Models, teleconnections and nowcasting

[knocker]

And later in the week a lobe of the vortex drops down near Iceland > tight thermal gradient > rapid cylclogenisis > 929mb surface low

[knocker]

Which ever way you hack this it's a very impressive jet running south of the upper trough and driving the cyclogenisis north east

[knocker]

And quite a cold lower strat

[knocker]

The frontal rain, which will be quite heavy at times, is steadily moving north east up the country today with much clearer weather behind. But over the next 42 hours it never really clears Scotland as the low associated with this tracks north to be south of Iceland and then fills as it drifts back south east towards Scotland. All of this results in strong winds with gales here on Monday with heavy showers of snow on the high ground

From this point events upstream that have been discussed on previous occasions quickly evolve and by midday Thursday a lobe of the tpv is over the tip of Greenland and the UK ridge is under pressure.

From here, and over the weekend, it will be windy and unsettled courtesy of the intent tpv lobe now over Iceland creating a squeeze with the subtropical high and thus a jet  across the Atlantic touching 200kts

Edited February 2, 2020 by knocker

[knocker]

A quick look at the changing structure and intensity of the tpv, and the Aleutian ridge, over the 15 day period of the GEFS 500mb gph

 

Edited February 2, 2020 by knocker

[knocker]

The gfs and ecm det runs diverge quite sharply this morning regarding upstream developments and the tpv lobe over Iceland, starting as early as t96

A comparison at t120, 144

So sticking with the ecm, still unsettled but more of a N/S divide

Edited February 2, 2020 by knocker

[knocker]

The ext mean anomalies all agree on a strong Aleutian ridge with the main tpv lobe over northern Canada although differing on the general structure of the latter vis in the Greenland/Iceland area. Thus although the indications are of an unsettled period the detail awaits some firming up

 

[knocker]

Not a very pleasant day tomorrow over Scotland and N/Ireland and NW England according to the latet fax for 06 and the 0600 ecm run

And wrf

Edited February 2, 2020 by knocker

[knocker]

Interestingly there still appears to be a frontal surface on the Camborne midday sounding

[knocker]

No surprises with the still very impressive jet and hopefully nothing too nasty gets cooked up in the active baroclinic zone that effects the UK

 

[knocker]

As we are all aware a lobe of the tpv is forecast to drop down and develop intensely at the end of the week in the Denmark Straits area and this requires some vigilance as this creates a very active baroclinic zone in the western Atlantic resulting in some rapid cyclogenisis that could adversely effect the UK The position at 1200 Saturday according to this morning's gfs.

And running trough the weekend these are the developments  The detail certainly isn't set in stone as in this pattern changes can occur very quickly and in any case the ecm could well be different

Edited February 3, 2020 by knocker

[knocker]

Meanwhile back in the here and now some very wintry weather over Scotland, and to a lesser extent, N. Ireland and the NW of England today as the low to the NW drifts south east.

Heavy squally showers are currently effecting western Scotland and these will spread east and south during today and this evening, turning increasingly to snow to quite low levels. Rain will also spread east effecting the SW and southern coastal areas of England

But the main feature of today will be the very strong winds effecting northern Scotland which will result in blizzard conditions if/when any heavy showers coalesce

 

Edited February 3, 2020 by knocker

[knocker]

And the ecm take on next weekend

Edited February 3, 2020 by knocker

[knocker]

The NH profile of the ext anomalies this morning is pretty consistent across the board albeit, not surprisingly, the tpv alignment shows a little less intensity. Nevertheless it still dominates the North Atlantic portending a period of unsettled weather

Edited February 3, 2020 by knocker

[knocker]

0900

 

[knocker]

This week

Tuesday

After a windy and showery start, particularly in the north. things will start to improve as the high cell edges east

Wednesday

high cell dominating thus sunny intervals after a morning frost and patchy fog

Thursday

High cell still in charge but sliding east as pressure mounts in the west

And by Friday the pressure is starting to take it's toll

 

[knocker]

A lot of rain in the south west from the weakening cold front, possibly augmented by the waving front to the south

[knocker]

The developments involving the intense upper trough in the Greenland /Iceland area > the cylogenisis south in the Atlantic and the surface analysis over the weekend according to the gfs

 

[knocker]

The very impressive vortex lobe at t144 with 500mb height down to 4770m near SW Iceland  and 130kts on the southern flank

[knocker]

The ext EPS mean anomaly this evening has increasing amplification in the eastern Pacific/North America resulting some realigning  of the tpv which doesn't do the UK many favours, Still a very strong westerly upper flow across the Atlantic indicating a quite windy and unsettled period

 

Edited February 3, 2020 by knocker

[knocker]

[knocker]

The North Atlantic 500mb and surface analysis for midnight

Today sees the transition to a few days of drier, calmer and brighter weather as a ridge moves east across the UK. But currently still quite a few showers mainly effecting western Scotland in the strong NW wind and some will spread a little further south through the morning but later tending to fizzle out as the wind abates..But taking the wind into account quite a chilly day

Weds and Thursday mainly fine with sunny intervals but cloudier over the north with some showers courtesy of a couple of stray fronts

But by Friday an upper trough, centred over the Denmark Straits has tracked east across the Atlantic and the surface fronts will bring rain to western parts of the UK through the afternoon and evening

The rain tracks east across the country Friday night and through Saturday but further cyclogenisis has taken place in the Atlantic and rain from the next fronts effects N. Ireland by the evening

 

Edited February 4, 2020 by knocker

[knocker]

But over the weekend the much discussed intense lobe of the tpv has developed in the Iceland area so there is now a very strong jet running across the Atlantic and SW > NE across the UK

Thus Sunday and Monday two very windy days with frequent heavy and squally showers which could well be wintry on Monday which will be a much colder day. All this according to the gfs

At around this time the gfs spawns a low at the base of the upper trough centred over the Labrador Straits (a little different to yesterday) and over the next 24 hours it undergoes rapid cyclogenisis as it tracks rapidly east. Jus a watching brief at the moment

 

 

Edited February 4, 2020 by knocker

[knocker]

The ecm has the orientation of the tpy lobe and associated troughs somewhat different to the gfs and thus the handling of the low which, according to the ecm, develops further south towards the Carolinas before tracking north east. As previously stated a watching brief at the moment

[knocker]

And some light at the end of the tunnel

Edited February 4, 2020 by knocker