August 2009 - Very wet in most places; mild and dull for most of month

Big Tone

http://www.met.ie/news/display.asp?ID=25

After the wettest July for over 50 years in places, August was another month of very unsettled weather, with rainfall totals well above normal in western and southwestern areas. There was very little variation in the weather pattern throughout August: areas of low pressure passing close to Ireland’s north coast brought a succession of Atlantic frontal systems, giving some significant falls of rain and localized flooding at times. These conditions also gave a mild and cloudy month, but with daytime temperatures only rarely rising above 20°C.

It was the wettest August since 1992 at both Malin Head and Belmullet and the wettest since 1985 at Valentia Observatory. Some rainfall was measured on each day of the month at a number of western stations. The number of wetdays recorded during the month (days with 1mm or more rainfall) was well above normal everywhere; there were between 15 and 22 wetdays at most stations compared with the August average number of between 10 and 14. At Valentia Observatory, a total of 27 wetdays was recorded, the highest number of any summer month on record at the station. The heaviest daily falls were measured during the second half of the month, particularly on the 19th/20th, 23rd and 31st.

Mean air temperatures for the month were a little higher than normal generally, but it was a cooler than normal month in the south. While it was the warmest August at Dublin Airport since 2004, it was the coolest for between seven and 15 years at some stations in the west and south. Mean minimum temperatures were over a degree above normal in places, but mean maximum values were below normal generally. Over parts of the west and southwest of the country, the temperature did not rise above 20°C on any day during the month; here, mean maximum values were the lowest for August for between 15 and 17 years. Sunshine totals were below normal except in the east, with around 80% of normal sunshine at many stations. The sunniest day of the month in most places was the 5th, when Casement Aerodrome recorded 13.9 hours, its sunniest August day for 14 years.

1st to 31st: Atlantic depressions passed close to the north of Ireland throughout the month, while anticyclones centred to the south or southeast of the country occasionally extended a weak ridge of high pressure over the country. Rain or showers affected parts of the country each day, but amounts were fairly small during the first half of the month over the eastern half of the country. Heavy falls in all areas from the 14th onwards brought flooding in places, particularly in parts of the south, west and northwest in the period 19th/20th and on the 23rd. Daytime temperatures were near or below normal, but nights were very mild. Much of the month was overcast. Winds were between southerly and westerly throughout almost all of the month and were at their strongest during the final week. A deep depression close to Ireland on the 26th/27th- the former hurricane Bill- brought gales along western coasts.
Wind and elements: Mean windspeeds for the month of between 7 and 14 knots generally (13 and 26km/h) were above normal everywhere and were the highest for August for around 20 years generally. The month’s highest gust, 58 knots (107km/h), was measured at Malin Head on the 27th, its highest August gust since 1997. Most thunderstorms during the month were recorded in the period 20th to 24th, while there were no reports of hail.

For more information see our August 2009 Monthly Weather Summary
http://www.met.ie/climate/monthly_summarys/aug09.pdf

Mobhi1

The Dublin area somehow seems to have sneaked by with slightly below normal rainfall, above normal temperature and slightly above normal sunshine.