High of 41.4°C in Córdoba

Figure 1

It looks like it will be another very hot day for mid May in Córdoba, Andalusia Spain, although it may not top the 41.4°C (106.5°F) that it reached their yesterday (fig 1). It looks like temperatures have been on the rise in that part of Spain for the last four days or so (fig 2).

Figure 2

According to the climate information in Wikipedia from the Agencia Estatal de Meteorología, yesterdays maximum of 41.4°C (fig 3) was still a long way short of the existing June all time maximum of 45.0°C.

As is fairly typical for Iberia it’s also been fairly sunny in Spain this May, and at the moment Córdoba is also probably the sunniest place in Europe, with over 164 hours of sunshine in the first 12 days of May (fig 4).

Figure 4

May 2017 – mean MSLP and anomaly chart

Figure 1 – Data courtesy of NCEP/NOAA 20th Century Reanalysis

You can understand why May ended up being the second mildest on record since 1910, when you see the mean pressure chart for the month (fig 1). There was a large negative anomaly (-13 hPa) in central Atlantic, which distorted the flow around a large elongated low of 1006 hPa (49N 30W), which pushed the Azores high further south than usual, producing a SSW flow over western Britain. Pressure over central Greenland was much higher than average (+15 hPa) pushing the normal Icelandic low south. The Greenland high ridged southeastward into Scandinavia and central Europe, with a mean northerly flow over much of that region.

Monthly Weather Summary – May 2017

Data and charts courtesy of the Met Office.

Monthly Weather Report – May 2017

Climate data & weather charts courtesy of the Met Office – LWT data courtesy of the CRU/UEA.

May 2017 from space

Warmest May since 2008 in Central England

Figure 1

It’s been the warmest May since 2008 in Central England, not what you’d call a particularly earth shattering headline is it, but that’s how it panned out. In the ranking back to 1659, the +2.05°C mean anomaly (calculated with respect to the 1961-1990 long-term averages), makes it around the 15th warmest. Since 1910, the year that the Met Office choose to start their climate records from, its seventh in the rankings. The month set a new highest maximum for CET on the 26th, and also two highest minimums on the 16th and 27th.

Northern Ireland sunniest place in UK so far this May

Figure 1

It’s neck and neck at the top of the sunshine table between Aldergrove and Ronaldsway airport on the Isle of Man this month. With just a few days left this May, Aldergrove with a total of 248.4 hours is just in first place. Tiree, who had been sunniest for the first 12 days has now slipped to 5th place. There are some missing values for stations in my list, but it maybe that Liscombe in Somerset might once again be the dullest place in the UK, but that does look a little suspect to me even though I’ve received all 26 sunshine values from their observations.

Figure 2

Hottest 26 May in UK since 1880

Figure 1

Yesterday’s maximum of 29.4°C was the hottest 26th of May since 1880 in the UK, that’s according to the table of daily extreme maximum on the TORRO website. It just pipped the previous record of 29.3°C set 137 years ago in the days of Queen Victoria in Norwood, North London in 1880. It might have gone that bit higher either there or at Kinloss if it hadn’t been for the sea breeze along the Moray coast that didn’t relent till 14 UTC. Temperature may reach the same kind of levels today in that part of the world, but only if the sea breeze slackens its grip.

Figure 2

The anomalies for yesterday’s maximum temperatures, according to the long-term daily averages that I’ve computed, were astonishingly high for the month of May for places in the north and northwest of the UK (fig 3). The maximum at Lossiemouth for example was +14.5°C higher than the average daily maximum for the average I’ve calculated for the 26th of May.

Figure 3


Hot, really?

Most of you must know what an old curmudgeon I can be in this blog of mine. So I was just wondering about the term ‘hot’ and what exactly it meant in forecaster parlance. In the last couple of days it seems to be tripping of the tongue of just about every weather presenter on the TV. There was a pamphlet issued by the Meteorological Office ‘Your Weather Service’ which did list the terminology in a table used by presenters when forecasting the temperature and frost in the 1950’s, and which you can find if you do a search the archives of the Weather Magazine (page 138 in the 1964 volume). As far as I can see from the table, which in itself is a little ambiguous about each range, the definition for hot for the summer period, is a temperature that’s between +6°C and +7°C above the long-term average, and very hot when its >+7°C, i.e. +8°C or higher.

As you can see for yesterday’s maximum temperature anomalies [06-18] for large parts of the countries that weren’t affected by an onshore sea breeze where in the hot category, and many parts in the north and northwest were in the very hot range, with Aboyne +12.4°C above the long-term average for that day. Generally along the south coast and the southeast temperatures were in the very warm category (fig 1).

Figure 1

Here’s a more detailed analysis of yesterday’s highest anomalies from across WMO block 03 (fig 2). So it may have felt hot at Heathrow yesterday, and it certainly was with an anomaly of +7.8°C, but a temperature that was just one degree higher produced an even larger anomaly in the Highlands where it was very hot.

Figure 2

I think it would be a good idea if the Met Office could update and reissue the original pamphlet ‘Your Weather Service’ on their website. They produce may helpful factsheets, but none of them cover forecast terminology used in their forecasts or by their presenters, as far as I can see. I am sure it would help the general public to standardising terminology used to describe just how cold or warm it was expected to be, how severe a frost was expected to be, or how windy it would be tonight. Until they do, we will never really know exactly what they mean when then say there’ll be a sharp frost or it will be blustery day, or it’ll be hot, when what they really mean is that it’ll be very hot in the northwest.

Wall to wall blue skies… well almost

Figure 1 – Courtesy of the Met office and EUMETSAT

Almost wall to wall blue skies across the country today (fig 1), oh how I do hate that particular cliché, but when you need a title it’s any port in a storm. I noticed the southeasterly has started to level out the temperatures across the southeast in the last hour (fig 2). The cumulus that’s bubbled up across a large part of the Midlands is also affecting temperatures across central England. This has given the north of Scotland a chance to catch up with places live Aviemore and Aboyne getting some shelter from the Grampian already around 25°C or more.

Figure 2

I expect to see Kinloss and Lossiemouth warm up quickly this afternoon, once that is they’ve lost the sea breeze that’s kept temperatures pegged down this morning. Spare a thought for the people on Fair Isle with a 12 UTC temperature of 11.3°C though, it’s much warmer than that on top of the Cairngorms at the moment (15.3°C).

Figure 3