Author: Eric Gilbert

Two weather fronts dominated Monday with thick cloud until mid-afternoon with light drizzle observed for a couple of hours, starting just before 11.30. However, the precipitation was light and only dampened surfaces eventually measuring 0.2mm. As the clouds thinned and eased eastwards after 14.00 the sun broke through strongly pushing the thermometer to a peak of 16.2C late in the afternoon at 17.20 being 2.1C above average. The clearing skies meant the past night was chilly that saw the temperature drop to a low of 3.9C at 06.06C before the sun got to work lifting the temperature to 7.8C by 08.00.

Tuesday initially arrived with weak sunshine. The moist air and falling temperature overnight caused radiation fog to form in the River Og valley during the early hours, that quickly dispersed as the sun got to work, as a result by 07.00 it had completely cleared. Humidity of 89% was measured at 08.00, the highest for over a week.

A depression is now approaching Ireland that will later today arrive over central Ireland. This low pressure system is projected to cross southern England this evening pushing two weather fronts across the UK with possible substantial rainfall. The current barometric pressure of 1016.7C, logged at 08.00, will drop substantially as the centre of the depression is currently reading 996mb, this will result in the wind picking up during the afternoon ahead of the rain expected just before midnight.

Any measurable rainfall that falls during the night would be very welcome for gardeners so that it can be absorbed into the soil, rather than quickly evaporating if during daytime, as we have had less than 9mm of precipitaion over the last 52 days. This timing would be fine for those currently on holiday!

At 08.50 the radar showed showers breaking out over Devon and Cornwall with a thick bank of cloud leaving Ireland heading for the west country.

Sunday gave us bright sunshine from mid-morning until mid-afternoon that resulted in the temperature rising slowly to a peak of 14.1C at 14.28 being exactly equal to my long-term average, thereafter cloud built up again. The day was dry although a small area of thicker cloud passed to the northwest of Marlborough that gave some raindrops on my windscreen as I approached the north of Swindon at 18.50. The thick cloud overnight produced a mild night with the minimum of 9.5C at 05.43 being a significant 5.5C above my long-term average.

Monday after dawn revealed very dull, gloomy conditions with almost a total calm. We are under the influence of the recent depression, now heading towards the east, that is throwing considerable cloud over the UK. These conditions will only worsen as we approach midday when two weather fronts pass over central England that over the next few hours might produce a little light rain or drizzle, but of no real quantity. The breeze, when it picks up, will be light and veer from the southwest to west towards the afternoon.

The temperature at 08.00 read 10.2C making it the warmest start to a new day, at that time, this month. The barometric pressure of 1007.9mb at 08.00 is almost exactly the same as yesterday.

A new area of low pressure is developing to the northwest that will close in towards Wednesday, with possible useful rainfall for gardeners!

Two days ago the station recorded an alleged peak wind speed of 62mph. Sadly, with all the progress in electronics these glitches seem to appear occasionally. I could interrogate my older station, that was not on line, to delete these gross errors. Although Davis instruments have been advised by a number of people about the situation, they have yet to come up with a solution that would allow such errors to be removed, such is progress!

The forecast Jet Steam track suggests that it will begin to loop to the north of the UK from Thursday allowing a ridge of high pressure to form. This should bring brighter, perhaps sunnier weather, which will mean it should become a little warmer than at the start of the week.

The sun was very strong on Saturday pushing the temperature to reach a maximum of 17.1C at 14.54, after the sun broke through around 11.15, although in the brisk easterly breeze it sometimes felt cooler. The high was 3C above my long-term average making it the warmest day since the 12th (21.6C). The sun was particularly strong under skies that did not have thin high cloud, as a result the UV level at its peak, rose to the ‘High’ category, only the second time this month.

The drift of cool air from an easterly quadrant under relatively clear skies, meant a cool night with a minimum of 4.3C being just 0.6C above average.

Sunday revealed broken cloud with welcome bursts of sunshine. The recent depression is still lurking over France that is directing the air stream, originating from Scandinavia, to come from the northeast early today, then veering into the east and southeast towards evening.

April has so far been a very dry Spring month with just 2.9mm of precipitation, when the 41-year average is 57.6mm, due to the main rain bands moving north to the west and east of our area. The loss of equivalent rainfall due to evaporation from ground sources and plant life amounts to 52mm so far this month.

Once again the bulk of the heavy rain was to the west of our area on Friday, with just drizzle observed during the afternoon at 16.50, also the automatic rain gauge was triggered at 03.15 early Saturday that indicted light showers for perhaps 15 minutes. The daily rainfall total was only 0.8mm, which took the monthly total to just 2.9mm against the 41-year average of 57.6m. With just 11 days to go in April I wonder if this month is following the pattern of the very dry month that we experienced in March?

The maximum of 13.3C on Friday, logged at 14.54 due to the cloudy skies with no sunshine, was 0.8C below my long-term average, only the second below average maximum this month. Not surprisingly, it has been a mild night thanks to the thick cloud cover minimising loss of any warmth into the atmosphere with the thermometer hovering around 9.5C for much of the early hours, which in fact was the minimum at 03.40, only rising to 9.6C by 08.00 Saturday.

Saturday dawned dull and grey with very light intermittent and short lived rain around 07.30. As the depression has relocated around the Bay of Biscay the breeze today will come predominantly from the west, a cool direction, possibly strengthening mid-morning, so no heat wave today, especially as there is little chance of sunshine due to the depression lurking close by throwing banks of cloud across the UK. The rain radar at 08.30 indicated a wider rain band heading our way during the morning but if the patten of previous days continues, this will thin and break up as it moves north across our area.

The depression is forecast to hang around for a couple of days, moving across France and eventually probably over the Netherlands by Monday. So the holiday weekend will bring mixed weather, sunshine and showers covers it.

The forecast track of the Jet Stream indicates that later in the week, perhaps from Thursday onwards, a small area of high pressure will develop over the UK, or at at least a ridge of high pressure, that will influence our weather with brighter conditions and slightly higher temperatures.

Thanks to the southerly breeze on Thursday, and also much being lighter than on Wednesday, the temperature rose to a peak of 16.1C being 2.0C above my long-term average. The day was dry with the maximum solar radiation moving into four figures for the first time this year with exactly 1,000W/m2 logged 13.25.

Initially overnight under clear skies the thermometer dropped steadily downwards reaching a minimum 4.2C at 02.23 early Friday but increasing cloud from the depression to the west of the UK saw the thermometer do an about turn and begin to rise reaching 9.4C at 08.00.

Friday gave us a very brief glimpse of brightness after dawn but cloud quickly thickened with spots of rain between 07.30 and 08.00. The rain radar shows an advancing band of fragmented rain heading our way for around midday.

The low pressure system, just off the tip of southwest Ireland, will linger around that area all day throwing cloud and rain northwards. We will once again be on the periphery of heavy, more consistent rain until later in the day and especially Saturday morning when we could have a more substantial fall of rain.