Model output discussion - mid-winter

[andymusic]

[karyo]

3 minutes ago, ShortWaveHell said:

Can typhoons on the other side of the globe send the models into a spin? Excuse the pun ! What has caused the ‘flip’ ?!?!?

Is there a typhoon anywhere?

[Dennis]

i know we have to pray for the winter 

[karlos1983]

5 minutes ago, karyo said:

Is there a typhoon anywhere?

No, there is a Tropical Cyclone in the Indian Ocean just east of Madagascar, but that's it. Don't think that can affect NWP for the NH, but I could be wrong..

Edited January 15, 2018 by karlos1983

[karyo]

3 minutes ago, ShortWaveHell said:

Berguitta is due to strengthen into a tropical cyclone , wondered if this confuses models ?

That's in the southern hemisphere so I doubt it can affect our outlook much.

[karyo]

The Aprege 6z offers a slight shift south of Thursday's low. Still too far north for England and Wales to benefit but the shift is important as the Aprege has had the most northerly track so far.

https://www.meteociel.fr/modeles/arpegee_cartes.php?&ech=66&mode=0

[Malcolm Edwards]

20 minutes ago, karyo said:

Is there a typhoon anywhere?

Yeah a couple were sent to intercept Russian aircraft.(sorry i just had to)

 

[karlos1983]

1 minute ago, karyo said:

The Aprege 6z offers a slight shift south of Thursday's low. Still too far north for England and Wales to benefit but the shift is important as the Aprege has had the most northerly track so far.

https://www.meteociel.fr/modeles/arpegee_cartes.php?&ech=66&mode=0

Appears to be a trend this morning. N England perhaps coming back into the game.. 12z will be interesting..

 

[snowstorm27x]

9 minutes ago, karlos1983 said:

Appears to be a trend this morning. N England perhaps coming back into the game.. 12z will be interesting..

 

It certainly is a few more adjustments and NW England will be in the frame for heavy snow again its already moved nearly 100 miles in 6 hours. This morning it was through Northern Scotland now it's through North East England. This afternoon's will be interesting normally when it trends south it just keeps on going.

[Daniel*]

22 minutes ago, karyo said:

The Aprege 6z offers a slight shift south of Thursday's low. Still too far north for England and Wales to benefit but the shift is important as the Aprege has had the most northerly track so far.

https://www.meteociel.fr/modeles/arpegee_cartes.php?&ech=66&mode=0

Very nasty sustained 60mph winds for the north Norfolk coast and extreme east of Lincolnshire as it pulls away.

[karyo]

2 minutes ago, Daniel* said:

Very nasty sustained 60mph winds for the north Norfolk coast and extreme east of Lincolnshire as it pulls away.

Yes, if the low track is placed further south then so will the strongest winds.

As others have already said let's see what happens this afternoon.

[bobbydog]

whats fascinating about this storm is, we are discussing its predicted track within a hundred miles or less, when it doesn't even exist yet! in fact its beginnings are just visible on this mornings charts- 

just a kink in the isobars right now.

already there is a met office warning out for it.

on a side note, my local meto forecast is suddenly showing light snow for me (west sussex) for tomorrow night!

to quote 'Wayne's World' - "yeah, and monkeys might fly outta my butt!"

[weirpig]

lm always weary of the Arpege with windspeeds  however the Icon is also showing Brutal winds for Wales North Midlands and the north of England. Spreading east as it moves away,  certainly a move south on all models.  

[A.J]

I was musing to myself yesterday morning that this nasty little LP for wednesday night/thursday would be tough for the model suites to accurately predict....I saw many hyperbolic posts stating how it would be slamming into Scotland with a flattening of the general pattern afterwards.....so I decided to do a little experiment, lets take each model run (GFS) from the overnight (00z) suites and make an small incremental southwards adjustment on each subsequent run of say 30 miles and see where it ends up come thursday....The answer is that the LP centre would basically traverse the M4 corridor bringing winter nirvana to many!......and then this morning I see Fergie's tweet about there's a possible +/.- margin of error of 250 miles......Now, of course, the reverse could be true, an incremental adjustment northwards of a similar amount would have the LP blasting it's way to the north of Scotland taking the worst of the winds etc across the Shetland Islands...................The moral of the story for some members is don't shoot your bolt too soon, wait and see what pans out...after all, no one likes a messy premature reation? 

[andymusic]

13 minutes ago, ajpoolshark said:

I was musing to myself yesterday morning that this nasty little LP for wednesday night/thursday would be tough for the model suites to accurately predict....I saw many hyperbolic posts stating how it would be slamming into Scotland with a flattening of the general pattern afterwards.....so I decided to do a little experiment, lets take each model run (GFS) from the overnight (00z) suites and make an small incremental southwards adjustment on each subsequent run of say 30 miles and see where it ends up come thursday....The answer is that the LP centre would basically traverse the M4 corridor bringing winter nirvana to many!......and then this morning I see Fergie's tweet about there's a possible +/.- margin of error of 250 miles......Now, of course, the reverse could be true, an incremental adjustment northwards of a similar amount would have the LP blasting it's way to the north of Scotland taking the worst of the winds etc across the Shetland Islands...................The moral of the story for some members is don't shoot your bolt too soon, wait and see what pans out...after all, no one likes a messy premature reation? 

totally agree - the models should give us some long lasting satisfaction and this week looks like it's gonna

[Duane S.]

1 hour ago, ShortWaveHell said:

Can typhoons on the other side of the globe send the models into a spin? Excuse the pun ! What has caused the ‘flip’ ?!?!?

Big time it can send the models into a spin.

Had a phone call last night from the mother in law, who spends 7 odd months a year in Mauritius (a win win situation).

Port Louis is on full alert for a direct hit. They are hoping it will be a near miss but it could be a big one should it hit (it is relatively rare for Mauritius).

When I checked yesterday it was strengthening over the very warm IO waters.

[tight isobar]

On 13/01/2018 at 22:58, tight isobar said:

Higher/lower resolution are as useful as an, ashtray on a motorbike as things stand- @day6-8..

Its model diabolics, as the switch is on' and the instablility will throw nwp into meltdown for obvious reasons via our maritime positioning...

Some substantial weather in the offing..

And big ramifications @around day3/4 for evolvement!!!

Have faith!..

Mods clearly on mass-confusion..

As n-hemisperic state is in a tangle itself..

I think some of us 'fully expected' miss modeling/divergance etc.

Nwp trying to get to grips here, but we are @cross roads via modeling of exactions and higher possibilities of favourable handle/synoptics for colder persuasion as evolvement straightens out!

Edited January 15, 2018 by tight isobar

[bluearmy]

The 06z  GEFS again show the weekend and into the early part of next week as being far from pinned down.   

[Nick F]

3 hours ago, carinthian said:

Latest GFS has the low further south on 06h run. Maybe start of a correction on the main models. Think UKMO raw output charts may be showing this, hence some uncertainty in the media forecasts. Anyway looking at the GFS 850mb temp chart , still a cold block over and to the NE of the British Isles and showing some resilience again in these charts. Interesting week ahead ! Wonder if we are going see another flip . Report back later .

 C

Although the operational runs have been churning out some rather unsavoury medium range charts for coldies yesterday and this morning, there does does appear to be quite a large spread developing in the ensembles from around the Sun 21st after winds briefly veer northwesterly or even northerly the day before. Could be that quite a few members are building a bit more of a ridge / weak block ahead of the next lobe of the trop PV that tries to push east out of NE Canada and turn the flow zonal / westerly. So perhaps we may see more of a delay than models currently show to the return Atlantic zonal onslaught early next week, with more of ridge perhaps forcing the jet a little further south as a result.

 

 

[Man With Beard]

Cluster 1 on the ECM ensembles was interesting this morning - Scandi ridge - Is this the @iapennell easterly about to strike for the end of January?

Looking at the last few cluster sets, this might be an emerging trend

[bluearmy]

15 minutes ago, Man With Beard said:

Cluster 1 on the ECM ensembles was interesting this morning - Scandi ridge - Is this the @iapennell easterly about to strike for the end of January?

Looking at the last few cluster sets, this might be an emerging trend

Was just about to reference these MWB - certainly a nice surprise given the mean. 

[Donna3397]

I know that the daily star is not a legitimate weather forecast company and that they tend to go a bit crazy about snow but I was reading an article and they did show the arpege map and the whole of the uk covered in snow. I checked the date. I’m so confused about what the weather is up to. Some models are showing one thing some completely different things

[nick sussex]

Just caught up with the outputs .

The GFS slowly increasing the upstream amplitude and some of the GEFS are interesting however the UKMO is really much flatter.

Again it’s the handling of that shortwave over Arctic Canada which it pushes southeast  because it’s flatter further upstream .

The UKMO fails to phase shortwave energy over the ne USA, the GFS does so there’s a lot of uncertainty starting well before T96 hrs.

We have to hope the UKMO will backtrack because it’s output is poor, it has been noted by NOAA that it’s solution is the most progressive of any but you can’t rule it out because the models are making a real drama over phasing upstream .

We’ll see in a few hours !

Edited January 15, 2018 by nick sussex

[karlos1983]

10 minutes ago, DonnaThw said:

I know that the daily star is not a legitimate weather forecast company and that they tend to go a bit crazy about snow but I was reading an article and they did show the arpege map and the whole of the uk covered in snow. I checked the date. I’m so confused about what the weather is up to. Some models are showing one thing some completely different things

They (tabloids) have one motive and one motive only, to sell papers. I always roll my eyes when my friends or family say, have you seen the papers today? 3 weeks of snow and subzero temperatures. 

APERGE for example, away from Scotland, shows Snow accumulating on high ground almost exclusively across the UK for the next 72 hours

Edited January 15, 2018 by karlos1983

[carinthian]

48 minutes ago, Nick F said:

Although the operational runs have been churning out some rather unsavoury medium range charts for coldies yesterday and this morning, there does does appear to be quite a large spread developing in the ensembles from around the Sun 21st after winds briefly veer northwesterly or even northerly the day before. Could be that quite a few members are building a bit more of a ridge / weak block ahead of the next lobe of the trop PV that tries to push east out of NE Canada and turn the flow zonal / westerly. So perhaps we may see more of a delay than models currently show to the return Atlantic zonal onslaught early next week, with more of ridge perhaps forcing the jet a little further south as a result.

 

 

Funny enough Nick, your words are exactly to what I have just heard from our portal forecasting providers over here. Where did the winter wonderland charts shown by many models at the end of last week go wrong or even did they I ask ? No real explanation, just wrong footed by what they were seeing. Think most forecasting agents were sure of the model outputs being correct at that instant . Their own model they tell me  was in the high certainly percentage range  to be heading for a full on protracted cold spell for UK and much of Euroland. Now the flip, was it too extreme and progressive over the weekend ? The answer from them, yes. Their shorter range model still has some concern about the low to enter the UK mid week, however the model is showing a disturbance in the flow rather than a full on low at this stage of proceedings. So a bit more southerly track envisaged but open to lot of uncertainty. Medium range charts hint as NF has posted , more of a delay to milder than previously shown on charts yesterday and look too progressive . Still some resilient cold upper over UK and more so to the NE as we enter next week. So perhaps the colder outlook charts not entirely dismissed, not exactly a full flip expected but a watering down of the much milder outcome for next week.

Finally, just to let you know the snowfall was constant this weekend but light, however visibility on the mountain was very poor. So it was mostly in the pub with my old cricket pals currently out here from blighty. Mrs C cooked up Roast Beef and Yorkshire pudding for all followed by her mother famous recipy for Apple Strudel and Vanilla Custard. Perfect ! Today the clouds have lifted and excellent ski-ing to be had on almost empty pistes.

C

 

 

 

 

Edited January 15, 2018 by carinthian