Short range model discussion - into 2018

[knocker]

The 0600 UTC geostationary is self-explanatory. Thick fog here with sky obscured

.

[knocker]

The ecm has it quite unsettled Thursday and Friday

and with cut off lows remaining very important an eye need be kept on the one in the western Atlantic and a possible new energy flow.

 

Edited May 29, 2018 by knocker

[knocker]

The 0900 UTC geo.

[knocker]

The high res. MODIS at 1100 UTC (courtesy Dundee Satellite Receiving Station)

[chrisbell-nottheweatherman]

9 hours ago, knocker said:

Not a lot of change on Saturday but the high pressure transition continues apace with, something I've touched on previously, a strong westerly jet in the tight thermal gradient north of the high pressure.



How far north is the jet!  Surely that's as close to the Pole as it ever gets?

[knocker]

18 minutes ago, chrisbell-nottheweatherman said:

How far north is the jet!  Surely that's as close to the Pole as it ever gets?

Certainly pushing the boundaries

[knocker]

Any showers/storms in the south and east will fizzle out this evening  but a more organized band of rain/storms will affect most of England and Wales as a front tracks north west through tonight and tomorrow. A much cooler day but picking up behind the front which could trigger the odd storm and as has been the way of late, the best weather in the north west. It must be great in the western Isles at the moment,

 

[knocker]

The latest fax charts for Thursday?Friday and the ecm take on the precipitation. On Friday has the surface low that has spawned from the Upper trough in the western Atlantic 10 degrees further east.. Another warm couple of days, still way above average in Scotland, but with the slack low pressure edging north the easterly feed is removed and thus an improvement in that area.

the 1800 geostationary

Edited May 29, 2018 by knocker

[knocker]

A look at last evening’s short term anomalies to see where we are going with this, if anywhere. The major players remain the weakening Canadian vortex and the strengthening one over northern Russia with the elongated blocking high pressure  ridging east >west between Scotland and Iceland

But in a not unimportant supporting role is the upper low in the western Atlantic which divides the flow exiting north east N, America, albeit some of it returns in mid Atlantic to support the strong westerly jet over Iceland,  but more to the point it also creates a channel south of the block to the low pressure south of the UK giving it the odd boost and perhaps an indication of future events?

So for the interim it looks like a continuation of a slack pressure gradient over the UK with temps above average but sunshine in many regions interrupted by showery/stormy outbreaks, the detail of which will be impossible to pin down much in advance.

Today

A front/trough, currently lying Dorset > Wash, accompanied by rain, showers/ storms and localized intense rain fall will track north west during the day. Clearer and drier weather behind in the south east where the odd Cb could pop up but remaining pretty cloudy along the east coast and some central areas. Again the best of the weather in the north west.

Thursday sees the large slack area of low pressure esconced over the UK heralding a warm humid day in England and Wales with cloud still the bugbear along the north east/east coast and perhaps central areas of England. Some home grown storms could be triggered where the sun gets going but just to add to the mix more showers/storms will track north west across central southern England and Wales during the day

The general pattern on Friday sees both the Bermuda and Azores high pressures ridging around the cut off lows in the Atlantic as the next phase of the evolution gets underway. On the surface this translates to another very warm humid day for the UK and with the heavy showers/storms extending further north one could pop up virtually anywhere. Meanwhile high pressure is building south of Iceland.

Saturday a drier day in England and Wales, the showers confined to Scotland, but still above average temps but 'cooler' air creeping in in the west as as the low to the west takes closer order and the high pressure continuing to ridge east north of Scotland

Another very warm day on Sunday but although the high pressure is becoming established to the north the low is quite adjacent to the south west so apart from home grown storms being triggered some could still move north from France and affect the south

Edited May 30, 2018 by knocker

[knocker]

Satellite at 0400 UTC, Currently some storms in the Peterborough area.

[knocker]

The 0600 UTC geostationary and the 0500 chart. Moderate rain around in the south Midlands which of course is no big surprise.

[knocker]

The ecm very similar/ Thursday/Friday

 

[knocker]

Alright up there in N. Ireland and Scotland? The high res. MODIS at 1146 UTC (courtesy Dundee Satellite Receiving Station)

[Guest]

5 hours ago, knocker said:

The ecm very similar/ Thursday/Friday

 

Those temps for tomorrow look hugely optimistic given instability around and likely debris from morning Imports.  

[carinthian]

On ‎28‎/‎05‎/‎2018 at 10:01, carinthian said:

Now then JH get to grips with this latest fax chart from HQ. Looks like a weather forecasters air traffic control visual with those lines waiting in the queue and all heading to Blighty. There must be some reasoning to these prog (fronts ) / lines of activity or is it guess work. I know we always looked for buckles in the isobar charts in the early days but this chart takes it to another level. Watched over the past week and not far off the mark by the head man/girl. Great stuff.

C

The actual real time chart show the synoptics at 12 noon today (below ) compared to the advanced (60t) fax chart shows just how much advanced forecasting has come on in the range out to 72t. Pressure values and frontal positions almost spot on. Well done UK Met Office, certainly these charts provide an excellent prognosis in the short term forecasts. Much better information provided by these charts than the daily worded forecasts they produce for the medium and longer term forecasts. I always remember the words of a senior forecaster I worked with , Stan Francis, " short term weather predictions, determine height, direction, speed and range and know your limits of predictability, anything beyond that the weather will make a fool of you ". I know that forecast models were in their infancy during Stan's forecasting days and things have moved on at a pace but I still  hold his words as a kind of sensible logic, as so to speak.

C

[Sperrin]

Absolutely stunning week so far in the North of Ireland. Regularly in mid 20s with hardly a cloud in the sky!!

[knocker]

Once today's rain has cleared away to the north west overnight tomorrow will dawn quite dry but rather cloudy and muggy with the perennial low cloud and mist along the east coast. But it will warm up quite nicely enough to trigger some storms in the south central areas which could drift north west.

But during the day a batch of more intentsive  storm activity will track north west from the continent and again this could produce some severe storms in places with intense rainfall and localized flooding.

Edited May 30, 2018 by knocker

[knocker]

The weekend sees the low spawned 48 hours earlier from the main trough in the western Atlantic south west of Ireland with a slack area of low pressure over the UK whilst the Azores ridges east between Iceland and Scotland.before sliding south on Sunday

So generally dry with any showers confined to Scotland, and down the east coast on Saturday, with temps still above average.

[knocker]

With the warm, muggy, air associated with the low pressure to the south drifting north over the next couple of days the spread of the unstable atmosphere will be conducive to a lot of storm activity, both home grown given the right trigger (temps) and imported from the continent associated with troughs within the circulation. The storms could occur virtually anyway but more prevalent in Wales and the midlands south today before moving north tomorrow. They could be very intense and where they do occur a distinct possibility of localized flooding. Settling down over the weekend as the high cell developing to the north west takes closer order.

So today some storms probably triggered in central southern regions (forecast sounding) before the more concentrated area tracks north west through southern regions into Wales during the day. There will of course be plenty of sunny intervals elsewhere but the east coast again subject to low cloud and mist.

The showers/storms will hang around in western areas overnight and through tomorrow and gradually drift north into Scotland. It will be another warm day in many areas but not cloudless, and not so much in Wales and the south west and the usual caveat vis the east coast but temps still generally above average.

So as we come to the weekend the pattern evolving sees the the Azores ridging north around the upper low south west of Ireland before curving east north of Scotland. with a very slack gradient over the UK. Another warm day, less so in coastal areas, with broken cloud cover but the showers and any residual storms now really confined to Scotland.

A not dissimilar story on Sunday except  much of central and southern England and all western areas will be warm with the north east and eastern areas cooler with the possible ingress of cloud to boot.

Sunday sees another relatively fine day but as the high pressure to the north takes closer order as the low pressure retreats a north easterly drift from the North Sea is once again initiated and thus quite a west/east split.

 

[knocker]

The last sentence above should obviously start MONDAY

the 0500 UTC chart. Noted for plenty of high dew points and mist

[knocker]

This morning's 0600 UTC geostationary not a particularly welcoming sight. A lot of cloud over central and eastern areas with a line of convective activity in the Channel

 

[knocker]

We appear to be entering the next phase of the evolution with more energy exiting north east North America directed south and thus promoting the trough in the western Atlantic to move E/NE as the blocking high attempts to ridge nearer Iceland. And the trough to the north east not without significance?

Edited May 31, 2018 by knocker

[carinthian]

Heck @knocker just seen your earlier presentation for the weekend weather. You must have been up with the larks to present that ! Anyway what a great post. You should be at HQ to show them how to make clear and simplistic to understand forecasts with the correct rhetoric and clear graphics. Keep up the good work. Look forward to your snow graphics for next winter !

C

[knocker]

The high res. MODIS at 1050 UTC (courtesy DSRS)

[knocker]

The 1200 UTC geostationary. A complicated image