Short range model discussion - into 2018

[knocker]

The high res. MODIS at 1145 UTC. There is a lot of showery activity over N. Ireland currently

[mb018538]

Next Tuesday potentially looking quite toasty now - quite a wide area into the mid and higher 20s. Let's see how long into the week it can hold on for. Perhaps a bit of eastern revenge for all the filth coastal areas have had to endure for weeks!

[knocker]

Another high res. MODIS at 1330 UTC (courtesy DSRS)

Still convective activity over N. Ireland. Here we have a lot of quite interest Ci, indicated to some extent on the midday sounding. Earlier there was some convective build up but this has dissipated, not surprisingly again looking the sounding.

[knocker]

I'm having a quick early look at tomorrow as I've an early start on a day trip to Coleton Fishacre.

A pretty clear night for most but by 0300 the occlusion and rain associated with the low NW of Ireland is into Ireland. This will track east during the day but by far the heaviest concentration of the rain will be north of the Midlands into central Scotland with it tending to light and patchy, before filtering out, further south. And it will quite quickly clear the south west and Wales during the morning. Fine and sunny with maybe some showers in the wake of the front and feeling a tad fresher than of late

[knocker]

The precise analysis by the ecm on Tues/Weds results in a very marked N/S temp differential.

On Tuesday a low tracks very quickly north east across N. Ireland and Scotland bringing rain and quite fresh winds whilst most of England and Wales remain south of the front with markedly higher temps.

By Weds the Azores has ridged in but the orientation is such that this also leads to marked N/S difference albeit the very warm temps are confined to the far south.

[knocker]

A band of showery rain associated with the low north west of Ireland is currently over N. Ireland and Wales.

This will track east through the day with the heaviest outbreaks over N. Ireland, northern England and Scotland. Further south it will be lighter and patchy fizzling out to just cloud as it arrives further east. Clearer weather behind the front will reach the south west later this morning, eventually spreading to all areas but accompanied by heavy showers, particularly in the north. Temps down a bit from late and certainly a fresher feel to the air

Quite a clear night and start to the day on Sunday but the next low is approaching to the north west and the associated fronts bring cloud and light rain/drizzle to western parts by lunchtime. Further east it will remain dry but cloudy albeit perhaps a tad warmer than today.

By Monday it's worth looking once again at the overall picture as this really indicates the direction of travel of the evolution. With the major upper trough to the north west extending south in the western Atlantic we have the classic breeding ground for lows in the baroclinic zone east of the eastern seaboard which travel north east on the jet around the Azores high pressure which ridges into the south of the UK. Thus we have the perfect set up for a N/S split across the UK which could well be the dominant theme for much of next week.

Thus by Tuesday we find the cooler, cloudier and windier weather with slight rain across the north, courtesy of a front straggled across Scotland, whilst further south much lighter winds and quite warm.

A similar story on Wednesday, although the decaying front has tracked further south, with a marked temp contrast between the NW and SE where it could well get warm, or very warm.

 

[knocker]

Satellite at 0400 UTC

[knocker]

I was out all day yesterday so having to catch up a tad but judging by last night’s short range EPS 500mb mean anomaly little has changed, certainly in this time period. Still ridging in western N. America and triple vortex lobes dominating proceedings resulting in a strong westerly upper flow across the Atlantic with the Azores high pressure struggling to ridge north east across the UK (not dissimilar at 100mb). This portends a N/S split with any systems, and the more unsettled and cooler weather, tending to track north east whilst it remains dry and warmer in the south but even here probably a south east bias.

Meanwhile a low to the west of Ireland is deepening and tracking north east to be east of Iceland and the associated fronts are moving slowly east. Thus during last night and through today cloud and patchy rain/drizzle already affecting some western regions (note medium and high cloud already on the Camborne 00 sounding) will move slowly east across the country although eastern regions will be mostly sunny and warm until later on. By late evening most of the precipitation and cloud will have cleared the east coast leaving a clear night for most.

So a relatively clear night for most tonight, and quite cool in some areas, and start to tomorrow but the next wave from the active front orientated across the Atlantic (this has been described in a tad more detail in earlier posts) is fast approaching and cloud and rain and strengthening wind are already into north western areas by midday and will continue to track east. A very marked temperature contrast either side of the front with the S/SE being less windy and sunny and quite warm.

The dry and fine weather in the south continues overnight and into Tuesday but the north continues cooler, windier and unsettled and looking at the overall north Atlantic pattern illustrates why ( as mentioned in a little more detail in earlier posts).

So on the surface this equates to the next wave west of Ireland, some unsettled weather in the north and dry and quite warm in the south with a very marked N/S temp gradient,

A not dissimilar scenario on Wednesday with fronts straddled across northern England with it getting very warm in the south east in contrast to single digits in northern Scotland.

Thursday a much better day for everyone being calm, dry and mainly sunny, albeit the temps down somewhat but more evenly distributed, as high pressure sneaks in from the south west

 

 

Edited June 17, 2018 by knocker

[knocker]

Also just musing over, as the gfs builds a high cell to west, on the likelihood of a subsidence inversion and a Sc layer between say, 3,000 and 4,500ft

[knocker]

The ecm temp anomaly Tues > Thurs

The 0600 geostationary. Currently some patchy low St here but the main cloud Ac and Cs

 

 

[knocker]

The 0900 geostationary

[knocker]

The high res. MODIS at 1134 UTC (courtesy Dundee Satellite Receiving Station) Some elements of banked St development in these parts at the moment, as we are possible in the warm sector)

Edited June 17, 2018 by knocker

[knocker]

Confirm the warm sector

[knocker]

The cloud and patchy rain/drizzle over much of the country at the moment will slowly clear western areas by tonight leaving a clear night in most places apart from central south and the south east.This will be slow to clear there in the morning whilst elswhere a bright and sunny start but quickly clouding over in N. Ireland and the north west with some light rain which then extends to other western areas during the afternoon. Temps very respectable over the parts of England that stay relatively cloud free

[knocker]

Just a spot observation that  this evening the gfs initiates the amplification of the Atlantic ridge at around T96 which by itself is not a great move but the evolution of the ridge, and thus the position of the surface high, from this point will be a key factor in the days following.

Edited June 17, 2018 by knocker

[knocker]

Weds sees the shallow wave cross Scotland and the associated fronts track south east down the country giving a pronounced temp boundary

[knocker]

Although the increasing influence of high pressure over most of the UK is pretty much nailed down in the medium term, the actual development of the upper ridge, and thus the surface high cell still remains to be resolved. This is important because although, fairly obviously, light winds and lack of precipitation are the percentage play, regional variations of temperature and cloud can be critically dependent on the position of the surface high. With that in mind it’s worthwhile keeping an eye on this from an early stage.

At the moment the GEFS and EPS are in the same ball park, but not in detail, with the general theme being ridging in mid Atlantic drifting east over time. This, for example from the EPS, would mean the high cell drifting across central and southern England eventually leading to a southerly drift before giving way a more westerly regime. But that is getting too far ahead of ourselves for the moment as slight variations on this can make a vast difference.

Currently in the short term a N/S split seems likely with any systems nipping around the ridge to the west in the north westerly upper flow.

meanwhile...................

The cloud and patchy rain/drizzle associated with fronts from the deep depression to the north west have slowly drifted east leaving a clear night for western areas and the cloud only still effecting the central and south eastern areas of England. This will slowly clear here during the morning giving way to a sunny and quite warm day, particularly in the south east but more cloud and patchy rain will move into north western areas later and then spreading a south east as the next system moves in from the Atlantic. Quite a temp variation either side of the front

The south east will stay clear during the evening but come Tuesday morning cloud and patchy rain will cover Wales and England from the Midlands south as the front stalls and temps today in this area are very dependent on whether the sun can break through for any length of time. The front has stalled due to another wave forming on it to west  which is tracking north east which in turn brings more cloud and rain to north western areas, and later in the day in general to northern areas as the front returns northwards.

 

By Wednesday the high pressure (as mentioned earlier) is starting to amplify in mid Atlantic but for the moment most of the UK remains in a cool showery regime as the front slips south again except that is for the south east which could well be quite warm and muggy. Again marked NW/SE  temp contrasts either side of the front.

By Thursday the high cell has tracked east over the UK so some variable cloud and some showers along east coastal regions but generally a reasonable warm day.

Ditto Friday but perhaps sunnier and less likelihood of showers with temps a tad higher

The rainfall distribution is another indication of the pattern tending to a N/S split

Edited June 18, 2018 by knocker

[knocker]

It's funny but looking at this morning's gfs output one can't help reflecting on the influence the cut off upper low over Iberia gas had on proceedings recently and how it might again. We shall see

[knocker]

The temp anom for Wed .Frid on this morning's ecm. Similar story of the front dissecting the country on Wednesday and the high cell drifting east over the next couple of days.

Still a fair bit of cloud over the UK on this morning's 0600 geostationary image and frontal bands can be seen SW of Ireland.

 

Edited June 18, 2018 by knocker

[knocker]

As there is interest in the lack of rainfall in certain areas I'll pop the EPS 15 day totals in here on occasion. They are obviously subject to the usual error margin at this range but it serves as a ball park figure and fits in with current evolution ideas

[Man With Beard]

That is a shocking rainfall chart Knocker. I spy a looming drought for southern areas.

Back to the current, with the 564dam line into the SE and a cold front promoting a draw from France in front of it, could we finally break the 30C duck for 2018? ARPEGE thinks so, others not quite there:

  

(I'm guessing the fax chart will update later today)

[knocker]

The 1200 UTC geostationary much as expected with the main front trailing SW from Ireland. Temps not looking bad on the 1200 chart

 

[mb018538]

4 hours ago, Man With Beard said:

That is a shocking rainfall chart Knocker. I spy a looming drought for southern areas.

Back to the current, with the 564dam line into the SE and a cold front promoting a draw from France in front of it, could we finally break the 30C duck for 2018? ARPEGE thinks so, others not quite there:

  

(I'm guessing the fax chart will update later today)

@Man With Beard I'd be amazed if we see a 30c on Wednesday to be honest. I think we may squeak a 27c out somewhere, but personally I'm going to stick my neck out and say no 30c.

[knocker]

A good example of lee waves over eastern Scotland, N. Ireland and east Wales on the high res. MODIS at 1227 UTC. (courtesy DSRS)

https://www.metoffice.gov.uk/learning/wind/lee-waves

[knocker]

Just mulling away ten minutes so a quick overview of the movement of the front according to the 06 gfs Tues/Weds