Model output discussion 10/02/21

[johnholmes]

The skew-T for the Doncaster area during Tuesday would suggest tops going to 10-11,000 ft with expected Mx and Td's, simply through daytime inland heating.

 

[Dominic Carey]

I’m really happy to see the cold/snow event get downgraded. Now on to chasing heat/plume events.

[Empire Of Snow]

 Certainly a minor downgrade in the morning runs with a slight shift to the East. Long term outlook though looks bleak with LP systems taking turns over us. Let's hope it won't verify. 

[Eugene]

26 minutes ago, Frigid said:

The whole country still under the -10c 850s. That's quite impressive for April.

Exceptionally cold dew points for midday Monday and Tuesday too even if it was in Winter. 

Chance of another northerly next Sunday too, all in all a very nice chilly week ahead apart from milder cloudy damp conditions late Friday into Saturday which hopefully will be pushed to our south and we stay colder and dry. 

[rwtwm]

I'm not seeing the downgrades that some posters are talking about. In terms of the progression of -10 850s the OPs at the moment are almost as severe as they have been at any point. 

At worst you can say they've oscillated around a theme. At best they've converged on one of the coldest scenarios shown 4 or 5 days ago.

[Empire Of Snow]

2 minutes ago, Dominic Carey said:

I’m really happy to see the cold/snow event get downgraded. Now on to chasing heat/plume events.

There's no downgrade regarding cold uppers at 850hpa. The slight shift to the East just means that many places inland might stay dry but it's again down to nowcast as convection can certainly play its role this time of the year. 

[I remember Atlantic 252]

1 minute ago, Empire Of Snow said:

There's no downgrade regarding cold uppers at 850hpa. The slight shift to the East just means that many places inland might stay dry but it's again down to nowcast as convection can certainly play its role this time of the year. 

So in my eyes huge downgrade for my location, can see on chart above, main thrust N sea eastwards, cold and dry in April really sucks, I love snow

April can be a warm month, so if dry, I want it warm

[Empire Of Snow]

1 minute ago, I remember Atlantic 252 said:

So in my eyes huge downgrade for my location, can see on chart above, main thrust N sea eastwards, cold and dry in April really sucks, I love snow

April can be a warm month, so if dry, I want it warm

I'm with you but unfortunately the other dominant option out there according to most models runs is wet and damp at 12C-13C.

[Polar Maritime]

UKV showing -14 850's over Northern parts with -12 over most of the UK. Certainly not to be sniffed at at during Spring..

 

[Methuselah]

I do get the impression that I'm spending more time looking either due north or due south, for our weather, these days?

    

For now, though, I'll put it down to wishful thinking!

[Kirkcaldy Weather]

I wouldn’t call it a downgrade, even if the instability ends up across the North Sea the dewpoints (and possible overnight lows) would then end up the main focus. Dewpoints well below 0 for 3 consecutive days (maybe more) isn’t too common for the UK in April I wouldn’t have thought  wouldn’t take this as exact but DP’s of -10s and below possible 

[Griff]

17 minutes ago, Kirkcaldy Weather said:

I wouldn’t call it a downgrade, even if the instability ends up across the North Sea the dewpoints (and possible overnight lows) would then end up the main focus. Dewpoints well below 0 for 3 consecutive days (maybe more) isn’t too common for the UK in April I wouldn’t have thought  wouldn’t take this as exact but DP’s of -10s and below possible 

Agreed, the cold is coming! 

I'm surprised by any downheartedness, there may yet be a few surprises, but I wouldn't gamble on a snowfest, we're the Kings of wishful thinking and suckers for punishment. 

Enjoy the charts, this time of year really does make things interesting, albeit transient. 

[The Northern Ramper]

1 hour ago, johnholmes said:

The skew-T for the Doncaster area during Tuesday would suggest tops going to 10-11,000 ft with expected Mx and Td's, simply through daytime inland heating.

 

 

1 hour ago, johnholmes said:

 

 

For the uneducated John (like myself) can you put this into English

Edited April 3, 2021 by Ramp

[Thundery wintry showers]

Regarding "downgrades", all that has happened this morning is that the UKMO has fallen into line with what the GFS and ECMWF models were showing in their 12Z/18Z runs yesterday.  Locally in Devon I see the 1025mb isobar covering the region for much of the northerly outbreak, whereas some earlier runs had it at 1015-1020mb.  There has been no toning down of the intensity of the cold, but it does mean that convection may be more limited inland.  Still, I would expect rather more in the way of showery activity to sprout up than is currently suggested by the GFS, with the unusually cold airmass combined with the relatively strong sun.  And again there is a chance of a dusting of snow here in Exeter early on Tuesday morning with a feed of snow showers through Wales and into Cornwall shifting east into Devon and perhaps Dorset/Somerset as well.  Low-lying parts of NE England in particular could also see some lying snow on Monday morning as a trough moves through.

For the longer term, though, significantly reduced chances of further northerly blasts with high pressure building to the south and the jet stream running over the top.  This is a shift in the outlook that I got very used to in the 2000s, it was very common for northerlies to be toned down in this way back then.  It's surprising to see it to this extent now with the models' improved accuracy at the 4-7 day timeframe in recent years, but it shows that today's improved models can still struggle with handling Atlantic blocking and northerlies.  NOAA's 8-14 day outlook suggests a mainly westerly flow:

Edited April 3, 2021 by Thundery wintry showers

[The Northern Ramper]

28 minutes ago, Kirkcaldy Weather said:

I wouldn’t call it a downgrade, even if the instability ends up across the North Sea the dewpoints (and possible overnight lows) would then end up the main focus. Dewpoints well below 0 for 3 consecutive days (maybe more) isn’t too common for the UK in April I wouldn’t have thought  wouldn’t take this as exact but DP’s of -10s and below possible 

To have it that cold with no snow in April would be a kick in the gonads but I’m still hopeful.

[Frosty.]

1 hour ago, Dominic Carey said:

I’m really happy to see the cold/snow event get downgraded. Now on to chasing heat/plume events.

Try telling those in Scotland it’s a downgrade..it ain’t!..especially north of the central belt they will feel the full fury of an unseasonably cold arctic blast with copious amounts of snaw..ice!..ps..some major frosty nights for much of the u k during most of the week ahead.  

[johnholmes]

34 minutes ago, Ramp said:

 

For the uneducated John (like myself) can you put this into English

A bit difficult to do it quickly, it is a 3 dimensional 'picture' of the predicted atmosphere that shows whether showers can develop because of surface heating?

Have a look at the section where all sorts of information is available, one on skew-t diagrams. If you have any questions then just send me a message and I'll try and answer in a private chat with you.

Sorry if this is not very clear I am just rushing out.

 

[Methuselah]

Still hoping for a post-Snowmageddon warm-up . . . but, if the GEFS 06Z Control is right, it could be an agonisingly slow and drawn-out process:

    

A bit like trying get the truth form a politician!

[Frosty.]

You read the netweather headline..winter bites back on Easter Monday!...stuff so called downgrades, read Michael Fish’s update......... ( video)..that guy is a LEGEND!!..anyway, I digress..what does digress mean?  , I’ve looked at the latest models (GEFS..GFS..ECM...etc..etc..and they show a much colder spell is coming from  the North....or am I a liar?...we don’t all live in southern England you know!    

Edited April 3, 2021 by Jon Snow

[Tim Bland]

2 hours ago, Kirkcaldy Weather said:

I wouldn’t call it a downgrade, even if the instability ends up across the North Sea the dewpoints (and possible overnight lows) would then end up the main focus. Dewpoints well below 0 for 3 consecutive days (maybe more) isn’t too common for the UK in April I wouldn’t have thought  wouldn’t take this as exact but DP’s of -10s and below possible 

Do many people get excited by low dew points Unless it’s going to snow (which for many it looks like it won’t) I’d rather it warm up now! 10th onwards looks good for temps to recover to 15c + just in time for the pub gardens

[Frosty.]

7 minutes ago, Tim Bland said:

Do many people get excited by low dew points Unless it’s going to snow (which for many it looks like it won’t) I’d rather it warm up now! 10th onwards looks good for temps to recover to 15c + just in time for the pub gardens

Wow.. I get excited by wet bulb temps..yeah..I’m saddd!..anyhoo. I’m excited by this cold plunge, some may not be but this is actually an exceptional event for the north, incredible cold energy sweeping south..at least it makes a change from the pathetic government COVID-19 announcements..what a joke!..

Edited April 3, 2021 by Jon Snow

[lassie23]

28 minutes ago, Jon Snow said:

You read the netweather headline..winter bites back on Easter Monday!...stuff so called downgrades, read Michael Fish’s update......... ( video)..that guy is a LEGEND!!..anyway, I digress..what does digress mean?  , I’ve looked at the latest models (GEFS..GFS..ECM...etc..etc..and they show a much colder spell is coming from  the North....or am I a liar?...we don’t all live in southern England you know!    

I just told everyone the Easter snow is off, so expect an upgrade. Hope you are as well as can be expected at this difficult time, regards to your dad.

[MATTWOLVES 3]

All I can say is this! Daffodils your dead!

I never really liked you anyway sitting there all pretty and colourful! Your attention seekers...end of! Quite a shock to the system on the way whatever the duration may be. Brrrr

Ps...no harming of Daffodils were made during the production of this post!

Edited April 3, 2021 by MATTWOLVES

[Frosty.]

50 minutes ago, MATTWOLVES said:

All I can say is this! Daffodils your dead!

I never really liked you anyway sitting there all pretty and colourful! Your attention seekers...end of! Quite a shock to the system on the way whatever the duration may be. Brrrr

Ps...no harming of Daffodils were made during the production of this post!

Great post Matt, you said this kind of thing could happen weeks ago....  

when all’s said and done..well done mate..it’s about to happen..we have cross model support for an exceptional arctic plunge ( by early April standards )...  !..some may not be happy, but you can’t please all the people all of the time can you?  

Edited April 3, 2021 by Jon Snow

[minus10]

48 minutes ago, MATTWOLVES said:

All I can say is this! Daffodils your dead!

I never really liked you anyway sitting there all pretty and colourful! Your attention seekers...end of! Quite a shock to the system on the way whatever the duration may be. Brrrr

Ps...no harming of Daffodils were made during the production of this post!

I should hope not !!