Stormy by day, wet by night

With another depression off the north west coast it was not surprising to experience a windy day on Saturday as the westerly wind was strong all day with a peak gust of 40mph at 14.18.

It was a mild day with temperatures around 9 to 10C most of the day but dropping lower during the evening to reach a minimum of 5.9C at 03.01 on Sunday mooring. At that time the cloud thickened and rain began to fall just before 2am bringing us 7.8mm of precipitation for four hours.

Sunday arrived with the hang back of thick cloud from the weather front and light drizzle as the wind began to freshen again. The temperature had begun to rise again with a reading of 10.4C at 08.00.

Review of January 2020

After a cool start to the month a wedge of warm air from the Azores arrived lifting temperatures into double figures with a maximum of 11.8C on the 7th, which was 4.8C above the 35-year average.

Shortly afterwards Storm Brendan, named by the Eire Metrological Office, arrived from the Atlantic bringing wet and windy conditions. There was a particularly turbulent period in the second week with maximum gusts of 46mph on the 11th and 42mph on the 14th as squall lines traversed the area.

Storms bring rain and this storm was no exception as rain fell every day from the 6th to the 17th as depressions followed depressions. There were particularly heavy rainfalls on the 13th and 14th with daily totals of 11.6mm and 21.6mm respectively.

Notable worldwide unusual events during this period saw 377mm of rainfall lash Jakarta in one day and Texas with 6cm of snow.

On the 14th it was reported that the world’s oceans were the warmest in 2019 than at any other time.

Mid-month the Jet Stream pushed a pocket of unusually high pressure over the UK as the result of a greater contrast in temperatures across the USA. The air pressure rose rapidly during the 18th and 19th to peak at a maximum of 1049.6mb. This was a record for my weather station that started in 1984 and was close to the UK record of 1053.6mb set in January 1902, beating the previous high set in January 1957.

It is no coincidence that the highest barometric pressures have been set in January. In that month the air is cold and thus more dense, therefore heavier.

The intense anticyclone brought a break from the wet and windy weather to give us three continuously dry days and calm conditions. The 18th and 19th saw maximum gusts of just 8mph and 9mph but many hours of total calm.

There was all change again for the last week of the month as the intense high pressure slowly ebbed away to reach the lowest pressure all month on the 28th with a minimum of 989.3mb. As a result the wind swung into the quadrant between south and west and brought modest rainfall of 5.9mm and 9.4mm respectively on the 26th and 27th.

A slight fall of snow, the first of the winter, fell in the early hours of the 28th, which slowly melted as the thermometer edged to a maximum of just 5C, the second coldest day in January.

There were 12 sunless days in January due to the frequent progression of depressions running across the country. This resulted in a warm month with a mean temperature 1.9C above the 35-year average, the fourth warmest I have recorded since the station started in 1984 and the warmest January since 2008.

The total rainfall for January of 92.5mm was just 2.1mm above the average. It has been a month remembered for the number of gloomy, dismal days, only 7 were dry when the average is 12. The extreme months were in 1997 with only 9.4mm and the very wet January in 2014 when 219.1mm of precipitation was recorded. The wettest day occurred on the 14th with 21.6mm.

There were a number of days when the wind was very strong, two in particular, when extreme gusts of 46mph and 42mph were logged on the 11th and 14th respectively.