Model Output Discussion - heading into April

[ItNeverSnowsInWindsor]

2 minutes ago, cyclonic happiness said:

it'd be good, it would help keep people indoors

Only the miserable lot who hate snow would stay indoors!

[Wilxy]

2 minutes ago, cyclonic happiness said:

it'd be good, it would help keep people indoors

But it would make it harder for key workers to get to and from work if there is disruption to travel because of snow!

[snowray]

OMG this is probably the best chart this year that I've seen, slider into very cold air, heavy snow event...Madness!

[stodge]

Evening all

An interesting set of 12Z outputs with sliders and shortwaves aplenty to keep us all guessing, I've ended up dazed and confused so a summary of sorts:

UKMO: dry but increasingly chilly with -8 850s into early next week. IF we get some clearer air overnight frosts (and quite sharp frosts) look certain but so much depends on the cloud in the circulation of the HP.

GEM: Not quite as good for the cold fraternity as you might expect from the 500HPA synoptics. The retrogression is clean enough but instead of a straight line N'ly, we get the trough coming in from Europe so a lot of cold rain with -4 850s.

GFS Control and OP: Curious runs to this observer. Retrogression is thwarted by shortwaves but northern blocking sets up and the Atlantic in far FI tries to come back on a delayed by a deep LP which forms to the east of Greenland and moves east rather than SE so the N'ly is transient and as usual back comes the PV and the Atlantic in far FI but with the jet displaced to the south of the British Isles.

ECM: Again, no real retrogression but the Scandinavian trough becomes the main influence and LP becomes negatively aligned pushing SE against some very cold air in situ. To be honest, I look at ECM and think higher elevations might well see some snow from the T+240 set up - frontal rain pushing into -8 850s could mean snow for the Pennines and Peaks perhaps (all very alliterative, I know).

My conclusion is there's a lot of confusion post T+144. There's plenty of options around the fate of the large HP to the NW - will it retrogress, decline SW or decline over the British Isles? I'm none the wiser.

 

[shaky]

9 minutes ago, stodge said:

Evening all

An interesting set of 12Z outputs with sliders and shortwaves aplenty to keep us all guessing, I've ended up dazed and confused so a summary of sorts:

UKMO: dry but increasingly chilly with -8 850s into early next week. IF we get some clearer air overnight frosts (and quite sharp frosts) look certain but so much depends on the cloud in the circulation of the HP.

GEM: Not quite as good for the cold fraternity as you might expect from the 500HPA synoptics. The retrogression is clean enough but instead of a straight line N'ly, we get the trough coming in from Europe so a lot of cold rain with -4 850s.

GFS Control and OP: Curious runs to this observer. Retrogression is thwarted by shortwaves but northern blocking sets up and the Atlantic in far FI tries to come back on a delayed by a deep LP which forms to the east of Greenland and moves east rather than SE so the N'ly is transient and as usual back comes the PV and the Atlantic in far FI but with the jet displaced to the south of the British Isles.

ECM: Again, no real retrogression but the Scandinavian trough becomes the main influence and LP becomes negatively aligned pushing SE against some very cold air in situ. To be honest, I look at ECM and think higher elevations might well see some snow from the T+240 set up - frontal rain pushing into -8 850s could mean snow for the Pennines and Peaks perhaps (all very alliterative, I know).

My conclusion is there's a lot of confusion post T+144. There's plenty of options around the fate of the large HP to the NW - will it retrogress, decline SW or decline over the British Isles? I'm none the wiser.

 

Surely that slider would be all snow down to all levels as it hits the -8 850 temps regardless of the time of year!!

[snowray]

20 minutes ago, TomW said:

But it would make it harder for key workers to get to and from work if there is disruption to travel because of snow!

It's not January Tom, be all gone by lunchtime in April, well this is normally what happens anyway. Although come to think of it, I'm not so sure if this would be the case should that D10 chart verify, some places could indeed get a dumping so might cause disruption, less than 5% chance of something like that coming off.

Edited March 25, 2020 by snowray

[cheshire snow]

10 minutes ago, prolongedSnowLover said:

Only the miserable lot who hate snow would stay indoors!

Only the sensible ones who like snow will stay indoors An unbelievable post under the current circumstances ECM as other have said would bring snow to most places.To be honest I am not really bothered Give me todays 16.8c and blue skies anytime.

C.S

[ItNeverSnowsInWindsor]

21 minutes ago, cheshire snow said:

Only the sensible ones who like snow will stay indoors An unbelievable post under the current circumstances ECM as other have said would bring snow to most places.To be honest I am not really bothered Give me todays 16.8c and blue skies anytime.

C.S

We’re all allowed one exercise a day!

[Allseasons-Si]

That's quiet an impressive ECM mean at 192.

 

[snowray]

8 minutes ago, Allseasons-si said:

That's quiet an impressive ECM mean at 192.

 

Surely is...So what are the chances then that everything will be back on course with the gfs on this evenings 18z run I wonder?

[lassie23]

Don't tell me .........it's back on again

23 minutes ago, snowray said:

Surely is...So what are the chances then that everything will be back on course with the gfs on this evenings 18z run I wonder?

 

[Tim Bland]

1 hour ago, snowray said:

It's not January Tom, be all gone by lunchtime in April, well this is normally what happens anyway. Although come to think of it, I'm not so sure if this would be the case should that D10 chart verify, some places could indeed get a dumping so might cause disruption, less than 5% chance of something like that coming off.

Sleet or wet snow on the ECM day 10, fine margins though, will be different on the next run. At this time of year it’s never going to be powdery long lasting snow 

[snowray]

7 minutes ago, lassie23 said:

Don't tell me .........it's back on again

 

Might be ..................might be not

Lets throw some dice

[lassie23]

7 minutes ago, snowray said:

Might be ..................might be not

Lets throw some dice

If the cold is still showing by April the 30th then it's nailed on

[Ben Lewis]

1 hour ago, TomW said:

But it would make it harder for key workers to get to and from work if there is disruption to travel because of snow!

It’s 10 days away. 
 

0.5% chance of verifying 

[Chesil View]

Blimey a springtime slider on tonight's ECM. Haven't seen one those since The famous April 81 blizzard.

[MATTWOLVES 3]

1 hour ago, lassie23 said:

If the cold is still showing by April the 30th then it's nailed on

If the cold is still showing by the 30th of April lassie, we  really are in trouble this spring.. Plenty of colder Conditions for the weekend and into next week... Gardeners beware... Protect those delicates..

[snowspotter]

Without posting loads of charts I have to say the eastward progression of the high pressure placement , shunting the cold air for weekend east of us is quite frankly entirely predictable. Just obvious really . After many a year watching the models they are still totally useless in these situations . You have to seriously question the credibility of the GFS however many upgrades it has had . When was the last time closer to the time the high pressure moved more favourably towards Greenland ? 

[stainesbloke]

2 hours ago, prolongedSnowLover said:

We’re all allowed one exercise a day!

True! Though much of the UK population also find it incredibly easy to exercise stupidity

[feb1991blizzard]

GFS 18z is a stonker.

[Allseasons-Si]

2 minutes ago, feb1991blizzard said:

GFS 18z is a stonker.

It gets the lower 850's in sooner but(there's always a but ha!ha!) i am not liking the heights to our NW on this run,see how she goes eh.

[feb1991blizzard]

Just now, Allseasons-si said:

It gets the lower 850's in sooner but(there's always a but ha!ha!) i am not liking the heights to our NW on this run,see how she goes eh.

Yes, couldn't manage the proper Greeny in so the -8c doesn't get right the way down the country like on the ECM

 

[Allseasons-Si]

1 minute ago, feb1991blizzard said:

Yes, couldn't manage the proper Greeny in so the -8c doesn't get right the way down the country like on the ECM

 

Just another variation of the same theme with the northerly,we just don't wan't a weakened/toned down variation,until these heights to our NW are nailed on closer the time,it will swing on roundabouts as usually does,the models was showing a northerly for this weekend last week,now we get a tame noreaster with the odd wintry shower

let's see where it sits in the ens later,it could be a mild outlier.

 

[Zak M]

Tomorrow looks like an exact repeat of today, with unbroken sunshine across the majority of the UK, and cloud and rain northern areas.

      

Thursday morning

On Thursday morning, the majority of places (e.g. most of England and Wales) will wake up to some nice, bright sunshine to start the day.

Across parts of northern England, Northern Ireland and Scotland, it will be the exact opposite - with cloud and patchy rain over these areas. If some places in the UK dip near/below freezing, then frosts could follow.

Speaking of the temperatures, it will be a cold morning across southern and central areas, with temperatures in the south ranging from -2 - 8c, and in the north, they should range from 4 - 8c.

      

Thursday afternoon

On Thursday afternoon, parts of south and central England will still see some sunshine, perhaps unbroken in places. The odd high level whisp of cloud can't be ruled out.

The cloud and patchy rain will also continue over northern parts of the UK, becoming wet in these places.

The majority of England will see a sharp rise in temperatures from the morning into the afternoon due to the strong spring sunshine, so it will feel very mild, with temperatures in the south ranging from 10-15c, and ranging from 7-12c in the north.

      

Thursday evening

On Thursday evening, it is the exact same picture as the morning and afternoon, with unbroken sunshine possible for the majority of England and Wales, and patchy cloud and rain possible in northern England, Northern Ireland and Scotland. 

If you live in a place where sunshine is likely tomorrow, then some of the sunlight reflecting off the high level cloud in the evening could lead to some pretty cool sunsets.

Temperatures in the evening in the south should range from 3-8c, and should range from 4-8c in the north.

      

Looking ahead

At the end of March, it is likely that we could have a little bit of a cold plunge to the east of the British Isles, bringing in some showers, perhaps falling as hail/sleet/snow in places. However, waiting in the Atlantic right afterwards, is an area of high pressure. The GFS 18z is showing the high dominating the UK at the end of March and into the start of April. But then again, another cold plunge could follow after the high, bringing some colder weather, particularly over parts of the north and Scotland.

         

Enjoy your Thursday! 

[Allseasons-Si]

The control is a peach at day ten and is very similar to the ecm