Winter Model Discussion 18Z 8/1/13. The hunt for cold (is closer).

[johnholmes]

Not sure why you are clapping and getting excited at such a long distance? Seriously people anything beyond 46hrs is FI in this current set up, we've even had mistakes made on a day to day basis.

I'll say it again from previous posts, the models are are absolultly rubbish at medium term ranges! Trends doesn't work either

being pedantic there is no 46 h output we see its 48, ie 24, 48, 72 etc-sorry to be so picky!

[Southender]

Well, The Ensemble for here ( and most of the UK ) is now showing a shorter lived cold snap

This to me is still good confirmation that yes, there is cold on the way.. For how long though?? Anyones guess. The west could barge right in our it couldn't.

I think the main thing to take away from this is that from today the uppers will start to drop. So this is good.

Even looking right up to FI , Yes currently it does show some warming again and becoming less cold however it still seems to keep with the colder theme and cooler air is never too far from us.

Today is certainly going to be interesting watching the models.

Not bad overall really. With the mean prob around -5 or -6 throughout as a whole. Not bad for western areas.

[cold snap]

Mods . Can we start a new thread please , makes it easier to follow with thanks , ready for 6zs

[SMU]

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

I will take those especially the control!!

The ensembles will always have Pterbations that dont 'see' the blocking pattern-

If we take the MEAN at 240

Considering there are 50 runs then thats VERY good...

eyes down for the 06z what will the hangover run bring...

S

[Weathizard]

I do find it strange how as soon as we get consistency it disappears? Its like the big 3 don't want to be like each other because its 'not cool' to copy other trends! First of all we have GFS Ens on side but no OP consistency. Mean while the ECM ens were alright and the ops were terrible, then the GFS switched and showed 4 consecutive very cold outputs but each time lost more backing from the ENS then the ECM comes on board with fantastic output and great london ENS especially. THEN we have the GFS op flip and the ENS suddenly shift back to colder! Absolutely bizzare turn of events and I've never known it like this, obviously there is always uncertainty but its unparralel to what we have right now! Wonder what the next episode of this crazy soap opera brings! All aboard!

[bradymk]

GFS has been quite consistent about snow on sat on its precip charts, why are no websites/ news showing this?

Even though it is consistent, I think this is because of the resolution of its precipitation charts. The GFS precip charts are not good for detail and only for a broad idea, the hatched snow charts are not run at a high resolution and so this limits how accurate the precip output is. Follow the UKMO video forecasts and warnings and Ian's guidance as they use much higher resolution models. Also, the public have access to the raw NAE model which is also a higher resolution precip model but this only goes out to 48 hours ahead but UKMO forecasts and warnings will most likely be most accurate. Edited January 9, 2013 by bradythemole

[Dexter29]

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

I will take those especially the control!!

The ensembles will always have Pterbations that dont 'see' the blocking pattern-

If we take the MEAN at 240

Considering there are 50 runs then thats VERY good...

eyes down for the 06z what will the hangover run bring...

S

Steve, if 06z follows on from the 00z should we be concerned?

Or should we be concerned if the 12z doesn't deliver?

[Methuselah]

The issue with Matt Hugo is, he is as unreliable as a long range GFS model! He himself uses models and then gives us a forecast based on those models.

I think we should have two threads on this forum, one for close range ( upto 46hrs ) and the second thread, anything behond that FI

Is that today's moment of enlightenment, VM: that Matt Hugo is human?

Anyway, time to concentrate on the models...

[bradymk]

http://www.knmi.nl/e...agse/index.html

I will take those especially the control!!

The ensembles will always have Pterbations that dont 'see' the blocking pattern-

If we take the MEAN at 240

http://www.meteociel...1-240.GIF?09-12

Considering there are 50 runs then thats VERY good...

eyes down for the 06z what will the hangover run bring...

S

Yes Steve, control run is a cracker and is actually almost a complete replica of the op. http://www.ecmwf.int/samples/d/inspect/catalog/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!168!pop!od!enfo!enplot!2009112700!!/ Look at those postages stamps, amazing how similar control and op are this morning and they are basically the same line on those de bilt ensembles before the control plunges out of the Op's forecast period. Ensembles for De Bilt are good, do you think the London ones wont be as good however?

[fergieweather]

Some fascinating analysis from UKMO for weekend. Snow probability increasing later Sat for places such as Birmingham etc, but heavy rain event to south, until retreat of rear-edge into early Sun offers wintry potential further south. However, UKMO focus firmly on developments into Mon with potential for "significant snow event" into W Country and environs. UKMO GM heavily modified to EC for this stage: raw GM and MOGREPS track of low to E/N not favoured solution. Confidence re Mon still too low for any early warning.

[lord stratus]

06z out soon. Keep an eye on the period 15th to 18th jan for a snow event

[bradymk]

Thanks for that Ian, hadn't realised the potential for sig snow event on ECM in West. http://www.yr.no/place/United_Kingdom/Wales/Carmarthen/long.html this forecast for near my location uses the ECM op as there input for there forecasts only and this shows the potential for some heavy snow Monday.

[weather eater]

Steve, if 06z follows on from the 00z should we be concerned?

Or should we be concerned if the 12z doesn't deliver?

To be honest no point at all in agonising about whether the GH will set up at this stage, it’s unrealistic IMO to expect every run to be as outstanding as the last, where we really don’t want to see downgrades is the period out to 120hrs.

[bradymk]

This graphic highlights the potential sig snow event Ian has highlighted in the W on Monday, interesting.

[Hammer]

On the GFS 6z at T36 when compared to 0z T42 are the low's deeper to our east and west. The low over Russia and the one in the Atlantic. ?

Edited January 9, 2013 by Hammer

[Bobby]

Overall things are looking good this morning, could be much worse.

GFS OP - poor

GFS ensembles - much better

ECM - superb

ECM ensembles - pretty good

UKMO - pretty good

GEM - superb

The ECM upper mean at +168 is similar to yesterday with -6c to -7c for most, blocking over Greenland looks reasonably strong still too out to +240

[Snowman31]

This graphic highlights the potential sig snow event Ian has highlighted in the W on Monday, interesting.

would this move east?

[BeastFromTheEast]

hi where could I view some snow charts for east anglia? thanks

[bradymk]

would this move east?

As Ian said "Confidence re Mon still too low for any early warning." But if the ECM for Monday was a reality, it would not move East but most likely move South/South eastwards but I don't have the data that UKMO do so best to ask Ian or wait for warnings if confidence increases.

[Methuselah]

hi where could I view some snow charts for east anglia? thanks

Here:

[Snowman31]

Some fascinating analysis from UKMO for weekend. Snow probability increasing later Sat for places such as Birmingham etc, but heavy rain event to south, until retreat of rear-edge into early Sun offers wintry potential further south. However, UKMO focus firmly on developments into Mon with potential for "significant snow event" into W Country and environs. UKMO GM heavily modified to EC for this stage: raw GM and MOGREPS track of low to E/N not favoured solution. Confidence re Mon still too low for any early warning.

Thanks Ian. What I don't understand though is if there going with the ECM then why would there only be snow from birmingham northwards, i'm looking at the ECM 850s temp for saturday and the 850 temps further south are the same as birmingham?

[Southender]

Out to 72hrs and no drama's so far. LP west of Ireland perhaps has a slightly better tilt to it allowing a decent undercut.

[BeastFromTheEast]

Here: http://forum.netweat...20#entry2472094

took me to the south east forum, where are the charts please?

[peterf]

cracking 06z for here,time to wax the sledge for Saturday morning.

[warrenb]

Wet bulb my friend, it takes time for humidity to leave the atmosphere thus the web bulb temp will be higher in the south,