Looks like summer at last, 21st May

Posted: May 20, 2012 by tchannon in Forecasting, weather


I’ve been watching the model forecasts, some good news for a change.


This Wednesday 21st May looks like the single first day of summer 2012, most of the country above 20C from mid morning through 10 at night. cloud-21mayFollowing days not as good.

Don’t know about cloud though, lets look

Cloud forecast from http://www.wetterzentrale.de/wz/pics/avnpanel3.html

Reason for fine weather is primarily no wind.

Funny how weather tends to the mean, get one you get the other.

There has been some kind of a spring heat wave over much of eastern Europe for weeks now. If this is a continuing blocking of normal northern circulation I wouldn’t be surprised if things cog around one and we get a blocking high too. The cool and wet weather has come from a kind of wall over Europe with either Atlantic weather sliding past, over us, have some falling drought, or Arctic air.

[UPDATE 21st 23hrs BST]


Forecast image on 21st


Difference. Surprisingly little, weather is stable as I suspected.

Ireland is slightly warmer as is part of France, northern Scandinavia more-so. Pressure change shows a growing high, even less wind.

GCM do work well sometimes. I think it would be interesting to see the various diagnostics on forecast stability, perhaps something which ought to be available to the public so we can make up our own mind. Occasionally public forecasters do let out ‘we are unsure what is going to happen’, or they only give a very short forecast.

[UPDATE] Finally this is the same forecast mid morning of the 21st May

Figure 6, Final


Tim Channon

  1. Brian H says:

    Been puzzling over what “have some falling drought,” might possibly mean, and am coming up empty. Care to explificate?

  2. Brian H says:

    P.S. Getting similar patterns here on Canada’s SW coast; a few days in a row of 17-20°C, then a few of 12-15°C. Ramping up. Classic summer in Vancouver is long stretches of uninterrupted sun, max ~25°C with rare one or two day excursions higher (~30°C). Felt very mild when I moved here a few decades ago, but now that seems sweltering!

  3. tchannon says:

    Offbeat Brit humour. We apparently have a severe drought with floods. Hence rain is falling drought. (had a death near here, a badly marked ford, car was swept away in floodwater and turned over, driver died, yet we continue with bans on hosepipe usage and with threats of the usage of standpipes.
    Actually a drought here, ho ho ho, we are a water producing region but happen to be within a water company region, and about legal boundaries. Welcome to England.

  4. Q. Daniels says:

    Ah, so “falling drought” is kinda like that white fluffy “Global Warming” we get around here sometimes.

    Continuing in that vein, back in January we had almost an inch of drought on top of 4 inches of Global Warming. That did a lot of damage to the trees in the area.

  5. Roger Andrews says:

    Whether the weather be fine
    Whether it raineth a lot
    Whether the weather be cold
    Whether the weather be hot
    We must weather the weather
    Whatever the weather
    Whether we like it or not

  6. tchannon says:

    Odd thing a month ago, very heavy hail. There was a surprising side effect, it “shot blasted” the roofs which over time gather a lot of moss. Not any more. Posed some problems keeping the debris out of the downpipes.

    Now consider: could this explain a few sedimentary layers if hail is an episodic weather pattern?

  7. Tenuc says:

    Still got the hosepipe ban down in deepest Sussex. Here’s what Ardingly reservoir looked like in December and how it looks now, after lots of weather only fit for the ducks….

    Source: http://www.mirror.co.uk/news/uk-news/drought-over-for-much-of-england-after-829235

    Luckily I’m on a agri supply so I’d be able to use a hose pipe if I needed to – but I don’t… 🙂

    Today was forecast to be warmer with sunny spells, but it has been grey cloud, windy and cool most of the day – at least it hasn’t rained yet.

  8. tchannon says:

    Looks like it could do with a good dredging. About time these things were covered too, reduce evaporation.

  9. tchannon says:

    Post updated with new information.
    Have fun.

  10. Tenuc says:

    This tickled me… 🙂

    Environment chiefs consider redefining droughts after record rainfall.


    Seems our government would rather spend money on trivia, rather than legislate to make the greedy water companies spend money stopping the leaks and building major new infrastructure to cope with the massive influx of immigrants we’ve had over the last 20y or so. Ayn Rand would be laughing her socks off.

  11. Stephen Richards says:

    This is the sort of weather pattern that we would likely see in a little ice age. It is thought (Lamb) that whatever causes a little ice age produces a high frequency of blocking highs both summer and winter. Hence, seasons become more extreme.

  12. tchannon says:

    Looks as predicted but the downturn tomorrow is less, ie. nothing and the far forecast points at blocking as I suspected so we might get decent weather into June.

    The tendency on temperature is is bi-modal. Most of the time it is below mean with shorter periods above mean. Actual mean is unusual. (do frequency binning and plot, get a double hump)

  13. tchannon says:

    Final image added.
    Weather is warm but not scorching because there is high haze, slightly milky sky. This is normal for England, we rarely get the clear blue sky which is common in less humid parts of the world. Twist here of course is it feels hotter than it is.

    The entropy will be high, as chiller engineers know, heavy load from humidity, although nothing in relation to the true tropical regions of the world.

  14. tallbloke says:

    What a difference 3 days makes, from the 18th May when I reported snow in the highlands to the 21st when Tim posted this article.

  15. Ulric Lyons says:

    My cooler week from the 18th turned out to be from the 14th, otherwise the ups and downs of this May have gone as expected. CET anomaly up to the 25th is at -0.1C

  16. Tenuc says:

    tallbloke says:
    May 24, 2012 at 2:46 pm
    “What a difference 3 days makes,..”

    Yes Rog, my veg plot is moving at last, even some swedes and early kale I thought I’d lost to the cold have shot up – amazing! These nice warm spring days following the deluge of the previous weeks have caused a massive growth spurt for the biosphere, I wonder how much CO2 has been removed from the atmosphere to fuel this high speed plant development?

  17. tchannon says:

    Warning, June frosts.

    I am watching a slug of Arctic air smacking into the Norwegian coast where a few days ago it was similar to England. If as the GCM are saying this floods into Scandinavia and the North Sea, walls of cold spread right down into France.

    June 1st is down far enough for ground frost. June 2nd showing possible air frost in the Midlands.

    GCM are not accurate but keep a weather eye if you are a gardener.

  18. Tenuc says:

    Thanks for the warning, Tim. Just checked the Accuweather forcast for my area and not looking too bad, with a min of 5C – fingers crossed… 🙂


  19. tchannon says:

    Fortunately we’ve little which is very frost tender. Air frost is the dire one and that is unlikely.

  20. Ray C says:

    All new tender new growth is vunerable to late frost. If you get up before the suns rays touch the plants you can spray/mist water over frozen leaves. This will raise the tempeature slowly and stop the frozen cells from bursting, hopefully! It is the rapid temp change that causes the damage. I’ve done it with my spuds this year when I got ‘caught out’ and reduced the damage.

  21. tchannon says:

    Is anyone here able to comment on whether the slug of cold air flowing as a rounded body is a MPH?

  22. Ulric Lyons says:

    A brief -NAO: http://policlimate.com/climate/ecmwf_nao_bias.html
    UK (west) looks coldest mornings of the 3rd and 4th June.

  23. tchannon says:

    I was wrong over a blocking high establishing a long hot period. Nevertheless things are nuts.

    It is blocked but the Arctic is taking a pop.