July frost

Posted: July 9, 2015 by tchannon in Analysis, weather

Wierding continues

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Morning of 9th July 2015 the Katesbridge Met Office site reported a frost, flat lining air temperature close to 0.0C which arguably means frost was forming on the Stevenson screen. Whether this was an air frost, don’t know. Dew formation produces a less clear flat but is not usually clear in hourly data.

Notoriously cold still air site, convective cooling, no wind. Sun was up by 5AM but there are low hills thereabouts.

Why?

More notably temperatures were widely below 10C (50F) in Northern Ireland, England and Scotland. Where there was a wind, a good example St Bees Head where it was off sea, 11C, Arctic air, reaching right across, Bridlington where the screen is almost on the east coast foreshore was also cool.

The very south was slightly warmer but even the Isles of Silly were cool, bouncing along at 14.1 / 14.2 during the night at the airport, sufficient wind to prevent a serious temperature fall.

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Mid afternoon on the 8th the characteristic cloud pattern of a polar air cell is over the ocean and UK. A just off west wind is gently bringing cool air to the west.

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By 6am UT the cloud bank has built up more but Katesbridge (Northern Ireland) is just in the polar air, the wind is able to drop and the air is clear.

For now the UK is holding north of the hot band in southern Europe.

For a couple of years now a lot of bad weather has been expressing itself in the eastern Mediterrinin, weather we did not get. We tend to get moderated by the Atlantic. A week ago a brief hot air breakout took place.

Archive of Meteosat immediate images (1MB zip), from here
Thumb plots from Datapoint PDF (1MB)
Datapoint data as CSV to 7hrs 9th. ZIP (69kB)

Images: EUMETSAT or the author. Data: Met Office Datapoint.

Post by Tim

Comments
  1. craigm350 says:

    Reblogged this on the WeatherAction News Blog and commented:
    Katesbridge, Co Down woke to a frosty 0.3C, Strathallan, Perthshire 2.3C and Gogarbank (Edinburgh Airport) 3.7C all set new cold records for July.
    […]
    Strathallan, Gogarbank and Katesbridge all recorded their coldest on record surpassing records set in 1994, 2000 and 2004 respectively. However, these are not near the Northern Ireland or UK records for July. For Northern Ireland, the record goes to Lislap Forest, Co Tyrone with -1.1C set in 1971, the UK record goes to both St Harmon, Powys and Lagganlia, Inverness-shire with -2.5C set in 1986 and 1977.

    http://www.markvoganweather.com/2015/07/09/a-very-warm-open-to-july-doesnt-mean-a-warm-july/

  2. It twas a wee bit nippy here in Manchester as well this morning. The Met office records for the North West in that last 24 hours state:-

    Lowest minimum temperature Shap 3.3 °C

    Shap is on the edge of the Lake District, and is the name of the highest point on the M6 Motorway.

    Like in cricket, you can find new records being set all the time. It might be indicative of changing climate, or might be just random variation. Whether the changing weather is a result of the former or the latter needs a theory that can discern between trend and random variation. The CAGW hypothesis can accommodate the extreme cold events, if I interpret correctly the BBC Climate Wars of a few years ago. According to a couple of temperature distributions drawn freehand, Global warming will not just move the distribution of temperatures, but it will also increase the spread of the bell-curve. So we may get record low temperatures being recorded as well as record highs. But for this hypothesis to hold the record highs must be far more frequent than the lows, and the new records by a greater increment to previous records for the highs against the lows.

    Instead we have cherry-picking of results. Don’t expect much reporting of these lows on the BBC.

  3. tchannon says:

    Correctly the length of the record gets mentioned but this presupposes both no other change and the nature of the noise. The former is definitely a major problem, the latter unclear.

    Shap, I vaguely remember before the M6, a different world. Can get a bit wild up there.

    I’m still working of the Heathrow matter, uncovered what will come as a surprise to most people.

  4. tchannon says:

    “Mid-July Frost Surprises Central Europe This Morning!”
    Article dated 10th July
    http://notrickszone.com/2015/07/10/mid-july-frost-surprises-central-europe-this-morning