Sunday, 1 March 2015

Weekly weather guide Monday 2nd to Sunday 8th March 2015

Headline: Rather cold with wintry showers, some prolonged, to mid week, then mild with a little rain in places

Last weeks highlights

Another half-hearted cold snap to start last week, snow hard to come by even at altititude! Much milder air arrived on Wednesday, it was the mildest day since mid January here at Llanwnnen  max 11.3c, with 13.4c Hereford mildest spot in the Midlands and 12.6c Milford Haven mildest for Wales. Rain or showers at times through last week but not in vast quantities. Mild again Saturday, Hereford again tops at 13.2c although we saw some strong winds and rain for a time.

February 2015 was another very average Winter month with near normal temperatures but little snow below 1000 feet. Rainfall for most rather below average although some spots did just exceed average levels. It was a sunny month. Some February rainfall totals:

Capel Curig 158.8mm
Llanwnnen 78.5mm (75%)
Pembrey Sands 72.8mm
Llanelli 85.1mm
Aberporth c. 60mm
Coventry, Bablake School 42.2mm (95%)
Long Lawford 40.4mm (101%)
Coleshill 33.0mm
Pershore 34.8mm
Little Rissington 46.8mm

Winter 2014/15 again very benign and average with few extremes. The lowest reading here at Llanwnnen was -8.4c back in December, we are a cold spot and for most places even -6c was not exceeded this Winter. Rainfall-wise again average or below so that we were spared the widespread storms and flooding of the previous Winter at least! Snow notable by its absence as with 2013/14, for most lowland places only the odd temporary slight coverings of 5cm at worst. For the Midlands it has been a notably sunny Winter (see Bablake School weather Coventry )

Some Winter (Dec - Feb) rainfall totals:
Llanwnnen, Ceredigion 405.9mm (100%)
Bablake, Coventry 159.0mm (89%)
Long Lawford, Rugby: 129.8mm (86%)

The week ahead

As we move into Meteorological Spring an unsettled and rather cold spell ahead with showers and some longer spells of rain, hail, sleet or snow, the latter mostly but not exclusively for hills. It dries up briefly mid week before milder air arrives but still with some mostly light rain or drizzle at times to end the week. For the Midlands though it could turn out dry and very mild next weekend, with the first 60f (16c) of the Season a possibility in places most favoured for some sunny breaks.

After a dry, bright start going downhill this Sunday afternoon as a squally trough brings showers or longer spells of rain across all parts. These heavy with hail at times, thunder for a few, and may turn to sleet or snow over high ground by late afternoon. Highs Sunday 8 to 10c but turning colder later on, and with a fresh to strong SW to west wind. Further showers in places tonight, these again wintry for high ground, a ground frost for many, lows 0 to 2c.

Monday and Tuesday will be similar days as we are in a cold, showery WNW flow, West Wales (WW) most prone to showers, with longer dry spells between for the Midlands. With ocean temperatures at their lowest of the year during March this means they have somewhat less of a moderating effect on the cold air reaching our shores, and therefore a greater chance for some snow showers even to lower levels? Both days then see sunny intervals but with keen west winds bringing wintry showers across at fairly regular intervals, these heavy with hail and thunder in places, and sleet or snow especially but not exclusively for hills above 300m. Indeed hills are likely to see coverings of snow, and with troughs accentuating the showers at times, then should these occur at night (a possibility on Monday night) even some low lying areas may wake up to a surprise slight covering of snow. Maxima decidedly cold for early March both Monday and Tuesday at between 4 and 7c, coldest for Snowdonia, with winds often quite strong making it feel even colder. There will be some slight overnight frosts as well provided winds ease sufficiently.

A ridge dries things out during Wednesday although still a few wintry showers about, but generally a mostly dry and bright if chilly day, highs 6 to 8c, and with less of a wind. Frosty with light winds and clear spells for Wednesday night. High pressure then to our south for the rest of the week means milder SW winds. Mostly dry and bright on Thursday for the Midlands, but clouding over WW with some rain late afternoon or evening. Highs Thursday milder at 8 to 10c. Rain at times for many places for a time during Thursday night, courtesy of albeit weakening Atlantic fronts, which may then clear before dawn to permit a ground frost.

Friday sees quite mild SW to west winds bringing plenty of cloud, with a little rain or drizzle about too, but parts of the Midlands having a dry and fairly bright day, highs 8 to 10c, so up to the average. Next weekend's fortunes depend on exactly where the high pressure is positioned, it may extend over southern Britain or remain over the Continent to our south. In any case a mostly dry and mild weekend can be expected. The latest ECM model output has the high over us with very mild air, such that given any sunny spells temperatures would reach 60f (16c) over the Midlands, and 12 to 14c for WW. However should the high remain over France then a more moist SW flow would mean greater amounts of cloud to spoil things, with even some drizzle for WW at times, and maxima more like 10 to 13c.

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