 ______ none (7/12)

________________________________________

*and 1674,1675,1694

The most remote top 20 cold months are October and November. For October, the most recent was 1919 (7.4, t16th coldest) and for November it was 1915 (2.8, 2nd coldest). Nov 1919, 1923 were also tied 8th coldest at 3.3. 

Note that 1986 has four of the twelve coldest months in modern times and the year starting Nov 1985 has five. Half of them fall in the span of 1980 to 1988 and 7/12 in the span 1979 to 1988. 

[Don]

3 hours ago, feb1991blizzard said:

It must have been a cracker!!   could have included some snow.

Definitely some snow involved there.

Didn't get much warmer either

Until right at the end

That must have saved it from being a record breaker.Not sure if its a good analogue for this month or not.

We were still in the cold pattern that delivered the last severe winter to the country.  I believe 6 inches of snow fell across the South Downs at some point during May 1979.

Edited May 9, 2019 by Don

[Don]

3 hours ago, Don said:

We were still in the cold pattern that delivered the last severe winter to the country.  I believe 6 inches of snow fell across the South Downs at some point during May 1979.

EDIT:  Have checked the Surrey weather book and 2 inches of snow lay at the top of Reigate Hill on 2nd May 1979, following a cold night with snow showers.  Not 6 inches then, but impressive all the same!

[Derecho]

7 hours ago, reef said:

 

Its worth noting that if the GFS 06z were to come to fruition, we'd be on 8.0C to the 23rd and a mean of 11.6C or below for the remaining 8 days would see us record the coldest May on record. We're still a long way from that though.
 

Is that just for our area of Eastern England? May has felt like a cold month here so far, especially with the lack of sunshine. I suspect that even with the more settled weather next week, the temperature for this part of the UK will still be firmly below average.

Edited May 9, 2019 by Quicksilver1989

[Summer Sun]

8.9c to the 9th

1.2c below the 61 to 90 average

1.8 below the 80 to 10 average

__________________________________

Current high this month 11.9 to the 1st

Current low this month 8.8c to the 6th & 7th

[BornFromTheVoid]

Below is the estimate of the CET over the next 10 days based on the 06z GFS

The first graph is the provisional data and forecast with daily max, min, mean and the rolling CET, as well as the 81-10 rolling mean. The second graph is the daily mean in relation the the daily high and low mean record values.

  

The mid month warm up has now diminished into a close to average period, meaning the CET is likely to more than 1C below average as we approach the final third of the month.
8.9C to the 10th would make this year the 4th coolest first 10 days of May in the last 30 years

[SunnyDazee]

7 minutes ago, BornFromTheVoid said:

Below is the estimate of the CET over the next 10 days based on the 06z GFS

The first graph is the provisional data and forecast with daily max, min, mean and the rolling CET, as well as the 81-10 rolling mean. The second graph is the daily mean in relation the the daily high and low mean record values.

  

The mid month warm up has now diminished into a close to average period, meaning the CET is likely to more than 1C below average as we approach the final third of the month.
8.9C to the 10th would make this year the 4th coolest first 10 days of May in the last 30 years

It’s gonna be cooler than average isn’t it? What temps would we need in the last 10 days for it to finish above? Must need constant 20 degree days and mild nights 

[BornFromTheVoid]

9 minutes ago, SunnyDazee said:

It’s gonna be cooler than average isn’t it? What temps would we need in the last 10 days for it to finish above? Must need constant 20 degree days and mild nights 

Assuming the forecast to the 19th is correct, we'd need the final 12 days of the month to average at least 15C to reach the 81-10 average by months end (but probably more than 15C if we include corrections).  So minima around 10C and maxima in the low 20s would do it.

[SunnyDazee]

12 minutes ago, BornFromTheVoid said:

Assuming the forecast to the 19th is correct, we'd need the final 12 days of the month to average at least 15C to reach the 81-10 average by months end (but probably more than 15C if we include corrections).  So minima around 10C and maxima in the low 20s would do it.

Finally, what was the last year to have a May below average do you know? It’d be interesting to see how the summer was after that considering I’m 80% sure this May is gonna be below average

[Derecho]

54 minutes ago, SunnyDazee said:

Finally, what was the last year to have a May below average do you know? It’d be interesting to see how the summer was after that considering I’m 80% sure this May is gonna be below average

There is a good chance although the ECM is warmer then the GFS still. 2015 and 2013 were the last 2 Mays with below average temperatures but both produced very different summers. Worth noting that May 2015 was dominated by cyclonic WSW winds whilst 2013 was dominated by NW winds however, so synoptically very different.

[SunnyDazee]

16 minutes ago, Quicksilver1989 said:

There is a good chance although the ECM is warmer then the GFS still. 2015 and 2013 were the last 2 Mays with below average temperatures but both produced very different summers. Worth noting that May 2015 was dominated by cyclonic WSW winds whilst 2013 was dominated by NW winds however, so synoptically very different.

Fantastic thanks for getting back to me, we’ve had N’lys but are we getting W/SW at the moment? I’m struggling to read the wind finder forecasts they’ve got wind coming from everywhere lol

[snowray]

Might end up with somewhat higher temps around the CET zone next week in any sunshine, the east is likely to be cooler with a brisk easterly wind developing in the SE and along the South Coast.

[Derecho]

2 hours ago, SunnyDazee said:

Fantastic thanks for getting back to me, we’ve had N’lys but are we getting W/SW at the moment? I’m struggling to read the wind finder forecasts they’ve got wind coming from everywhere lol

This month has been dominated by northerlies so far, although I think May 1991 was dominated by them to any even greater extent in its first half.

[SunnyDazee]

24 minutes ago, Quicksilver1989 said:

This month has been dominated by northerlies so far, although I think May 1991 was dominated by them to any even greater extent in its first half.

That was quite a backloaded summer wasn’t it?

[Derecho]

4 minutes ago, SunnyDazee said:

That was quite a backloaded summer wasn’t it?

Yup awful June but a very good July-September period

[Roger J Smith]

6 hours ago, SunnyDazee said:

Finally, what was the last year to have a May below average do you know? It’d be interesting to see how the summer was after that considering I’m 80% sure this May is gonna be below average

The last May to average below the 1981-2010 normal of 11.7 (or 1961-90 of 11.2) was 2015 (10.8). 

In general, most questions about recent CET values and averages or extremes can be solved by looking at the introductory post to these threads (which is always following the same format). The CET values for each year since 1981 are posted along with various 30-year averages. 

[SunnyDazee]

28 minutes ago, Roger J Smith said:

The last May to average below the 1981-2010 normal of 11.7 (or 1961-90 of 11.2) was 2015 (10.8). 

In general, most questions about recent CET values and averages or extremes can be solved by looking at the introductory post to these threads (which is always following the same format). The CET values for each year since 1981 are posted along with various 30-year averages. 

I realised this after I’d posted, thanks for clearing it up Roger and I’ll check the list next time

[The PIT]

Sunny Sheffield down to 8C -1.3C below normal. Rainfall up to 29mm 50.3% of the monthly average

[feb1991blizzard]

On 09/05/2019 at 18:59, Don said:

We were still in the cold pattern that delivered the last severe winter to the country.  I believe 6 inches of snow fell across the South Downs at some point during May 1979.

We have had some fairly severe winters since then though, 85-86, 95-96 (record low or near record low at Glasgow airport (around -26c), 09-10 fairly severe, then a sub zero month in Dec 2010.

[reef]

Currently running at 7.1C (-3.1C) here to the 10th.

A mean of 9.9C or less for the remainder of the month would see us record the coldest May on record. A long way to go, but something to keep an eye on.

[Don]

52 minutes ago, feb1991blizzard said:

We have had some fairly severe winters since then though, 85-86, 95-96 (record low or near record low at Glasgow airport (around -26c), 09-10 fairly severe, then a sub zero month in Dec 2010.

Yes and I’m ready for one of those winters again!  In fact, I’m always ready for a cold winter!

Edited May 10, 2019 by Don

[damianslaw]

On 09/05/2019 at 15:19, feb1991blizzard said:

It must have been a cracker!!   could have included some snow.

Definitely some snow involved there.

 

Didn't get much warmer either.

 

 

Until right at the end.

 

That must have saved it from being a record breaker.

Not sure if its a good analogue for this month or not.

 

I'm not very politically vocal, but uncanny timing a cold start to when the conservatives were voted back in... 

[feb1991blizzard]

2 minutes ago, damianslaw said:

I'm not very politically vocal, but uncanny timing a cold start to when the conservatives were voted back in... 

Im hoping for the brexit party to win the Euro elections.