Short range model discussion - into 2018

[knocker]

The high res. MODIS at 1230 UTC (courtesy DSRS). Note the sun shining on God's Little Acre. And the 1300 analysis. Note still a lot of moderate rain in the south east

Edited April 8, 2018 by knocker

[knocker]

Tomorrow afternoon and evening rain, occasionally heavy,  will move north west over southern England and Wales.Early signs also of depressed temps along the east coast

Edited April 8, 2018 by knocker

[knocker]

A sign of things to come maybe. A very strong jet exiting N. America south of the vortex lobe and then around the Atlantic high pressure. Only subsequently to hit the block comprising the negatively tilted trough associated with the vortex running into Iberia and the European high ridging towards Greenland. Thus upper wind divergence leading to colder air around Iberia but warm advection into central Europe, in particular, and the UK.

Edited April 8, 2018 by knocker

[knocker]

The overnight analysis shows low pressure to the west and south with a front to the south east moving NW during the day. So the UK can effectively be divided into two today and tonight vis the weather with N. Ireland, Scotland and until later N. England getting the best of the sunshine, albeit with a few showers, whilst rain will spread NW from the south east during the period thus cloudy and wet elsewhere.

The rain, heavy at times, will continue to push NW overnight and through Tuesday morning  Thus bringing N.Ireland. N. England and southern Scotland into the frame but by 1800 the upper low and associated surface feature has been forced south east between the block to the east and amplifying high pressure to the west. A movement that initiates the brisk easterly flow over the UK and which is depressingly going to negatively affect temps along the NE/E coast for a few days whilst elsewhere is quite warm.

Wednesday sees the consolidation of the high cell to the north east and the upper low over Iberia thus the twin easterly inflows pertaining with cold conditions under leaden skies in the north east north of the Wash whilst remaining dry and warm south and west of there.

Thursday see the very resilient block coming under increasing pressure from the energy exiting North America which has the affect of boosting the easterly flow over the UK. leveling the temp playing field a tad, whilst at the same pushing low pressure with associated front north into southern England introducing showery conditions with perhaps the odd storm

By Friday the pressure from the west has gained a little ground and low pressure has pushed NE over the UK with the associated front bringing patchy rain to Wales, England and N. Ireland. But it also veers the surface wind and cuts off the North Sea influence to a large extent except for the far north east of England and Scotland.(there it may take a tad longer) And as can be seen temps south of the border are pleasantly above average

 

Edited April 9, 2018 by knocker

[knocker]

In conjunction with the above the GEFS 5 day anomaly

[knocker]

The 0530 UTC satellite illustrates very well the current position

[knocker]

I appreciate that everyone is aware that, at best, 850mb temps can only give a guide to surface temps and at worst, if the temp profile in the boundary layer is compromised, they are useless. That/ss the case this week with the CAA along the east coast so it may be of interest to look at a forecast sounding which shows the CAA with a surface temp around the same as the 850mb. Or of coarse it may not.

[knocker]

The 0600 geostationary catching daylight approaching (courtesy DSRS)

[johnholmes]

43 minutes ago, knocker said:

I appreciate that everyone is aware that, at best, 850mb temps can only give a guide to surface temps and at worst, if the temp profile in the boundary layer is compromised, they are useless. That/ss the case this week with the CAA along the east coast so it may be of interest to look at a forecast sounding which shows the CAA with a surface temp around the same as the 850mb. Or of coarse it may not.

Show up well what is going to the damned weather for this side of the country until a flow from much further round starts to move in.

I hate spring easterly flows, be they anywhere between NE and SE SSE and it is okay. Sometimes in summer they are also not much good if moist as well even this far inland.

[knocker]

4 minutes ago, johnholmes said:

Show up well what is going to the damned weather for this side of the country until a flow from much further round starts to move in.

I hate spring easterly flows, be they anywhere between NE and SE SSE and it is okay. Sometimes in summer they are also not much good if moist as well even this far inland.

Yes it's not looking brilliant until the weekend, We can get something akin here near the north coast with a NW

[knocker]

Looking at the 0900 UTC geostationary you can see where the fine weather is (a cracking morning in these parts) but also the large low pressure area to the west in the Atlantic. It is this that is going to swing south east over the next 24 hours and set up the new pattern for the next two or three days.

[knocker]

The interesting high res. MODIS at 1115 UTC (courtesy the Dundee Satellite Receiving Station)

[knocker]

The front and extensive rain will continue to move slowly north west during the night and tomorrow morning clearing England and Wales by midday, although further outbreaks of rain will impact the south west and Lincolnshire and Norfolk coasts later. And a marked temp gradient already apparent.

[knocker]

Further to the above this evening's updated fax charts as we slide into the midweek pattern

[knocker]

As the sun sets the impressive area of low pressure and fronts to the west are highlighted. The 1800 UTC geostationary (courtesy DSRS)

Edited April 9, 2018 by knocker

[knocker]

There is currently a large area of rain affecting most of England and Wales which will gradually move north west during the day. Behind the front drier and brighter weather but the major trough to the west is in the process of tracking south east and troughs within the circulation will swing into the south, bringing, firstly, showery, thundery, outbreaks to the south west this evening and then through tomorrow morning another outbreak tracking west through the Midlands from Norfolk. Thus movement of the trough has initiated the expected N/S temp gradient. Hopefully all of this can be encapsulated within the following.

Weds

Elsewhere on Weds it will be drier but the the murk and colder regime is already in place further north and along eastern coastal areas.

Thus the general analysis by 1200 Thursday is a negatively tilted upper trough running from the tip of Greenland to western Europe under the the block to the north east which has a more positive tilt. The unstoppable force meeting the immovable object. This leads to quite a complex surface analysis with the UK under the influence of two airmasses. HP to the north east and LP to the south west resulting in cold and murky in the north east and Scotland whilst sunny interval and warm in the south albeit with some showers and maybe the odd storm thrown in.

No significant changes on Friday except perhaps the strengthening easterlies have been pushed a little further north by the pressure exerted by the trough and thus taking to murk a tad further north also but essentially the best and warmest of the weather to the south and west.

But by Saturday the low pressure has gained some traction, thank to the upper trough pushing north, and a slack area of low pressure covers the UK largely removing the North Sea influence apart from the far NE of England and Scotland. Elsewhere sunny intervals and the odd shower with temps a little above average. This is of course according to the GFS

 

 

 

 

[knocker]

Satellite at 0515 UTC Nice illustration of the negatively tilted trough to the south west

Edited April 10, 2018 by knocker

[knocker]

Fairly sparse 0600 chart but a lot of rain around in England as already noted.

[knocker]

The ecm more or less in agreement with the GFS with a slack southerly drift in place by Saturday with the North Sea influence snipped, much to the relief of many with the general improvement of the weather and temps in the north east and Scotland as the cold murk north of the Humber persists on Friday.

[knocker]

Noticeable colder air into the NE already.

[knocker]

Early this evening a band of showery rain will track NW across the south west and then later, overnight and through tomorrow morning, another more substantial belt, west from East Anglia > the Midlands > Wales. A marked temperature boundary roughly Bristol to the Wash.

Edited April 10, 2018 by knocker

[knocker]

The 1200 analysis and the 1345 high res. MODIS (courtesy DSRS)

[phil nw.]

Quite a chilly day tomorrow for many. Cloud and rain moving across e.anglia,midlands and wales suppressing readings and with a cool easterly wind blowing off the N.Sea where temperatures are around 5c.

The east coast will feel particularly raw from around the wash northwards.As a general comment this is often the case with Spring easterlies and anywhere from say the Aberdeen coast down to the Wash can be affected in these setups often with mizzle,low cloud and single figure temperatures.

The situation tomorrow mid-day with the fax,expected temperatures and wind flow direction and mean speeds.  

  

In contrast some warmth again creeping into the south east segment under brighter skies also where the wind is lighter.So we could see quite a difference in temperature within a short distances around E.Anglia for example.

Edited April 10, 2018 by phil nw.

[knocker]

Just a heads up

 

[knocker]

The ecm this evening has the change from the split pattern routine occurring overnight Friday/Saturday. Friday has a front and rain track NW from the North Sea over the north of England and Scotland clearing the far north by 0600 Saturday morning. Thus Saturday, and Sunday, the UK is in a very slack southerly drift with maybe some isolated showers.

Thus on Friday temps still in the 5-7C range north of the Humber with the 10-13Cs SE of a line Bristol>Wash

But on Saturday, apart from northern Scotland where temps remain in the 6-7C range elsewhere we are talking 14-18C

Sunday much the same with northern Scotland warming up as well.