Winter Model Discussion 18Z 5/2/13 onwards.

[Ryan Dutch Weatherman]

http://img812.imageshack.us/img812/5240/2766784.gif

[Panayiotis]

Very good and very interesting ensembles for 264hrs, with heights over Spain low (vital if we want cold and no zonal weather) and low pressure just to the south, this puts us into a v.snowy and cold feed from the east, within 11 days things could get interesting again, so far im not seeing the SW/W regime that the Metoffice seem to be hinting.

Edited February 6, 2013 by Panayiotis

[LomondSnowstorm]

a request please?

Does anyone know of a link that show what the average height over the north Atlantic is for February, say the past 25 maybe 50 years?

I cannot find any link that gives long term averages.

I will drop an e mail to UK Met to see if they can help as well.

thanks to anyone in advance if they can help.

John

http://www.esrl.noaa...es/printpage.pl I used this to plot it:

For different periods e.g. 61-90, 81-00, just enter in different years on the site and then hit plot.

A clear but slight increase in heights generally from January, as expected:

Edited February 6, 2013 by LomondSnowstorm

[Snowman.]

Gfs would most likely drop that slider low only for the ecm to pick it up. Would typical really.

[bradymk]

Last post from me tonight.

18Z GEFS mean at +240.

Atlantic moving in? No chance based on the above.

Keep an eye out tomorrow for an incredibly cold airmass to surge S out of the Arctic in the model output in FI.

GEFS mean is impressive along with the whole model suite, ECM ens not singing the same tune in regards to a potential very -ao next week. Big support for mid atlantic ridge from GEFS and staying below avg as shown by GEFS and EC Ens.

[Jason M]

Based on GEFS I think the earth has started spinning in the opposite direction. Running through them I could only find 2 westerly runs. Looks like our weather will be coming from the east for the forseeable.

After mid month, perhaps some deep cold. TEITS is spot on re very cold uppers in feb. you do need it colder at 850 level as feb wears on but ice days are still possible.

Jason

GFS not so bad after all :-)

[Mucka]

GFS 18z ensembles SE look a lot colder than ECM set.

http://176.31.229.22...un=18&runpara=0

http://modeles.meteo...un=18&runpara=0

Quite unusual to see snow probability forecast to above 30% for the entirety of FI.

Edited February 6, 2013 by Mucka

[Captain Shortwave]

Based on GEFS I think the earth has started spinning in the opposite direction. Running through them I could only find 2 westerly runs. Looks like our weather will be coming from the east for the forseeable.

After mid month, perhaps some deep cold. TEITS is spot on re very cold uppers in feb. you do need it colder at 850 level as feb wears on but ice days are still possible.

Jason

GFS not so bad after all :-)

Absolutely amazing. You have to think if we can get to this time this week and have a decent strong block to our north east with the atlantic on it's last legs I think we would be in with a great chance of a great cold spell.

Also the strengths and frailties of the gfs will be fully exposed. Can't predict a slider low at T92 but can pull out a block to the north west from T300. You can only laugh at that

[Ryan Dutch Weatherman]

Can somebody help me with the latest charts from the AO end NAO , i prefer those from weatherbell charts , but otherwise is also gut.

[grca]

Can somebody help me with the latest charts from the AO end NAO , i prefer those from weatherbell charts , but otherwise is also gut.

Here you go:

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.shtml

[Just Below Zero]

Absolutely amazing. You have to think if we can get to this time this week and have a decent strong block to our north east with the atlantic on it's last legs I think we would be in with a great chance of a great cold spell.

Also the strengths and frailties of the gfs will be fully exposed. Can't predict a slider low at T92 but can pull out a block to the north west from T300. You can only laugh at that

Someone said this afternoon that GFS cant detect sliders. The 18z has them coming along like buses. We are waiting at the next stop

[Zenarcher]

Glad it is not just me that thinks that , Can't really see Weathermasters view .. I think he called it way to early in the run,

Sorry a bit late for posting this as I said early in the morning about the GFS 00z run within the short time range we saw the GFS slide more over to agree with the ECM, the overall outcome of the 00z GFS wasn't too great but the early improvements proved that the GFS was sliding more to the ECM.

Today the GFS has started to show what the UKMO and ECM have been saying for a while now.

What the 00z GFS really needed was more energy to go under the block the 00z did make a slight attempt at it,

Meanwhile the ECM has more going under the block

06z GFS had more energy going under the block compared to the 00z

Then the 12z run continued to increase it,

And now the 18z continues to make the shortwaves stronger,

Now when you compare the 18z to this mornings 00z ECM the GFS has slowly throughout the day improved

[Ryan Dutch Weatherman]

The Artic Ossilation , Ao is going strong -ve i see.

This could be in for spectacuair unpredict weather patterns.

We could be in for a lons periode of colld spells , sometimes for britain an intermezzo for couple of day s ,.

But i dont see the zonale jetstream at al coming for a long time.

Even begin march we could be in for coll artic aoutbreaks or NE , with lot os snow.

Also i notice that doctor Piers Corbijn make some new comments about it.

At 8 februari something will occur at de the nordpool with the solar winds , that wil means that we wil be in for surprises.

[weather eater]

Well just got a chance to look at the 18z, a real danger the GFS could get popular, it would be just like the GFS to catch up the Euros, wait for them to go off the boil and then pick the path ahead, meanwhile the ECM having found the Easterly first scratches around not knowing quite what to do with it. Keep in mind this is the 18z we are talking about here, not everybody’s cup of tea, even for the unrated GFS its reckoned to have little merit, the 00z will be interesting in the morning .

[grca]

The Artic Ossilation , Ao is going strong -ve i see.

This could be in for spectacuair unpredict weather patterns.

We could be in for a lons periode of colld spells , sometimes for britain an intermezzo for couple of day s ,.

But i dont see the zonale jetstream at al coming for a long time.

Even begin march we could be in for coll artic aoutbreaks or NE , with lot os snow.

Also i notice that doctor Piers Corbijn make some new comments about it.

At 8 februari something will occur at de the nordpool with the solar winds , that wil means that we wil be in for surprises.

Hi Ryan...

Just a quicky, but to my knowledge and I am happy to be corrected but the NAO and AO predictions you are looking at are coming from the GFS output, therefore whatever the output of the particular run (ensemble) that is predicted by that run = the data you see on the AO NAO predictions.

Therefore this is not maybe not the best indicator of the cross model interpretation.

Best check back on future outputs to see consistency, then you have some idea if it is more likely to become reality...

[Panayiotis]

Hi Ryan...

Just a quicky, but to my knowledge and I am happy to be corrected but the NAO and AO predictions you are looking at are coming from the GFS output, therefore whatever the output of the particular run (ensemble) that is predicted by that run = the data you see on the AO NAO predictions.

Therefore this is not maybe not the best indicator of the cross model interpretation.

Best check back on future outputs to see consistency, then you have some idea if it is more likely to become reality...

Yes very true, they only reflect what the models show, they do not drive the weather.

[Ryan Dutch Weatherman]

The Artic Ossilation , Ao is going strong -ve i see.

This could be in for spectacuair unpredict weather patterns.

We could be in for a lons periode of colld spells , sometimes for britain an intermezzo for couple of day s ,.

But i dont see the zonale jetstream at al coming for a long time.

Even begin march we could be in for coll artic aoutbreaks or NE , with lot os snow.

Also i notice that doctor Piers Corbijn make some new comments about it.

At 8 februari something will occur at de the nordpool with the solar winds , that wil means that we wil be in for surprises.

End This is wat i mean , with all of this .

CFS 12z is supporting my vision.

1 march 2013 , the winter starts for UK .

[East_England_Stormchaser91]

That is the reason why the odds are more favoured for a white easter over christmas! Snow potential is so good at this time of the year, I believe because the PV is on a more weakening trend on average as we head toward spring, thus allowing for more colder outbreaks to dig further South, whereas December normally sees the PV at its strongest.

[be cause]

That is the reason why the odds are more favoured for a white easter over christmas! Snow potential is so good at this time of the year, I believe because the PV is on a more weakening trend on average as we head toward spring, thus allowing for more colder outbreaks to dig further South, whereas December normally sees the PV at its strongest.

for me it's the cold sea that causes more snow in spring .. it certainly used to before the art of modelling tried to call itself a science

[Crepuscular Ray]

That is the reason why the odds are more favoured for a white easter over christmas!

Could you explain the mechanism for this, perhaps?

[ScottSnow]

Could you explain the mechanism for this, perhaps?

They do if you read a bit further. I am sure statistically your more likely to see a white Easter than a white Christmas.

[Crepuscular Ray]

They do if you read a bit further. I am sure statistically your more likely to see a white Easter than a white Christmas.

Including when Easter is in mid-April? OK, I live in the south of England, but in 49 years I remember snow over Christmas a couple of times, but over Easter, never.

[Crepuscular Ray]

They do if you read a bit further. I am sure statistically your more likely to see a white Easter than a white Christmas.

Not where I live in the south-east.

[andy100]

Easter is coming anyway buddies

[Dave Kightley]

Slightly further west on the GFS 00z