A metre of rain

Just before 9am today December became the sixth month this year to reach 100mm of rainfall, and shortly afterwards 2012 became the first year to break the 1000mm barrier since the weather station was set up in 2007.

The previous all-year record here was 904mm in 2008, and the average annual total from 2008 to 2011 was 659mm. One record that hasn’t been broken this year is that for wettest month, which is still 148.8mm in November 2008: but the 144.2mm that fell in June this year is the more remarkable figure, because June is normally a much drier month than November.

It’s still raining as I type this . . . .

Heading for another 100mm this month

After a break yesterday the rain returned shortly after midnight, and will continue for a few more hours yet. With 85mm recorded so far December looks likely to pass the 100mm mark, the sixth month to do so this year – an extraordinary record.

If December does reach 100mm, then 2012 will also reach 1000m of which over 90% has fallen in nine months. These are figures we might expect to see in the Lake District or the Welsh mountains but not in the lowlands of  Somerset, where we are generally protected from high rainfall by Exmoor and Dartmoor.

More local flooding seems inevitable – there is nowhere for the water to go – but rainfall totals in Devon and Cornwall are higher still. The rainfall that has caused such devastating floods in those counties would have come our way, but for the high moors.

 

Here we go again

I’m getting a sense of deja vu after last night’s rain. Up to yesterday afternoon we had recorded just over 60mm so far in December, well within the normal range. In the last 12 hours (up to 10am) we have recorded another 17mm, and there is a jumble of low pressure systems out in the Atlantic carrying lots more water in our direction. Look back almost exactly a month, to 21 November, and the picture is depressingly familiar.

The ground was saturated before the current rainfall and the rhynes are filling rapidly, so there is nowhere for all this water to go. We can only hope we don’t get a repeat of the damage and misery caused last month. At the time of writing there is a flood alert for the Brue but nothing for Brent Knoll – keep an eye on the Environment Agency site for more news.

Flood warning

The low pressure system that I mentioned yesterday is expected to add to an already high tide expected at 7am tomorrow, and the Environment Agency has issued a Flood Warning for the Somerset coast. Fortunately the forecast is for an offshore wind but if you are likely to be affected by coastal overtopping, keep an eye on the Environment Agency site.

First hard frost of the winter

Last night saw our hardest frost so far this winter, with a low of -4.6C shortly after midnight. The clear, dry air we have seen for the past few days (with some magnificent views of Jupiter for those who braved the night time cold) has made a welcome change from persistent rain.

So far this month we have recorded only 17.8mm of rain, but it looks as if the high pressure that has been shielding us from Atlantic weather systems will be moving off soon, bringing an end to the overnight frosts. There is a deep low to our west, and the Met Office is currently warning of heavy rain by the end of the week.

2012 is now our wettest year on record

Last night our year-to-date rainfall exceeded the total for the whole of 2008, so with nearly a month to go this is now the wettest year since the weather station began recording in 2007. At the time of writing we have recorded 909.8mm for this year, compared with 904.4mm for all of 2008.

About 90% of this year’s rain has fallen since April. During the first quarter of 2012 we recorded just 80mm, less than half the expected figure, and there was talk of drought and hosepipe bans. Since April five out of eight months have exceeded 100mm, a total that has only been reached on five occasions in the previous five years – three times in 2008, and twice in 2009.

One record we haven’t broken is that for wettest month. The 148.8mm recorded in November 2009 is still our highest, closely followed by June 2012 with 144.2mm – but June is usually a much drier month than November, so the latter is the really remarkable figure.