Short range model discussion - into 2018

[knocker]

After a clear morning fog was advected in quite early down here which lifted to low stratus but only partially cleared by early afternoon. Mainly I suspect to the closeness of the decaying front and some high level broken Sc. So although an 850mb temp of 11C the surface struggled to 14C. The front depressed the temps in all the far west regions and N.Ireland and Scotland.

Edited April 19, 2018 by knocker

[johnholmes]

1 hour ago, knocker said:

After a clear morning fog was advected in quite early down here which lifted to low stratus but only partially cleared by early afternoon. Mainly I suspect to the closeness of the decaying front and some high level broken Sc. So although an 850mb temp of 11C the surface struggled to 14C. The front depressed the temps in all the far west regions and N.Ireland and Scotland.

Looks not unlike the profile in this part of the world much of last week. One major difference the surface T was bout 6-8 C lower than shown on the one above.

[Man With Beard]

Arome tomorrow has the heat much more concentrated on the SE corner. 26/27C for London, 22-25C from Hampshire across to Essex, not reaching 20C north or west of Birmingham

[knocker]

The decaying front is still affecting parts of the UK and N. Ireland and Scotland are in a different WSW airstream. The MODIS 1050 UTC high res.illustrates this as does some various temps for same time.

Heathrow 22C

Gatwick 23C

Blackpool airport 10C

Valley 8C

Culdrose 14C

Kinloss 15C

Prestwick 12C

Belfast 12C

[knocker]

Another warm day for most tomorrow but thundery showers tracking north east late afternoon and evening.

[ANYWEATHER]

Evening! Interesting for the Low on Friday, Big differences between ecm and gfs ,ecms low much further south than the gfs ....Watch this space....!

[carinthian]

Weird looking Infa Red image currently out in Mid- Atlantic. Looks like Concorde making a welcome homeward return North Atlantic crossing.

C

[ANYWEATHER]

Evening ,the gfs brings a drenching for southern Britain  on Friday along with some gusty winds and feeling cold, thereafter ,Saturday looks quieter in a slack weather pattern but some slow moving thunderstorms, Air frosts possible overnight into Sunday morning ,not good news for growers and gardners

[knocker]

Last night's NOAA and this morning's GEFS and EPS medium term anomalies indicate quite an amplified pattern.

Upstream low pressure over the Arctic, ridging western North America and a quite intense vortex northern Canada with associated trough negatively inclined across Iceland/UK/ western Europe all the way down to north Africa, This trough complimented by high pressure in south east Europe ridging north west through Scandinavia.

Thus, although there is quite a strong westerly upper flow leaving North America south of the vortex, and around the Atlantic high pressure, it hits the buffers in the eastern Atlantic when it meets the aforementioned trough/ridge axis.and diverges tending to leave the UK in a weak W/SW upper flow. This portends a quite complex and slow moving evolution dominated by a slack low pressure area in the vicinity of the UK, thus changeable weather, with temps a little below average but perhaps creeping up towards the end of the period as the trough weakens. As always the det. runs will need to sort the details of all of this.

[knocker]

The 0900 geostationary (courtesy Dundee Satellite Receiving Station) showing copious showers over the north west, N.Ireland and Scotland and the low revving up to the southwest.

Which develops through today and overnight to be 995mb over Cornwall by 1200 tomorrow.

[knocker]

Interesting to note that the METO have issued a heavy rain warning for East Anglia and SE England Sunday evening through Monday.

Saturday midday there is a neutrally aligned upper trough just to the west of the UK coming under some pressure from the Bermuda high ridging to the west. Thus on the surface the UK in a very slack gradient with low pressure concentrated to the south.

The trough comes under further pressure over the next 24 hours and starts to realign south of the UK thus the surface low and associated fronts become more organized and start tracking NE though France.into the southern North Sea.

This realigning of the upper trough and development of the Surface low continues through Monday

Obviously what is crucial here is the precise track of the low and fronts and in view of the warning may well be close enough. I'll post yesterday evening's fax charts but again obviously need to see today's updates.

 

[knocker]

Many showers on the 1200 high res. MODIS and cloud from the system to the south west fast approaching.

[knocker]

Rain from the system approaching from the west should reach Cornwall by early evening and Cs and Ci is already encroaching with the Cu being damped down and moister air aloft on the 1200 sounding.

Whilst showers will continue in the north rain will spread east overnight and through tomorrow, reaching as far north as the around Manchester, before clearing into the North Sea.

Edited April 26, 2018 by knocker

[knocker]

Given the time frame involved there are major differences between the gfs and ecm vis the low and associated precipitation moving north over Sunday/Monday with the ecm keeping both closer to the east coast.

The rain hasn't started here just yet but it will not be long with thickening As

[knocker]

Today

A very wet day for England and Wales as the low and associated fronts tractkeast across southern England before clearing into the North Sea later tonight. Elsewhere across N. Ireland and Scotland, and even northern England isolated showers, perhaps thundery.

Saturday

Cloudy and quite cool across central and eastern England with patchy rain whilst brighter elsewhere with isolated showers in the light winds. The neutrally aligned upper trough to the west stretching a fair way south and is about to play an important role over the next couple of days.

Sunday

A generally dry day but the upper trough is being realigned as it comes under pressure from the high pressure ridging to the west and the block to the east and it spawns a surface low over France which is becoming a major feature by 1800.and is developing rapidly as it moves north into the North Sea. The key here is how far west will it track as it is accompanied by heavy rain and quite likely northerly gales.

Similar theme through Monday before the low moves east so certainly quite a cool and wet period for eastern and south eastern areas with even the possibility of some snow on the higher ground in the south. But just to repeat this is according to the gfs and there is still some uncertainty about how far west it will track

Edited April 27, 2018 by knocker

[knocker]

Satellite 0530 UTC

[knocker]

Continuing uncertainty with the track of the low Monday with the ecm keeping central Channel longer and the front running straight up the country.

Nice 0600 UTC geostationary

 

[johnholmes]

2 hours ago, knocker said:

Today

A very wet day for England and Wales as the low and associated fronts tractkeast across southern England before clearing into the North Sea later tonight. Elsewhere across N. Ireland and Scotland, and even northern England isolated showers, perhaps thundery.

Saturday

Cloudy and quite cool across central and eastern England with patchy rain whilst brighter elsewhere with isolated showers in the light winds. The neutrally aligned upper trough to the west stretching a fair way south and is about to play an important role over the next couple of days.

Sunday

A generally dry day but the upper trough is being realigned as it comes under pressure from the high pressure ridging to the west and the block to the east and it spawns a surface low over France which is becoming a major feature by 1800.and is developing rapidly as it moves north into the North Sea. The key here is how far west will it track as it is accompanied by heavy rain and quite likely northerly gales.

Similar theme through Monday before the low moves east so certainly quite a cool and wet period for eastern and south eastern areas with even the possibility of some snow on the higher ground in the south. But just to repeat this is according to the gfs and there is still some uncertainty about how far west it will track

What a wonderful looking set of charts for Monday rain and strong winds-hello spring!

[knocker]

25 minutes ago, johnholmes said:

What a wonderful looking set of charts for Monday rain and strong winds-hello spring!

I know and the medium term outlook doesn't exactly fill one with optimism either.

[mb018538]

11 minutes ago, knocker said:

I know and the medium term outlook doesn't exactly fill one with optimism either.

How so? GFS, ECM and GEM all show high pressure building in by next Friday. Looks optimistic to me!

[knocker]

Rather depends how you define 'building'. To me it still appears that there is too much energy being generated from the vortex east bound to allow any sustainable high pressure so it looks much like a continuation of changeable but tending towards a N/S split as the different airmasses phase. Just my opinion of course.

Edited April 27, 2018 by knocker

[mb018538]

That could very well be right. We will have to wait and see....anything better than the tripe we are being served up today, this weekend and into Monday is good with me!

[knocker]

7 minutes ago, mb018538 said:

That could very well be right. We will have to wait and see....anything better than the tripe we are being served up today, this weekend and into Monday is good with me!

Well that wouldn't be difficult, the 0900 geostationary

.

[knocker]

The high res. MODIS (courtesy DSRS) at 1100 UTC. We have some sort f clearance down here, near the center of the low, with a lot of large Cu,

[chrisbell-nottheweatherman]

2 hours ago, knocker said:

Rather depends how you define 'building'. To me it still appears that there is too much energy being generated from the vortex east bound to allow any sustainable high pressure so it looks much like a continuation of changeable but tending towards a N/S split as the different airmasses phase. Just my opinion of course.

That was my reaction on seeing the outputs the poster to whom you're replying posted; classic N/S divide in terms of ppn. and temperature.

Edited April 27, 2018 by chrisbell-nottheweatherman