UK meteorology

Today's view:
Today and overnight.

Scotland will be quite chilly with outbreaks of snow, sleet and rain depending on location and these will continue through to tomorrow morning. Further south not unpleasant with broken cloud and plenty of sunshine as the temps creep up but showery rain will move into the south west late in the morning and consolidate and move north during the day By morning this will have cleared southern England and Wales and thus much drier. The sat. image is for 0400.





Much the same story for Tuesday with Wales and the south remaining dry with sunny spells whilst the north, N. Ireland and Scotland outbreaks of showery snow, sleet and rain will continue, the former restricted to high ground. Still quite a latitudinal temp variation.





By midweek low pressure continues to be the controlling influence with the upper trough and associated surface lows dominating the Atlantic and points east. Ergo the unsettled weather with outbreaks of showery rain, perhaps thundery, will continue interspersed by sunny intervals and as the temps creep nearer average albeit still cold at night with ice and patchy fog in the north



This scenario continues over Thursday and Friday with low pressure still dominating the eastern Atlantic with the two upstream energy flows coalescing in mid Atlantic. I notice the METO referred to this yesterday as a cyclonic block
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First day I've not needed snow chains since last Tuesday, nice sunny day here.

Had one of those odd weather events last night, popped out for some coal and to get stuff from the car. No street lights at mine so I had a head torch on and it was a white out I could barely see 5 yards in the 'fog'. On closer inspection it was ice crystals swirling about reflecting the light, if I turned the torch off it was light like a quarter moon night. Very odd especially as I could hear the drip of the thaw all around me.
 
First day I've not needed snow chains since last Tuesday, nice sunny day here.

Had one of those odd weather events last night, popped out for some coal and to get stuff from the car. No street lights at mine so I had a head torch on and it was a white out I could barely see 5 yards in the 'fog'. On closer inspection it was ice crystals swirling about reflecting the light, if I turned the torch off it was light like a quarter moon night. Very odd especially as I could hear the drip of the thaw all around me.
Might have been a light graupel shower?
https://en.wikipedia.org/wiki/Graupel
 
I'll post last Malcolm's comments on the anomalies from last night, then his thoughts on this morning's operational:
Little change with the anomalies this evening. Upstream a diffuse vortex NW Greenland to NE North America with ridging centrally and the important ridge in the north west Atlantic to the Labrador Sea. So still the two upper flows, one running south east across southern Greenland and the other, stronger one, exiting the eastern seaboard, which coalesce in mid Atlantic. Thus a favourable environment for depressions to track into the UK on the resulting quite strong WSW upper flow. This would portend a period of unsettled weather with possible gales and temps a little below average. The usual caveats vis the det. runs.

 
The general theme over the next five days (and longer) is unsettled with low pressure dominating.



For most practical purposes today and tonight the UK can be divided into two. Scotland will remain on the cold side with outbreaks of rain, sleet and snow, probably more confined to the north by tonight, whilst the rest will have sunny spells and the odd shower once the cloud and rain has cleared the north, Overnight the showers will die out apart from in the west and more general rain will encroach the south east. Still quite cold in the early morning in many areas.





Wednesday has low pressure covering the country with the center west of the Hebrides with small disturbances in the general circulation thus again sunny spells and rain showers,some heavy, falling as snow on the high ground in Scotland. At this stage probably an idea to keep an eye on the far south west and the energy exiting the eastern seaboard, Temps improving but still a little below average.



The sunny spells showery weather continues through Thursday with snow on the high ground in the north as low pressure continues to be influential with perhaps some longer spells of rain thrown in. Away to the south west a large depression is slowly tracking north east.



By 1200 Friday the UK low is still centred near the Hebrides but a front associated with the low to the south west, that is still moving slowly north east, is already affecting the south of England with rain. The front continues to track north as a small wave forms on it.



Progress of the front/rain, perhaps some snow on the high ground, and quite strong winds north through England and Wales on Saturday is slow as the main, deep low, drifts slowly east to be north west of Coruna by 00 Sunday.



This is of course according to the gfs.

According to the ecm an interesting temp contrast north and south of the warm front at 1200 Saturday which is orientated Bristol to the Wash. To the south 10-13C and the north 4-6C
 
Today's thoughts:
The upper trough and low pressure continue to dominate the eastern Atlantic and the UK over the period with the energy flow across the Atlantic being the sub tropical jet out of the southern US with systems thus tracking a little further south than normal.



Today and tonight.

The rain, sleet and snow will finally clear the far north of Scotland and during the day the rain will also slowly clear the south east and East Anglia. This will the leave most places quite sunny with the odd shower thrown in but which may be heavier and of snow over the Scottish mountains. By this evening and overnight a frontal system will encroach from the west bringing a band of rain with it as it tracks eastward across Wales, the south west and central and southern England. Still quite chilly under areas with clear skies.





Thursday sees the system and rain clear into the North Sea leaving the UK with sunny periods and scattered showers but these may be more frequent and heavy in the north, Meanwhile the next major depression is getting organized away to the south west and it is this that is going to introduce rain and much warmer air on Friday/Saturday.



So Friday starts off in similar vein to Thursday with sunny intervals ans scattered showers but by evening rain from the warm front associated with the low is already impacting the south west and moving north across Wales and England with the noticeable warmer air behind.



by Saturday the rain has spread north, perhaps snow on the high ground, with the frontal systems straddling the country and much warmer air over Wales and England with temps touching 13C.



Sunday sees the whole of the UK in the milder air but the analysis is quite a complex low pressure area dominating portending sunny interval and showers but best left here.


The ecm differs from the GFS vis the treatment of the low over the weekend so still to be resolved. Also the 850mb temp anomaly and contours

 
My anxiety is bad at the moment so I'll just post Malcolm's thoughts from this morning:
The system that produced last night's rain. sleet and snow on the high ground in Wales and the Midlands will soon clear away to the east leaving many places with plenty of sunshine with just a few showers that will be mainly confined to the south west. These will clear overnight but further snow showers may occur in the highlands. Elsewhere it will be a clear night leading to some fog patches in places and quite a widespread light frost.





The mainly sunny scenario continues on Friday in most places but by 1200 the fronts associated with a complex low to the west of Cornwall 973mb have already brought heavy rain to the south west This belt of rain tracks north during the day and the fronts straddle Wales and the Midlands by 00 Saturday.as the complex low moves a little further east.





Through Saturday the front continues to track north as little waves form on it and the rain may fall as snow on the high ground in Scotland leaving unsettled showery conditions in it's wake whilst the low deepens to the west. Apart from bringing wind and rain the system also introduces much milder air to the UK and at 1800 we are looking at max temps in the +13C range in England but still only 3-6C in Scotland.



On Sunday the rain/snow belt continues it's journey over Scotland whilst the filling but still deep low tracks closer to Cornwall riding the crest of a wave, so to speak of the jet exiting the south east seaboard , aided and abetted by the secondary flow from Canada running around the Labrador Sea block



The precipitation through this period is biased towards western England and Wales


A couple of spot checks on the weekend low from the ecm as it brings another front and more rain and wind into the south west later on Sunday. And the 850mb temp anomaly and contours

 
Today's thoughts:
A fairly benign start to the day in most areas apart from Scotland where there will be a a mixture of showers this morning, with some mist and fog patches but fronts associated with the deepening area of low pressure to the south west will bring patchy rain quickly into Cornwall this morning This will become heavier and more persistent and move north east across England and Wales during the day.





The band of rain, perhaps some snow on the high ground in the north will continue to move north overnight and Saturday morning into N. Ireland and southern Scotland leaving cloudy and much milder conditions in it's wake although the cold front will bring some patchy rain into the south west Saturday morning. The milder conditions are worth another mention in the context of last week and the exceptionally cold thickness charts that the easterly produced compared to the tongue of warm air that the deep depression has advected up from the south over the weekend, albeit not quite reaching Scotland By 00 Sunday the front and rain have cleared to the north east.





Sunday and Monday there is a bit of a N/S split with the north staying relatively dry but the south windier with showers and maybe longer periods of rain as the filling low in the south west tracks east through the Channel



So by 1200 Tuesday we can take a step back and take an overview and, well, fancy that. An upper trough just to the west of the UK, a block around the Labrador Sea and the jet zipping east from the south east US seaboard and a complex surface low pressure area in the eastern Atlantic with the next frontal system set to encroach the UK with more rain and strong winds after a transient ridge through late Monday into Tuesday.


The ecm still not in agreement with the GFS vis the handling of the complex two center low over the weekend albeit the north/south dry/showery split still pertains.

 
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