Models, teleconnections and nowcasting

[knocker]

Fog here at the moment and as can be seen on the 0600 chart mist/fog is pretty extensive at the moment

[johnholmes]

13 hours ago, mushymanrob said:

Thanks john, it helps to a degree, but atm i dont really understand fully the skew-t charts. Ill have to find an explanitory vid on youtube 

Have a look on the Learning area many years ago I did a skew-t tutorial. Not sure if all the diagrams still work but pm me when you have had time to read it with any questions and I'll try to help

Fax Synoptic Charts From The UK Met Office  Neweather.tv

WWW.NETWEATHER.TV

sorry not sure what happened there I'll try and give the link again

Edited April 24, 2020 by johnholmes

[johnholmes]

11 minutes ago, knocker said:

Fog here at the moment and as can be seen on the 0600 chart mist/fog is pretty extensive at the moment

Low ST here after a clodless dawn

[knocker]

About the only thing the ecm and gfs agree on through next week is that is going to be changeable, although the ecm does have further amplification towards the end of the week

[knocker]

30 minutes ago, johnholmes said:

Have a look on the Learning area many years ago I did a skew-t tutorial. Not sure if all the diagrams still work but pm me when you have had time to read it with any questions and I'll try to help

 

sorry not sure what happened there I'll try and give the link again

Is this the link John?

https://www.netweather.tv/forum/topic/16002-a-simple-guide-to-understanding-skew-t-diagrams/

[knocker]

Let's see if I can get any sense out of the ext anomalies this morning. Although they are not in agreement they are all pretty much on the same page.

A ridge NW North America adjacent to a similarly orientated tpv N. Russia to N. Canada with associated trough into the NW Atlantic, Downstream some ridging srill into southern Greenland with a trough in the eastern Atlantic as the subtropical high attempts to amplify in Europe. Fairly obviously the alignment and intensity of the downstream features are critical to any assessment on forthcoming weather so I will take a rain check on that

The Stratus and fog have now dissipated here

Edited April 24, 2020 by knocker

[johnholmes]

1 hour ago, knocker said:

Is this the link John?

https://www.netweather.tv/forum/topic/16002-a-simple-guide-to-understanding-skew-t-diagrams/

It is k

[knocker]

A slightly unusual rainfall pattern

[knocker]

The output from the gfs and ecm det runs fit pretty well with the pattern of the medium term anomalies this evening with an extension of the tpv down eastern North America and a strong westerly upper flow crossing exiting south of this across the Atlantic south of the trough in the east. Thus systems tending to track towards the UK from the south west indicating  unsettled

[knocker]

A very slack low pressure area covers much of western Europe at the moment but specifically today the much discussed trough to the NW will take closer order. Once the Stratus over eastern regions has retreated to coast this morning it should be another fine day for most althouigh cloud may linger around the south west with showers developing over Wales this afternoon courtesy of the trough

Some cloud and the odd shower in the north courtesy of the weak cold front associated with the aforementioned trough, otherwise a clear night with the odd frost patch

A cloudier day on Sunday with showers and longer periods of rain although some spots like the south east will remain quite sunny

By Monday the pattern is evolving as previously discussed as the UK trough merges with the main one to the NE and further troughs track down from northern Canada into the Atlantic, all of which creates a cut off high cell over Iceland, And more specifically a cloudy and cooler day for the UK with rain in the north  thanks to the trailing occlusion

The pattern continues to evolve in the Atlantic on Tuesday with a very slack gradient across the UK resulting in a much cooler day with frequent showers, some of which could be quite intense

By Wednesday the Atlantic low is filling and drifting east covering much of the UK, thus it will be quite cloudy, and the associated occlusion will bring a band of rain as well

Edited April 25, 2020 by knocker

[knocker]

The detail for the rest of the week is tricky as, according to the gfs, there is a trough stationed over the eastern Atlantic being 'topped' up by the energy flows from the NW and SW. All of which portends unsettled with showers and longer periods of rain

[knocker]

A pleasant morning here with a fair bit of Ac

[knocker]

Early morning Altocumulus

[knocker]

The detail will vary but the overall trend to unsettled with low pressure dominating the Atlantic is similar with the ecm

[johnholmes]

Yes the detail of course will slowly be refined by the models but the overall change to a more changeable pattern looks pretty certain. Shown also on the 500 mb anomaly charts

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

All 3 show similar type charts in the 6-10 day period.

 

This idea was already starting to show when I last put the anomaly charts on here, Tuesday 21 April.

Edited April 25, 2020 by johnholmes
spelling

[knocker]

A gloomy day down here with Sc, St

[knocker]

In the middle of next week the gfs is looking to develop a wave in the south west quadrant of the complex upper trough

and tracking it east to be west of Ireland on Friday

Edited April 25, 2020 by knocker

[knocker]

As can be seen the detail is a long way from being nailed down next week

[knocker]

Currently low pressure dominates western Europe and much of the Atlantic underlying high pressure building north of Iceland. More specifically a front associated with a shallow low in the North Sea will bring cloud and showers to northern and central areas through today and some of these could be heavy during this afternoon. There will also be showers in the far north in the cooler air. .South of the midlands generally another warm and sunny day

Tonight the cloud and patchy rain will continue to edge south whilst the showers continue in the north

By Monday the low is over southern Norway but the weakening cold front is still f draped across the south where it is still quite warm resulting in a few showers bubbling up in the afternoon. But it is generally cooler with further showers in Scotland courtesy of a stray trough

There is quite a lot going on over Monday night and through Tuesday with developments in mid Atlantic and, more to the point, a wave develops on the old front which tracks north bringing rain to southern and central areas

By Wednesday the Atlantic is starting to take over as the trough moves east and the associated front will bring rain to most areas south of Scotland

By Thursday the country is nestling under low pressure, ergo continuing unsettled with heavy showers. longer periods of rain and sunny intervals

 

Edited April 26, 2020 by knocker

[knocker]

To continue over the weekend with the gfs but the detail be treated with caution

By Friday the low in the south west has developed and tracked north east with the weakening front bringing some rain to the country/

But over the weekend amplification of the subtropical high zones more or less halts eastward movement of the trough, although the UK just about remains under the influence of the eastern flank.

Edited April 26, 2020 by knocker

[knocker]

The ecm for next weekend skipping the upper air charts which follow a similar theme as the gfs

Edited April 26, 2020 by knocker

[knocker]

Out of interest a look back at yesterday morning

Low stratiform cloud over eastern UK and convection in SW

[knocker]

A lot of cloud in these parts again

[johnholmes]

My first measurable rain since 0.2 mm 12th, 0.8 mm and the Doncaster prediction looks about right looking at the clouds around here in the past hour.

[knocker]

Now if that trough takes on a negative tilt rather than a positive