Short range model discussion - into 2018

[knocker]

Foehn Effect norh east Scotland tomorrow

[knocker]

Today a west/east split south of the Scottish border In the west a dying front is lingering so tending to cloudy  with the odd spot of drizzle/ rain and some low cloud around the coasts. To the east more in the way of sunshine although some cloud may encroach during the day. N. Ireland cloudy with some drizzle maybe brighter later whilst the west of Scotland will probably get the worst of the rain. But the north east will be quite warm. I suspect these temps may be under cooked for Aberdeenshire as the METO are suggesting 20C.

So on to the bank Holiday. There is a grave danger of repetition here so will try to keep this brief. Overall about as good as would could expect but there is still very much a NW/SW drift with the evolving analysis with the clearer skies and warmer temps in the south and east compared to the north west where patchy rain and drizzle may linger, and to some extent the west which could well see more cloud. But overall not bad.

Saturday

The active front lying just west of the Western Isles

Sunday

The front still lingering over north west Scotland as the wave on it moves north east. The rest of the Uk in the ridge stretching from the high in the north east.

Monday

Some changes are afoot by now with another upper trough ejected from the Canadian/Greenland trough complex and by midday the surface low associated with this and associated fronts are  tracking east in mid Atlantic whilst at the same time the old  front is lingering over Scotland.

It has been noted on previous anomaly charts that westerly upper flow will tend to back rather abruptly in the vicinity of the UK courtesy of the block to the east and thus systems tracking east will tend to do the same and turn north east and this appears to be the case on Tuesday with out Atlantic low, albeit the fronts do affect the WN/W of the UK illustrating a clear case of the split.

 

 

Edited May 4, 2018 by knocker

[knocker]

This above

There is a grave danger of repetition here so will try to keep this brief. Overall about as good as would could expect but there is still very much a NW/SW drift with the evolving analysis

Should of course read

There is a grave danger of repetition here so will try to keep this brief. Overall about as good as would could expect but there is still very much a NW/SE drift with the evolving analysis

Won't be long now knocker

Onwards and upwards the 0600 geostationary (courtesy DSRS)

 

[knocker]

As always with these energy east bound/blocking scenarios it inevitable poses the problem how far east will the systems travel before diverging? Not that far according to the ecm this morning vis the first attempt but it needs to be watched as further incursions could well produce some very wet and windy conditions in the north west.

Edited May 4, 2018 by knocker

[knocker]

0600 fax chart ans 0800 surface analysis.

[knocker]

he 0900 UTC geostationary

[knocker]

Nice 1200 UTC high res. MODIS (courtesy DSRS) and 1200 surface chart. I see the temp was 19C at Dyce

[knocker]

Just out of interest the updated WRK's stab at temps tomorrow. Noticeable quite a split down to different airflows and probably cloud cover

 

Edited May 4, 2018 by knocker

[knocker]

The 1500 geostationary. The cloud hung around all day here underneath this inversion. 850mb temp +9.7C and surface +10.4C

Edited May 4, 2018 by knocker

[knocker]

Today

A dry sunny start to the holiday weekend for most areas but with fronts lingering to the west so more cloud is possible with patchy rain in the northwest. Mist and low cloud quite likely in western and coastal areas as well so temps depressed somewhat.

Overnight a similar scenario with patchy rain persisting in western Scotland and mist and low cloud around western coasts with clear skies elsewhere.

.

Sunday

The wave that can be seen away to the south west on the 00 fax chart tracks north east to be  just west of the Hebrides at midday so again patchy rain and cooler conditions for the north west of Scotland whilst elsewhere plenty of warm sunshine apart from some coastal areas where mist and fog may well persist

Monday

Still a  very slack gradient over most of the UK under the influence of the ridge so another sunny and very warm day for most areas, particularly the south east (I take no responsibility for model temps which are I suspect under cooked by two or three degrees in places) the exception once again being Scotland where a front is lingering. But changes are afoot with an upper low ejected from the Canada/Greenland trough complex into the Atlantic with the associated surface low in mid Atlantic on it's travels east.

Overnight and through Tuesday the low tracks quite sharply NE/N courtesy of the block to the east but the associated fronts do partly traverse the UK bringing patchy rain and cooler conditions to the west with the east and southeast remaining very warm and sunny. But the aforementioned trough factory is in full production now and another intense upper low is on it's way east and this has spawned an nasty surface low of 965mb by 00 Wednesday. This is of course according to the gfs.

On Wednesday this low also curves north east, albeit slightly further east than the previous one, but the associated fronts also partly cross the country bringing rain, sometimes heavy along with strengthening winds,  and cooler conditions to the west and inland as they progress east. This could well initiate some thundery activity in the east.

 

Edited May 5, 2018 by knocker

[knocker]

Satellite at 0530 UTC, Thick fog down here at the moment

[knocker]

The 0600 geostationary (courtesy DSRS)

[knocker]

The ecm is broadly similar to the gfs

[knocker]

The 0600 analysis

Edited May 5, 2018 by knocker

[knocker]

Interesting high res. MODIS at 1200 UTC ( courtesy DSRS) showing the frontal cloud over NW Scotland, sea fog around the coasts and the cloud and fog along the north Cornwall and Devon coasts which so far has failed to lift here despite a couple of promising attempts.

[knocker]

Still stuck with fog here under this inversion with the surface temp just 0.5C higher than the 850mb. Exeter has 20C

[johnholmes]

31 minutes ago, knocker said:

Still stuck with fog here under this inversion with the surface temp just 0.5C higher than the 850mb. Exeter has 20C

Your situation today reminds me of N Sea St for days on end here

[knocker]

21 minutes ago, johnholmes said:

Your situation today reminds me of N Sea St for days on end here

Yes there is a certain similarity and I have a bad feeling it may be the same tomorrow. Perhaps it might be worth going down to the south coast

The 1500 geo.

[knocker]

Come Tuesday and the breakdown of the fine weather sees the complex upper trough dominating the Atlantic with surface depressions sweeping east on twin jets which merge in mid Atlantic before curving north east as they hit the block to the east. But the associated fronts do push slowly across the country bringing patchy rain along the way and the possibility of some thundery outbreaks in the east.

[knocker]

Today will be not dissimilar to yesterday with most areas having plenty of sunshine in light winds but temps will be a couple of degrees warmer. The exceptions again being north west Scotland which continues to experience patchy rain from adjacent frontal activity and western coastal areas where sea fog is again liable to be persistent. Yesterday the max at Camborne and Valley were 12C and 11.8C respectively

.

Tomorrow again not a dissimilar scenario but temps warmer again, in the 27-28C range in the south east and possibly the sea fog either much thinner and not so widespread.

But as discussed in previous posts the complex upper trough and associated surface depressions are stating to dominate the Atlantic and by 00 Tuesday the first low is curving NE/N to the west of the UK courtesy of the block to the east but the associated fronts do traverse the country through Tuesday bringing some wet and windy weather to the west and north west with the south east staying relatively dry and still quite warm. Whilst this low tracks north of Iceland the next deep low has arrived west of Ireland

This low follows a similar track to the previous one and also curves north east but the front crosses the country on Wednesday bringing more showery rain and generally cooler conditions.

The gfs appears to have gone walk about this morning.

 

Edited May 6, 2018 by knocker

[knocker]

The 0600 geostationary (courtesy DSRS) I can confirm thick fog here and very warm air aloft with the 500mb temp only -13.5C

[knocker]

Following on from the previous post the ecm has another low quickly following the first two which deepens rapidly to 956mb and is liable to bring very wet and windy conditions to the north and west towards the end of the week. The anomaly chart illustrates very well the influence of the deep and large upper trough and the block to the north east.

[knocker]

The 1200 UTC geostationary.

The sea fog actually cleared here quickly this morning but I understand it was still over Portreath at midday.

[knocker]

Cracking high res. MODIS at 1245 UTC

[knocker]

Tomorrow another similar day to today with temps a tad higher with the south east 28C possibly a 29C but generally in the low and mid 20s in England and Wales. The exception being north west Scotland although there the decaying front not anywhere as influential as it has been over the last couple of days. The sea fog may well not inundate western coasts quite as much either but sea breezes elsewhere may kick depressing coastal temps.

Overnight Monday and through Tuesday the front(s) associated to the low to the west which is curving north will push slowly east into the western half of the UK bringing some patchy and cooler temps with the east/south east staying quite warm. Always a chance of some thundery outbreaks here.

The front tends to linger and decay over the UK on Wednesday so generally a cloudy and cooler day but to the west the occlusion associated with the next low curving north to the west is already impacting Ireland.

 

Edited May 6, 2018 by knocker