Model output discussion 8th Feb - Cold for now, but then what?

[karlos1983]

7 minutes ago, Daniel* said:

Indeed, certainly not overwhelming yet. However, scope for most wintriest part of the 'winter', snow? Arriving in meteorological Spring It would not surprise me in the slightest.

more likely than snow at Christmas... seen many snowy days in March even right on the south coast, although it doesn't hang around for long, but who cares 

Edited February 20, 2017 by karlos1983

[Frosty.]

12 minutes ago, Ali1977 said:

 the latest METO does not support any cold spell at all early March.

If the 12z is like the 00z / 6z I'm sure it will mention something tomorrow..fingers crossed!

Edited February 20, 2017 by Frosty.

[jvenge]

22 minutes ago, Ali1977 said:

I think a mean over this period isn't a great chart to use, as the cold which may come in starts around the 1/2 Mar.  I think Sid may need a hutch full of straw early March if the GFS Op is correct.

 A long way to go yet before any coldie celebrations though - the latest METO does not support any cold spell at all early March.

Not much better looking at the individual days.

The OP is showing something very different, of course.

[Nick F]

IMO we are beginning to see the models finally latch on to the upper flow amplification effects of MJO passing through P8-1  ... having passed through P8 at an unusually high amplitude. Also the troposphere will eventually start to reflect what's happening in the stratosphere too end of month and early March, i.e. a warming at the pole and displacement of the sPV across Scandinavia and NW Russia

So it's inconceivable that there won't be extra-tropical impacts from  both the lagged colder 8-1 phases of MJO and the stratospheric downwelling. The typical MJO lag is about 10 days,  so P8-1 impacts in a window from 28th Feb/1st March through into the first week of March + the tropospheric upper flow pattern beginning to reflect the stratosphere too.

What looks most likely, looking at medium range and extended EPS and GEFS is height rises near or just east of Greenland while the Candian trop PV sinks south and the jet + trop troughing sinks south over the Atlantic. So we are likely to see increased chance of colder air leaking south then perhaps eventually SW across the UK from high latitudes as we enter early March.

Obviously, this could go wrong for the south, with the low pressure systems perhaps not tracking far enough south - which means the cold air stays over northern UK while the south stays mild. But a lot of water to go under the bridge until we can firm up on this IMO likely pattern change away from low heights dominating to our north like now.

But, don't think today's temps reaching 17-18C in the southeast marks the end for deep cold and snow potential this season ... yet.

Remember, the models guidance for the trop can often play catch up with what the MJO and stratosphere precursors are indicating ...

 

Edited February 20, 2017 by Nick F

[karlos1983]

These very warm temperatures are all very nice n'all, but it's not good for keeping our ground temperatures down for when the snow hits in early March 

[Frosty.]

There is plenty for coldies to be encouraged about with the GEFS 6z, some absolutely stunning output which shows the type of wintry charts in early March which would tie in with the second and final SSW..fingers crossed the best is yet to come!

[Ali1977]

The GFS Op not as extreme with its Northerly followed by big block on this run, although still a cold blast early next week. Also very different on the Alaskan side of the NH!!!  Hopefully the GFS keep with the theme of a cold block setting up later next week and the ECM has a great evening run.

[Summer Sun]

GEM has the low a lot further south on this run

12z                                                               00z

[Ali1977]

2 minutes ago, Summer Sun said:

GEM has the low a lot further south on this run

12z                                                               00z

Much better 12z with the removal of lots of PV (purple) to our North and a decent Atlantic ridge - this would follow the earlier GFS I reckon.

[MattTarrant]

28 minutes ago, Ali1977 said:

Much better 12z with the removal of lots of PV (purple) to our North and a decent Atlantic ridge - this would follow the earlier GFS I reckon.

Interesting to see what has caused the GFS to not follow the last couple of runs, it looks like the ridging is just flattened to quickly in my eyes. Maybe though it was responding to the MJO phase 8 - 1 to quickly but interesting to see. 

Whatever the reasons behind it not following the last few runs, it is safe to say it not a run for the coldies of this forum. Though not exactly warm either, maybe a decent diurnal range. 

Edited February 20, 2017 by MattTarrant

[Matty M]

Let us not ignore developments around 60-84hrs with potential for a very disruptive wind-storm to sweep eastwards across the spine of the UK....

Storm rapidly deepening during passage will bring potential for Storm force winds in Irish Sea and gusts from 60-70kt in parts...large swathe of inland 50kt gusts.

Likely the worst storm of the year. Doris is coming at last!

Edited February 20, 2017 by Matty M

[knocker]

The gfs still has some amplification next week with ridging mid Atlantic and the depression pushed south east to be over southern Britain 988mb by T192 but the energy emerging upstream flattens it fairly quickly.

And in keeping with the spirit of the thread throwing in the odd chart at the end of the run

[Seasonality]

At the risk of sounding churlish I'm not seeing anything particularly exciting about the 12z GFS for coldies. Just being honest mind you, happy to be proved wrong if anyone has a different view.

[knocker]

6 minutes ago, Matty M said:

Let us not ignore developments around 60-84hrs with potential for a very disruptive wind-storm to sweep eastwards across the spine of the UK....

Storm rapidly deepening during passage will bring potential for Storm force winds in Irish Sea and gusts from 60-70kt in parts...large swathe of inland 50kt gusts.

Likely the worst storm of the year. Doris is coming at last!

Well to be honest it doesn't look that bad on the GFS but I haven't checked on what the METO are going for

[Ali1977]

GEFS looking good next week for a cold spell , atleast half looking potentially v wintery ...if ECM follows suit take note and hopefully a wording change on the METO long range.

[Ali1977]

GEFS looking good next week for a cold spell , atleast half looking potentially v wintery ...if ECM follows suit take note and hopefully a wording change on the METO long range.

[Eugene]

23 minutes ago, Seasonality said:

At the risk of sounding churlish I'm not seeing anything particularly exciting about the 12z GFS for coldies. Just being honest mind you, happy to be proved wrong if anyone has a different view.

Big improvement for next week compared to GFS OP's this past weekend which were showing the dreaded high just to our south and mild air dominating, at least this run has a short cold northerly shot mid next week, as Ali says GEFS looking very promising for us cold weather fans.

 

 

[The PIT]

It would be funny if March gave more snow than the whole winter combined. Sadly deep lala land so won't happen.  At least have some interest this week. A rare windy spell only the second one this winter.

[Summer Sun]

The ECM weeklies issues overnight going out to March 19th show temps always at or a bit above average (the signal by week 4 is weaker for parts of the south)

As for rain weeks, 1 and 3 look to be the wettest

[bluearmy]

6 minutes ago, Summer Sun said:

The ECM weeklies issues overnight going out to March 19th show temps always at or a bit above average (the signal by week 4 is weaker for parts of the south)

As for rain weeks, 1 and 3 look to be the wettest

have these ever been cross checked gav?  I understood that the output wasn't released until 10pm

[ArHu3]

14 minutes ago, Summer Sun said:

The ECM weeklies issues overnight going out to March 19th show temps always at or a bit above average (the signal by week 4 is weaker for parts of the south)

As for rain weeks, 1 and 3 look to be the wettest

what are they based on today's 0z or yesterday's 12z because these looked very different (I posted yesterday's 12z on the previous page, it reminded me of december 2015)

[Summer Sun]

23 minutes ago, bluearmy said:

have these ever been cross checked gav?  I understood that the output wasn't released until 10pm

Not sure was a bit surprised to seem then out already as it's normally a Tuesday when I see them updated

Will check them again tomorrow to see if they are any different

[Summer Sun]

Back to the shorter term the weekend is looking rather windy

[Gael_Force]

19 minutes ago, ArHu3 said:

what are they based on today's 0z or yesterday's 12z because these looked very different (I posted yesterday's 12z on the previous page, it reminded me of december 2015)

If it is the correct monthly update it will be from 00z today. These charts are on an official European site so they may well have the data earlier than what is released to the pay to view sites.

[comet]

23 hours ago, Bring Back1962-63 said:

 

As expected really and not just be myself height rises being modelled to the north of the UK in roughly 8 days time very similar time line to what we saw with the stratosphere warming and trop response earlier in the month. This is what led to the Scandi ridge and there is no reason why this should not happen again perhaps with a more potent cold spell this time.

This is almost certainly a trop response to the ongoing strat warming