Model Output Discussion

[Richard Lake]

But this Winter is no ordinary winter...

[Optimus Prime]

But this Winter is no ordinary winter...

Neither was 1997 and yet that one ended very mild going into February.

The last few months have clouded peoples minds going into February. Just because Dec and Jan have been cold it doesn't mean February will be. If low pressure does push though like what the GFS does in the more reliable time frame we'd be looking at a mild unsettled and more usual to recent years start to February.

[MR EXTREMES]

Yeah good point.

We still need to remember we haven't had a decent easterly since 1991. Since then it's been failure after failure. The GFS in any situation outside the summer months seems to screw everything up. ECM is the most reliable but UKMO looks far more plausible to me.

Cold then less cold by the looks of things.

decent easterly since 91 well i must have had memory block because im sure we just suffered at the hands of an easterly over christmas with 6inches of lying snow that lasted about 7 days not seen that since the 80s.

all i can say is id very very suprised if we dont get some sort of easterly,models every day for a week or more have been picking up on this signal.

i think its was only a matter of time before the blocking won the battle ofcoarse its not 100% but id go 80% of some kind of cold blast from the east during feb.

Edited January 29, 2010 by badboy657

[Optimus Prime]

decent easterly since 91 well i must have had memory block because im sure we just suffered at the hands of an easterly over christmas.

Eh? The easterly in December wasn't cold, it wasn't until we had some snow and winds fell lighter the temperatures were decently low by night. Daytime temperatures still got above freezing in most areas. The very cold start to January was thanks to light NEs and Northerlies over frozen ground.

Does surprise me how quickly people change and let that judgement cloud over what we've had since 1996.

[LomondSnowstorm]

Yeah good point.

We still need to remember we haven't had a decent easterly since 1991. Since then it's been failure after failure. The GFS in any situation outside the summer months seems to screw everything up. ECM is the most reliable but UKMO looks far more plausible to me.

Cold then less cold by the looks of things.

Define decent easterly - there have been a few decent easterlies since then, Feb '09 being a good example. I don't think we've seen anything spectacular since '91, but that does not mean to say that this is going to fall through. The AO looks set to plunge, the NAO is negative, and the models are in reasonable agreement, moreso than the last easterly, which always looked a bit more flimsy.

[John Cox]

Absolutely agree,

I will stick my neck out.

I have been watching every 6 hourly updates every winter and particularly this winter and I observe the following:

- Extremely cold pool to the east. Have not seen one like it in years.

- The synoptics and delivery in January. Have not seen one like it in years.

- Current synoptics showing constant migration from E to W or W to E of high pressure. Have not seen one like it in years.

A long time on here and have plenty of patience (just for the newbies).

I see the 12z models have a much colder feel this evening with northern blocking kicking in a fair bit earlier than the 06z runs.

Apart that is from the UKMO, which doesn't like the cold at all, I am sure it will be eventually dragged kicking and screaming to Siberia very soon and be given hard labour.

The ECM begins to take shape post T120, and really gets its act together at T168 as the low begins to slip under the block, opening the door to Siberia.

The GFS is also good and takes a similar route to the ECM, but just a little later in the time frame, then some of the projected charts go off the scale of reality, if they come off, then a repeat of Jan 87 is on the cards.

Edited January 29, 2010 by John Cox

[Optimus Prime]

Define decent easterly - there have been a few decent easterlies since then, Feb '09 being a good example.

Feb 09' was for me the mildest easterly I have ever recorded under what was an exceptionally long sourced high pressure. February 2005 was just as poor.

I do agree re the AO and NAO. That does look very interesting but it doesn't automatically mean the UKs going to see cold. It means Europe will likely get more freezing weather. I.e 2006.

Decent easterly? Below freezing daytime maxima (around -1c) falling below -5c at night with some snow showers.. THAT's my experience of a good proper easterly. 1987 was just ridiculous.

Edited January 29, 2010 by Optimus Prime

[thegreat316]

The JMA is looking alright tonight, no upper air above 0c gets into the uk throughout

[Freezing-Point]

Neither was 1997 and yet that one ended very mild going into February.

The last few months have clouded peoples minds going into February. Just because Dec and Jan have been cold it doesn't mean February will be. If low pressure does push though like what the GFS does in the more reliable time frame we'd be looking at a mild unsettled and more usual to recent years start to February.

I see your point, but you have not considered the cyclic pattern of the weather, which nobody can argue..... for 4 years we have been entering a period of colder winters compared to 90s. I expect winters to be colder for some years to come before the cycle changes again and we go back milder. So 1997 is irrelevant because that was in a warm cycle.

We are going to get hit sooner or later by the cold being controlled by the Siberian high. It keeps getting delayed, but I think the longer the delay the more intense the cold will be. You mention 1991 as the last real Easterly and you are right. Can you also recall how NE Europe was frozen for weeks before hand?

[Optimus Prime]

for 4 years we have been entering a period of colder winters compared to 90s.

Sorry that's one point that's been brought up here and on that pain in the ass TWO board.

2006/2007 and 2007/2008 were exceptionally mild winter. Both more than 2.0c above normal. In truth it's been warming up compared to the 90s EVEN with 2008/2009 included. Admittedly 2009/2010 will probably sort that out.

[MP-R]

Wow, to go from that to that within a space of two days - that's really quick, would there be such a change round in such a short space of time in reality?

Thu 04th

http://www.wetterzentrale.de/pics/Rtavn1441.html

Sun 07th

http://www.wetterzentrale.de/pics/Rtavn2161.html

Something interesting to keep an eye on. Back to the present however, I've noticed on weather forecasts today from the BBC that with the wind veering more northwesterly later on Saturday into Sunday, there may be a higher chance of some snow showers penetrating inland around these parts.

http://www.wetterzentrale.de/pics/Rtavn481.html

[MR EXTREMES]

Feb 09' was for me the mildest easterly I have ever recorded under what was an exceptionally long sourced high pressure. February 2005 was just as poor.

I do agree re the AO and NAO. That does look very interesting but it doesn't automatically mean the UKs going to see cold. It means Europe will likely get more freezing weather. I.e 2006.

Decent easterly? Below freezing daytime maxima (around -1c) falling below -5c at night with some snow showers.. THAT's my experience of a good proper easterly. 1987 was just ridiculous.

to a degree i agree lol.

but i was always more in favour of siberian air when i was younger this is something we have not seen much of,

if i recall 96 we had a good siberian blast.

but im just really hyped over the trend this winter infact im not really that bothered if its deep cold we get as long as we get something more like winter of old which so far has produced the good.

the models right now are having some wobbles here and there,

but over all there seems to be very good agreement ofcoarse the finer detail is not there yet but the general trend is.

[Freezing-Point]

Sorry that's one point that's been brought up here and on that pain in the ass TWO board.

2006/2007 and 2007/2008 were exceptionally mild winter. Both more than 2.0c above normal. In truth it's been warming up compared to the 90s EVEN with 2008/2009 included. Admittedly 2009/2010 will probably sort that out.

You are right if you judge a mild winter as being AVERAGE TEMPERATURE, but I am thinking about the actual weather patterns. I judge a cold winter on the amount and severity of cold incursions. If it was constantly 3 deg C with rain for the whole winter that would on average be cold, but would you remember that as a cold winter?

How many years was it before Feb2005 before we saw an Easterly? And since then have we not had an Easterly of some sorts every winter?

Do you recall the roaring SW powerhouse that dominated our winters for years? When did you last see that over an extended period?

Look at the trends mate and you cannot deny that winter patterns are different from the 90s up to 2005. And if the history of the cyclic trend is a consideration then we are entering a period of colder winters.

[Optimus Prime]

You are right if you judge a mild winter as being AVERAGE TEMPERATURE, but I am thinking about the actual weather patterns. I judge a cold winter on the amount and severity of cold incursions. If it was constantly 3 deg C with rain for the whole winter that would on average be cold, but would you remember that as a cold winter?

How many years was it before Feb2005 before we saw an Easterly? And since then have we not had an Easterly of some sorts every winter?

Do you recall the roaring SW powerhouse that dominated our winters for years? When did you last see that over an extended period?

NOV 2005 - April 2006 I was ready to agree we have entered a colder climate with much decrease in westerlys. Although it wasn't necessarily a cold winter that year it was intense over the continent. Then came that astonishing come back May 2006 - May 2007. That was an astonishingly warm period. Never have I known it to be so mild and for so long. Constant westerlys, unseasonable warmness and cloudy humid conditions.

After that I actually said we're going to get some kind of correction over the next few years. NEVER does it get that warm without nature ironing things down a little.

Summer 2007 was cool and so was autumn. 2007/2008 was exceptionally mild for the most part aside from a cumulative 4 days of snowy and cold conditions.

2008 went on in the same modern way 2007 did (aside from April) a another correction over summer and the rest of Autumn and especially December.

2009 carried this on with a big mild blip in Late February March, April and May. From then on it was generally cool.

In my opinion this will probably be the end of the correction and once we get winter and Spring out the way we're going to have some big debts to pay back to mr mild.

Edited January 29, 2010 by Optimus Prime

[Mark Bayley]

ECM ensembles now out, ECM was close to the mean, however more towards the top end of the ensembles with quite a few going colder. Overall the trend is down

[grab my graupel]

Folks, sorry to interrupt this interesting discussion, but could we get back to the Model output please?

Thank you

[BLAST FROM THE PAST]

Some weird posts on here this evening, well the cold is going to happen.

Halleluja to the 12z ECM....is it a sudden switch OR are the models falling in line very nicely with the signals...the latter me thinks.

Anyway, T96 re models was called By Nick S as FI and I supported that and I think we can see why. All I have seen today is a solidifying of the cold development.

BFTP

[cooling climate]

Some weird posts on here this evening, well the cold is going to happen.

Halleluja to the 12z ECM....is it a sudden switch OR are the models falling in line very nicely with the signals...the latter me thinks.

Anyway, T96 re models was called By Nick S as FI and I supported that and I think we can see why. All I have seen today is a solidifying of the cold development.

BFTP

Not just saying this but I can not honestly believe there are still doubters with all the

other indices that are supporting this evolution, which I am quite sure were not there

in past failures.

[Tim Bland]

Some weird posts on here this evening, well the cold is going to happen.

Halleluja to the 12z ECM....is it a sudden switch OR are the models falling in line very nicely with the signals...the latter me thinks.

Anyway, T96 re models was called By Nick S as FI and I supported that and I think we can see why. All I have seen today is a solidifying of the cold development.

Agreed, the cold is coming! All ensembles show cold by the end of next week so its now 98% What isn't certain is how cold and how snowy! Worse case scenario as far as cold could mean best case scenario for snow with a stand off between continental cold and atlantic. My punt at the moment is for Easterlies veering North East as the high shifts in orientation.

Edited January 29, 2010 by Tim Bland

[TEITS]

Great to see an improvement on the JMA/NOGAPS. In recent days the output from these has been relatively poor. At the moment the UKMO +144 is looking rather lonely. Having said this I would be much happier if the 0Z outputs trends towards the E,ly tomorrow morning.

P.S Keep an eye on the trough currently in the N Sea. This will swing SW into NE England/Humber/Lincs/E Anglia later tonight. Some could wake up to a decent covering.

[John London]

Loooking at the models and radar I think the trough currently in the North Sea might swing south westerly towards E Anglia later tonight and give a top up to the two inches of snow already on the ground http://www.bbc.co.uk/suffolk/content/webcams/lowestoft_webcam.shtml

[nick sussex]

Some weird posts on here this evening, well the cold is going to happen.

Halleluja to the 12z ECM....is it a sudden switch OR are the models falling in line very nicely with the signals...the latter me thinks.

Anyway, T96 re models was called By Nick S as FI and I supported that and I think we can see why. All I have seen today is a solidifying of the cold development.

BFTP

I think looking at the trend so far this evening I'd agree that prospects for a much colder outlook have improved. Looking at all the models the UKMO is totally alone with its 144hrs chart, IMO it drives too much energy eastwards, at least for the Netherlands the ECM operational run has rock solid support for colder conditions there, looking at the UKMO output if there was backing for its run in the ECM ensemble suite then we would expect to see milder air push into that region and reflected by some backing at least from a few members, absolutely no support for this in the ECM ensembles.

Given all this I would be very surprised if the UKMO don't modify their fax charts towards the ECM this evening. Upstream NOAA's outlook looks positive for western Europe:

MODEL CONSENSUS DEPICTS THE NORTHERN

ATLANTIC RIDGE AXIS NEAR SCANDINAVIA, A PATTERN THAT IS NOT CONSISTENT WITH A

NEGATIVE NAO (WHERE THE RIDGE WOULD BE FARTHER WEST). THIS REDUCES THE ODDS FOR

INTENSE COLD OVER THE CENTRAL AND EASTERN U.S. IN THE MEAN.

So overall then this evening I think a little step forward towards the easterly but still a few more hurdles to overcome.

Edited January 29, 2010 by nick sussex

[Southender]

I think looking at the trend so far this evening I'd agree that prospects for a much colder outlook have improved. Looking at all the models the UKMO is totally alone with its 120hrs chart, IMO it drives too much energy eastwards, at least for the Netherlands the ECM operational run has rock solid support for colder conditions there, looking at the UKMO output if there was backing for its run in the ECM ensemble suite then we would expect to see milder air push into that region and reflected by some backing at least from a few members, absolutely no support for this in the ECM ensembles.

Given all this I would be very surprised if the UKMO don't modify their fax charts towards the ECM this evening. Upstream NOAA's outlook looks positive for western Europe:

MODEL CONSENSUS DEPICTS THE NORTHERN

ATLANTIC RIDGE AXIS NEAR SCANDINAVIA, A PATTERN THAT IS NOT CONSISTENT WITH A

NEGATIVE NAO (WHERE THE RIDGE WOULD BE FARTHER WEST). THIS REDUCES THE ODDS FOR

INTENSE COLD OVER THE CENTRAL AND EASTERN U.S. IN THE MEAN.

So overall then this evening I think a little step forward towards the easterly but still a few more hurdles to overcome.

Didnt they say the same axis will be near the uk yesterday?!

[bluearmy]

strange goings on in the 6/10 day discussion from cpc. on wednesday, they talked of the higher heights axis in the ireland/iceland area. yesterday, they talk of these heights in the uk area. today, they refer to them being in the scandi area. its odd for things to change on a daily basis on cpc discussions so to have the models moving this axis each day is a tad strange. they use the position of this axis to highlight the fact that it doesnt support a west based -NAO which is signifcant for eastern usa temps. i have a feeling that the fact they keep mentioning the lack of support for this feature may mean that they expect it to become reality at some stage in the near future. so does GP. the mean charts show a superb negative zonality and the euro trough is mighty close to the south indicating that the ecm 12z may not be too far from the mark with its propensity to slide the shortwaves underneath us

http://www.cpc.ncep.noaa.gov/products/predictions/610day/610day.03.gif

http://www.cpc.ncep.noaa.gov/products/predictions/814day/814day.03.gif

looks like a mean location for an upper rex block to be just to our north. strong mean east to west flow with the mean trough not far south.

[Nick F]

As I have mentioned in the technical thread, I dare to say that I think we are almost into a win-win situation for cold in the longer-term outlook for February, certainly the first half. I have been keeping an eye on the forecasted H500 anomalies for the northern hemisphere for the last week, and with each day, particularly the last few days, there has been growing support for a significant +ve height anomaly towards and over the Barents Sea - which eventually expends W towards/over Greenland, and that hasn't changed on the recently updated CPC 6-10 day and 8-14 day forecast H500 patterns. This maybe a block that is hard to budge.

But as others have mentioned, it may not be a clear-cut transition to an easterly, but I've even more confidence today than yesterday of cold or perhaps severe cold coming our way in February. Maybe not next week though.