That is truly unbelievable. I guess if it's going to hit us, it may as well be record breaking. Personally I want this like a bullet in the head, but what will be will be.

It would probably not be record breaking even if it did reach 507dam...

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

Even for Kent, the record in April is 510dam. That won't have happened for many a year!

I'd love to see the effects of it, mind you; strong April sunshine plus deep cold air is a recipe for some fantastic convection.

Down here the runs are see-sawing around with the extent of any cold pluming and, as usual, I'm not expecting to see anything wintry (aside from perhaps some hail if I'm really lucky). Even a frost is an outside chance as it'll just be too windy for most of the time.

I'm more interested in the wild swings in temperature next week, with the 12z GFS for MBY showing a high of 18C on Wednesday followed by a high of just 8C on Thursday as a chill NE'ly blows in. That'd be worth experiencing but I suspect it'll be moderated somewhat! The action actually happens on Wednesday evening, with 16C at 4 PM and 7C at 7 PM as the wind veers.

(EDIT: Of course, given cold air aloft a quick and shortlived swing in temperatures is quite normal for April, but this wholesale switching of airmasses is something more than that - something quite special if it comes off.)

 

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GFS Control a Plant killer. insects might get the chop too. Wont complain about that!

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The GFS12z has a 1104hpa greenland high.

I'm not kidding.

 

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The GFS12z has a 1104hpa greenland high.

I'm not kidding.

 

 

Yes it seems to be producing some ridiculous extremes since the upgrade.  Other models look much more realistic. 

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The GFS12z has a 1104hpa greenland high.

I'm not kidding.

 

I see 1080 in the control that's it!? Is the operational the new para then?

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I see 1080 in the control that's it!? Is the operational the new para then?

https://meteologix.com/uk/model-charts/standard/greenland/sea-level-pressure/20210404-0300z.html

 

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https://www.theweatheroutlook.com/twodata/chart.aspx?chart=/charts/gfs/12_183_mslp500.png 
1100hpa...hmmm

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I've checked on windy. The centre is actually 1107mb!

Its probably even higher than that on the 1hr charts!

 

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I've checked on windy. The centre is actually 1107mb!

Its probably even higher than that on the 1hr charts!

 

The record as far as I can see is only 1083mb so this is just nonsense from GFS. 

 

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Excellent 18z GFS! 

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Excellent 18z GFS! 

How about this then? It's from one of the ensemble members this morning.

https://www.meteociel.fr/modeles/gefs_cartes.php?code=12&ech=192&mode=1&carte=0

(EDIT: And thinking what Q said about ice days, -14.2C at 850 here gives a high of 0.5C. Looks like it'd be -15C or even colder to gaurantee an ice day at this time of year. )

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16-dayer much as yesterday, though  n more rain around and over the Uk in week 2

Jetstream - the current W-ly splits into a branch to the N of the UK and another over Spain; by Fri 2nd the N branch has curled round to visit the UK from the N while the S branch has fragmented. Through the following week the N branch predominates at first, with the UK on the inside of a loop centred N Atlantic while the S branch re-organises and gathers strength to become the major feature by Thu 8th. Finally on Mon 11th the system is back to a point where the Atlantic feed splits into two one running across Scotland and the other through the Med.

GFS - brief burst of warmth Tue/Wed of this week as HP brings up a plume from the S but by Fri 2nd the HP has moved to SW Iceland 1040mb and N/NE winds are setting in over the UK. The real action starts on Tue 6th with LP moving down form the N ro be over NI 965mb  and extreme N-ly Gales off the W coast. That LP stays and slowly fills until being displaced by Atlantic SW-lies from Sun 11th. [the extended BBC last night also had a large blob of LP with snow moving down from the N on Mon 5th]

GEFS - as noted previously temps are high this week but fall off a cliff Fri 2nd (a day later than previous, and less notable in the N) and then dip further around Tue 6th everywhere (most runs 7 or 8 C below norm, one outlier 20C below!) before struggling back to norm Tue 13th. Rain Mon 5th onward, rather more than previously in the S, also an earlier burst this week in NW.

ECM - has a slower build-up of cold weather but similar LP in position Wed 7th with N-ly feed 970 mb S Ireland

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Looks less and less likely that the cold plunge gets here, thank heavens. Warm air hanging on longer next week turning the first cool down into a toppling high pressure, then low pressure getting involved once the second big northerly flow sets up (as depressions are wont to do, with the instability) and deflecting the cold air westwards.

Thats the ECM, but GFS does much the same by the look of things.

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An Arctic plunge that was over-modelled and is then subtlety delayed before it gradually fades in depth and longevity as the original time approaches.
What a shocker! 😂😂

One day a sharp and deep Northerly in virtual space might actually happen but I won’t hold my breath.

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You can blame (or indeed thank) me for this one.

Yesterday I said to my other half - “it looks to be bitterly cold over Easter, it might even snow.”

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You can blame (or indeed thank) me for this one.

Yesterday I said to my other half - “it looks to be bitterly cold over Easter, it might even snow.”

 

well done. Nobody wants snow and cold at this time of year. Great to see that the models are rolling back from it.

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well done. Nobody wants snow and cold at this time of year. Great to see that the models are rolling back from it.

Yes good if in another few runs the warmth remains and it's all deflected away from the UK.

It’s the cold around the 5th and 6th that we really need to see diluted (unless cold in April is your thing).

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OH MY GOD.

Ensemble 12 on the 0Z

No words.

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I've hunted for exceptionally cold ensembles for several years. Occasionally you find record breakers.

The all time UK record T850, as far as I'm aware is -19.5C which was set in Kent during the January 1987 cold wave.

 

In actuality I've never seen T850s lower than about -17C (possibly set during the 2018 cold spell) but occasionally you do get ensemble forecasts that  get a bit lower. I've seen some ensembles get to around -21C for example.

But never, never have I seen -23.5C which is extraordinary before we even discuss the month.

 

 

 

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