I think Q has hacked into the GFS. Much colder set of ens in the short term

-20 possible even down here on this one!

 

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The Op has another cold weekend next week

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-20 still on the GEFS!

Never seen it at 18h before!

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If Michael and Richard don’t wake up to a decent covering of snow tomorrow it’s time to officially give up. 😀

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I love cold April convective days. Sunlit white cumulonimbus anvils marching south with dark bases and shafts of soft hail or snow lit by the sun.

I remember an April day in the early 70's in a northerly, walking up to the top of Otley Chevin in Yorkshire in the strong morning sun with my pal, we were 13 or 14. We were greeted at the summit with the above sight coming in from the north Pennines. It was a monster, mature cumulonimbus.

We started off home quickly with a huge wall of sunlit snow approaching from behind. As it reached us you could see the huge flakes falling well before they fell on us.

It was a white out within minutes as the temperature fell from 6 C to zero. It lasted an hour and put down 3 ins. We were freezing cold, plastered in snow and so glad to get home, needless to say we hadn't been suitably dressed!

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If Michael and Richard don’t wake up to a decent covering of snow tomorrow it’s time to officially give up. 😀

It will probably be stuck to north facing surfaces thanks to the 60mph wind gusts that are forecast. 

I see that there is now a snow weather warning it for northern parts on Tuesday (as well as later today and tomorrow).

https://www.metoffice.gov.uk/weather/warnings-and-advice/uk-warnings#?date=2021-04-04

Snow is not unusual in April, but this depth of cold is. It is a bit hard to believe when the temperature is in the low teens here.

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Yes sods law Moomin. I bet you any GFS chart like that 10 days away in the winter would be downgraded. As for this it has as you said been consistent for over a week now and if anything it's upgrading. The 18z ENS 850s mean for London is  -11.6c.😳

Also if we don't get any single snow shower from that deep cold air coming here I will be very shocked because it impossible to stay dry throughout while other countries get snow storms to snow showers activities.  I never see a 5C max here under wall to wall sunshine in April so hope to see something out of it tomorrow for some interest while same time we get decent sunshine in between after weeks of boring cloudy March weather.

 

Also if we don't get any single snow shower from that deep cold air coming here I will be very shocked because it impossible to stay dry throughout while other countries get snow storms to snow showers activities.  I never see a 5C max here under wall to wall sunshine in April so hope to see something out of it tomorrow for some interest while same time we get decent sunshine in between after weeks of boring cloudy March weather.

 

Given from mid February until the very end and even march we saw virtually no more wintry weather *maybe thanks to the la Nina) or record breaking zonal winds I am hopeful we will see something wintry.

The heat of the day and from warmer land is enough to radiate back put above and help build/enhance shower activity.

Let's hope we see something wintry like good old April's we use to have April 1998 being one of them.

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Sumburgh Airport - in the Shetlands - looks like seeing truly exceptional deep cold air. From the 6z GFS:

http://wxweb.meteostar.com/sample/sample_C.shtml?text=egpb

Screencap for posterity!

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Its so warm and sunny out here now, everyone in their gardens having drinks and BBQs

Hard to believe this time tomorrow its going to feel like winter again

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Sumburgh Airport - in the Shetlands - looks like seeing truly exceptional deep cold air. From the 6z GFS:

http://wxweb.meteostar.com/sample/sample_C.shtml?text=egpb

Screencap for posterity!

Unst, which is a little bit further north is pretty impressive too: 

http://wxweb.meteostar.com/sample/sample_C.shtml?text=EGPW 

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Unst, which is a little bit further north is pretty impressive too:

http://wxweb.meteostar.com/sample/sample_C.shtml?text=EGPW 

501dam - brr!

(Annoyingly the "thickness extremes" charts only have the north of Scotland rather than the Northern Isles:

http://web.archive.org/web/20040212210545/http://www.booty.demon.co.uk/tthkxtrm.htm

I think that's 507dam or so as the record in April, so this spell will be right on the brink of equalling it!)

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501dam - brr!

(Annoyingly the "thickness extremes" charts only have the north of Scotland rather than the Northern Isles:

http://web.archive.org/web/20040212210545/http://www.booty.demon.co.uk/tthkxtrm.htm

I think that's 507dam or so as the record in April, so this spell will be right on the brink of equalling it!)

I am wondering if the North of Scotland chart actually includes or refers to Shetland (based on the reference to 491dam at the bottom of the page). It’s hard to know for definite though.

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Reckon I'm looking at a max tomorrow of about 5C.

 

 

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https://www.shetlandwebcams.com/town-hall-east/ 

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The automated Met Office forecast for Lerwick is absolutely bonkers.

https://www.metoffice.gov.uk/weather/forecast/gfxnjyxk4#?date=2021-04-04 

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Oh joy, winter arrives with a vengeance tomorrow and I am doing outdoor cricket coaching. Terrific.

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So it’s looking more and more likely that tomorrow will be dry here rather than the initial soft hail and snow shower fest I expected.

Are the experts able to dig deeper on what the issue could be assuming things don’t kick off inland tomorrow.

My guess is the the flow is too fast to allow widespread inland convection. Maybe a cold pool with slack winds and strong sun is what’s needed to really allow deep convection to kick off.

Are the forecast ultra low DP’s hindering things too?

I expect the odd light flurry but nothing more.

The temp drop is going to be a real shock. Probably below zero all day on top of the Pennines.

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The change feels like it's beginning to arrive here now. Thick cloud is rolling in from the north west and the wind is gradually picking up. Feeling cooler too.

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Wintry showers now in Orkney

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