Sunday morning gave us 1.85 hours of sunshine before cloud bubbled up then thicker cloud from the next weather front obscured the sun.
Rain returned again in the evening starting at 19.40 and continued into Monday morning, slowly easing away. The past twenty-four hours have produced 18.2mm of rain, the wettest April day since 2014.
The thermometer struggled to reach 7.3C on Sunday due to the minimal sunshine but predominantly from the wind that had moved back into the northeast for the majority of the day before veering into the southeast in the evening.
Monday arrived with the hang back of cloud and light rain from the extensive weather front now slowly departing to the east. The thermometer, fell to its lowest point at 00.09 early this morning with a minimum of 1.3C before recovering to 7.2C at 08.00 as the wind backed slightly, now into the south as the milder air slowly moves north.
Monday update at 17.00: throughout the day we have been plagued by low cloud delivering light showers of drizzle. Late afternoon the cloud thinned and the sky brightened with limited hazy, week sunshine. However, the thermometer has still been depressed with a maximum of 10.3C when the April average is 14C.
March 2018 Summary
What a month as more records broken – cold, wet and windy with considerable snow.
The lack of sunshine and frequent strong winds, with many days from the northeast, meant that temperatures were depressed. The mean temperature for the month was 1.6C below the 34-year average but it was not the coldest March on record as that occurred in 2013 when the mean was 3.7C below the average. My records show that a colder March occurred in the years 1984-1987, 1996 and as mentioned 2013.
The month began with record low daytime temperatures for the dates of the 1st and 2nd. On the 1st the thermometer never got above freezing with a maximum of -2.0C. It is not surprising that the following night was the coldest of the month with a minimum of -6.1C . This cold spell followed the coldest end to February on record for those last two days.
The intense low temperatures by day and night meant that the cold percolated into the ground so that on the 1st the ground temperature at a depth of 5mm was -1.3C. There were 10 air frosts throughout the month being just above the average frequency
There was considerable snow in the strong northeasterly winds that meant considerable drifting occurred. Snow fell on both the 1st and 2nd also 17th – 19th. With snow around our bungalow, varying from 1cm to over 40 cm, obtaining the equivalent rainfall total for each day was not straightforward.
I thought it might be of interest to describe the recommended technique to obtain the equivalent rainfall on such days. As little snow remained in the rain gauge that could be melted due to the wind blowing across the mouth of the gauge, a different technique had to be employed. The standard 5 inch Meteorological Office rain gauge (or 12.5cm) was removed from the ground. The inverted funnel was inserted vertically into a representative area of lying snow, avoiding drifts or areas where snow had been removed by strong winds, to obtain a ‘snow core’ sample down to ground level. As far as possible, all of the snow in the area enclosed by the rain gauge funnel was collected in the funnel, after placing a thin piece of wood under the funnel at ground level. This snow was placed into a suitable receptacle and the procedure repeated twice. The container with the resulting accumulated snow was placed in a bowl of warm water to slowly melt and then measured in the standard graded glass measuring jar. The resultant liquid was then divided by three to get the best guestimate of the equivalent rainfall total.
The equivalent rainfall for the month came to 130.9mm, which was a record for this station that commenced recording in 1984. This total was 228% of the 34-year average or 73.5mm above and was considerably more than the previous record of 113.7mm set in 2001. We don’t need to be reminded that there were only 4 dry days in March!
It was not a sunny month. There were just 55.3 hours of strong sunshine. This total was only 2 hours more than that recorded in January and only half of that which we enjoyed in the very sunny February. It was not a surprise to find that the highest UV level during the month was the lowest since this instrument was installed in 2010.
Such a miserable month was due to the frequent depressions crossing the country, born out by the barometric pressure data being a significant 18mb below the long-term average.
We all hope that the new month will bring much warm sunshine although on the 1st April the maximum temperature was only 7.3C, which was almost 7C below the average for April and that was not a joke!