Short range model discussion - into 2018

[knocker]

I think today has been adequately covered so just posting a couple of fax charts and fingers crossed the sea fog remains just that. Just to note vis that as the fog rolled in again last night there was a 7.5C inversion from just above the surface to around 2,000ft. But I digress

Overnight clear skies for most but the fog may well return along western coasts but by 0600 rain from the front(s) associated with the low to west is already impacting N. Ireland and the Western Isles

Through the day this rain band will move slowly east bringing showers and cooler conditions in it's wake whilst the east/south east remains warm still, However there is the probability of thundery activity breaking out in these areas later in the day.

Wednesday  generally a cooler and cloudy day as the front lingers but by 1200 front(s) associated with next Atlantic depression, that is curving north south of Iceland, are already bringing rain and freshening winds to N. Ireland and western areas of the UK, This light patchy rain will move slowly east during the day although not encroaching as far as the far east where it will remain quite warm

The front has decayed by Thursday leaving a brief interlude with some weak transient ridging with scattered showers and generally a cooler day.

By 1200 Friday quite an intense upper low is situated south of Iceland and the cold front associated with the surface low is orientated western Scotland/Ireland  The patchy rain associated with this will struggle east through Friday but again the east and south east tending to remain dry although some thundery outbreaks may occur later in the day. The battle against the block to the east is on going

 

 

 

Edited May 7, 2018 by knocker

[knocker]

Satellite at 0509 URC. Currently thick fog here

 

[knocker]

The 0600 geostationary (courtesy DSRS). No surprises there

[knocker]

The ecm has the end of the week low starting to form at the base of the upper trough away to the WSW at T72 and deepens it rapidly over the next 24 hours as it tracks north east and then north before slowly filling. As previously mentioned the associated front will struggle east Friday/Saturday

[knocker]

Another excellent high res. MODIS at 1140 UTC (courtesy DSRS) showing the sea fog on western coasts and also eastern coasts (sea breeze?) and the decaying front still affecting N. Ireland and northern Scotland

Edited May 7, 2018 by knocker

[knocker]

After a very warm day for most, this evening and overnight will continue to be clear and quite mild, apart from western coastal areas where the sea fog that has been around all day, will ingress further inland so much cooler in these areas  But by 0600 a band of rain associated with the front(s) approaching from the west will be over N. Ireland and western Scotland and this patchy rain will struggle slowly east during the day but will not stop another fine and warm day in these areas, albeit a distinct chance of some thundery convection bubbling up during the afternoon.

Edited May 7, 2018 by knocker

[knocker]

The 1800 geostationary showing the systems to the west that are slowly going to become more influential and the continuing sea fog along western coasts.

[knocker]

The EPS disruption of the trough in theT96-120 range with the Bermuda high amplifying, and intensifying heights to the north east, has the potential to create yet another cut off low to the south and again a divergent upper flow in the eastern Atlantic with slack pressure over most of the UK.

Edited May 7, 2018 by knocker

[knocker]

Very much an weest/east split today with the band of frontal rain, currently over Ireland and nudging the Western Isles, will struggle slowly east decaying somewhat as it goes leaving a cooler showery regime in it's wake. But the east/south east will remain in the sunnier and warmer air with temps again much above average and even the possibility of some thundery showers bubbling up later in the day.

Any rain will clear into the North Sea by evening leaving a clear and cooler night for most with a clear start to Wednesday morning.

But through Weds a deep depression is tracking north east south of Iceland and it's associated front(s) bring some heavy rain and strengthening winds to the western half of the UK accompanied by much cooler conditions but the the east will remain dry with quite a pleasant day.

The weakening front soon clears overnight Weds with the UK under the the influence of a weak transient ridge on Thursday and essentially a sunshine and showers day with temps back generally to around normal But out in mid Atlantic the intense upper trough has spawned another surface surface low but despite a lot of energy exiting south of the Canadian vortex/trough complex tending to fight a losing battle against the block to the north east.

But by 1200 Friday the front associated with the aforementioned depression does make some headway east and after a bright start a band of rain will traverse the country clearing the east early Saturday morning leaving sunshine for most but quite probably frequent showers.

What happens after this is perhaps key to the immediate evolution.

 

Edited May 8, 2018 by knocker

[knocker]

Satellite at 0500 UTC

Edited May 8, 2018 by knocker

[knocker]

The rising sun on the 0600 geostationary (courtesy DSRS)  silhouetting the systems to our west

[knocker]

What happens post t96-120 still appears to be quite important with the block creeping west north of the UK and a lot of energy still exiting North America and the high pressure attempting to amplify in mid Atlantic. Place your bets

[knocker]

Last night's NOAA and this morning's GEFS and EPS anomalies continue a similar trend in the medium term.

The key players are the Hudson Bay vortex and associates trough orientated south east into the Atlantic and the the high pressure to the east of the UK which is ridging through northern Scandinavia into the Arctic.

How they precisely orientate is crucial as the trough appears to want to retrogress and deconstruct to some extent so that the strong westerly upper flow will diverge in the eastern Atlantic leaving the UK at the sharp end of some possible interesting synoptics, such as the Azores ridging NE or much of the UK in a very slack gradient col conditions, which the det. runs will need to get their teeth into and sort the details. Temps generally will be around average.

[knocker]

The 1200 UTC geostationary and I can firms that the front is through here with plenty of sunshine and some wispy Ci.

And Sidney is out and about weighing up the options

[knocker]

The 1200 chart illustrates the west/east split

[knocker]

[knocker]

Once any showers in the east clear into the North Sea it will generally be a clear and dry night, albeit cooler than of late, and starting tomorrow but by 0900 frontal rain approaching from the west will already have reached Ireland and the western Isles and this will track east during the day although the east should stay dry, certainly until late. and quite pleasant although temps will be down from the recent highs.

[knocker]

The 1800 geostationary highlighting the very large low that has bombed into mid Atlantic

[knocker]

An example tonight on how resilient this block is at the moment. Both the gfs and ecm have the trough deconstructing to the west as the Atlantic ridge amplifies towards the westward spreading eastern block. But the cut off upper low has nowhere to go cocooned as it is by the high pressure and the jet is forced to track sharply north over the UK

Edited May 8, 2018 by knocker

[knocker]

After a relatively cool night today will dawn quite dry and bright in most places but frontal rain will ingress N. Ireland and the Western Isles by 0900 and will slowly cross the country during the day and evening. Thus most of the eastern half will remain dry and pleasant with temps still above average before the rain arrives and clears unto the North Sea by Thursday morning.

So once rain has cleared Thursday wil generally be a dry and sunny day with showers, more frequent in the north, as a transient ridge becomes briefly influential, witrh temps back to around average.

But by Friday the battle between the eastbound energy exiting North America and the block gets underway in earnest with the block to the east unrelenting and the Bermuda high amplifying in the Atlantic deconstructing the trough. Thus the surface low south of Iceland is almost stationary as the associated front struggles to push east across Ireland in the gently southerly flow over the UK. So again the eastern half of the UK remaining dry and generally temps still around average.

The front eventually clears into the North Sea early Saturday and as the low south of Iceland slides SSE and loses it's identity all is pretty quiet over the UK with sunshine and showers, probably more frequent in the west with the odd trough popping up, with temps still around average.

And thus by 00 Monday we are left with this intriguing position vis the battle between the energy and the block

 

 

[knocker]

Satellite at 0445 UTC

[knocker]

Very nice geostationary at 0600 UTC this morning (courtesy DSRS) showing the deep depression at 25W and frontal structures approaching the UK

[knocker]

The ecm has the filling low sliding down west of Ireland Saturday with slack low low pressure over the UK with the front slow to clear East Anglia on Saturday. Quite interesting how this morning's runs are migrating the Scandinavian ridge.

 

[knocker]

Quite impressive WAA through Scandinavia into the arctic

[knocker]

Brilliant high res. MODIS at 1130 UTC (courtesy Dundee Satellite Receiving Station)