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The interesting thing is the contrast with July. Under blocked conditions almost any wind direction in July brings warm weather, except a Northerly. Even if the East coast is cool and cloudy under an Easterly the West is hot.In September the wind direction matters more. We need something in the Southerly half of the wind rose, or dead calm.Hence the scatter in temps despite uniformly blocked and dry ensembles.
I'd say anything S of NEly can be good in September- at least in the first half of the month, if the upstream conditions are right:
http://www.wetterzentrale.de/reanalysis.php?map=1&model=noaa&var=2&jaar=1991&maand=9&dag=5&h=0&nmaps=24
5th Sep 1991, and:
http://www.wetterzentrale.de/reanalysis.php?jaar=1999&maand=9&dag=3&uur=1800&var=2&map=1&model=noaa
from 1999; and:
http://www.wetterzentrale.de/reanalysis.php?jaar=2006&maand=9&dag=6&uur=1800&var=2&map=1&model=noaa
from 2006. Hopefully there are some later Sep ENElies that do the job too- 1987?
All change this morning as both GFS and ECM produce a nasty little low over S Scandinavia which promptly serves up a very cool northerly flow. GFS generates it a little earlier, with ECM waiting till +144.
That is the trouble with looking so far ahead.
I would expect that with higher sea temperatures now that low cloud would be less of an issue for eastern areas than it was in June.
I disagree. Cloud is always going to be an issue for eastern areas under easterly winds and at this time of year would be less likely to burn off than in June because of the weaker sun.
Low cloud was a big problem for the east during the easterly September 2002 which was only sunny in western parts.
https://www.metoffice.gov.uk/pub/data/weather/uk/climate/anomacts/2002/9/2002_9_Sunshine_Anomaly_1961-1990.gif
Fortunately I spent as long weekend in Arrochar from the 20th to 23rd and it was glorious clear blue skies whereas back home it was cloudy.
September 2014 was another one that brought lots of cloud to the east. We had a whole week of fog and overcast skies from the 13th to 19th. Somehow Northumberland managed above average sun but the rest of the east was rubbish
https://www.metoffice.gov.uk/pub/data/weather/uk/climate/anomacts/2014/9/2014_9_Sunshine_Anomaly_1961-1990.gif
Static snapshot of this. Wow!
The cold chart at the end looks even more interesting when you zoom out. North of the UK pretty much the coldest part of the northern hemisphere, apart from Greenland:
What's most impressive for me is how much tropical characteristics that hurricane has that far north. If that comes off that could pack quite a punch if it hits the UK!
The upset to the nice looking set ups that appeared up to about a day ago is caused in both GFS and ECM by a proper discrete low forming between the HP N of the UK and the HP over N Russia. This effectively prevents extension of our HP over Scandinavia, which led to the very positive warm E/SEly set-ups modelled.
That signal continues in the GFS 06z but again the green line is low in the chart. The Control handles it interestingly- it develops a separate robust little HP over S.England (1025mb) by T + 210:
https://www.theweatheroutlook.com/twodata/chart.aspx?chart=///www.theweatheroutlook.com/charts/gefs/0_210_500mb.png?cb=78
This bulges and settles eastward, allowing the warm ENEly hitherto hinted at to gain a foothold.
https://www.theweatheroutlook.com/twodata/chart.aspx?chart=///www.theweatheroutlook.com/charts/gefs/0_276_850tmp.png?cb=996
The Control is quite high in the graph, but has support from a handful of other members.
https://www.theweatheroutlook.com/twodata/chart.aspx?chart=/charts/gefs/gefsens850london0.png?cb=441
Much cooler at the end of the week and some rain
Notice GFS is teasing us again, just out of range of the unforgivable.
https://www.theweatheroutlook.com/twodata/chart.aspx?chart=///www.theweatheroutlook.com/charts/gfs/12_225_mslp850.png?cb=622
Notice GFS is teasing us again, just out of range of the unforgivable.https://www.theweatheroutlook.com/twodata/chart.aspx?chart=///www.theweatheroutlook.com/charts/gfs/12_225_mslp850.png?cb=622
It would be nice to see the last 30C of the year and a proper farewell for 2018. Still looking good and warm this week then slightly cooler at the end of the week before warming up again. Surprised to see the LP out there when yesterday models show nothing at all so either is a mistake as it not possible to form out of no where without a reason.
The end of the week is looking rubbish if the Countryfile forecast is anything to go buy.
I don't trust the models since they been showing very settled first week or 2 of September then suddenly they wanted to create a home grown LP over us without a specific reason to cause the LP to form? I don't see it coming out from anywhere with huge HP around us. Hopefully a correction back where it was before.
Big eddy in jetstream Thu through Sunday https://www.netweather.tv/charts-and-data/jetstream
Is it time to put the fan away yet for another year?
That depression being steered in by the jet stream for the coming weekend looks cool (that dreaded 'green blob') but latest forecasts shows most of the rain in the north. But it looks as if a lot more moisture will come in off the Atlantic in a week's time.
http://www.wxmaps.org/pix/prec4
Maybe not!
The actual forecast for here next week keeps changing between cool with showers to warm and dry. It's currently on the cool side on BBC. It's my holiday next week and I'm not feeling too optimistic
A question on the cloud cover charts. How accurate are they and which model do people think is the best?
Indeed. Now you see it, now you don't1 The rain band that was forecast to envelop us next week is now positioned ober Germany & Poland, and the Uk (especially the South) is pretty well dry. Temps about average overall, which hasn't changed.
http://www.wxmaps.org/pix/temp4