Model Output Discussions 12z 08/03/17

[snowray]

Dream charts............for January!

[knocker]

It will be interesting to see how the EPS evolution plays out post the brief hiatus this week that has sent the pulses racing.  In the 6-10 range it brings the the Atlantic trough rapidly into play removing the amplified meridional pattern and introducing a more zonal flow. But, and certainly not without interest it intensifies the east European ridge and extends it NW north of Scandinavia which has the knock on effect of retrogressing and deconstructing the Atlantic trough. This results in a fairly slack W/WSW airflow over the UK.

Moving into the later period the trough continues to deconstruct creating a shallow low pressure area to the south west and with pressure rises to the north east the UK is very much plunged into a slack pressure area with a southerly drift that would bode well for  temps above average.

Edited April 22, 2017 by knocker

[Methuselah]

Suffice it to say that, after upcoming cold snap, summer will, just like Tigger, bounce back!

[Frosty.]

25 minutes ago, Ed Stone said:

summer will, just like Tigger, bounce back!

You could be right Ed, there is talk of May being a month dominated by high pressure with a chance of it becoming very warm during the second half.

[MP-R]

1 hour ago, snowray said:

Dream charts............for January!

True, but those last few are not far off a warm cyclonic setup with southeasterly like last May I.e. good thunder potential and much needed rainfall from more continental style conditions.

[Eugene]

54 minutes ago, MP-R said:

True, but those last few are not far off a warm cyclonic setup with southeasterly like last May I.e. good thunder potential and much needed rainfall from more continental style conditions.

Also not far off a pattern like May 1996.

[MP-R]

29 minutes ago, Eugene said:

Also not far off a pattern like May 1996.

True, although unlikely. A half way house would be interesting with the south getting warmer influence from the southeast and the north in a cool northeasterly. Lots of options on the table.

[lassie23]

BBC really watering down the northerly for the south. 13c by day, just cold in the shade. It looked potent from the models....oh well, I guess the sun is just too strong this time of year.

[Frosty.]

26 minutes ago, lassie23 said:

BBC really watering down the northerly for the south. 13c by day, just cold in the shade. It looked potent from the models....oh well, I guess the sun is just too strong this time of year.

That's strange, the outlook from Exeter is becoming much colder with blustery wintry showers and night frosts..13c sounds a bit optimistic to me.

[MattTarrant]

9 minutes ago, Frosty. said:

That's strange, the outlook from Exeter is becoming much colder with blustery wintry showers and night frosts..13c sounds a bit optimistic to me.

13 is for London, majority of places will around 8/9

[Summer Sun]

1 hour ago, lassie23 said:

BBC really watering down the northerly for the south. 13c by day, just cold in the shade. It looked potent from the models....oh well, I guess the sun is just too strong this time of year.

Yes temps still make it into double figures for the south (only just) but feeling colder with the wind some big storm clouds building early next week too - Thursday onwards milder air returns to all

[ACCOUNT DELETED]

Going to Tenby, SW Wales camping for a few days, really hope and pray those big downpours and thunderstorms that's showing up on the forecasts and charts miss us as it'll bad enough trying to keep warm in our tent let alone trying to stop everything getting damp! 

Latest GFS still indicates a fair amount of cape in the area on Tues but shows much less now on Weds. 

Edited April 22, 2017 by DJ RY

[Bogman]

2 hours ago, lassie23 said:

BBC really watering down the northerly for the south. 13c by day, just cold in the shade. It looked potent from the models....oh well, I guess the sun is just too strong this time of year.

 

 

Sod that. It's nearly May. Winter is past, time for warmth.

[lassie23]

7 minutes ago, Bogman said:

 

 

Sod that. It's nearly May. Winter is past, time for warmth.

I think May will be dominated by high pressure.

[Summer Sun]

UKMO shows a northerly for Tuesday with the colder air and strong sunshine temps will range from around 6c in Scotland to around 12c in parts of this south the combination of the colder air and sunshine will also build some big storm clouds any snow looks unlikely away from northern hills

 

 

[snowray]

2 hours ago, lassie23 said:

BBC really watering down the northerly for the south. 13c by day, just cold in the shade. It looked potent from the models....oh well, I guess the sun is just too strong this time of year.

Northerly....what northerly?

I always said that this northerly would get watered down like the rest of them lassie, a cold blast on Monday night into Tuesday yes, then practically all over. I doubt there will even be much of a frost in the south anyway.

 

Lets look forward to summer aye.

 

[Frosty.]

The Gfs 12z through low res looks much better with high pressure and warmer temps, even some plume potential too with temps into the 20's celsius at times..becomes blocked

Edited April 22, 2017 by Frosty.

[Frosty.]

It's starting to look like a blink or miss it cool snap now, by midweek the colder air supply is cut off and thereafter temperatures start to recover.

[Optimus Prime]

8 minutes ago, Frosty. said:

It's starting to look like a blink or miss it cool snap now, by midweek the colder air supply is cut off and thereafter temperatures start to recover.

Did not see that coming. Really shocked at that.

[snowray]

14 minutes ago, Frosty. said:

It's starting to look like a blink or miss it cool snap now, by midweek the colder air supply is cut off and thereafter temperatures start to recover.

This happens every time Karl, every run under the T120 timeframe shortens cold spells by small steps, the intensity of the cold is toned down more and more......and then its GONE, or almost gone like this time.

 

Maybe thats why we never saw SM posting who would have taken some interest surely, seen it all before.

[Frosty.]

Looking into May, the GEFS 12z mean shows a pattern change to much more benign pleasantly warm anticyclonic conditions..as did the 6z mean..so, could be a largely blocked and nice last month of spring.

Edited April 22, 2017 by Frosty.

[knocker]

I find the quite impressive part of this evening's gfs is the speed it cuts off the Atlantic around the T200 mark. it drops the deep trough spawned in N.Canada into mid Atlantic and rapidly intensifies the east European ridge in conjunction with Azores which disintegrates the trough to our east to set up a surface high cell over Scandinavia.Which of course places much of the UK into an easterly flow.

Not unsupported by the GEFS but I would not expect this evolution to remain unchanged over the next few runs.

Sidney was quite phlegmatic when I mentioned the short lived northerly.

[Frosty.]

13 minutes ago, snowray said:

This happens every time Karl, every run under the T120 timeframe shortens cold spells by small steps, the intensity of the cold is toned down more and more......and then its GONE, or almost gone like this time.

 

Maybe thats why we never saw SM posting who would have taken some interest surely, seen it all before.

Lol yep, never even saw him lurking..a bad sign..anyhoo, longer term signals are more promising with warmer temps and higher pressure during May.

[Summer Sun]

I think it's also important to point out that next week the UV levels will widely be 4 or 5 maybe even 6 on Tuesday around Exeter so if you're exposed to the sunshine for any lengthy period sun cream could still be needed

Monday to Thursday left to right

[Frosty.]

2 minutes ago, Summer Sun said:

I think it's also important to point out that next week the UV levels will widely be 4 or 5 maybe even 6 on Tuesday around Exeter so if you're exposed to the sunshine for any lengthy period sun cream could still be needed

Monday to Thursday left to right

Yes its amusing isn't it, we may catch a wintry shower and also get Sun burn.