Model output discussion - deep cold inbound?

[Kentspur]

3 minutes ago, Harsh Climate said:

Fax chart for saturday. Oh my looks perfect to me! Heavy snow showers spreading down the whole eastern side of the UK! 

 

Genuine question as I'm not the greatest at reading fax charts- would this be snow down in the south, or still rain/sleet?  every post thats deemed great atm ( I anxiously wonder automatically if its great for everywhere apart from the south/SE) where weve been burnt all winter long down here

[DAVE_ALLEN]

ECM @ 72+ has a small High Cell appearing over Poland.  Lets hope this doesnt affect the limpet low moving away later in the run to the SE.  

[bluearmy]

5 minutes ago, Harsh Climate said:

Fax chart for saturday. Oh my looks perfect to me! Heavy snow showers spreading down the whole eastern side of the UK! 

 

that was issued yesterday evening

9 minutes ago, pages said:

Do the met office see ECM before it rolls out to public? Or do we think their latest update is just from what mogreps show?

 

no

10 minutes ago, TSNWK said:

What is telling on that graphic is that there is no sign of any Iberia low pumping up mild air towards us.. of course we don’t know the key but just look at it and compare with 144 on GFS

the beeb forecast is raw ec op …...can people please stop putting it in here - we know what the last ec op looks like without having to see it on a bbc forecast !!!!

[Mike Poole]

ECM T96, somewhere between UKMO and GEM, I reckon here:

[If Wishes made Weather]

A question for someone who has a good technical understanding of the models.

I understand that the op run is produced at higher resolution than the control.  So its data output should have a higher predictive value.

In calculating the mean value charts then is the op run ‘discounted’ so that every member of the set is treated equally (giving an even mean), or if not, the mean must surely always have a bias to the op run sort of built into it.

Many thanks anyone

[Timmytour]

1 minute ago, DAVE_ALLEN said:

ECM @ 72+ has a small High Cell appearing over Poland.  Lets hope this doesnt affect the limpet low moving away later in the run to the SE.  

Gone at T96 I think

[DAVE_ALLEN]

1 minute ago, Kentspur said:

Genuine question as I'm not the greatest at reading fax charts- would this be snow down in the south, or still rain/sleet?  every post thats deemed great atm ( I anxiously wonder automatically if its great for everywhere apart from the south/SE) where weve been burnt all winter long down here

On that fax chart at that time stamp I would say snow or hail most likely from The Wash across to Chester, north. Maybe further south later on if the fronts move S or SSW later.

[WINTRY WALES]

1 minute ago, bluearmy said:

that was issued yesterday evening

no

the beeb forecast is raw ec op …...can people please stop putting it in here - we know what the last ec op looks like without having to see it on a bbc forecast !!!!

Have you just stubbed your toe or something blue?

[chris55]

1 minute ago, Mike Poole said:

ECM T96, somewhere between UKMO and GEM, I reckon here:

Looks identical to GEM to me.......

[That ECM]

Is that the low over spain Kold has spoken about once or twice?

[Mike Poole]

Just now, That ECM said:

Is that the low over spain Kold has spoken about once or twice?

Yes, but it doesn’t look anywhere near as influential as the GFS run.

[Harsh Climate]

6 minutes ago, Kentspur said:

Genuine question as I'm not the greatest at reading fax charts- would this be snow down in the south, or still rain/sleet?  every post thats deemed great atm ( I anxiously wonder automatically if its great for everywhere apart from the south/SE) where weve been burnt all winter long down here

In my opinion the met office are going 100% with their own model the UKMO which as you can see is picture perfect.

In the fax chart's own right for saturday 12z which it shows, would probably be more sleet and rain the further south east you head. But look at the position of that occluded front straddling the country and changing frames from friday to saturday, later saturday any sleet/rain would be turning more readily to snow and by sunday would be frequent snow showers blowing in on strengthening easterly winds!

Edited February 2, 2021 by Harsh Climate

[Griff]

Looks ok

[Chris.]

 

Sticking to its guns?

[Mike Poole]

ECM T120, pulling away to east, but a little further north than I’d like:

The next low is clearly going under so should be OK

 

Edited February 2, 2021 by Mike Poole

[Cloud 10]

ECM 96hrs,great cross-polar flow example.

 

edit.for 120hrs BOOM!

 

Edited February 2, 2021 by Cloud 10

[Bartlett High]

16 minutes ago, lawrenk said:

Just need that cold over us to more closely match the colour of her dress.

Just look at those uppers!!

[That ECM]

5 days time.

[chris55]

3 minutes ago, If Wishes made Weather said:

A question for someone who has a good technical understanding of the models.

I understand that the op run is produced at higher resolution than the control.  So its data output should have a higher predictive value.

In calculating the mean value charts then is the op run ‘discounted’ so that every member of the set is treated equally (giving an even mean), or if not, the mean must surely always have a bias to the op run sort of built into it.

Many thanks anyone

Im no expert, but I see the mean as "one of the tools" used to make a forecast, though it is mainly used in the mid term (day 5 plus) to gauge the broader pattern.

The Operational is the starting point, and the main run. 

The ensembles will show the confidence in the operational run, that is the only reason the ensembles are run alongside the operational. The spaghetti graphs are best the way to judge the likelihood of the Operational being correct in its forecast. Tight clustering means high confidence, low clustering or scatter means low confidence. 

[Man With Beard]

T120 ECM - no significant change from the morning's run. Very good sign. ECM op is capable of running down to T0 from this point

[tight isobar]

Ecm 12z runnin.. the GEFS are 7 outta 10’s... on scale @dynamics.. the arming of Euro heights are the thorn.. but it’s how can run the fastest.. whom gets to the midway point... jogs.. and stabilise!!.. @easterly inflow.. or advecting height yo temper the situ.. @examples..

[Mark wheeler]

Just now, Lloyd1 said:

Does anyone have any idea how long this cold snap will be in for? BBC Weather seem to think this spell will last only till the 10th February and get milder thereafter. Haven't looked at previous comments so sorry if this has already been discussed. 

We don’t know how the weekend will pan out and is why many are here to find out , enjoy the ride as we find out together. Any Ecm ok at 120 

[Johnp]

Just now, Lloyd1 said:

Does anyone have any idea how long this cold snap will be in for? BBC Weather seem to think this spell will last only till the 10th February and get milder thereafter. Haven't looked at previous comments so sorry if this has already been discussed. 

Lol - we don't even know if there will be a cold spell, let alone when it will end.

[MJB]

1 minute ago, Mike Poole said:

ECM T120, pulling away to east, but a little further north than I’d like:

Cold enough Mike and still plenty of time for a correction S/SE

[kold weather]

Slightly further north from the ECM which keeps an onshore flow further south whilst a heck of a snow event happens over the northern half of the country. That may sink south further at the run goes on but probably not too much more.

I think the models are coming towards a conclusion (apart from the GFS) for a snow event further north, the cold probably just about making it further south but less snow than further north.