Sunday, 15 November 2015

Weather guide Monday 16th to Sunday 22nd November 2015

Last weeks review: Often very mild, cloudy and quite windy with rain at times (mainly Wales) but a cooler, showery Friday

Much of last week was very mild and cloudy, record breakingingly mild for November overnight Monday as temperatures over parts of the UK did not fall lower than 16c which would be a warm July night! Hereford was the mildest place that night in our regions (min 14.5c) but many places remained above 13c. Up until Thursday WW saw occasional rain and drizzle, very little though within the 'rain shadow' of the Midlands which was mostly dry but quite cloudy. Snowdonia really sponged up the moisture as Capel Curig received 110.6mm (over 4 inches) in the 24 hours to Tuesday morning - 90mm of which falling in just 12 hours on Monday and after which the rain gauge seems to have developed a fault and so the total for the week is not known although it must be well over 200mm! The Midlands had the highest temperature readings last week peaking Tuesday at Newport (Salop) at 17.5c (7c above normal).

A measure of the exceptional mildess of this November to date is that many parts of the Midlands had maxima above 14c from the 4th to 12th and that nowhere across our regions has had an air frost (min below 0c) as yet, and some not even a ground frost. Friday was then the first day of the month to register below average temperatures in some places as most only reached 9 to 11c (Milford Haven 11.3c, Pershore 10.8c, Capel Curig max 7.8c) it was windy with showers in many places. Wet in many places yesterday (Saturday) with parts of WW getting quite large totals. A mild and rather windy day although it was late afternoon before the mild air reached the East Midlands. Temperatures peaked Saturday evening (Hereford 16.2c, Trawsgoed 14.9c) with an exceptionally mild night following (Hereford min 14.8c).

The coming week: Often mild with spells of rain and wind; colder more showery from Friday (some wintry)

Further heavy rain for Snowdonia on Saturday night, Capel Curig having had 62.8mm in the 24 hours to Sunday morning, elsewhere little or no rain has fallen in general. Capel Curig has had about 400mm (16 inches) in the past 11 days, so flooding is likely in North Wales this week. Mild for the most part but we may well be getting our first taste of Winter with a cold snap and even snow in places next weekend.

Very mild, mostly cloudy and windy this Sunday afternoon (gusts above 60mph last night over NW Wales) - mainly dry for much of the Midlands but some rain and drizzle at times across Wales, and again further heavy falls which may result in flooding for North Wales. A few bright or sunny intervals possible over the Midlands where temperatures could reach an exceptionally mild 17c locally, with it generally a very mild day at 14 to 16c. A more general band of rain overnight on a cold front, although again this should be mostly light for the Midlands, and clearing from all parts by around dawn. A cool down behind the front, as low as 5c in places but holding above 10c for the SE Midlands.

A semblance of a ridge Monday, sunny intervals with the outside chance of a light shower and less windy. Maxima Monday 12c for the Midlands and 9 to 11c WW.  The next lot of fronts bringing rain and increased winds to WW during the evening which soon spreads east into the Midlands overnight raising temperatures into double figures again after midnight. A low then crosses the UK during Tuesday so spells of rain, heavy in places and there could also be strong to gale force winds associated with this feature. Very mild in spite of the wind and rain, highs 13 to 16c. The worst of the rain should be clearing through Tuesday evening leaving a scattering of showers overnight, strong winds likely to keep up with gales for some.

Any ridging very transient early Wednesday as further lows and their fronts move in from off the Atlantic. Wales and England will come within a broad moist warm sector during the day, this once more having the potential to produce copious rainfall over the hills of Wales, so expect further large totals for the Capel Curig environs and to be hearing of flooding for parts of Wales midweek. Some rain may also affect the Midlands, more especially later in the day after some mild, brighter intervals here. Highs Wednesday very mild at 13 to 15c but it will end up another windy day as the SW wind increases. Fronts may then become slow moving across our regions during Wednesday night and so exacerbating any flooding, temperatures holding up above  a very mild 10c for most.

The latest GFS model output is concerning from a rainfall/ flooding perspective as it maintains active fronts across Wales and the Midlands during Thursday with a thoroughly wet day in prospect should this come to fruition. Not all models suggest such a wet day however, as some have the rain more intermittent and showery in nature, but in any case another mild day is likely, highs 11 to 14c, but strong winds for many areas once more, with a risk of gales at least for a time. A big cool down is underway by Thursday night as a cold front moves down from the north clearing the rain to more showery conditions.

Quite a potent late Autumn cold snap is being shown for the weekend and will be a shock to the system after a thus far exceptionally mild November! Fresh to strong northerly winds as the UK is set to lie between low pressure to our east and high pressure to our west. Friday appears to be the transitional day to this colder weather, a day of sunny intervals, cool NW winds and showers, some heavy with hail, and which may turn wintry over high ground by evening.  Maxima Friday 8 to 11c.

Saturday then looks a cold and potentially wintry day with a northerly blast bringing showers or longer spells of rain, hail, sleet and even snow. Lying snow though should be restricted to hills above 1000 feet, although virtually anywhere could see their first snow shower of the season during Saturday. Maxima a cold 3 to 6c feeling raw in the north wind and a total contrast to what we will be experiencing for much of this coming week and with frost likely overnight! Still cold with some wintry showers in places Sunday but suggestions of a ridge that would tend to kill most of these off.

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