December 2021 C.E.T. and EWP forecast contests -- start of the new contest year for 2021-2022

[Roger J Smith]

Almanac for 8th December

The "Daniel Defoe" or "Great" storm of 1703 occurred on 26-27 Nov in the Julian calendar, but if Britain had been on the Gregorian calendar like continental Europe, then this storm would have taken place on 7-8 December. There was also a very strong wind event with record low pressure over Armagh (922 mbs) on this date in 1886 with the worst storm damage in parts of eastern Ireland and Lancashire.

The highest daily mean (1772-2020) was 12.1 in 1856. This replaced 11.2 from 1848, which had replaced 11.0 from 1831. The warmest since 1856 was 11.4 in 2015. Other mild averages were 11.1 in 2016, 10.7 in 1974, 10.6 in 1934, 10.5 in 1942, 10.2 in 1778 and 1964 and 10.1 in 1979.

The lowest daily mean (1772-2020) was -5.4 in 1807. Other cold mean daily values for 8 Dec include -4.4 in 1812, -3.7 in 1879, -3.0 in 1819, -2.7 in 2010, -2.3 in 1871, -2.2 in 1967, -2.1 in 1885, -2.0 in 1803, -1.7 in 1774, 1815 and 1844, -1.3 in 1796 and -1.1 in 1867. The three-week cold spell of 1981 began with -0.3 on this date. The average for 8-28 Dec 1981 was -2.0 C. 

The highest maximum (1878-2020) was 13.8 in 1964 replacing 12.9 from 1934. Other mild daily maxima include 13.3 in 2016, 12.6 in 1900, 12.5 in 1907, 12.2 in 2015, 12.1 in 1942 and 12.0 in 1925.

The highest minimum (1878-2020) was 10.6 in 2015. This replaced 10.0 from 1974, and it was also 9.5 in 1979. Another high value was recorded in 2016 with 8.9 C. 

The lowest maximum (1878-2020) was -0.7 in 1967 which replaced 0.2 from 1879. Other cold values include 0.8 (1885), 1.2 (1981), 1.5 (2010), 1.6 (1878) and 1.7 (1945). 

The lowest minimum (1878-2020) was -7.5 in 1879. Other cold minima include -6.8 in 2010, -4.9 in 1885 and -4.5 in 1980.

The wettest 8th of December (1931-2020) in the EWP data was 21.91 mm (1954), followed by 18.23 mm (1983), 13.67 mm (1962), 12.87 mm (1965), 12.86 mm (2007), 11.31 mm (1993) and 10.51 mm (1964). 

The wettest week ending 8th December (2nd - 8th Dec) was 63.63 mm in 1934 again just ahead of 58.45 mm (1972) followed by 51.12 mm (1994), 50.49 mm (2000) and 50.36 mm (1959).

The least amount falling in a week ending 8th December was 0.01 mm in 1991, 0.61 mm in 1989, 1.47 mm in 1968, 1.59 mm in 1963, 1.67 mm in 2004 and 1.75 mm in 1971.

-----------------------------

(map for 08 Dec 1886,  very strong westerly winds Irish Sea, Lancs (and eastern Ireland) -- map has missed some isobars however as Armagh observatory had record low pressure in the 920s.) 

https://www.wetterzentrale.de/reanalysis.php?jaar=1886&maand=12&dag=8&uur=1200&var=1&map=1&model=noaa

Edited December 9, 2021 by Roger J Smith

[Summer Sun]

4.9c to the 7th

0.2c below the 61 to 90 average
0.8c below the 81 to 10 average

___________________________

Current high this month 7.3c on the 1st
Current low this month 4.9c on the 7th

[Roger J Smith]

EWP update _ about 35 mm in the account now, 26 to end of 6th, 6 mm est 7th and 3 mm so far today before 12z GFS takes over with ten-day outlook of about 20 mm to the 18th. That brings the total to a rather average 55 mm. With blocking high pressure then in charge I didn't look at output for the 19th-24th which is not likely to be all that reliable after a blocking episode anyway. As to the CET, probably more upward than downward pressure on that in next two weeks but with a blocking high shown nearby, could cut back the warming influence on the CET after a few undoubtedly mild days. Would imagine the CET will be into the high 5 to low 6 zone at some point, blocking highs can be followed by cold spells though, so not a guarantee of much (then there's the adjustment, don't get me started on that ...) . 

[The PIT]

Sunny Sheffield at 4.1C -2.5C below normal. Rainfall at 30.6mm 35% of the monthly average.

[Roger J Smith]

Almanac for 9th December

The highest daily mean (1772-2020) was 11.8 in 1934. This replaced 11.7 from 1856 and previously 10.7 from 1847. The warmest since 1934 was 11.0 in 2016. Other mild averages were 10.5 in 1900, and 10.1 in 1787, 1833, 1942 and 1997.

The lowest daily mean (1772-2020) was -4.0 in 1803. Other cold mean daily values for 9 Dec include -3.9 in 1812, -3.2 in 1774, -3.1 in 1819, -2.9 in 1815, -2.8 in 1784, -1.9 in 1967, -1.7 in 1844 and 1855, -1.6 in 1791 and 1878, -1.5 in 1981 and -1.3 in 1796.  

The highest maximum (1878-2020) was 13.5 in 2016 replacing 12.7 from 1997, which had replaced 12.5 from 1979. Other mild daily maxima include 12.4 in 1934 and 1978, 12.3 in 1939 and 11.9 in 1913 and 1964.

The highest minimum (1878-2020) was 11.2 in 1934. This replaced 9.2 from 1900. Since 1934 the highest value has been 8.6 in 2016. 

The lowest maximum (1878-2020) was 0.8 in 1981 which replaced 1.2 (1899); other cold values were 1.6 (1878) and 1.8 (1967 and 1968). 

The lowest minimum (1878-2020) was -5.6 in 1967. Other cold minima include -4.8 in 1878 and 1928, -4.7 in 2010, -4.5 in 1885 and -3.8 in 1981.

The wettest 9th of December (1931-2020) in the EWP data was 17.80 mm (1965), followed by 17.09 mm (1982), 15.19 mm (1979), 13.40 mm (1938), 13.00 mm (1966), 12.28 mm (1977), 11.61 mm (2017) and 10.98 mm (1997). 

The wettest week ending 9th December (3rd - 9th Dec) was 60.04 mm in 1934 again just ahead of 57.79 mm (1972) followed by 56.24 mm (2000), 52.02 mm (1965) and 50.59 mm (1994).

The least amount falling in a week ending 9th December was 0.00 mm in 1991, then 0.60 mm in 1975, 0.65 mm in 2003, 0.78 mm in 1989, 1.04 mm in 1971, 1.31 mm in 1963, 1.38 mm in 2004 and 1.89 mm in 1968.

-----------------------------

(map for 09 Dec 1934,  very mild and wet interval as part of formerly tied warmest December before 2015) 

https://www.wetterzentrale.de/reanalysis.php?jaar=1934&maand=12&dag=9&uur=1200&var=1&map=1&model=noaa

Edited December 9, 2021 by Roger J Smith

[Summer Sun]

5.0c to the 8th

Bang on the 61 to 90 average
0.5c below the 81 to 10 average

___________________________

Current high this month 7.3c on the 1st
Current low this month 4.9c on the 7th

[damianslaw]

Could be a sandwich month average first third, mild middle, average or cold last third?

[BornFromTheVoid]

Latest CET projection, based on the 06z GFS.

  

Before corrections, the chances of finishing:
Close to average (4.5C to 5.5C) is 42% (3 days ago was 40%)
Above average (>5.5C) is 33% (3 days ago was 24%)
Below average (<4.5C) is 25% (3 days ago was 36%)

The period of the 9th to the 14th is forecast to average 7.3C, 2.4C above the 91-20 average.

Here's the change in projections

[The PIT]

Sunny Sheffield down to 4C -2.4C below average. Rainfall 47.4mm 54.2% of the monthly average.

[Roger J Smith]

Posting this a bit earlier than usual as I may not be around at the usual time. We are entering that period where 1981 gets interesting, that will be tomorrow's almanac map feature. Today's is from 1878, looks a bit snowy in the southeast on these maps. 

Almanac for 10th December

The highest daily mean (1772-2020) was 10.9 in 1997. This replaced 10.8 from 1856 which was almost equalled by 10.7 in 1942. Other mild averages were 10.4 in 1851, 10.3 in 1941 and 1978, 10.2 in 1821 and 2016, and 10.1 in 1921 and 10.0 in 1772, 1820, 1827, 1847 and 1852. Interesting how many mild days at this time of year seem to be from well back in the records, unlike many other parts of the year.

The lowest daily mean (1772-2020) was -4.5 in 1784. Other cold mean daily values include -4.0 in 1981, -3.6 in 1878, -3.5 in 1819, -2.9 in 1807 and 1873, -2.8 in 1796, -1.5 in 1773 and 1882, -1.3 in 1844, -1.2 in 1815, -1.1 in 1885 and -1.0 in 1881. This also has a dominant number of occasions from the distant past. The climate of mid-December was obviously more variable then.

The highest maximum (1878-2020) was 14.4 in 1994 replacing 14.3 from 1978  from 1997. Other mild daily maxima include 13.7 in 1997, 13.3 in 1961, 13.2 in 1915, 12.5 in 2000, 12.1 in 1941 and 2006, and 12.0 in 1942.

The highest minimum (1878-2020) was 9.7 in 2016. This replaced 9.4 from 1942. It was also 8.7 in 1921, 8.5 in 1941 and 8.0 in 1997.

The lowest maximum (1878-2020) was -1.2 in 1981 which replaced -1.1 (1878); other cold values were 0.8 (1881), 1.2 (2017),  1.3 (1899), 1.5 (1890), 1.6 (1882 and 1933) and 1.7 (1885). 

The lowest minimum (1878-2020) was -6.8 in 1981 which replaced -6.0 from 1878.  Other cold minima include -4.5 in 1882, -4.3 in 1987, and -3.9 in 1885 and 1930.

The wettest 10th of December (1931-2020) in the EWP data was 11.41 mm (2006), which is the lowest daily record for December, followed by 10.70 mm (1958).

The wettest week ending 10th December (4th - 10th Dec) was 56.44 mm in 1934 which is also the lowest weekly record for December. Next came 55.92 mm (1972) followed by 54.72 mm (2000), 51.30 mm (1982), 50.38 mm (1965) and 50.21 mm (1977).

The least amount falling in a week ending 10th December was 0.00 mm in 1991, then 0.59 mm in 1975, 0.75 mm in 1989, 0.78 mm in 1971, 0.80 mm in 1963, 1.45 mm in 2004 and 1.68 mm (1987).

-----------------------------

(map for 10 Dec 1878,  very cold interval) 

https://www.wetterzentrale.de/reanalysis.php?jaar=1878&maand=12&dag=10&uur=1200&var=1&map=1&model=noaa

Edited December 11, 2021 by Roger J Smith

[feb1991blizzard]

52 minutes ago, Roger J Smith said:

Posting this a bit earlier than usual as I may not be around at the usual time. We are entering that period where 1981 gets interesting, that will be tomorrow's almanac map feature. Today's is from 1878, looks a bit snowy in the southeast on these maps. 

Almanac for 10th December

The highest daily mean (1772-2020) was 10.9 in 1997. This replaced 10.8 from 1856 which was almost equalled by 10.7 in 1942. Other mild averages were 10.4 in 1851, 10.3 in 1941 and 1978, 10.2 in 1821 and 2016, and 10.1 in 1921 and 10.0 in 1772, 1820, 1827, 1847 and 1852. Interesting how many mild days at this time of year seem to be from well back in the records, unlike many other parts of the year.

The lowest daily mean (1772-2020) was -4.5 in 1784. Other cold mean daily values include -4.0 in 1981, -3.6 in 1878, -3.5 in 1819, -2.9 in 1807 and 1873, -2.8 in 1796, -1.5 in 1773 and 1882, -1.3 in 1844, -1.2 in 1815, -1.1 in 1885 and -1.0 in 1881. This also has a dominant number of occasions from the distant past. The climate of mid-December was obviously more variable then.

The highest maximum (1878-2020) was 14.4 in 1994 replacing 14.3 from 1978  from 1997. Other mild daily maxima include 13.7 in 1997, 13.3 in 1961, 13.2 in 1915, 12.5 in 2000, 12.1 in 1941 and 2006, and 12.0 in 1942.

The highest minimum (1878-2020) was 9.7 in 2016. This replaced 9.4 from 1942. It was also 8.7 in 1921, 8.5 in 1941 and 8.0 in 1997.

The lowest maximum (1878-2020) was -1.2 in 1981 which replaced -1.1 (1878); other cold values were 0.8 (1881), 1.2 (2017),  1.3 (1899), 1.5 (1890), 1.6 (1882) and 1.7 (1885). 

The lowest minimum (1878-2020) was -6.8 in 1981 which replaced -6.0 from 1878.  Other cold minima include -4.5 in 1882, and -3.9 in 1885 and 1930.

The wettest 10th of December (1931-2020) in the EWP data was 11.41 mm (2006), which is the lowest daily record for December, followed by 10.70 mm (1958).

The wettest week ending 10th December (4th - 10th Dec) was 56.44 mm in 1934 which is also the lowest weekly record for December. Next came 55.92 mm (1972) followed by 54.72 mm (2000), 51.30 mm (1982), 50.38 mm (1965) and 50.21 mm (1977).

The least amount falling in a week ending 10th December was 0.00 mm in 1991, then 0.59 mm in 1975, 0.75 mm in 1989, 0.78 mm in 1971, 0.80 mm in 1963, 1.45 mm in 2004 and 1.68 mm (1987).

-----------------------------

(map for 10 Dec 1878,  very cold interval) 

https://www.wetterzentrale.de/reanalysis.php?jaar=1878&maand=12&dag=10&uur=1200&var=1&map=1&model=noaa

Was just thinking  why nothing from 2010 but of course that was the short period where temps bounced back to average, felt really mild though after the -20c i eperienced just a week before.

 

[The PIT]

Sunny Sheffield back up to 4.1C -2.2C below average. Rainfall 49.6mm 56.7% of the monthly average.

Onwards and upwards for the foreseeable future.

An average to mild month looks to be on the cards at this point in time.

[Summer Sun]

5.1c to the 9th

0.1 above the 61 to 90 average
0.3c below the 81 to 10 average

___________________________

Current high this month 7.3c on the 1st
Current low this month 4.9c on the 7th

[Roger J Smith]

Almanac for 11th December

The highest daily mean (1772-2020) was 12.6 in 1994. . This replaced 11.4 from both 1898 and 1978. Other mild averages were 10.8 in 1961, 10.6 in 1831, 10.4 in 1852, 10.3 in 1941, 1997 and 2000, and 10.2 in 1820. 

The lowest daily mean (1772-2020) was -6.7 in 1784. Other cold mean daily values include -6.0 in 1819, -3.7 in 1882, -3.3 in 1991, -3.1 in 1878, -2.8 in 1981, -3.1 in 1844, -2.9 in 1791 and 1873, -2.6 in 1879, -2.2 in 1899, -2.0 in 1885, -1.6 in 1835, -1.4 in 1817, -1.1 in 1951 and 1983 and -1.0 in 1846. (recently -0.9 2012).

The highest maximum (1878-2020) was 14.5 in 1994 replacing 13.5 from 1978. Other mild daily maxima include 13.2 in 2000, 12.3 in 1998, 12.2 in 1898 and 1961, and 12.1 in 1938.

The highest minimum (1878-2020) was 10.8 in 1994. This replaced 10.6 from 1898. It was also 9.4 in 1961, 9.3 in 1978, 9.1 in 1942, 8.9 in 1941, 8.8 in 1997, 8.6 in 1909 and 8.5 in 1931.

The lowest maximum (1878-2020) was -0.8 in 1882; other cold values were -0.6 (1878), -0.5 (1981), -0.4 (1991), -0.3 (1899), 0.9 (1890), 1.1 (2012), 1.5 (1879) and 1.8 (2017). 

The lowest minimum (1878-2020) was -6.7 in 1879 which was almost equalled by -6.6 in 1882. Other cold minima include -6.2 in 1885 and 1991, -5.5 in 1878, -5.1 in 1967 and 1981, -4.7 in 1951, -4.3 in 1983, and -4.0 in 1878 and 1899.

The wettest 11th of December (1931-2020) in the EWP data was 13.81 mm (2014), which was the only 11th Dec to break 10 mm, second highest was 9.89 (1972).

The wettest week ending 11th December (5th - 11th Dec) was 56.92 mm in 2000. Next came 55.89 mm (1972) followed by 53.39 mm (1977) and 51.95 mm (1982).

The least amount falling in a week ending 11th December was 0.00 mm in 1991, then 0.64 mm in 1971, 0.96 mm in 1996, 1.10 mm in 1975, 1.32 mm in 1968, 1.47 mm in 2004, 1.51 mm in 2010, and 1.66 mm in 1987.

-----------------------------

(map for 11 Dec 1981,  cold with heavy snow, 11" at Heathrow -- click on later dates where even colder temperatures developed.) 

https://www.wetterzentrale.de/reanalysis.php?jaar=1981&maand=12&dag=11&uur=1800&var=1&map=1&model=noaa

(also record warmth in 1994)

https://www.wetterzentrale.de/reanalysis.php?jaar=1994&maand=12&dag=11&uur=1200&var=1&map=1&model=noaa

 

 

Edited December 11, 2021 by Roger J Smith

[Summer Sun]

5.2c to the 10th

0.2c above the 61 to 90 average
0.1c below the 81 to 10 average

___________________________

Current high this month 7.3c on the 1st
Current low this month 4.9c on the 7th

[BornFromTheVoid]

Latest CET projection, based on the 06z GFS.

   

Before corrections, the chances of finishing:
Close to average (4.5C to 5.5C) is 44% (2 days ago was 42%)
Above average (>5.5C) is 43% (2 days ago was 33%)
Below average (<4.5C) is 13% (2 days ago was 25%)

The period of the 9th to the 14th is forecast to average 8.7C, 3.8C above the 91-20 average.

Here's the change in projections

[The PIT]

Sunny Sheffield at 4.2C -1.9C below normal. Rainfall 49.6mm 56.7% of the monthly total.

Up up and away for the next five days at least. Very little in the way of rainfall though.

[Roger J Smith]

Almanac for 12th December

The highest daily mean (1772-2020) was 12.9 in 1994. This was the highest December daily mean until broken in 2015 (13.1 19th). The daily record replaced 11.7 from 1842. Other mild averages were 12.1 in 2000, 11.4 in 1900, 10.9 in 1961, 10.8 in 1898, 10.7 in 1778, 10.3 in 1941, 10.1 in 1938, and 10.0 in 1831 and 1848. 

The lowest daily mean (1772-2020) was -8.5 in 1981 which broke the daily record of -3.7 set in 1791. Other cold mean daily values include -3.5 in 1991, -3.3 in 1878, -2.8 in 1882, -2.6 in 1844, -2.4 in 2012, -1.7 in 1879 and 1899, -1.5 in 1890, -1.4 in 1812, -1.3 in 1817, -1.2 in 1784, -1.1 in 1788 and 1920, and -0.9 in 1846.

The highest maximum (1878-2020) was 13.9 in 1994 replacing 13.1 from 1964. Other mild daily maxima include 13.2 in 2003, 13.0 in 1900, 1956, 1972 and 2000, 12.9 in 1918, 12.6 in 1961, 12.5 in 1898.

The highest minimum (1878-2020) was 11.9 in 1994 which survives as the highest daily minimum for December. The daily record  replaced 9.7 from 1900; other mild minima for the 12th include 11.1 in 2000, 9.2 in 1961, 9.1 in 1898, 9.3 in 1941, 8.4 in 1938 and 8.3 in 1953.

The lowest maximum (1878-2020) was -3.8 in 1981; other cold values were -1.2 (1878), 0.0 (2012), 0.4 (1899 and 1991), 0.6 (1879 and 1920), 0.7 (1882) and 0.8 (1890). 

The lowest minimum (1878-2020) was -13.2 in 1981 which replaced -6.3 from 1882. Other cold minima include -7.4 in 1991, -6.2 in 2017, -5.3 in 1878, -4.8 in 2012, -4.6 in 1951 and -4.0 in 1879.

The wettest 12th of December (1931-2020) in the EWP data was 20.33 mm (1993), followed by 19.30 mm (1964), 16.70 mm (2011), 14.66 mm (2000), 14.61 mm (2008), 14.27 mm (2019), 12.51 mm (2003), 11.24 mm (1978), 10.32 mm (1986) and 10.27 mm (2015). This was eight more days over 10 mm than the previous day had produced. 

The wettest week ending 12th December (6th - 12th Dec) was 63.70 mm in 2000, followed by 56.96 mm (1978), 56.51 mm (1993), 55.48 mm (1964), 53.34 mm (1977) and 52.30 mm (1982).

The least amount falling in a week ending 12th December was 0.04 mm in 1991, then 1.06 mm in 1987, 1.17 mm in 1971, 1.28 mm in 1996, 1.32 mm in 1968, 1.35 mm in 2004, 1.51 mm in 2010, 1.69 mm in 1984, and 1.73 mm in 2001.

-----------------------------

(map for 12 Dec 1882,  another cold spell soon after 1878 and 1879) 

https://www.wetterzentrale.de/reanalysis.php?jaar=1882&maand=12&dag=12&uur=0600&var=1&map=1&model=noaa

 

Edited December 12, 2021 by Roger J Smith

[Roger J Smith]

EWP about 44 mm to 10th and will only add about 6 mm to reach 50 mm by 21st, also looks to stay dry to near the end of the current GFS run, so no guidance to show anything higher than 50 mm, plus whatever falls 28th to 31st. CET looks like it would increase steadily for the next week then drop back slowly after that, no doubt to around 5.4 which I abandoned in favour of 3.8 oh well. Counting on the adjustment and some ultra cold days showing up later (so far the cooling trend is modest at best, but with long clear nights it could get down below freezing even in a fairly tame locally sourced high). A good forecast looking like 5.0 and 55-60 mm at this point. 

[Summer Sun]

5.3c to the 11th

0.3c above the 61 to 90 average
0.1c above the 81 to 10 average

___________________________

Current high this month 7.3c on the 1st
Current low this month 4.9c on the 7th

[The PIT]

Sunny Sheffield up to 4.5C -1.7C below average. Rainfall 51mm 58.3% of the monthly average.

Interesting on breakfast they were talking about how mild the month has been. Mmmm it hasn't.

[Roger J Smith]

Almanac for 13th December

The highest daily mean (1772-2020) was 11.6 in 1918. The highest since then was 11.3 in 1994. The record in 1918 replaced 11.2 from 1842. Other mild averages were 10.6 in 1793, 10.2 in 1980 and 10.1 in 1922.

The lowest daily mean (1772-2020) was -6.5 in 1981 which broke the daily record of -5.1 set in 1920. Other cold mean daily values include -4.2 in 1878, -4.0 in 1846, -3.8 in 1805, -3.1 in 1812, -3.0 in 1844 and 1890, -2.6 in 1819, -1.9 in 1788, -1.4 in 1950, and -1.1 in 1801, 1830 and 1859.

The highest maximum (1878-2020) was 13.5 in 1972 with 13.4 in 1998 the highest since then. Other mild daily maxima include 13.1 in 1918, 12.9 in 1942 and 2003, 12.8 in 1893 and 1985, 12.6 in 2016 and 12.4 in 1922, 1929 and 1961.

The highest minimum (1878-2020) was 10.8 in 1994 which replaced 10.1 from 1918. Other mild minima for the 13th include 8.7 from 1900 and 1980, and 8.3 in 1964. The 10.8 reading in 1994 was followed by a maximum of only 4.9 so it appears to be only the morning low and not the 24h minimum (meaning that the 1918 value is probably more legitimate as a date record).

The lowest maximum (1878-2020) was -1.9 in 1920; other cold values were -1.0 (1878), -0.8 (1890), 0.4 (1899), 0.8 (1950), 1.2 (1925) and 1.3 (1968). Despite the very cold start to the day, 1981 warmed to 2.9. 

The lowest minimum (1878-2020) was -15.9 in 1981 which replaced -8.2 from 1920. This was the lowest minimum in both December and the entire year, since 1878. It is quite possible that lower values occurred before this data set began, perhaps in Jan 1838 or Dec 1796 which had days with daily means around -11 C. Other cold minima on 13 Dec include -7.3 in 1878, -5.4 in 1991, -5.1 in 1890, and -4.7 in 2012 and 2017.

The wettest 13th of December (1931-2020) in the EWP data was 24.02 mm (1989), followed by 17.74 mm (1979), 16.98 mm (1981), 16.62 mm (1936), 10.97 mm (2008), 10.92 mm (2020), 10.58 mm (1948), and 10.36 mm (1955). The 1989 amount was followed by a total of 39.20 mm over the next three days, for 63.22 mm in four days and 77.34 mm from 11th to 16th. This is highlighted by today's map link. 

The wettest week ending 13th December (7th - 13th Dec) was 64.20 mm in 1979, followed by 64.08 mm (1978), 63.90 mm (2000), 51.88 mm (1982), 51.82 mm (1964), and 51.24 mm (1954).

The least amount falling in a week ending 13th December was 0.04 mm in 1991, then 0.85 mm in 1987, 0.94 mm in 2001, 1.00 mm in 1968, 1.15 mm in 2004, 1.38 mm in 1996, 1.44 mm in 1971, and 1.84 mm in 2010.

-----------------------------

(This was a very wet day in 1989 and the following three days were also quite wet with a six day total by 16th of 77.34 mm) 

https://www.wetterzentrale.de/reanalysis.php?jaar=1989&maand=12&dag=13&uur=1800&var=1&map=1&model=noaa

 

Edited December 13, 2021 by Roger J Smith

[damianslaw]

A fair rise anticipated in the days ahead probably stalling by Friday followed by a slow drop.. possibly steeper as we near Christmas.. 

Very little rain in the forecast- some places could be about to see a lengthy run of dry days not synonymous with December. 2021 the year with long periods of dry weather punctuated by short wet spells.

[The PIT]

Sunny Sheffield at 4.8C -1.3C below average, Rainfall 51.5mm 58.9% of the monthly average

[LetItSnow!]

Curiosity strikes me as I wonder what we’d be looking at if a GEM scenario came off. Temperatures in the CET zone will be falling away quite quickly this week. I know some were worried about cloud but I think in the south the high pressure doesn’t look to be the type to bring in excessive damp, drizzly, frost inhibiting conditions. You tend to see that when there’s a more westerly/northwesterly element. I’ve been caught out before thinking a month was going cold (February 2021 ) only to not, but could we be seeing the coolest December since 2010 unfolding? It wouldn’t take much. Watch this space!