Short range model discussion - into 2018

[knocker]

The 1500 UTC geostationary ( DSRS) showing the low west of southern Norway, the showers over the UK and the occlusion that has kept the south east under cloud, and more to the point for the next couple of days,, the massed cloud to the west of the approaching systems.

[knocker]

The showers currently around will ease this evening and overnight except perhaps in the north of Scotland leaving a clear night thus fog patches in some rural areas and a light air frost by morning These will quickly clear giving another fine day in most areas with a few showers returning but the question here is when will the rain arrive from the west? The answer is mid afternoon for N. Ireland and then progressively west.

Edited March 25, 2018 by knocker

[phil nw.]

By late Weds(T84hrs) Net Weather's Med range model shows quite cold air winging in on a strong westerly after Tuesday's fronts have gone through.

Some showers packing in to western facing coasts and hills though with the marginal dew points snow looks unlikely at this stage apart from the Scottish highlands.

Edited March 25, 2018 by phil nw.

[knocker]

My post above should of course end.'and then progressively east' Numpty

[knocker]

The updated fax charts for 00 and 12 Wednesday has Tuesday's front swiveling around the low to the west of Scotland and become virtually stationary over Scotland. which could dump a fair whack of snow over the high ground. Whilst at the same time a wave scoots across the south of England bringing with it some heavy rain and strong winds

[knocker]

There still seems to be some disagreement on the precise position of the front on Wednesday that could affect the snowfall in Scotland

https://weathermodels.com/index.php?r=site/models&mode=animator&set=UKMET 17 km&area=Europe&param=6-h Precipitation&offset=0&thumbs=0&tmodel=UKMET&tregion0=Europe&tregion1=Europe&tarea=Europe

[knocker]

Today heralds the next stage of the evolution which sees the upper trough, currently separating from the Canadian vortex, dominating the UK weather for the rest of the week with some help from the Russian vortex/trough and Atlantic ridging.

The current surface analysis has a transient ridge over the UK with plenty of sunshine and light winds today with a few light showers building during the afternoon. But a low to the west is moving east and the associated front and rain will affect Ireland by mid afternoon and then move east through this evening and overnight, bringing some snow to the high ground in Scotland, before clearing the west by morning leaving showery conditions in it's wake. Thus temps holding up pretty well and frost free in the morning.

Through Tuesday the front clears to the east leaving sunny intervals and the odd showers but still windy with snow on the hills in northern Scotland with the low in close attendance near the Hebrides. But further south a wave is forming south of Ireland and is about to track east

This it duly does through Wednesday bringing rain to the south with the rest of the country now in a cooler, showery and quite windy westerlyregime, particularly in Scotland, where snow showers will persist over the high ground.

Thursday sees the high pressure amplify in the western Atlantic which forces a realignment of the upper trough south east over the UK with a surface low near south west Ireland and associated fronts pushing north east over south west England and Wales. Generally with low pressure now to the fore quite unsettled albeit temps are only a little below average.

Not a huge change to this scenario on Friday with the low drifting around in the south west approaches and fronts/troughs circulating within the general circulation bringing showery outbreaks so still unsettled with quite a diurnal temp variation,.

 

 

Edited March 26, 2018 by knocker

[knocker]

Satellite at 0500

[knocker]

The ecm at T72 with the trough on the cusp of moving SE and the surface wave that had nipped across N. France now en route for Poland and the at T96

This morning's fax charts vis the wave

[knocker]

Wall to wall sunshine earlier but Ci and Ac have encroached recently which of course is no big surprise.

The 0900 UTC geostationary. (courtesy Dundee Satellite Receiving Station)

[knocker]

Sunny day for most of England on the 1100 UTC MODIS ( courtesy DSRS) as the cloud creeps in from the west

 

Edited March 26, 2018 by knocker

[knocker]

The showers bubbling up today

[knocker]

Rain spreading east this evening, some snow on the high ground in the north, and overnight with showers behind the clearance by morning. Quite windy in the north, maybe touching gales force.

[knocker]

The weather vis the wave on Weds still not pinned down, Possibility of snow on high ground?

[knocker]

The fronts and rain associated with the low west of Scotland will continue to move east across the country this morning clearing the east coast around midday although the rain and hill snow will hang around in northern Scotland. Elsewhere clearer behind the front although there could well be some heavy rain showers in places.

By 1800 the wave depression is forming west of Cornwall and this continues to evolve and track east overnight and through tomorrow morning bringing rain, and possibly some sleet/snow to the south west and south, before clearing in the afternoon.

Thus by 1800 the low is over northern Germany and the front has finally shifted a little NE away fro Scotland with the centre of the large low to the west just south west of Iceland 978mb. Temps a little below average.

Thursday midday sees the upper trough and associated surface low centres sliding south east as the high pressure amplifies to the west with the main low centre over south west Ireland and the associated front and rain impacting the south and Wales, The other active front is still not far from northern Scotland with waves continuing to form on it. Temps still a little below average.

According to the GFS another low forms near the center of the upper trough to the SW of the Uk and the surface feature deepens and tracks into northern France though Thursday evening and Friday which will affect the south of England bringing some rain whilst at the same time initiating an easterly wind component over the rest of the UK.with showers which may fall as snow on the high ground. further north, albeit temps in general are holding up.

No significant changes to this scenario on Saturday

 

Edited March 27, 2018 by knocker

[knocker]

Satellite at 0440 UTC

Edited March 27, 2018 by knocker

[knocker]

The ecm broadly similar to the GFS Thursday/Friday with the low centred to the south west with fronts/disturbances running around the circulation over the UK so unsettled is the name of the game with occasional longer periods of rain.

A couple of latest fax charts

 

[knocker]

The fronts taking their time clearing east as still low St, fog and drizzle here

[knocker]

A clearance here now and the forming wave can be seen on the 0900 geostationary (Courtesy DSRS)

[chrisbell-nottheweatherman]

12 minutes ago, knocker said:

A clearance here now and the forming wave can be seen on the 0900 geostationary (Courtesy DSRS)

Are you referring to the cloud west of the Iberian penninsular, Malcolm?

[knocker]

7 minutes ago, chrisbell-nottheweatherman said:

Are you referring to the cloud west of the Iberian penninsular, Malcolm?

I was thinking more of the 'boomerang' shaped cloud west of Brest with the apex (fronts?) SSE of the far cross Chris.

Edited March 27, 2018 by knocker

[chrisbell-nottheweatherman]

4 minutes ago, knocker said:

I was thinking more of the 'boomerang' shaped cloud west of Brest with the apex (fronts?) SSE of the far cross Chris.

Cheers - I have no idea how I miseed it!

Edited March 27, 2018 by chrisbell-nottheweatherman

[knocker]

The 1200 geostationary (courtesy DSRS) and surface chart

 

[knocker]

Excellent 1330 UTC MODIS illustrating the showers behind the front and approaching cloud from the wave, And apropos nothing at all the midday Camborne ascent also illustrates how modern day humidity censors pick up moisture in the upper troposphere (Cirrus) which was a definite no, no years ago.

[knocker]

Rain and hill snow will tend to persist over northern Scotland this evening and overnight with scattered showers elsewhere. But by midnight cloud and rain rain will be affecting Cornwall and overnight and through Wednesday morning this will track east affecting south Wales and southern England. Perhaps some snow on the high ground..

 

Edited March 27, 2018 by knocker