Model Discussion And Chat 19th Feb.2012

[Frosty.]

There's always next winter I guess:

Best laugh I have had all day.

The latest models look fairly benign for many days to come, very mild then cooler and then milder again next week.

[cooling climate]

There's always next winter I guess:

Maybe worth keeping an eye on LOL great stuff.

[Broughty]

There's always next winter I guess:

Looking forward to November already.

What could possibly go wrong??

[john pike]

t954 aint too bad

look at the date

[Cheese Rice]

Interesting colder members popping up on the ensembles, best highlighted on the Oslo ensembles.

[Troubleatmill]

Best laugh I have had all day.

The latest models look fairly benign for many days to come, very mild then cooler and then milder again next week.

Ha ha, dont know why but that reminded me of this Frosty!

[Don]

There's always next winter I guess:

You should save that chart for a laugh!

Edited February 22, 2012 by Don

[Tim Bland]

Is that a Scandinavia high I see on thee 06z with PV retreating west!

[Thundery wintry showers]

It is indeed, but the main issue as we head into March is that the continent warms up and the North Sea remains cold, and so easterlies delivered by a Scandinavian high have a strong "dry and cloudy" tendency- the one in FI on the GFS 06Z would be no exception.

Tomorrow is still looking exceptionally warm across many parts of England- a 17 or 18C is possible locally- though it will be dull and damp across most of Scotland, Wales and north-west England. Still some uncertainty over how far north and east the high pressure will penetrate afterwards, with GFS suggesting a moist westerly flow this side of T+168 and UKMO likewise, but ECMWF sneding the high in across southern Britain which would promote sunnier conditions and cooler nights. All three models have high pressure close to the south, though, so no alleviation of the concerns in the drought-affected areas.

[nick sussex]

In terms of the GFS 06 hrs run, it continues the same theme of the 00hrs with that troughing in the mid Atlantic forcing high pressure to ridge further north but as TWS mentioned what might look like good synoptics in the middle of winter don't have the same bite in March, if you're going to get a Scandi high at this time of year you need a good cold pool to tap into and in these situations need a piece of the PV to head south into western Russia so that the deeper cold can get advected west on the southern flank of the high.

The ECM operational runs are reluctant to develop enough amplification in any mid Atlantic troughing to allow the ridge further north and ne. Looking at the ECM ensemble mean it does look less progressive than the operational output and so some of the ensemble members probably do ridge high pressure further north but really even the GFS would need a much more digging trough further west and more amplification.

I would say though that given the reluctance of the PV to leave the Greenland area that the only way out of the current milder pattern would have to come from high pressure ridging north, I can't see any other possible route to colder conditions at the moment and we'd need alot of help from troughing in the Atlantic.

[phil nw.]

After today High pressure looks to be the dominant theme for much of the next 2 weeks as it builds towards the UK from the Azores.

and further into week 2 the mean hts and forecast amnomality charts.

There are only minor differences wrt to the orientation of the High but essentially decent agreement i think of the overall pattern.

The north west will likely be affected by some rain at times from frontal systems moving across the top of the High but many places look to be dry and mild with varying cloud amounts which of course doesn`t help to aleviate the drought conditions in parts of the South and Midlands.

[Frosty.]

A nice ecm 00z T+240 chart with a very cold westerly (veering nwly) of arctic origin blasting across the uk but until then it looks like limpet high pressure close to the southeast of the uk for many days although probably tending to be more changeable across northern britain at times with a brisk westerly flow. The coming weekend looks a little colder with high pressure building northeast and some overnight frosts but daytime temps back down to average but then by next monday it will be turning much milder yet again with swly winds and temps into the low to mid teens celsius, a little cooler in the very far north but still on the mild side. As I said at the beginning, a nice end to the ecm and indeed, a nice gfs 06z in late FI with an easterly although not much sting to it as it's well into march by then.

[johnholmes]

After today High pressure looks to be the dominant theme for much of the next 2 weeks as it builds towards the UK from the Azores.

and further into week 2 the mean hts and forecast amnomality charts.

There are only minor differences wrt to the orientation of the High but essentially decent agreement i think of the overall pattern.

The north west will likely be affected by some rain at times from frontal systems moving across the top of the High but many places look to be dry and mild with varying cloud amounts which of course doesn`t help to aleviate the drought conditions in parts of the South and Midlands.

One of the ingredients showing on the above 500mb anomaly charts is the tendency, seen over the last 3-4 days, for the +ve area to slowly migrate NE/ENE from SW of the UK several days ago. Noaa shows this up perhaps rather more than ECMWF and GFS..

[Zakos]

Very nice GFS 12z FI Cold never quite makes it to the UK, but very close to some very wintry weather indeed.

One of the handful of runs this winter to completely get rid of the PV over Greenland.

Looking at these charts it doesn't require much imagination as to what this could potentially deliver given small tweaks.

Beautiful.

Now of course this is FI, but this has been hinted at many times by the GFS. It has stayed consistent with a Scandi High in FI

The first chart illustrates what I expect to happen early march. Some kind of pressure rise over Scandinavia. However knowing how terribly the block was modelled a few weeks ago, this is likely to be modelled variably over the next few days.

The second chart illustrates exactly what we need after say the first week of march or so. As the continent begins to warm we would need to see A N/NE flow as has been stated on this thread.

The CFS has also trended from showing a very mild March to now near average.

http://www.cpc.ncep....uT2mProbMon.gif

Still all to play for IMO. I must stress I am not cold ramping, There is no reason to get your'e hopes up just yet from a cold perspective, and I for one would like to see some typical spring showers to end this drought.

Edited February 22, 2012 by Zakos

[Frosty.]

Well the Gfs 12z op run has T+384 hours on a cliffhanger..a few frames more and we would be plunged into a bitterly cold arctic spell, even early to mid march would deliver blizzards and ice days with an airmass like that, before then we have a bit of fun with an easterly as a scandi high builds but as usual, the coldest air dives into france and leaves the uk on the edge, much as the uk was on the very edge of the last siberian freeze, the same thing happens again but the potential Northerly reminds me of late feb/early march 2006 when blizzards struck the north and east of scotland with trains stuck in snowdrifts. There is a lot of benign weather ahead for southern areas but windier and more unsettled further northwest and a brief spell of -5 850's for the far north on fri/sat before it turns less cold. A fine weekend for the south with high pressure in charge, FI looks like slowly turning more unsettled with the high being pushed away southeast into europe but a new high ridging up from the azores to the south of the BI, then that bit of excitement in the depths of FI.

[Polar Maritime]

The GFS once again is showing settled weather over all but the far North, with average or sometimes above average temps for the next 6/7 days with night time frosts under clearing sky's and the odd spell of rain, hopefully for those much needed areas. The week after is still looking a little more interesting, showing colder air spilling in from the East, and as Frosty states things could get a little more exciting than the benign weather we are all experiancing at the moment.

[Summer Sun]

ECM is high pressure dominated once more so far tonight, looks quite mild at times too

http://www.wetterzen...ics/Recm242.gif

http://www.wetterzen...cs/Recm1442.gif

http://www.wetterzen...cs/Recm1682.gif

[Frosty.]

Well the Ecm 12z is showing a largely settled outlook for the south under high pressure but further north looks windier and more changeable with nw britain more exposed to atlantic influence which is not unusual. The outlook is also on the mild side for many and very mild at times but at least with some good sunny spells but with drizzly, misty and rainy weather to the northwest corner. Later in FI is not as amplified as the ecm 00z and shows brief polar maritime followed by mild sector and so on, so not very appetizing for coldies but we still have a colder gfs further in FI until the 18z.

[Geordiesnow]

Looks to me the ECM is a bit on its own regarding how far North the high will ridge over us whereas the GFS/UKMO look a bit flatter too me. I probably will believe the GFS more as it looked like it had the pattern over America correct where the PV would spill across the eastern side of Canada/US whereas the ECM developed a big low and threatened to send a bit of WAA towards Southern Greenland but that has dissapeared on this afternoons ECM output.

I'm not sure if I would call the output settled in all honesty but it does look like quite a mild outlook for southern areas where more Northern areas will see some weak PM outbreaks like this weekend for example but at times there will be some mild air even further North. It will be interesting what angle the jet stream will be at in the next few days because it would not surprise me if we see a severe gale event occuring.

One thing the GFS FI did point out is the strengthning of the PV just to the west of Greenland, perhaps not quite as extreme as some FI's outputs did suggest but it certainly looks the strongest it has been all winter.

I must admit, I think in terms of snowfall for this winter, this appears to be all but over sadly although you can't rule out some in spring and lets hope so as I have seen very little this winter.

[Cheese Rice]

GFS keen on height rises over the UK/North East.

However, we are really going to struggle to see cold over the UK and North West Europe. Height rises look confined over our area with the jet too strong to our north to allow a high to push north. Most members are going for deep cold pushing into Eastern Europe with some pushing it as far west as France. I wouldn't be at all surprised to see a repeat of late Jan/early Feb except not as severe, this time though any cold reserved south of the UK.

Edited February 22, 2012 by Cheese Rice

[bluearmy]

One of the ingredients showing on the above 500mb anomaly charts is the tendency, seen over the last 3-4 days, for the +ve area to slowly migrate NE/ENE from SW of the UK several days ago. Noaa shows this up perhaps rather more than ECMWF and GFS..

in practice john, both the ecm suite and ncep suite must head that way as the NOAA cpc charts are derived from their outputs. (though the bits the forecasters perceive as relevant rather than the automated stuff shown on the automated mean op offerings (oh how i am coming to detest that particular output).

[Cloud 10]

One of the ingredients showing on the above 500mb anomaly charts is the tendency, seen over the last 3-4 days, for the +ve area to slowly migrate NE/ENE from SW of the UK several days ago. Noaa shows this up perhaps rather more than ECMWF and GFS..

That trend continues on today's update.

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

[The Northern Ramper]

ECM is high pressure dominated once more so far tonight, looks quite mild at times too

http://www.wetterzen...ics/Recm242.gif

http://www.wetterzen...cs/Recm1442.gif

http://www.wetterzen...cs/Recm1682.gif

Scandi high and cool Easterly flow on the gfs.

Edited February 22, 2012 by Snow Guy

[bluearmy]

That trend continues on today's update.

http://www.cpc.ncep....y/814day.03.gif

and on the 6/10 dayer, the upper ridge just to our east with strong support from the surface anomoly placement over the southern north sea shows that a mobile flow across the uk is unlikely through next week. shame that this is a 'warm high', though at this time of year, frosts are likely where cloud cover allows.

[Frank Trough]

Scandi high and cool Easterly flow on the gfs.

but that's the GFS at T+ 288. You'll forgive me if i reserve judgement for now! David Beckham practicing drawing lines and circles has as much chance of verfiying.