Model Output Discussion

[Frosty.]

Even though the ECM 12z only gives us a 1 day Northerly blast, further on it has a nicer jet axis more NW / SE and a chance of reloads, unlike the dire gfs. Still time for improvements but also downgrades, shame the ecm 00z was not a trend setter. I don't think it's worth building my hopes up about a N'ly just as the E'ly idea failed miserably.

[aspire27]

All I'm saying is watch out for a Greenland strong Block forming Mid Feb or just before. I can't say anything else because the people I speak to are not aloud to release this early . I will say it looks like WAA looks to become our friend.

I agree the first attempt at the Northerly will be a 48hr topple because the state of the atmosphere currently means that this is the most likely outcome. Teleconections look to become a lot more farourable though shortly .

Fair play. But mid Feb is more than a life time away going by the ups and downs of the current model output.

[bluearmy]

I posted this earlier which I am surprised no one commented on.

http://www.accuweather.com/mt-news-blogs.asp?partner=accuweather&blog=Anderson&pgurl=/mtweb/content/Anderson/archives/2010/01/february_looking_busy_for_me_1.asp

i did comment on it CC. i said it sounded like a west based -NAO which could easily mean us being in a sw flow with the trough too far west. admittedly, its better than a flat northerly jet.

this afternoons NOAA discussion offers soem insights into the upstream pattern which is crucial to the retrogression etc.

WE ARE STILL SEEING A LARGE AREA OF OF HIGH LATITUDE BLOCKING FROM

ALASKA ACROSS CANADA TO NWRN EUROPE IN CONJUNCTION WITH A NEGATIVE

NAO. TWO CENTERS WITHIN THIS AREA WILL DOMINATE. AT THE BEGINNING

OF THE PERIOD...A POSITIVE HEIGHT ANOMALY OVER NW CANADA WILL

WEAKEN AND SLIDE SE...WHILE TREMENDOUS DEEPENING AND COOLING

OCCURS BETWEEN THE GREAT LAKES AND HUDSON BAY. FARTHER E...A NEW

STRONG POSITIVE ANOMALY CENTER DEVELOPING W OF THE BRITISH ISLES

WILL BE DOMINANT.

apparently CC, we are in a -NAO !! looking at those systems running up through iceland, you'd never believe it!!

now the important stuff wrt the 12z's

THE 12Z/23 DETERMINISTIC GFS IS QUITE CONSISTENT THRU DAY 6 WITH

ITS EARLIER 00Z RUN...WHICH LEAVES IT STILL FASTER BY FRI DAY 6

WITH THE NEXT SRN STREAM SYS OVER THE SRN PORTIONS OF THE PLAINS

AND MS VLY THAN OUR PREFERRED BLEND OF THE 00Z/23 CANADIAN AND

ECMWF.

THE NEW 12Z/23 CANADIAN IS ALSO QUITE CONSISTENT WITH ITS PRIOR

00Z CONTINUITY BUT HAS TRENDED A BIT FASTER...TOWARDS THE

GFS...WITH THE SRN STREAM SYS APPROACHING THE LOWER MS VLY BY FRI

DAY 6.

WHILE THE 12Z/23 UKMET HAS DECENT CONTINUITY THRU DAY 6 WITH THE

FIRST SRN STREAM SYS MOVING ACROSS THE SWRN BORDER STATES...IT

MAKES A HUGE CHANGE FROM ITS 00Z CONTINUITY FOR FRI BY DAY 6 IN

PULLING THE POLAR VORTEX OVER FAR ERN CANADA BACK TOWARDS HUDSON

BAY. THIS HAS THE EFFECT OF MAKING THE PATTERN OVER THE GREAT

LAKES AND NEW ENG CONSIDERABLY WARMER AT THAT TIME. THE NEW 12Z/23

ECMWF HAS ALSO TRENDED SW WITH THE CANADIAN VORTEX BY THU

EVE....AND HAS A WARMER LOOK OVER THE NERN CONUS THAN ITS 00Z

CONTINUITY. WE THINK THAT THE UKMET/ECMWF WARMING HERE IS OVERDONE

AND WILL ACCEPT ONLY A SLIGHTLY WARMER SCENARIO THAN CONTINUITY.

CONCERNING THE SRN STREAM SYS...THE 12Z/23 ECMWF SHEARS IT APART

FRI/SAT DAYS 6-7 IN A COMPLEX INTERACTION WITH NRN STREAM

ENERGY...A LOW CONFIDENCE PROPOSITION AT BEST. IN OUR FINALS...WE

ARE STAYED WITH 00Z ECMWF AND 00Z/12Z CANADIAN SCENARIO.

THERE IS STILL LOTS OF UNCERTAINTY OVER THE SERN STATES TOWARDS

THE END OF NEXT WEEK.

basically, they prefer the GEM coninuity. they think that GFS is too fast which may explain why retrgression isnt as good on this model. they really dont like the 12z ecm days 6/7 where the s and n arms interact. given this is at the point where the ecm flattens the pattern off the eastern seaboard, there is another positive. they dont like the ecm and ukmo 12's wrt their placement of the canadian p/v and resultant pattern over ne america.

gievn this update, i'd say the consensus that the GFS/ecm 12z is right and the northern arm will fire up and flatten the pattern beyond the northerly are necessarily a done deal.

[Weather-history]

It would seem GFS is the only model that doesn't make much of the northerly, all others seem to do before it topples.

I'm not sure this talk of a Euro high though.

ECM 240hr shows a NWly flow with a trough in eastern Europe. Thats not a Euro high scenario

http://www.ecmwf.int/products/forecasts/d/getchart/catalog/products/forecasts/medium/deterministic/msl_uv850_z500!Geopotential%20500%20hPa!240!Europe!12!pop!od!oper!public_plots!latest!chart.gif

GFS mean chart at 240 hr chart is not a Euro high

http://www.wetterzentrale.de/pics/Rz500m10.gif

To me this is a Euro high

http://www.wetterzentrale.de/pics/archive/ra/2006/Rrea00120060124.gif

[bluearmy]

http://www.knmi.nl/exp/pluim/Data/PLUIM_06260_NWT.png

the end of the run has both the op and control as windy and warm outliers.

the op is too cold day 8 and too calm which means that the ens have the flow a bit further east. we would prefer the op to be supported at this time. if its windy in holland the trough is likely to be further east. the fact that the mean max temps are positive is supportive of the mean flow being off the north sea which tallys with this.

[PB22]

ECM ensembles for Holland:

http://www.knmi.nl/exp/pluim/Data/PLUIM_06260_NWT.png

Went from being one of the colder runs to one of the milder runs in FI. Some impressive cold early next week though with that easterly there.

[nick sussex]

It would seem GFS is the only model that doesn't make much of the northerly, all others seem to do before it topples.

I'm not sure this talk of a Euro high though.

ECM 240hr shows a NWly flow with a trough in eastern Europe. Thats not a Euro high scenario

http://www.ecmwf.int/products/forecasts/d/getchart/catalog/products/forecasts/medium/deterministic/msl_uv850_z500!Geopotential%20500%20hPa!240!Europe!12!pop!od!oper!public_plots!latest!chart.gif

GFS mean chart at 240 hr chart is not a Euro high

http://www.wetterzentrale.de/pics/Rz500m10.gif

To me this is a Euro high

http://www.wetterzentrale.de/pics/archive/ra/2006/Rrea00120060124.gif

Having looked at the latest ECM De Bilt ensembles for the Netherlands the operational run for days 9+10 is a precipitation and wind outlier, the majority of members have a slacker flow with little precip. This all suggests to me that its got the jet too far south and the high will be further north.

[KTtom]

Having just seen the ECM, it has, as previously posted totally changed its output to its longer term outlook in line with the GFS.

The GFS, maybe a slight upgrade to the 24hr northerly seens to be the hot favourite. Again, I'm not sure why some constantly slate the GFS.

UKMO was awful yesterday and ECM the same today....just as the GFS has abysmal outputs. Shame we only have access to one model, life would be much easier!

[cooling climate]

i did comment on it CC. i said it sounded like a west based -NAO which could easily mean us being in a sw flow with the trough too far west. admittedly, its better than a flat northerly jet.

this afternoons NOAA discussion offers soem insights into the upstream pattern which is crucial to the retrogression etc.

WE ARE STILL SEEING A LARGE AREA OF OF HIGH LATITUDE BLOCKING FROM

ALASKA ACROSS CANADA TO NWRN EUROPE IN CONJUNCTION WITH A NEGATIVE

NAO. TWO CENTERS WITHIN THIS AREA WILL DOMINATE. AT THE BEGINNING

OF THE PERIOD...A POSITIVE HEIGHT ANOMALY OVER NW CANADA WILL

WEAKEN AND SLIDE SE...WHILE TREMENDOUS DEEPENING AND COOLING

OCCURS BETWEEN THE GREAT LAKES AND HUDSON BAY. FARTHER E...A NEW

STRONG POSITIVE ANOMALY CENTER DEVELOPING W OF THE BRITISH ISLES

WILL BE DOMINANT.

apparently CC, we are in a -NAO !! looking at those systems running up through iceland, you'd never believe it!!

now the important stuff wrt the 12z's

THE 12Z/23 DETERMINISTIC GFS IS QUITE CONSISTENT THRU DAY 6 WITH

ITS EARLIER 00Z RUN...WHICH LEAVES IT STILL FASTER BY FRI DAY 6

WITH THE NEXT SRN STREAM SYS OVER THE SRN PORTIONS OF THE PLAINS

AND MS VLY THAN OUR PREFERRED BLEND OF THE 00Z/23 CANADIAN AND

ECMWF.

THE NEW 12Z/23 CANADIAN IS ALSO QUITE CONSISTENT WITH ITS PRIOR

00Z CONTINUITY BUT HAS TRENDED A BIT FASTER...TOWARDS THE

GFS...WITH THE SRN STREAM SYS APPROACHING THE LOWER MS VLY BY FRI

DAY 6.

WHILE THE 12Z/23 UKMET HAS DECENT CONTINUITY THRU DAY 6 WITH THE

FIRST SRN STREAM SYS MOVING ACROSS THE SWRN BORDER STATES...IT

MAKES A HUGE CHANGE FROM ITS 00Z CONTINUITY FOR FRI BY DAY 6 IN

PULLING THE POLAR VORTEX OVER FAR ERN CANADA BACK TOWARDS HUDSON

BAY. THIS HAS THE EFFECT OF MAKING THE PATTERN OVER THE GREAT

LAKES AND NEW ENG CONSIDERABLY WARMER AT THAT TIME. THE NEW 12Z/23

ECMWF HAS ALSO TRENDED SW WITH THE CANADIAN VORTEX BY THU

EVE....AND HAS A WARMER LOOK OVER THE NERN CONUS THAN ITS 00Z

CONTINUITY. WE THINK THAT THE UKMET/ECMWF WARMING HERE IS OVERDONE

AND WILL ACCEPT ONLY A SLIGHTLY WARMER SCENARIO THAN CONTINUITY.

CONCERNING THE SRN STREAM SYS...THE 12Z/23 ECMWF SHEARS IT APART

FRI/SAT DAYS 6-7 IN A COMPLEX INTERACTION WITH NRN STREAM

ENERGY...A LOW CONFIDENCE PROPOSITION AT BEST. IN OUR FINALS...WE

ARE STAYED WITH 00Z ECMWF AND 00Z/12Z CANADIAN SCENARIO.

THERE IS STILL LOTS OF UNCERTAINTY OVER THE SERN STATES TOWARDS

THE END OF NEXT WEEK.

basically, they prefer the GEM coninuity. they think that GFS is too fast which may explain why retrgression isnt as good on this model. they really dont like the 12z ecm days 6/7 where the s and n arms interact. given this is at the point where the ecm flattens the pattern off the eastern seaboard, there is another positive. they dont like the ecm and ukmo 12's wrt their placement of the canadian p/v and resultant pattern over ne america.

gievn this update, i'd say the consensus that the GFS/ecm 12z is right and the northern arm will fire up and flatten the pattern beyond the northerly are necessarily a done deal.

Cheers for the response. Sorry missed your reply to my earlier post. I still think it is very much all to play for certainly regarding a potent northerly and then beyond as I still very much feel that a very cold pattern will lock in for most of February.

Just seen the ECM ensembles and am not at all surprised that the operational ended on the warm side.

There are two different indexes that measure the NAO, the CPC would not class this as a - NAO I do not think.Off hand I can not remember what the other index is called that they measure the NAO by.

Edited January 23, 2010 by cooling climate

[LomondSnowstorm]

Having looked at the latest ECM De Bilt ensembles for the Netherlands the operational run for days 9+10 is a precipitation and wind outlier, the majority of members have a slacker flow with little precip. This all suggests to me that its got the jet too far south and the high will be further north.

Am I the only one who would rather have the high further south? The ECM +240 looks much better to me than a horrendous flow from the southwest http://212.100.247.145/viewimage.pbx?type=gfs;date=20100123;time=12;ext=240;file=h500slp;sess=ca5e424ced003664569453a0e455cd01 which would probably be pretty dreich for most. http://www.wetterzentrale.de/pics/Recm2161.gif http://www.wetterzentrale.de/pics/Recm2401.gif Those are charts I could live with! Wind and rain beats a boring drizzly cloudy scenario by miles! Anyway, still a long way to go before the models are decided on this pattern.

LS

[damianslaw]

I believe the ECM has got it right with respect to the overall patterns for later next week, i.e. a northerly will develop, not a half baked North westerly and for a window of say 48 hours it will be quite potent and bring down some cold uppers, perhaps no more than a few snow showers in exposed eastern and northern coastal parts and more generally the hills of northern Britain, but still cold overall.

Thereafter, mmm I must admit the chances of a sustained northerly are weakening, heights don't look like will transfer north into Greenland for long enough, a classic toppler situation.

Longer term - high pressure looks like achoring itself close to the south west of the UK, so a milder spell and rather dry, but every chance given the upstream signals for heights to rise again to the NW, I'm certainly not in the belief we are going to see a sustained mild spell, the atlantic is in very quiet mode and it will only be a matter of time before we see favourable northern blocking again setting us up for a sustained cold pattern. Feb is rarely dominated by the atlantic, and after its dormanct in recent weeks, this is not the time of year when you would expect it to fire into gear.

Next week - cold to start, becoming milder mid week then cold to end with a northerly

First week Feb - generally mild and settled some rain in the NW

Second week Feb - heights building to the NW, becoming colder and wintry.

[nick sussex]

Am I the only one who would rather have the high further south? The ECM +240 looks much better to me than a horrendous flow from the southwest http://212.100.247.145/viewimage.pbx?type=gfs;date=20100123;time=12;ext=240;file=h500slp;sess=ca5e424ced003664569453a0e455cd01 which would probably be pretty dreich for most. http://www.wetterzentrale.de/pics/Recm2161.gif http://www.wetterzentrale.de/pics/Recm2401.gif Those are charts I could live with! Wind and rain beats a boring drizzly cloudy scenario by miles! Anyway, still a long way to go before the models are decided on this pattern.

LS

I think it depends where you live, but of course in Scotland the ECM 240hrs could give something wintry. There is though some uncertainty upstream regarding the eastern USA trough so we might still see the earlier northerly upgraded before the high topples.

[KTtom]

Lol, well there is an argument for that LS!

The other thing that comes to mind, certainly with the 'easterly' and a classic example with the latestDe Bilt Ensembles output, which shows temps for the beginning of nest week -5 to -10c, that they are pretty pointless unless you live in Holland, which i'm guessing is the whole idea of them and pretty pointless here?

Edited January 23, 2010 by KTtom

[Frosty.]

ECM ensembles for Holland:

http://www.knmi.nl/exp/pluim/Data/PLUIM_06260_NWT.png

Went from being one of the colder runs to one of the milder runs in FI. Some impressive cold early next week though with that easterly there.

I think those ensembles are just rubbing our noses in it, anyway it's time to forget the easterly that never was and just hope the upstream pattern amplifies enough to enable a Northerly which lasts more than 24 hours.

[nick sussex]

Lol, well there is an argument for that LS!

The other thing that comes to mind, certainly with the 'easterly' and a classic example with the latestDe Bilt Ensembles output, which shows temps for the beginning of nest week -5 to -10c, that they are pretty pointless unless you live in Holland, which i'm guessing is the whole idea of them and pretty pointless here?

They're not pointless at all because looking at the ECM operational run and then comparing it to the ensembles we get a decent picture of certain synoptics. For example we can tell that the operational run is not well supported for days 9 and 10 because its too wet and windy for Holland, which means given the set up,this implies the high will be further north which impacts on the UK, we can also often tell when theres a switch from an easterly to an onshore flow over there, not all easterlies grind to a halt in Holland! There are many ways that the De Bilt ensembles can help but you need to take the time and effort to look at them in conjunction with the overall model output and the expected pattern. The London ones will be out much later.

Edited January 23, 2010 by nick sussex

[LomondSnowstorm]

I think it depends where you live, but of course in Scotland the ECM 240hrs could give something wintry. There is though some uncertainty upstream regarding the eastern USA trough so we might still see the earlier northerly upgraded before the high topples.

I acknowledge that the high staying a bit further north could give southern areas some reasonable sunny weather, but it doesn't look very good to me! Regardless, the northerly beforehand still looks interesting, even if fairly short lived, and if things upgrade a bit and the flow is a bit more of a northeasterly then perhaps some more widespread snow showers may develop. I'm also not entirely sure if I want to discount the ECM 00Z either given the NOAA seems to think it is a bit more plausible than the 12Z, though the other runs seem to have backed away from that a bit.

Nonetheless, any sustained mild spell still appears to be in FI, so slight nudges here and there in the more reliable timeframe are likely to change the charts for the beginning of February a lot in the coming days, which means we're still unlikely to be talking too much about the dreaded b word!

LS

[aspire27]

sorry but its like pulling teeth tonight on here!

[Ben_Cambs]

GFS 18z really no different so far to 12z, up to T+108. Hopefully an upgrade in length for the Northerly later in the run...

Edited January 23, 2010 by Snowman0697

[bluearmy]

sorry but its like pulling teeth tonight on here!

then maybe you can find a dental forum somewhere!!

meanwhile, the NAEFS 12z doesnt upgrade on the 00z and we find ourself between the block and the trough. no sign of the block retrogressing to greenland. in fi it doesnt sink into europe but drifts across us and then drifts ne as the siberian block drifts sw. we end up with blocking to our north from scandi across to iceland. not particularly strong at the moment but we are talking T384!! uppers, predictably repsond by dropping below -5c which isnt bad for such a long range. now i wouldnt pay too much attention to such a long range ens output (GEM/GEFS combined) - however, i note that the extended ecm ens show a majority chunk of runs going into the freezer at the same timescale. hmmm ........

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

thats impressive at two weeks in anyone's language. MMW anyone ????

[Snowstorm1]

Interesting the 18z gfs brings a northerly on eastern coasts starting from thursday when on the previous run it was in the north sea.

The block is making a fight

Edited January 23, 2010 by Snowstorm1

[Cloud 10]

The 18z looks to be trending towards the ukmo at +120 with the high further NW,allowing a more potent northerly.

[Snowly does it]

Subtle differences on the 18z, rather better ridging and a better and colder N based flow with a better pattern around GL.

Will sink I think, but a better 2-3 day effort than before.

[lukemc]

Hi,

Just asking if this high pressure expected after the projected northerly blast would result in frosts by night and if mild only mild by day for example might we expect something similar to February 2008? Or January 2009 with it being cold by day? Just asking as I normally do not look at the models myself.

Also I have a question for you on here. It seems that a lot of posters on here do not seem to be optimistic about a cold and/or snowy February, at least for the first half with a mainly downbeat mood prevailing. Why is this so considering we have had the one of the coldest winters for the last 30 years and the fact that for this part of the world February is often the coldest month and for where I live at least it is the snowiest month. Is their any credible scientific basis at the moment to say that February will mild or will at least not be cold considering the winter we have had so far and especially looking at how cold parts of mainland Europe have been which has not been the case in the mild winters of the last two decades?

Luke

[Ben_Cambs]

GFS 18z at T+144 PPN charts shows widespread snow showers for the country

Favourable Uppers for a lot of places by then too:

Edit: -12C Uppers knocking on the door of Northern Scotland at T+150..

Edited January 23, 2010 by Snowman0697

[davehsug]

Hi,

Just asking if this high pressure expected after the projected northerly blast would result in frosts by night and if mild only mild by day for example might we expect something similar to February 2008? Or January 2009 with it being cold by day? Just asking as I normally do not look at the models myself.

Also I have a question for you on here. It seems that a lot of posters on here do not seem to be optimistic about a cold and/or snowy February, at least for the first half with a mainly downbeat mood prevailing. Why is this so considering we have had the one of the coldest winters for the last 30 years and the fact that for this part of the world February is often the coldest month and for where I live at least it is the snowiest month. Is their any credible scientific basis at the moment to say that February will mild or will at least not be cold considering the winter we have had so far and especially looking at how cold parts of mainland Europe have been which has not been the case in the mild winters of the last two decades?

Luke

I think Luke, it's because the general synoptics we're seeing now are of the "been there, got the T shirt" type. The displaced Siberian high caused a little excitement for a while, but generally, we're back in familiar territory. If we get height riese over Grrenland, If the Northerly is a little further west, if the Northern arm of the jet relents a little...& so on!

Might be wrong of course, but I think we're back to trying to get the best out of largely unfavourable patterns.