October 2015: average temps and rather dry

This October was the coolest since 2012 though the mean of 11.7C is just 0.1C below average – nearly 2C colder than the same month last year.

The last week of the month saw the leaves turning in earnest. The horse chestnuts, such as this one in Wanstead Park however, turned much earlier because of the leaf miner pest

The last week of the month saw the leaves turning in earnest. The horse chestnuts, such as this one in Wanstead Park however, turned much earlier because of the leaf miner pest

A persistent anticylone around mid-month pumped quite cool air from the north-east for a time, prompting some cold nights. Though we have yet to experience an air frost this autumn the ground temperature fell below freezing on five nights – that’s five occasions more than last year: -2C was recorded during the early hours of the 8th.

The month was rather dry: some 46.8mm of rain fell which is 70% of what we can expect in an average October. The wettest day was the 27th when 19.4mm fell. The heavy rain in the early hours of the 28th was quickly replaced by sunshine and a stunning day followed.

Just over 91 hours of sunshine were recorded – that’s 86% of what we can normally expect in an average October.

What has November got in store weatherwise? The models today (November 1st) suggest this week will see a gradual decline in conditions overall as the ridge from Europe weakens and weak Low pressure edges up from the south and SW. Thereafter it looks like winds will settle SW’ly as high pressure relocates to the south of the UK, bringing this area mild temperatures and mostly dry and bright conditions – though a little rain will be possible at times. Overall the models continue to have little appetite to serve us up anything remotely cold and stormy.

My long range outlook method suggests that November will be average to rather mild temperature-wise, a mean of about 8.9C, at 56% probability. The next highest probabilities are for rather cold or cold, at 18% probability. The chance of a very mild month comes out at just 6% probability.

The highest probability for rainfall is 69% for something average to rather dry, between 37mm and 59mm. A wet November comes in at 20% probability.

My data for sunshine only stretches back to 1878. The signal is for something average, at 60% probability.

Looking beyond November it is notable that October 2015 was very similar to October 1997 – the year another strong El Nino occurred. A very mild winter unfolded from 1997-98, though I’m sceptical about how much influence ENSO has on our part of the world.

With the sun lower in the sky at this time of year there's often a great opportunity for a decent sunset

With the sun lower in the sky at this time of year there’s often a great opportunity for a decent sunset

My October outlook for temperature was good in that I estimated that there was a 44% chance of the mean being average. My rain estimation was way out in that a signal for a rather dry October was only a 22% probability – though bearing in mind that the probability for a wet October was only 33% it is not surprising the outcome was wrong.

Here follows the full weather diary for October…Full stats for the month here:http://1drv.ms/1rSfT7Y

1st Sunny with just a few wispy clouds. Heavy overnight dew.
2nd Sunny and clear all day and evening. Mist thickened overnight with fog elsewhere in the UK.
3rd Misty start and cloudy till midday. Evenutally cleared to leave sunny spells. Cooler than yesterday.
4th Sunny start but with a few cumulus developing during the day. Clouding over during the night with few drops of rain from high-level feature before obs time.
5th Cloudy start with rain spreading in after midday, this being steady on and off into evening before turning to drizzle late evening and lasting into early hours. Another outbreak of rain at 9.30am to obs time.

There were five ground frosts during the month of October

There were five ground frosts during the month of October

6th Rain to start, some of it heavy. Drying up a bit at 11.30am. More rain in the evening and overnight into the early hours. Rain again at 9.20 until obs time.
7th Cloudy start but with rain moving in again. This rain dried up a bit at 11am but then more rain at 2.30pm before petering out and clearing overnight to leave it cold.
8th Sunny, clear start with just a few cirrus. More cloud at noon and through the day. Cleared at dusk to give a cold night and heavy dew.
9th Sunny start but cloud bubbled up from noon to give cloudier periods.
10th Bright start though stayed mostly cloudy and cool. Milder overnight than of late.
11th Sunny start with a bit more of a breeze. Some alto-cumulus late on made for a stunning sunset. Cloud overnight held up temperature.
12th Cloudy start, some brightness at 11am.
13th Cloudy, cold start with cloud off North Sea making it feel colder. Cloud was very thick at 3pm with drops of drizzle.
14th Clearer periods overnight saw temperature fall sharply but too much wind for frost.
15th Sunny with just a few cumulus – very cold wind though. Cloud thick enough at times for brief showers through day. Quite overcast at night
16th Cloudy start though with some brightness. Strong easterly breeze.
17th Cloudy though warmer than past week. Felt a bit muggy.
18th Cloudy and breezy start, cloud persisting through the day.
19th Bright start and was more glimpses of sunshine than past few days. However, cloud returned with a vengeance last afternoon – felt like it was getting dark at 5pm.
20th Cloudy all day. Clearer overnight.
21st Cloudy start. This turn to long sunny spells and a pleasant afternoon.
22nd Rain to start which fell until 2.30pm. Then outbreaks of rain into the afternoon. Cloudy and damp overnight.
23rd Bright start though mostly cloudy through the day.
24th Cloudy all day. Feeling colder.
25th Cloudy start with light rain around 10.40am then intermittent. Very heavy burst of rain after dark before the skies cleared to leave a cold night.
26th Bright start with cloud breaking to long sunny spells – pleasant in the sun. Temp fell away quickly at dusk. Precip was dew accumulation.
27th Sunny start. Some cloud developed through the day but then largely melted away to leave a warm late afternoon.
28th Cloudy start. This broke to sunny spells into the afternoon in Rye. Light rain seen in Rye at 8pm – this turned heavier into the evening but most fell at dawn.
29th Bright start but quickly clouding over with rain in the evening and overnight.
30th Light rain and drizzle to start then cloudy all day and overnight.
31st Bright start, the cloud gradually clearing to leave a warm afternoon.

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One response to “October 2015: average temps and rather dry

  1. Pingback: Wanstead weather: 2015 review | Wanstead Meteo·

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