Models, teleconnections and nowcasting

[knocker]

The ext anomalies this evening show the tpv northern Russia > Alaska whilst in the Atlantic sector there is a fading Atlantic ridge (the peak amplification occurs  towards the end of the 10 day period) flanked on either side by two troughs The surface analysis rather depends on the intensity and alignment of these features

Edited March 22, 2020 by knocker

[knocker]

Apart from the NW of Scotland. particularly the Hebrides. where there will be quite a lot of rain over the next three days, it should be relatively pleasant over the rest of the country after morning frosts

but by Thursday the upper trough to the NW is on the move as the subtropical high amplifies in the Atlantic and the front at last tracks south east as the winds pick up in the showery airstream. note the little trough near Kent that has broken away from the main trough to the south

Over the weekend there is some complex phasing of the upper troughs as the ridge continues to build north east resulting in the surface wind veering and strengthening Sat > Monday

Not much point in going into further detail at this range so suffice it to say it will feel distinctly chilly, particularly in the fresh wind, with plenty of showers in eastern regions. According to the gfs of course

[knocker]

On Saturday the ecm does not develop the breakaway trough to the southeast so straightaway one gets the inkling that it is not going to follow the gfs

And of course you would be correct

Edited March 23, 2020 by knocker

[knocker]

The preamble vis the ext anomalies is much the same as last evening and although on the same page the differences are self-evident

[knocker]

The 06 gfs still persisting with the trough in the southern North Sea and thus different surface analysis to the 00 ecm

[johnholmes]

Interestingly the NOAA 6-10 last evening, to me, looks more like GFS than it does to EC?

Might just be me!

Over the years NOAA and EC are usually closer to one another is what I had found.

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

 

[knocker]

Next weekend appears to be a fine balancing act between the interaction of the troughs north and south and the amplification of the ridge north east. Well as I see it anyway 

[knocker]

The standout feature from this evening's gfs is the increasing amplitude of the subtropical in mid Atlantic. This, coupled with the maneuvers  of the troughs to the south and south east, establishes a very strong north easterly wind over the UK which later veers easterly Await the ecm with interest because if the trough influence is reduced then the high may push further east

Edited March 23, 2020 by knocker

[knocker]

Slightly different orientation of the high cell and less influence fro the southerly trough initially from the ecm

not forgetting of course quite warm in England/Wales and parts of Scotland tomorrow and Weds

Edited March 23, 2020 by knocker

[knocker]

The North Atlantic 500mb and surface analysis for midnight

After a cool start to the day most of England and Wales will sunny and quite warm but further north cloud and rain will persist over western Scotland ad and creeping a rad south to N. Ireland. This will continue this evening and overnight whilst temps drop quickly further south. Tomorrow a similar story

On Thursday the font has moved a little further south

Over Friday and Saturday the subtropical high builds strongly in mid Atlanric with the UK on the eastern flank thus the surface wind veering northerly. Still some patchy rain on the weakening front as it continues to track south

[knocker]

Over the Sun/Mon the gfs has a lot of interaction between the troughs to the NE and south resulting in a strong north east wind over England and Wales and some rain in the SE of the England,

[knocker]

Predictable the ecm has a different take on Sun/Mon although it does include showers down the east coast on Sunday with possible some frontal rain in the south east

Edited March 24, 2020 by knocker

[knocker]

Personally I think it rather pointless to take too much notice of the ecm, or any model det run for that matter, in the 8-10 range/ So just to note the eps does not extend the Atlantic high north into Greenland quite as the det does

[knocker]

Dry aloft;Sc gloom below

[knocker]

Very hazy here today with various amounts of Sunshine as St drifs across on the S/Se wind

[knocker]

The gfs this evening

Saturday

A cold north easterly across the country

Sunday

Another cold day and the low pressure to the south east has made inroads. Thus many more showers that could fall as hail or snow and perhaps more persistent rain in the south east

By Monday the wind veers a tad and eases somewhat

Needless to say the nights will be cold with a widespread frost by morning

Edited March 24, 2020 by knocker

[knocker]

The ecm

Saturday

A cold north east with some showers along the east coast

Sunday winds easing with less showery activity but a front bringing rain/snow to Scotland

Overnight and through Monday the trough runs south down the North Sea and thus rain down the east coast and the south east

[knocker]

Although they are not in agreement the ext anomalies seem to moving rapidly towards a pattern that has been hinted at quite recently.

Namely the movement of the tpv allied with the retrogression of the Atlantic subtropical zone and the trough in the western Mediterranean, results in a trough running south in the vicinity of the UK with the likelihood of temps below average. As I said no agreement on the detail of this a yet

[knocker]

The North Atlantic 500mb and surface analysis for midnight

The front and rain will move a tad further south today thus the rain mainly over the central belt of Scotland with some clearer and colder air to the north of this. Further south England and Wales will have another sunny and warm day. Perhaps some cloud creeping into the far south west

Tonight cloud and rain/drizzle will persist over parts of Scotland and N. Ireland whilst a clear night further  south means temps will plunge giving a widespread frost by morning. A good example of diurnal variations at this time of year

Tomorrow still some patchy rain/drizzle southern Scotland and N. Ireland but another warm and sunny day further south

Over Thursday night and through Friday the high cell is slowly shifting orientation as the front contibues to slide south. Cloud and patchy light rain in the vicinity of this whilst colder to the north and still quite pleasant to the south

Over the weekend the high intensifies to the west of Ireland resulting in the surface wind veering north easterly across the UK Thus becoming colder with showers along a weakening from and along eastern coastal regions

[knocker]

According to the gfs the UK remains under the auspices of the high through the first half of next week so remaining cold with showers down the east coast that could be of snow on the higher ground. But changes are afoot as an upper trough breaks east from northern Canada across Greenland and pressure is brought to bear on the ridge. Best left here

 

[knocker]

The general evolution is similar to the gfs next week but the detail starts to divert by midweek with the cold front poised by midday Weds. But of course rather a long way ahead to worry overly much about detail

Edited March 25, 2020 by knocker

[knocker]

The tpv appears to be re-aligning N,Russia > N. Europe at the moment and the lower trop, which is still very vld, doing the same

Edited March 25, 2020 by knocker

[knocker]

A few more of these wouldn't go amiss. A nice dry and sunny sounding

But apparently the usual suspects are becoming quite emotional at the thought of a cold front plunging south resulting in some quite unpleasant weather. Go figure. But not to worry it's the usual 8 days away

[knocker]

A glance at the weekend. Plenty of sunshine but quire chilly in the NE wind which eases a tad On Sunday. Widespread early morning frosts and some showers along eastern coasts

[knocker]

There is agood reason why it is unwise to jump straight to the unreliable end of the outputs

The last three runs of the gfs for 0600 Thursday 2 April Guess which one was the fav?