Sunday, 7 June 2015

Weather guide Monday 8th to Sunday 14th June 2015

Headline: Mostly dry with sunny spells to Thursday, turning more unsettled and potentially wet in places from Friday; cool to average temperatures

Last weeks highlights

A cool, unsettled and windy start to last week, last Sunday inspite of sunny intervals in the afternoon nowhere managed higher than 15c. A few heavy showers with hail and thunder affected parts of Wales late Sunday evening into the early hours of Monday, sheet lightning from an active little storm heading inland from Aberystwyth was observed from Llanwnnen some 25 miles away just before midnight. Chilly Sunday night, 2.2c the low at Shobdon, Herefordshire with a grass frost here and in Shropshire.

It became unseasonably cool, wet and windy during Monday, particularly over West Wales (WW) where it ended up really wild with heavy rain, although only a little rain for the sheltered SE Midlands. Around an inch of rain fell over much of Wales and temperatures not bettering 14c anywhere, very poor for the 1st of June (max Aberdaron 10.7c, Pershore 13.9c, wettest Capel Curig 60mm, Trawsgoed 37.4mm, Llanwnnen 27.6mm, in contrast Evesham 1mm). Selected max wind gusts for Monday: Capel Curig 78mph, Aberdaron 74mph, Pembrey 66mph, Llanwnnen 45mph, some trees blown down, one onto a parked car in Swansea ( ). The low bringing all of this as it crossed northern Scotland was one of the deepest UK depressions on record for June as pressure dropped to 973mbar at Tiree, Hebrides (UKWW June 1st deep low discussion ).

The rain cleared to a few showers Tuesday, quite windy again, but temperatures higher (Coleshill 19.5c, Trawsgoed 15.8c, Capel Curig 13c). Fine, dry weather through Wednesday which was still though a cool day for many (Coleshill 18.5c, Llanwnnen 16.9c, Aberdaron 13.2c). Clear and very cool Wednesday night with localised grass frost in a few spots (lowest in the air Tirabad +0.8c, Shobdon 2.1c). Thursday which was warm and sunny, 20c reached for the first time at Coventry (max 21.5c), the latest occasion since records began in 1892. Most inland places likewise topped 20c some even 21c (70f) for the first time this year (Pershore 22.1c, Llanwnnen 21.6c, Aberdaron 16c). 

A plume of very warm air flirted with  SE England on Friday but the heat remained over on the near Continent with 34c (93f) in Paris, Belgium and Holland! The Midlands managed another rather warm day though before a cold front arrived afternoon dropping the temperature sharply, while for WW the cold front with a little rain had cooled it off during the morning so maxima were quite low in spite of the afternoon sun, in fact many parts of WW were cooler for a time in the afternoon than they were during the previous night (Nottingham 23.3c, Coventry 23.1c, coolest max Aberdaron 15.1c). Mostly dry and bright Saturday but back to being rather cool and breezy (Pershore 17.7c, Llanwnnen 16.4c, Capel Curig 12c).

Max wind gusts Wales Monday 1st June

May 2015 highlights

May was a dull, cool and wet month for the majority of places. All the cloud did however restrict the late Season frosts that can occur in May, with only the occasional grass frost even in this prone spot at Llanwnnen. Warmth also limited to just the odd day here and there, many places failed to reach 20c. It was the dullest May in Coventry since 2007.

Some May rainfall totals:

RAF Mona 131.2mm
Trawsgoed c. 119mm
Llanwnnen 95.7mm 124%
Aberporth c. 67mm 
Pembrey Sands 103.6mm 149%
Hereford 76.8mm 150%
Coleshill 53.6mm 101%
Hinckley 76.5mm
Coventry, Bablake 72.4mm
Long Lawford 65.1mm 113%
Church Lawford 64.0mm 111%

Spring 2015 highlights

A very average March, dry and warm April then unsettled and quite cool May, we were spared any real extremes this Season, no snow, storms, floods, nor widespread damaging late frosts nor droughts. Overall temperatures averaged out near normal, sunshine was above average and it was quite a dry Spring almost everywhere.

Some Spring rainfall totals;

Llanwnnen 197.8mm 83%
Hinckley, Leic. 149.5mm
Coventry, Bablake School 141.6mm
Long Lawford 115.9mm 80%

The week ahead

Plenty of fine and dry, if not especially warm weather to come this week and less of that cool breeze, the best of the sunshine for WW. It does though look like turning unsettled with some rain at times from Friday into the weekend. Another very cool one last night, down to 2c in places (Llanwnnen 2.2c) with a touch of ground frost very locally. Dry with sunny spells then this Sunday afternoon, a cool NNW breeze and highs between 15 and 18c. Clear periods tonight, another chilly one with a grass frost in a few spots, temperatures in the air down generally between 2 and 5c inland.

A nice strong high centred over or close to Ireland through to Wednesday so similar weather up to then, basically dry with sunny spells, sunny mornings and evenings, with areas of cloud developing during the afternoons, particularly over the Midlands where threatening an isolated light shower perhaps. The flow is from the NE and still quite cool so maxima only likely to be in the 15 to 19c range, it may be a touch warmer though by Wednesday as the high orientates more favourably? Largely clear skies by nights means these will be distinctly cool and threaten further grass frost in some areas, minima for most 1 to 4c, but milder for most coasts and town centres, dawn valley mist is possible also. Winds only light to moderate through this period.

The high looks like pulling back west into the Atlantic during Thursday but this should be another mostly dry and fine day and a bit warmer as we should lose the North Sea influence so a chance of 22c (72f) in places with the warm sunny spells. By Friday we are seeing a weak cold front moving into Scotland while at the same time a thundery low is close by over the near Continent, this containing warm air. The outcome of all this seems that it turns unsettled in time for the weekend and that we are likely to remain on the wrong side of the Continental warmth.  Some bands of rain edging north during Friday, so some areas may end up cool and rather wet, with others escaping with little if any, it would be a very cool day where cloudy and wet, no higher than 13c, although where it brightens up to 18c  (the relevant areas cannot be pinned down at this early forecasting stage).

The jury is out regards next weekend but it does look at least somewhat unsettled and there is the threat of some wet periods (potentially with a lot of rain in places) as energetic lows are close to the south at times, in this scenario the wet zones would be very cool, no better than 13c. On the other hand it may not turn out so bad being more a case of sunny intervals and a few showers, in any event it is likely to be on the cool side although with any sunshine it would get close to average (17 to 20c). Aleady indications are that June will end up quite a cool month with more uninspiring charts appearing in the further outlook so certainly no 'Flaming June' again this year!

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