Models, teleconnections and nowcasting

[knocker]

For the rest of this week the UK remains under the influence of the filling low. currently quite a deep affair west of Ireland,

as it tracks north east to be in the North Sea by midday Saturday So continuing unsettled, albeit much milder, although by Saturday the patchy rain confined to the north

But as one low moves away then another arrives from the south west and the associated frontal system will track north east across the country Saturday night through Sunday accompanied by heavy rain and strengthening winds

By Monday the low is centred near stornoway so a breezy day with rain in the north and perhaps the far south

 

 

Edited January 30, 2020 by knocker

[knocker]

There are still major differences between the gfs and ecm midday Tuesday regarding the trough in the western Atlantic and the downstream amplification

So for a brief appraisal of next week I'll stick with the ecm

Edited January 30, 2020 by knocker

[knocker]

As the ext anomalies have been indicating recently the restructuring of the tpv prior, and during this period,kooks like leading to a zonal Atlantic and the demise of any subtropical amplification, albeit some slight variation on the remaining influence in this area. Thus a much more unsettled outlook

 

[Jordan S]

Wind gusts have already been high over the mountains of Scotland this morning very strong winds will develop widely from midday into the afternoon gusts of around 40-50mph are likely for many parts of Scotland but some areas on hills and coasts possibly seeing gusts of 60-70mph, Very strong winds also developing for parts of the pennines through this afternoon lasting into this evening with gusts of 60-80mph likely. 

[knocker]

According to the gfs the movement of the east coast storm and subsequent trough development in the western Atlantic and the downstream amplification

But by midweek there is a lot of energy exiting the eastern seaboard crossing the Atlantic south of the Greenland trough putting the ridge under pressure ( Note the cold plunge over Europe courtesy of the tpv lobe )

 

[knocker]

We know from earlier runs that the restructuring/realignment of the tpv will likely lead to a strong zonal upper flow and this evening's GEFS mean anomalies highlight this in spades

Edited January 30, 2020 by knocker

[Always a red]

4 minutes ago, knocker said:

We know from earlier runs that the restructuring/realignment of the tpv will likely lead to a strong zonal upper flow and this evening's GEFS mean anomalies highlight this in spades

Beautiful, so beautiful...….

[knocker]

The strength of the jet exiting NE North America continues to question how long much of the country can hang on to high pressure next week

And is that where we want a lobe of the spv?

Edited January 30, 2020 by knocker

[knocker]

Over today and tonight the deep low to the wet of Ireland will track north east, fill, and lose it's identity by midday Saturday. Thus not a bad day for many with rain still across the north and the far south

But by Sunday another low is tracking north east and the associated fronts will bring rain and strengthening winds to most areas

By midday Monday the low is centred near the Hebrides so wet and windy in the north with showers in the blustery westerly airstream elsewhere. but note the much mentioned storm over the NE North America has arrived with downstream amplification under way

This continues over Tuesday as the ridge moves east the surface wind will veer northerly with some wintry showers in the north and along the east coast

 

Edited January 31, 2020 by knocker

[knocker]

Continuing through the week with the ecm which essentially is the high pressure battling against the considerable amount of energy exiting NE North America south of the trough in the NW Atlantic and not winning

 

 

Edited January 31, 2020 by knocker

[knocker]

A quick glance at the mean 5-10 det outputs more or less sums it up

 

[knocker]

A quick look at the EC weeklies update for the last week of Feb and the first of March

22 > 29

Aleutian ridge with the main tpv lobe northern Canada with associated troughs eastern NA and the NW Atlantic

A strong westerly upper flow exiting the eastern seaboard but abating a tad in the east as the European subtropical high is still quite influential with some positive anomalies.

Probably indicating a N/S split for the UK regarding changeable weather

01 > 08

Upstream everything a tad less intense leading to a retraction of the NW Atlantic trough allowing the subtropical high in the east to gain more traction and thus possibly a more settled period for much of the UK

 

 

Edited January 31, 2020 by knocker

[knocker]

This morning's ext mean anomalies. Previous comments should suffice

Edited January 31, 2020 by knocker

[knocker]

The much mentioned NE coast storm

[knocker]

A photo from 1939

Remember the nifty slide rule to do the calculations @johnholmes

[knocker]

Not suggesting for one moment it will pan out like this but:-

Intense upper trough in the NW Atlantic > very tight thermal gradient > breeding ground for rapid cyclogenisis > Iceland in the firing lineagain

Edited January 31, 2020 by knocker

[phil nw.]

7 minutes ago, knocker said:

Not suggesting for one moment it will pan out like this but:-

Intense upper trough in the NW Atlantic > very tight thermal gradient > breeding ground for rapid cyclogenisis > Iceland in the firing lineagain

It's relentless isn't it Malcoln. 

The jet firing up again with the sub tropical heights being flattened. 

[knocker]

21 minutes ago, phil nw. said:

It's relentless isn't it Malcoln. 

The jet firing up again with the sub tropical heights being flattened. 

I'm always wary of these scenarios Phil.....you never know what they may cough up

[knocker]

The low associated with the fronts that bring the rain on Sunday then drifts east to being some quite inclement weather to Scotland Monday/Tues

From this point the amplification takes place and the battle against the energy as the ridge moves. For now I'll skip the detail of this just to note the strength of the jet, 200kts, next Saturday on this evening's ecm

[knocker]

A reforming vortex in a lousy position

Edited January 31, 2020 by knocker

[knocker]

The North Atlantic 500mb and surface analysis for midnight

The low NW of Ireland is filling rapidly and losing it's identity but the heavy showery rain rain currently over western Scotland and N. Ireland will move south east through today but tending to fizzle out as it goes. Some heavy showers will follow in it's wake over NW areas. Further south cloudy with sunny intervals with perhaps some rain touching the south coast.

But another low is tracking up from the south west and the associated frontal system will bring rain into Cornwall by 2200 this evening which will continue north east through the night

and through Sunday, clearing everywhere except Scotland and N. Ireland where the heavy rain will persist with strengthening winds as the low continues to track NNE. Note the marked N/S temp difference

Over Sunday night and through Monday the low continues to deepen and track north and with a trough embedded in the circulation this results in a very wet and windy day for Scotland with gales in the west. Elsewhere breezy with sunny intervals

By Tuesday the low has finally cleared away but out to the west the west coast storm and upper trough have initiated downstream amplification resulting in the wind veering over the UK and thus cooler temps with showers down coastal regions and the north where they could be wintry

By Wednesday the high is cenred over NW France but coming under pressure from the west but at least a much better day after morning frost

Edited February 1, 2020 by knocker

[knocker]

According to the gfs the next five days are dominated by the intensification of the tpv in the area norther Canada > Greenland > Iceland resulting in some very active cyclogenisis in the baroclinic zone to the south in the Atlantic bringing the UK ridge under continuous pressure

Not to get too wrapped up with detail at this stage in this volatile environment but some charts (not to be taken as gospel) to illustrate this

 

[knocker]

The ecm in the same ball park but with a different orientation of the main lobe to the NW, thus variation in detail. As a overview unsettled with a marked N/S split

Edited February 1, 2020 by knocker

[knocker]

By way of some variation the structural changes of the tpv over the 15 day period using the EPS NH 500mb geopotential height charts ending with an unsettled outlook

 

[knocker]

Quite windy across Scotland on Monday with some snow on the higher ground