March 2023 C.E.T. and EWP forecast contests

[Weather-history]

22 minutes ago, Don said:

Nope

So everyone should go away with these two examples for future references.

1) A SSW does not guarantee a below average month  (March 2023)

2) A below average month is not dependent on a SSW  (December 2022)

 

Edited April 2, 2023 by Weather-history

[Froze were the Days]

3 hours ago, Snowyowl9 said:

But also who needs a near record cold month when you can get near record snowfalls instead..

One of the few very lucky ones then!...I've seen one or two wet snowflakes all winter, I remember the days when the east coast use to be the place to be for good snowfall, not anymore. 

[The PIT]

Sunny Sheffield finished on 6.7C +0.3C above average. Rainfall 128.7mm 212.4% of the monthly average.

Rainfall wise the year pretty well average now. Temperature wise sitting above normal due to January.

[Don]

1 hour ago, Froze were the Days said:

One of the few very lucky ones then!...I've seen one or two wet snowflakes all winter, I remember the days when the east coast use to be the place to be for good snowfall, not anymore. 

It did indeed, I'm guessing it's often too marginal now?

Edited April 2, 2023 by Don

[snowray]

2 hours ago, Froze were the Days said:

One of the few very lucky ones then!...I've seen one or two wet snowflakes all winter, I remember the days when the east coast use to be the place to be for good snowfall, not anymore. 

Yes that's true, for many years the east of the country was a good place for snowfall, a lack of cold easterlies and persistent Scandi highs in Winter months is the problem, they usually turn up outside of Winter months these days.

[snowray]

9 hours ago, Scorcher said:

You called 7.0C quite a few days ago to be fair to you Don.

I was on 6.9c and thought I would end up a degrees or two short, but I got increasingly concerned that we could hit 7c or even 7.1c, and I could end up too low, kept thinking, surely not!..... Funny old game this.

[Froze were the Days]

1 hour ago, Don said:

It did indeed, I'm guessing it's often too marginal now?

Worrying thing is the models have been pretty good the last few winters in predicting the marginality/rain events on the east coast (4 I think) other than Feb 2021 when dp's and temps for once clearly low enough which doesn't happen often. 

[Derecho]

8 hours ago, Earthshine said:

Wow, thought I seriously overestimated the CET considered the hype at the start of the month.  The weighting towards warmer is just so strong these days that despite a SSW we can't even manage below the 1961-1990 average.

I think that graph is a bit too simplistic. December 2010, early March 2018 and a lot of December 2022 proved notable cold is still possible. I'd probably go for something like this.

Months of notable cold will still be possible but months that return higher anomalies will become more frequent with a few pushing the boundaries as well.

3 hours ago, Weather-history said:

So everyone should go away with these two examples for future references.

1) A SSW does not guarantee a below average month  (March 2023)

2) A below average month is not dependent on a SSW  (December 2022)

 

Yup and the MAD thread should take note. The SSW talk dominated the thread too much. Too many T384 charts with a red anomaly blob over Russia and people going boom. Too much faith obsession has been placed in SSWs since 2018 and the thread is poorer for it. 

[Don]

1 hour ago, Froze were the Days said:

Worrying thing is the models have been pretty good the last few winters in predicting the marginality/rain events on the east coast (4 I think) other than Feb 2021 when dp's and temps for once clearly low enough which doesn't happen often. 

Wasn't February 2021 a bit borderline at first with less snow than forecast as a result?

Edited April 2, 2023 by Don

[JeffC]

2 hours ago, Quicksilver1989 said:

I think that graph is a bit too simplistic. December 2010, early March 2018 and a lot of December 2022 proved notable cold is still possible. I'd probably go for something like this.

Months of notable cold will still be possible but months that return higher anomalies will become more frequent with a few pushing the boundaries as well.

Yup and the MAD thread should take note. The SSW talk dominated the thread too much. Too many T384 charts with a red anomaly blob over Russia and people going boom. Too much faith obsession has been placed in SSWs since 2018 and the thread is poorer for it. 

Not forgetting March & April 2013 which were notably cold, we had Ice days on 1st & 2nd April.

[Don]

4 minutes ago, JeffC said:

Not forgetting March & April 2013 which were notably cold, we had Ice days on 1st & 2nd April.

Indeed, Easter 2013 was freezing!

[Frigid]

1 hour ago, JeffC said:

Not forgetting March & April 2013 which were notably cold, we had Ice days on 1st & 2nd April.

April and May 2021 also, very cold months compared to normal. We had snowfall three times in April with harsh frosts. Coldest min CET on record in April.

May was cold with numerous days in single digits, and it stayed chilly up until the final days. 

Edited April 3, 2023 by Frigid

[richie3846]

On 01/04/2023 at 23:15, Roger J Smith said:

I know you prefer 1-16 and 17-31 as halves of 31-day months (I probably do as well) but playing along with the theme here, I had a look at v2.0 data base to find the warmest values for 16th to 31st, those are: 

Rank ____ Year ____ Avg CET 16-31 (v2.0)

_ 01 _____ 2005 ___ 10.34

_ 02 _____ 1938 ___ 10.04

_ 03 _____ 2023 ____ 9.58

_ 04 _____ 2012 ____ 9.39

_ 05 _____ 1945 ____ 9.36

_ 06t_____ 1803 ____ 9.34

_ 06t_____ 1936 ____ 9.34

_ 08 _____ 2017 ____ 9.30

_ 09 _____ 1957 ____ 9.15

_ 10 _____ 1815 ____ 9.11

_ 11 _____ 1920 ____ 9.08

_ 12 _____ 2021 ____ 9.03

_ 13t_____ 1830 ____ 8.84

_ 13t_____ 1998 ____ 8.84

_ 15 _____ 1779 ____ 8.78

(note, some of my numbers are different from the discussion above, I come up with 8.6 for the relevant period in 2022, and to get 9.2 I can only find that as an average for 16th to 29th. Possibly the discussion above is based on numbers somebody was working on before the month ended and do not extend to the 31st. The last two days of March 2022 were quite cold). 

This explains my observation that tree growth is well ahead of average. There are some pretty big trees about to come into full leaf in the south. 

[Relativistic]

On 02/04/2023 at 10:39, Earthshine said:

Wow, thought I seriously overestimated the CET considered the hype at the start of the month.  The weighting towards warmer is just so strong these days that despite a SSW we can't even manage below the 1961-1990 average.

An SSW just five years ago led to one of the most extreme (albeit short) March spells on the CET record and a comfortably below-average month overall.

Edited April 3, 2023 by Relativistic

[cheeky_monkey]

Edmonton finished on -8.6c which is 6.1c below average...also had just 2mm of precip which is below the 15.8mm mean ..so a cold dry month this year 

[Froze were the Days]

19 hours ago, Don said:

Wasn't February 2021 a bit borderline at first with less snow than forecast as a result?

I can only go what I observed but the 7th the first day of the impending cold spell was only marginal whilst waiting for a nagging LP cell to clear off south eastwards and less cold uppers thereafter dp's dropped like a stone as the wind tuned more ENE and for a week the warmest daily max I recorded was 0.5c so hardly any thaw (the coldest daytime week since Dec 1996/Jan 1997 cold spell)...snow was a bit of a disappointment with a max of 2 inches here although up the coast near Clacton and the Suffolk had nearer to 5 to 6 inches, amazing variabilities. Snowfall from this event effected a small area with largely eastern Essex and Suffolk in the best areas...always amazes me the size of the UK and such micro events.

I believe this was from the effects of a displaced sudden stratospheric warming.

Edited April 3, 2023 by Froze were the Days

[Earthshine]

On 02/04/2023 at 16:59, Weather-history said:

So everyone should go away with these two examples for future references.

1) A SSW does not guarantee a below average month  (March 2023)

2) A below average month is not dependent on a SSW  (December 2022)

 

I don't think anyone was contesting that.  A SSW is a strong indicator for the emergence of high latitude blocking, which can bring very cold weather.  The last few very cold March's have been preceded by a SSW so there is certainly a link.

[ItNeverSnowsInWindsor]

On 03/04/2023 at 15:26, cheeky_monkey said:

Edmonton finished on -8.6c which is 6.1c below average...also had just 2mm of precip which is below the 15.8mm mean ..so a cold dry month this year 

I’m sure Norwegian towns also finished well below average!

[Sun Chaser]

On 01/04/2023 at 16:12, Frigid said:

2nd halves of March CET's

2023 - 10.2C

2022 - 9.2C

2017 (3rd warmest March CET) - 9.9C

1938 (2nd warmest March CET) - 10.7C

1957 (warmest March CET) - 9.8C

March 2023 really did a December 2022, a cold first half, then exceptionally mild second half. 

 

 

This is exactly why CET is not very representative of how "warm" a month feels. Cloud can keep minimums up by several degrees, bringing up the CET despite lacklustre maxes. I think everyone would say that March 2022's second half was significantly better than March 2023's, due to much higher maximum temps, however clear skies meant a lot of frost during that month so it was overall colder.

This is especially evident in the spring, though can apply at any time of year - for example June 2007 (wet) has a higher CET than June 2022 (quite sunny and had two hot spells), and May 2022 (dull) has a higher CET than May 2020 (sunniest month on record).

[Don]

11 minutes ago, plymsunshine said:

This is exactly why CET is not very representative of how "warm" a month feels. Cloud can keep minimums up by several degrees, bringing up the CET despite lacklustre maxes. I think everyone would say that March 2022's second half was significantly better than March 2023's, due to much higher maximum temps, however clear skies meant a lot of frost during that month so it was overall colder.

This is especially evident in the spring, though can apply at any time of year - for example June 2007 (wet) has a higher CET than June 2022 (quite sunny and had two hot spells), and May 2022 (dull) has a higher CET than May 2020 (sunniest month on record).

Final days of March 2022 were cold and wintry which would have dragged the CET down a bit, too.

[Roger J Smith]

March 2023 now in the books at 136.8 mm, third wettest ahead of 1818 (134.7 mm). It will make tiny differences to the already posted scoring in terms of average error (anyone who entered March and all other months will add 0.45 to average error, those who entered March and two other months will add 0.60 and those with two months including March will add 0.90). This may change one or two ranks. 

As part of the procedure of updating table values, Feb 2023 remains unchanged at 16.5 mm, and Jan lost 0.2 from 97.8 to 97.6 mm. Keep in mind that March could be adjusted before settling at a "forever" value but the changes are rarely more than 0.5 mm, so I think that third place finish is safe. I will edit any relevant posts of mine over the next day or two with this announced March value. 

[Sun Chaser]

On 05/04/2023 at 22:33, Don said:

Final days of March 2022 were cold and wintry which would have dragged the CET down a bit, too.

I suppose but that was only really the final day, possibly final two days further north. 14th-28th March was very sunny and had maximum temperatures far above average in the main