Consecutive months of heavy rain

Tombo2001

Noting that round my neck of the woods anyway - this will the 9th consecutive month where rain totals exceed the equivalent months rain in the two years preceeding - i.e. June 2023> June 2022/2021; July 2023> July 2022/2021..... etc.

(I'd say on today alone, weve probably exceeded last weeks monthly total for Feb).

Statistically, this seems like something really unusual?

igCorcaigh

Statistically, I'd like to see the data put through the appropriate statistical tests, but that's certainly not a job for me.

Of course, it does depend on the location as well. It does seem to have been very wet the past year.

And there is another factor too, not just total rainfall, but the "clumping" of it. Very heavy rainfall in a short period of time may not be picked up when measuring totals over, say, a month.

Cluedo Monopoly

Where are you OP? I thought January was a very dry month in comparison to the average.

Rainfall stats along west coast - average Jan rainfall in brackets

Athenry: 94mm (116)

Mace Hd: 76mm (138)

Valentia: 126mm (173)

Sherkin: 80mm (132)

Newport:125mm (166)

Shannon: 75mm (102)

And a lot of that rain fell during the 2 storms.

Did any stations exceed the average in January??

Tombo2001

https://www.boards.ie/discussion/comment/121731258#Comment_121731258

Dublin - Dublin Airport stats is what I looked at.

Tombo2001

https://www.boards.ie/discussion/comment/121731258#Comment_121731258

Those are all Atlantic stations, am guessing it was relatively wetter East Coast. I was looking at Dublin.

Also - I think its a given that rainfall totals will be influenced by storms; maybe your point relates to hours of rainfall vs total rainfall and I suppose that is relevant.

One thing for me is that the soil, fields, football pitches, whatever .... is absolutely sodden and to that extent it doesnt matter much if the rain comes in a few heavy days or several light days. Especially in cold weather.

Jim_Hodge

https://www.boards.ie/discussion/comment/121731258#Comment_121731258

East Coast has been consistently wetter than average for many months. The ground is permanently saturated.

magicbastarder

https://www.boards.ie/discussion/2058334991/consecutive-months-of-heavy-rain

the chances vary depending on whether you predict it before (and how you set parameters) or look at it after.

for example, i can make a good case that all other things being equal, the chances of that happening in the next nine months are 1 in 262,144. but it's akin to the difference between predicting 'the next four coin tosses will all be heads' and looking at a coin that has been tossed 100 times and seeing a run of four heads in that pattern.

however, the 1 in 262,144 stat would suggest it's very rare either way!

Furze99

https://www.boards.ie/discussion/comment/121733109#Comment_121733109

And yet greater Dublin is under water supply pressures according to the ads.

magicbastarder

we've seen quite a few burst pipes around the area (D9/D11) in the last few weeks - i don't think that cold spell we had was severe enough to have caused that?

Jim_Hodge

https://www.boards.ie/discussion/comment/121733192#Comment_121733192

That's a completely different issue.

Furze99

https://www.boards.ie/discussion/comment/121733274#Comment_121733274

It is a different but related issue. Irish Water can only distribute to Dublin what falls from the sky over the Dublin & Wicklow hills.

AyeGer

As a fair weather golfer I’ve noticed that too. It seems to be raining more and more often. Basically from late June it seems to have been wet at weekends more often than dry where I am.

Cluedo Monopoly

https://www.boards.ie/discussion/comment/121733045#Comment_121733045

The rainfall in Dublin Airport in January was below the average too - but only just!

61mm v 62mm average

Cluedo Monopoly

https://www.boards.ie/discussion/comment/121733109#Comment_121733109

I don't see any stations around Dublin that were above average rainfall in January though and the ground is usually saturated in winter due to the relative lack of evaporation. Dublin airport is showing below average rainfall over the past 3 months.

Dublin airport over past 3 months (Average in brackets)

November: 65mm (72)

December: 68mm (72)

January: 61mm (62)

The water levels around Dublin also seem to be well below Median flood levels. Realtime waterlevel

Tombo2001

Here is the data I was looking at.

Cluedo Monopoly

https://www.boards.ie/discussion/comment/121733630#Comment_121733630

Yep, your missing the LTA figures which is the long term average.

Tombo2001

https://www.boards.ie/discussion/comment/121733710#Comment_121733710

Yes - but at the outset the point made was that I was comparing current year to previous two years. I never mentioned LTA - but nonetheless, fair point - compared it LTA its not nearly so stark, maybe we had relatively low rainfall last year and year before.

Cluedo Monopoly

https://www.boards.ie/discussion/comment/121733782#Comment_121733782

Yeah you certainly had great Januarys in the last 2 years. 2021 looks a bit of a shocker though.

In the flip side, last January was very wet in Galway compared to this year and the average. Swings and roundabouts.

Supercell

July to December were pretty wet in Loughlinstown, south Dublin, my second wettest year on record overall. January this year was about average, February, too early to call.

What's interesting to me is that there does appear to be a trend towards heavier rainfall events in recent years which would add to the impression of being wetter overall I suppose.

M.T. Cranium

A longer perspective:

___ monthly precip at Shannon (A) 1945-2023 in mm ___

YEAR __JAN _ FEB _ MAR _ APR _ MAY _ JUN _ JUL _ AUG _ SEP _ OCT _ NOV _ DEC __ TOTAL (rank)

1945 __ -----_ -----_ -----_ -----_ -----_ -----_ -----_ ----- _ 61.8 _94.3 _42.7_120.2 __ ----

1946 __103.8_ 88.7_ 25.5_ 35.7_60.5_ 65.6_ 73.9_125.3_105.4_57.8_ 97.2_147.8__ 987.2

1947 __ 80.7_ 60.3_128.6 _76.5_83.8 109.1_ 68.9_ 22.8_ 98.5_ 54.6_ 146.0_ 96.6_ 1026.4

1948 __201.1 _ 56.2_ 48.1_94.5_52.7_ 77.0_ 49.7_ 60.3_ 83.9_ 58.5_ 74.3_ 204.2_ 1060.4

1949 __ 62.7 _ 75.5 _58.2_ 53.1_39.7 _15.5 _60.1 _66.3 _40.2_178.1 119.8_141.1 __910.3

1950 __ 57.8 _138.2 _28.3 _57.6_37.8 _57.3 105.5 130.8 137.1 _77.9 _94.9 _ 77.6_ 1000.8

1951 __112.2 _ 92.4 _72.2 _48.8_37.4 _55.1 _48.0 103.6 128.0 _30.9 _103.4 180.5_ 1012.5

1952 __130.0 _ 30.4 _46.0 _59.0_61.4 _71.2 _20.3 _67.3 _36.0 100.1 _47.4 _100.7 __769.8

1953 __ 41.0 _ 34.1 _18.7 _54.3_19.0 _34.8 _99.7 112.5 138.0 _56.8 _93.0 _ 75.8 __ 777.7

1954 __ 68.9 _116.2 _74.8 _38.1_57.7 _47.3_90.5 _63.6 110.9 124.3 _95.6 _107.0 __994.9

1955 __ 59.6 _ 42.8 _37.1 _66.1_108.3_87.5_13.5 _58.0 _85.3 _46.1 _83.1 _ 92.8 __780.2

1956 __106.6 _ 22.3 _95.4 _12.9 _39.1 _61.4 _99.9 142.7 _104.2 _65.9_57.8 136.2 _ 944.4

1957 __111.4 _ 62.7 _97.1 _38.6 _41.1 _36.1 _79.8 _60.5 _131.8 114.8 _33.3 _74.9 _ 882.1

1958 __115.6 _ 92.8 _52.0 _30.2 _97.6 _63.2 _89.3 107.2 _ 91.9 _ 72.3 _55.1 _72.5 _ 939.7

1959 __ 76.0 _ 21.2 _ 63.7 _72.1 _58.0 _75.4 _61.2 _29.9 _ 44.7 _139.4 _87.7 239.8 _969.1

1960 __ 83.1 _ 47.2 _ 44.7 _70.6_109.4_80.2 121.0 _82.9 _106.5 _ 72.6 182.0 175.1 _1175.3 (5)

1961 __130.9 _ 97.1 _ 18.0 _95.9 _32.6 _42.2 _81.1_76.5 _ 94.2 _ 84.8 _67.4 _83.7 __904.4

1962 __147.6 _ 37.7 _ 68.7 _57.5 _49.1 _46.1 _53.9 131.9 _107.6 _47.5 _83.0 _90.6 _ 921.2

1963 ___11.2 _ 34.7 _ 82.2 _59.4 _54.3 _46.0 _57.8 _91.5 _61.1 _116.1 145.3 _29.8 _ 789.4

1964 ___48.5 _ 20.4 _ 74.8 _62.1 _82.0 106.0 _69.5 _99.4 _ 68.5 _ 96.4 _ 74.8 148.7 _951.1

1965 __127.7 __ 4.7 _ 65.8 _95.8 _94.3 _99.2 _69.3 _87.2 _ 49.9 _ 26.9 _ 87.0 159.4 _968.1

1966 ___73.1 _ 93.7 _ 47.8 116.5 _89.9 133.2 _39.7 _96.1 _59.2 _ 78.1 _ 50.2 100.0 _977.6

1967 ___57.4 _119.1 _60.7 _ 29.6 _86.0 _35.4 _44.6 _68.9 _ 94.4 _167.9 _71.5 _42.6 _878.1

1968 __113.6 _ 24.5 _ 73.7 _39.2 _43.0 _ 49.6 _32.7 _76.2 _141.7 _93.2 _ 90.0 163.9 _941.3

1969 __141.8 _ 43.9 _ 44.4 _61.5 _61.5 _ 75.4 _31.1 _30.6 _ 49.6 _52.5 _115.4 116.5 _824.2

1970 ___47.0 _136.6 _ 45.9 _93.2 _35.4 _ 46.2 _98.8 _52.6 _ 94.2 _75.3 _170.2 _46.4 _941.8

1971 ___67.7 _ 65.0 _ 63.6 _ 29.7 _24.3 _ 68.2 _39.1 _70.4 _ 57.3 _ 97.0 _ 88.2 _38.6 _709.1 (least)

1972 __103.8 _ 59.4 _ 85.5 _ 72.5 _84.6 _ 65.8 _57.4 _57.7 _ 13.2 _ 43.8 _145.3 105.8 _894.8

1973 ___70.7 _ 92.8 _ 30.5 _ 40.8 _104.3 _17.3 _65.6 110.5 _116.2 _50.8 _143.8 _95.8 _941.8

1974 __168.2 _102.4 _ 40.7 _ 21.4 _52.0 _ 37.1 _82.1 139.0 _170.1 _53.7 _ 97.3 _88.5 _1052.5

1975 __125.5 _ 41.7 _ 43.9 _ 58.0 _28.6 _ 15.7 _ 75.7 _37.6 _145.0 _81.7 _ 83.9 _ 73.5 _810.8

1976 __126.0 _ 57.9 _ 59.0 _ 21.4 _65.3 _ 34.4 _ 59.5 _13.5 _93.1 _136.3 _85.8 _111.6 _863.8

1977 ___50.5 _102.6 _ 67.9 _ 75.2 _22.1 _ 44.3 _71.4 _93.1 _70.4 _ 88.3_145.7 _ 71.4 _ 902.9

1978 ___89.5 _ 68.9 _120.2 _ 80.0 _16.7 _ 46.3 _ 82.1 _94.6 _ 45.6 _ 46.6 _90.6 _114.7 _895.8

1979 ___75.3 _ 64.7 _ 94.2 _ 81.9 _112.8 _65.9 _ 21.8 _117.6 _70.1 _94.7 155.5 _159.5 _1114.0 (9)

1980 ___73.3 _ 82.6 _ 76.4 _ 25.4 _28.0 _ 75.0 _100.4 _114.1 122.5 _127.8 103.5_116.5_1045.5

1981 ___67.2 _ 77.3 _106.7 _ 15.6 141.4 _ 60.8 _34.8 _ 27.2 _126.3 _ 83.9 _68.9 _ 66.4 _ 876.5

1982 ___76.2 _ 85.4 _118.2 _ 16.1 _72.5 _131.2 _22.3 _ 89.6 _ 74.8 _129.5 133.2_144.9 _1093.9

1983 __134.2 _ 72.0 _ 72.0 _ 56.1 _88.7 _ 47.4 _ 12.6 _ 46.3 _106.1 _145.7 _44.6 _129.8_ 955.5

1984 __193.8 _ 94.6 _ 34.5 _ 46.0 _27.5 _ 33.4 _ 35.2 _ 65.0 _ 82.3 _ 96.2 _105.7 _ 89.9_ 904.1

1985 ___34.1 _ 33.6 _ 91.1 _ 56.3 _71.4 _ 74.6 _ 94.8 _181.4 _69.1 _ 53.3 _ 46.9 _ 90.7 _ 897.3

1986 __137.9 __ 0.8 _128.8 _ 56.4 _106.4 _91.5 _40.8 _113.7 _10.0 _ 96.4 _109.0 155.9 _1047.6

1987 ___39.0 _ 52.6 _ 69.6 _ 53.7 _ 20.9 _109.2 _41.7 _ 37.7 _102.3 104.2 _69.8 _ 56.6 _ 757.3

1988 __173.1 _ 97.1 _110.5 _ 32.5 _62.4 _ 45.0 _133.1 _111.2 _80.9 _115.1_47.3 _ 70.9_ 1079.1

1989 ___84.2 _ 94.3 _126.6 _ 58.1 _23.8 _ 56.8 _ 16.8 _ 69.1 _ 51.5 _129.5 _53.2 _ 77.7 _ 841.6

1990 __125.8 _204.7 _ 32.6 _ 57.5 _22.2 _ 72.6 _ 46.4 _ 67.7 _ 25.8_ 157.8 _66.4 _144.4_ 1023.9

1991 ___85.8 _ 92.3 _ 72.0 _ 97.4 _ 10.1 _ 86.4 _ 56.6 _ 60.3 _ 61.0 _ 84.3 _114.3 _ 59.1 _ 879.6

1992 ___66.3 _ 54.3 _105.6 _ 76.6 _35.2 _ 28.5 _ 68.8 _154.4 _77.1 _ 60.4 _ 99.9 _ 88.7 _ 915.8

1993 ___88.1 _ 16.5 _ 48.7 _ 84.9 _90.0 _ 74.0 _ 68.2 _ 53.1 _108.4 _ 48.5 _ 59.9 _217.7 _ 958.0

1994 __152.4 _124.1 130.6 _115.5 _76.6 _ 66.1 _ 72.4 _ 77.0 _ 59.7 _ 67.8 _ 71.1 _181.0 _1194.3 (4)

1995 __190.2 _156.8 109.0 _ 26.8 _ 64.7 _ 25.9 _128.6 __4.2 _ 43.6 _108.3 _101.7 _71.9 _1031.7

1996 ___70.3 _117.4 _ 91.6 _ 57.9 _46.5 _ 22.7 _ 63.6 _ 86.3 _ 34.2 _145.0 _121.1 _29.4 _ 886.0

1997 ___35.7 _113.0 _ 19.1 _ 43.4 _60.1 _121.5 _ 69.4 _230.8 _44.9_108.5 _ 71.9_108.6_ 1026.9

1998 __130.5 _ 34.2 _ 97.5 _100.8 _30.9 _127.9 _ 64.5 _ 77.6 _ 92.5 _147.6 123.4_117.1_ 1144.5 (8)

1999 __124.9 _ 64.6 _ 66.3 _ 67.1 _ 84.4 _ 55.3 _ 50.7 _ 60.6 _149.8 _ 54.1 _ 97.2 220.9 _1095.9

2000 ___77.8 _124.1 _ 37.3 _ 62.2 _65.6 _ 60.8 _100.8 _ 69.5 _106.7 176.3 _137.6 _78.3 _1097.0

2001 ___50.1 _ 55.5 __75.6 _ 96.8 _34.5 _ 61.6 _ 75.0 _ 58.6 _ 53.6 _116.5 _ 63.8 _51.9 _ 793.5

2002 __121.3 _185.8 _ 40.9 _ 74.0 _97.1 _ 74.9 _ 46.0 _ 60.1 _ 15.5 _130.1 _131.6 _91.6 _1068.9

2003 ___44.7 _ 50.6 _ 50.9 _ 50.0 _ 91.8 _105.0 _77.0 _ 11.3 _ 37.3 _ 50.6 _111.4 _ 92.7 _ 773.3

2004 __108.7 _ 28.4 _ 69.0 _ 43.9 _35.8 _ 63.4 __71.4 _ 88.2 _ 94.9 _142.5 _ 66.5 _ 91.0 _ 903.7

2005 __123.4 _ 44.9 _ 60.7 _ 92.0 _90.0 _ 56.6 _ 45.9 _ 71.4 _ 78.3 _106.4 _ 72.9 _ 71.7 _ 914.2

2006 ___54.3 _ 38.3 _104.8 _31.0 _126.2 _19.2 _ 28.4 _ 41.7 _149.0 _93.7 _115.2_166.7 _ 968.5

2007 ___93.5 _ 71.4 _ 62.9 _ 11.2 _66.3 _103.6 _ 96.9 _100.6 _51.6 _44.3 _ 52.9 _166.3 _ 921.5

2008 __220.7 _ 62.1 _102.7 _49.6 _35.8 _105.8 _ 94.4 _187.8 _86.5 156.6 _ 92.0 _75.3 _1269.3 (1)

2009 __120.4 _ 15.7 _ 64.0 _ 86.5_103.2 _ 58.5 _115.3 _120.9 _58.3 _87.0 _263.2 _72.7_1165.7 (6)

2010 ___30.8 _ 35.1 _ 80.4 _ 71.4 _56.8 _ 33.4 _123.1 _ 39.1 _138.9 _76.8 _133.3 _26.0 _ 845.1

2011 ___74.1 _149.0 _ 34.3 _ 42.2 _93.3 _112.5 _31.7 _ 54.1 _ 94.7 _99.1 _ 87.2 _144.7 _1016.9

2012 __111.8 _ 38.6 _ 28.3 _ 78.2 _38.8 _166.9 _112.8 _89.1 _61.9 _85.6 _121.0 _113.7_1046.7

2013 __107.0 _ 49.6 _ 30.2 _ 63.1 _68.0 _ 64.2 _ 57.4 _ 72.9 _ 38.9 _132.2 _ 89.0 _160.2 _ 932.7

2014 __175.9 _195.1 _ 87.2 _ 38.3 _90.4 _ 40.5 _ 35.8 _ 90.0 _ 72.4_105.2 _129.3 _110.2_1170.3 (5)

2015 __130.6 _ 91.1 _106.8 _ 63.6 _111.2 _27.2 _ 82.7 _93.4 _ 87.9 _ 49.7_190.5 _ 233.2_1267.9 (2)

2016 __107.7 _144.6 _ 64.4 _ 42.0 _45.4 _ 68.0 _ 66.9 _107.4 _ 88.5 _ 35.3 _ 69.2 _ 74.0 _ 913.4

2017 ___53.2 _ 71.1 _133.9 _ 17.5 _45.2 _ 86.5 _133.6 _82.7 _ 99.2 _80.6 _125.1 _139.6_1068.2

2018 __197.3 _ 71.9 _ 53.6 _ 78.1 _55.1 _ 13.6 _ 57.2 __ 60.8 _ 80.5 _ 48.0 _ 89.1 _159.8 _965.0

2019 ___71.4 _ 58.4 _177.2 _68.2 _30.8 _ 55.8 _ 51.0 _167.2 _108.1 _101.9 104.9_117.1 _1112.0 (10)

2020 ___74.8 _244.5 _ 97.4 _ 39.6 _16.2 _84.0 _130.6 _174.8 _41.6 _114.8 102.2 _131.0 _1251.5 (3)

2021 __105.5 _ 82.6 _ 82.6 __15.4 _ 91.6 _17.3 _ 85.3 __ 80.5 _ 72.0 _131.7 _53.6_112.3 _ 930.4

2022 ___46.6 _146.1 _ 41.3 _ 48.2 _ 51.9 _ 76.3 _ 20.7 _ 40.5 _104.0 _142.5 135.9 _ 93.7 _ 947.7

2023 ___93.4 _ 21.4 _114.6 _ 52.6 _ 56.7 _ 89.3 _155.0 _ 70.5 _113.8 _137.8 100.9_140.1 _1146.1 (7)

2024 ___75.9

LTA ___102.3 _ 76.2 _ 78.7 _ 59.2 _ 64.8 _ 69.8 _ 65.9 _ 82.0 _ 75.6 _ 104.9 _ 94.1 _104.0 _ 977.5

NOTES:

These are recent LTA not entire data set. Top ten annual totals are identified. Wettest months are also identified (bold type)

Other tables of data were posted in a thread which is now on page three of thread menu.

BRIEF ANALYSIS

Rankings show evidence of an increase in rainfall last 20-30 years; 8 of top 10 yearly totals are 1994 to present and seven are 2008 to present.

2012 was a wet year in other regions also. Oct 2013 to Feb 2014 and Nov 2015 to Feb 2016 look to be very wet intervals. Aug 2019 to Feb 2020 could be a little wetter than current run. July to Nov 2000 quite wet.

I will do a bit more investigation later.

Tombo2001

V interesting -

From 1945 to 1990 = two years with rainfall exceeding 1100mm = circa 5% frequency.

From 2013 to 2023 = five years with rainfall exceeding 1100mm = circa 50% frequency.

Chris_5339762

https://www.boards.ie/discussion/comment/121733351#Comment_121733351

Yes, since last June there has been a brutally unfair contrast between rain at the weekends and dry (maybe not sunny but dry) during the working week.

I wonder if someone could look into it, see if it is a trend. I hate it. Eight weekends in a row last summer ruined. This weekend absolute trash.

blanch152

https://www.boards.ie/discussion/comment/121733308#Comment_121733308

The reservoirs are completely full, overflowing, the problem with the water supply is there is not enough capacity to treat it.