Model Output Discussion - Stormy Period Inbound...

[winterof79]

Whatever the temp anoms say has little bearing to locality.

http://modeles.meteociel.fr/modeles/gens/runs/2015010806/graphe3_1000_269_32___.gif

The best for a long while i would wager for central Northen England.

Longer term many of the GEFS ,which still point to some pettern change around the 18-20th and have consistently,now show a movement of the core of the Vortex and also to low pressure systems filling to our e/se and an Atlantic height rise cutting off the Atlantic flow.Very interesting to watch.

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=384

Edited January 8, 2015 by winterof79

[Cheshire Freeze]

This mornings Day 16 Mean, even more Amplified than the chart i posted last night...

 

 

ENS once again looking good in FI,

 

Cold spell gathering pace maybe?

 

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=384

 

And amongst them there is even a visit from THE BEAST!!!

 

 

 

 

That's quite a feat for a MEAN chart 16 days out.

[SE Blizzards]

That's quite a feat for a MEAN chart 16 days out.

 

Yes CC. And it has been showing now for the last 3 or 4 runs.

 

Of course, at Day 16 we have to be careful not to get 'too' carried away, but as you rightly say, that is some signal there being picked up by the GEFS.

 

More of the same from the 12z's please.

[Paul]

 

 

sorry this has already been picked up in the appropriate strat thread. Mods please delete.

 

Just for your and anyone elses info - you do have the option to hide your own posts, with a link to do so just at the bottom of the post.

[johnholmes]

GFS 06 ensembles Central England

 

 

 

Just a hint of things settling down and that some colder weather may be arriving last week of Jan.

Also that is quite a cold zonal signal for 13th to 19th with mean 850's around -4c (suggesting they will dip to -6c or so at times)

 

looking at the amount of scatter after 13-14 January with variations in temperature at 500mb in excess of 25C is hard to arrive at any real conclusion other than marked variability, with just a possibility that the trend MIGHT be downwards for temperatures at 850 and 500mb. Certainly not something to hang anything on at the moment.

The anomaly charts I am finding quite hard to read as to what signal they MAY be showing. Yes there are some longer tele links that SUGGEST some kind of cooling down is possible but that is all at the moment. Probability to me is no higher than 30% for any marked cooling down, More of the same temperature wise variability although the wind aspect will be less as time moves on.

[winterof79]

Yes CC. And it has been showing now for the last 3 or 4 runs.

 

Of course, at Day 16 we have to be careful not to get 'too' carried away, but as you rightly say, that is some signal there being picked up by the GEFS.

 

More of the same from the 12z's please.

Agreed SE i have been closely following the GEFS as you may have noted.They have been banging the drum for days and were the first to pick the signal up for a change around the 18-20th when it was at 360 hrs and its getting closer according to GFSP 06Z

http://modeles.meteociel.fr/modeles/gfsp/runs/2015010806/gfsnh-0-252.png?6

Lets hope we can count down to 138z.The end of Jan smacks of cold to me and our recent warmings,contrary to what some say,may just be doing us a favour shortly

http://modeles.meteociel.fr/modeles/gens/runs/2015010806/gensnh-21-7-6.png

http://modeles.meteociel.fr/modeles/gens/runs/2015010806/gensnh-21-3-384.png

[lorenzo]

GEFS seems to be off on one with the MJO and the analogs for Jan for Phase 7 support a substantial Greenland Block.

 

Pretty high amp transfer through phase 7.

 

Other models less keen

 

JMA / UKMO / ECM

 

 

Indices from Mike Ventrice page point at MJO decaying into phase 7 versus the outright decay in phase 6. For the phase 7 effects to pull through we would really hope that the MJO projection as analysed today on chart below were further east. i.e at amplitude in Phase 7.

 

 

How much this evolution pulls through onto GEFS Ens for later in the month c 20-30 is still unclear, would be wary of blocking and look at what vortex is doing as the lead mode. Weak wave 2 projected, can it gather pace..  MJO cycles as per ECM and likely to re-emerge again from C.O.D into maritimes Phase 5 for final third of Jan as per ECM above.

 

 

[marksiwnc]

Just to add to other posts regarding ian f s comments he also adds

but ultimately cooler nonetheless, with colder (more N'rly) spells possible. But no reliable sign of major/lengthy cold

End of matter now hopefully. So looks like cold or cool zonality. That's better than nothing

[Nouska]

GEFS seems to be off on one with the MJO and the analogs for Jan for Phase 7 support a substantial Greenland Block.

 

Pretty high amp transfer through phase 7.

NCPE_phase_21m_small.gif

 

Other models less keen

 

JMA / UKMO / ECM

 

JMAN_phase_51m_small.gifUKME_phase_23m_small.gifECMF_phase_51m_small.gif

 

Indices from Mike Ventrice page point at MJO decaying into phase 7 versus the outright decay in phase 6. For the phase 7 effects to pull through we would really hope that the MJO projection as analysed today on chart below were further east. i.e at amplitude in Phase 7.

 

twc_globe_mjo_vp200.pngpost-7292-0-73596600-1420312035.jpg

 

How much this evolution pulls through onto GEFS Ens for later in the month c 20-30 is still unclear, would be wary of blocking and look at what vortex is doing as the lead mode. Weak wave 2 projected, can it gather pace..  MJO cycles as per ECM and likely to re-emerge again from C.O.D into maritimes Phase 5 for final third of Jan as per ECM above.

 

The other model ensembles have shown a tendency to produce an increasing number of amplified members in the last couple of runs - the NCEP might be too bullish - perhaps a half way house is the way ahead.

[winterof79]

Just to add to other posts regarding ian f s comments he also adds

but ultimately cooler nonetheless, with colder (more N'rly) spells possible. But no reliable sign of major/lengthy cold

End of matter now hopefully. So looks like cold or cool zonality. That's better than nothing

Yes and signs of low pressure to our east dragging in N/ne winds possibly the cause.

[ribster]

Just to add to other posts regarding ian f s comments he also adds

but ultimately cooler nonetheless, with colder (more N'rly) spells possible. But no reliable sign of major/lengthy cold

End of matter now hopefully. So looks like cold or cool zonality. That's better than nothing

If you mean end of the matter with regard to the METOs view of the situation then yes, other than that it doesn't put the end to anything.

[bluearmy]

Or perhaps the MJO may not be the driver second half jan?

My recollection of MJO/trop relationship is that if the oscillation is the driver, the trop situation when it enters the COD is left as the prevailing one going forward.

FWIW, I don't curently subscribe to the MJO as being the sole/major driver of the current trop pattern anyway.

[mulzy]

Deleted

Edited January 8, 2015 by mulzy

[bluearmy]

Have to take the GEFS with a pinch of salt particularly in deep FI.   For example compare the bias corrected 0z set with the base 6z set at day 16.  Will be interesting to see what happens when the 6z set is 'bias corrected'.

 

 

 

 

 

i nearly fell for that one ! its yesterday's 12z run. sylvain!!!

 

incidentally, gefs probably is on the MJO cycle as it has thrown out 4 runs with a seriously neg AO control

[mulzy]

i nearly fell for that one ! its yesterday's 12z run. sylvain!!!

 

incidentally, gefs probably is on the MJO cycle as it has thrown out 4 runs with a seriously neg AO control

 

Sorry about that - should actually pay attention to the date!!!

[Frosty.]

6z shows cold zonality digging in across northern britain this weekend with snow showers for exposed north western areas but during next week, possibly penetrating further south and east at times with icy conditions and frosty nights but with bouts of wet and very windy, milder spells too, again with a risk of leading edge snow and then back edge snow along active cold fronts before showery polar maritime air digs in, so it's a very disturbed outlook, occasionally stormy, especially in the north whilst southern areas see the best of any fine intervals between weather systems. Cold air and mild air will keep slugging it out, trading blows but my hope is that cold weather will become more dominant as time goes on, as for the 6z, it's even more wintry looking than yesterday, so another upgrade there :-)

Edited January 8, 2015 by Frosty.

[BlueHedgehog074]

6z shows cold zonality digging in across northern britain this weekend with snow showers for exposed north western areas but during next week, possibly penetrating further south and east at times with icy conditions and frosty nights but with bouts of wet and very windy, milder spells too, again with a risk of leading edge snow and then back edge snow along active cold fronts before showery polar maritime air digs in, so it's a very disturbed outlook, occasionally stormy, especially in the north whilst southern areas see the best of any fine intervals between weather systems. Cold air and mild air will keep slugging it out, trading blows but my hope is that cold weather will become more dominant as time goes on, as for the 6z, it's even more wintry looking than yesterday, so another upgrade there :-)

Good summary, Frosty. Agree with the top part in particular. Aside from some spells of wet weather to endure tomorrow, particularly for North-Western areas (in fact, the GFS doesn't show much precipitation down here in the South), it does look as though a chilly Polar Maritime flow will develop behind Friday Night's/Saturday morning's cold front this weekend.

The 850 hPa temperatures along with Dewpoints around, or below, freezing should certainly support sleet and snow showers to low level areas towards Northern and Western areas:

Would definitely seem, though, Southern and South-Eastern areas will generally stay dry and bright. But some of these wintry showers could scrape the Northern Midlands area at times from the Chesire Gap. Looks as though the snow shield over my house will stay untouched (nooo...), although hopefully some of these showers will crumble your and other cold fans' snow shields to the North/North-West.

That possible storm for the middle of next week will probably still need watching, although it's only really the GFS model that makes the most of this...

...with most other models making much less of this feature. Certainly still not worth ignoring yet, and even without this possible stormy secondary Low coming off, it does look apparent next week could be quite cool and unsettled for places at times, especially towards the North-West.

Beyond next week and there could still be possibilities that the Atlantic could start slowing down with hints that the Vortex over the Canada or Greenland area could become less invasive. And if so, could cause the Jetstream to become less strong and more waiver. This of which could allow some more blocked and/or amplified solutions to develop to the West and North of the UK and perhaps provide those after freezing weather with something snowy and chilly. Not definite mind you, since most of the potential is still locked behind the cupboard door in FI (the cold and snow fans' may just end up with a standard Northerly toppler for example, unless High Pressure can amplify enough to our West and get drawn over Greenland or something). The models will need to be able to find the key to unlock these possibilities so they reach a much more closer time-frame. Always a risk the pattern could flatten out somewhat closer to the day itself. But still nice to see some models continue to trend towards some possible colder and blocked solutions - even the ECMWF towards the end of its run looks like an improvement for cold weather possibilities with Lows dropping to our East.

The NOAA 8 to 14 Day 500mb Anomaly chart seems to hint at lows/troughs going to our East along with lower than average heights to our North-East. With higher than average heights to our West along with the 500mb flow between the West/North-West over the UK, then it's possible some chilly weather could develop from the North-West or North for a time. Especially if a proper Scandinavian trough develops.

Edited January 8, 2015 by DiagonalRedLine

[Mucka]

GFSp more in line with this mornings UKMO in moving the core of the trough toward Scandinavia from 12th rather than holding it just North of the UK as with earlier GFS operational and GFSp output which in theory should enhance wintry prospects further South in the run up to mid month.

 

Comparison charts.

 

 

 

 

It does make much less of the next low than UKMO this afternoon though.

 

Edited January 8, 2015 by Mucka

[Captain Shortwave]

UKMO

 

GFS (P)

Both setting up a potent wind and rain event for the second half of next week.

A little later 

Severe gales over the northern half of the UK.

 

Beyond this, can we clear enough of a gap to get a ridge in behind this low.

 

GFS finally coming out

Potential snow event on the northern flank of this low, absolutely ghastly for the south with an endless train of rain from the associated front which spans both secondary lows.

Edited January 8, 2015 by Captain shortwave

[Mucka]

UKMO

 

GFS (P)

Both setting up a potent wind and rain event for the second half of next week.

A little later 

Severe gales over the northern half of the UK.

 

Beyond this, can we clear enough of a gap to get a ridge in behind this low.

 

 

Wind rain (and snow if GFSp is to believed)

 

 

 

 

This is one of those times where any snow could well be trivial in comparison to wind and flood risk though. That could be the coup de grace of the stormy period for any weakened structures. Could well be nasty and make the headlines with stormforce winds getting further South. 

Actually the weather could well be in the headlines quite frequently from this weekend,

Edited January 8, 2015 by Mucka

[winterof79]

Good summary, Frosty. Agree with the top part in particular. Aside from some spells of wet weather to endure tomorrow, particularly for North-Western areas (in fact, the GFS doesn't show much precipitation down here in the South), it does look as though a chilly Polar Maritime flow will develop behind Friday Night's/Saturday morning's cold front this weekend.

The 850 hPa temperatures along with Dewpoints around, or below, freezing should certainly support sleet and snow showers to low level areas towards Northern and Western areas:

image.jpgimage.jpg

image.jpgimage.jpgimage.jpg

image.jpgimage.jpgimage.jpg

Would definitely seem, though, Southern and South-Eastern areas will generally stay dry and bright. But some of these wintry showers could scrape the Northern Midlands area at times from the Chesire Gap. Looks as though the snow shield over my house will stay untouched (nooo...), although hopefully some of these showers will crumble your and other cold fans' snow shields to the North/North-West.

That possible storm for the middle of next week will probably still need watching, although it's only really the GFS model that makes the most of this...

image.jpg

...with most other models making much less of this feature. Certainly still not worth ignoring yet, and even without this possible stormy secondary Low coming off, it does look apparent next week could be quite cool and unsettled for places at times, especially towards the North-West.

Beyond next week and there could still be possibilities that the Atlantic could start slowing down with hints that the Vortex over the Canada or Greenland area could become less invasive. And if so, could cause the Jetstream to become less strong and more waiver. This of which could allow some more blocked and/or amplified solutions to develop to the West and North of the UK and perhaps provide those after freezing weather with something snowy and chilly. Not definite mind you, since most of the potential is still locked behind the cupboard door in FI (the cold and snow fans' may just end up with a standard Northerly toppler for example, unless High Pressure can amplify enough to our West and get drawn over Greenland or something). The models will need to be able to find the key to unlock these possibilities so they reach a much more closer time-frame. Always a risk the pattern could flatten out somewhat closer to the day itself. But still nice to see some models continue to trend towards some possible colder and blocked solutions - even the ECMWF towards the end of its run looks like an improvement for cold weather possibilities with Lows dropping to our East.

The NOAA 8 to 14 Day 500mb Anomaly chart seems to hint at lows/troughs going to our East along with lower than average heights to our North-East. With higher than average heights to our West along with the 500mb flow between the West/North-West over the UK, then it's possible some chilly weather could develop from the North-West or North for a time. Especially if a proper Scandinavian trough develops.

image.jpg

NOAA 8-14 sniffing what the GEFS have been suggesting that's interesting now.

[SE Blizzards]

All i can say is.... Watch out for deep FI on the GFS op.

 

One word.... BOOM!!!!!

[gottolovethisweather]

All i can say is.... Watch out for deep FI on the GFS op.

 

One word.... BOOM!!!!!

 

or BUST!     

 

Seriously though I agree with Mucka, Diagonal and Frosty amongst others that the signal may still be of zonality for the next seven to ten days but its showing an increasingly cooler PM influenced trend. Akin to much as I expected via my previous posts.

 

For instance upon looking at the bigger NH view yesterday, I stated the following.

 

"The NH Jet which is soon to be at record speed strength (240mph forecast) is shown to weaken by around the aforementioned latter timescale too. As indicated on the chart attached above, the snow risk probabilities for London by way of example are at low risk levels at best, although that's quite something given the lack of snow since March 2013 in this region and I anticipate they will remain that way until the NH Jet does weaken. In fairness, this aspect proves there is not too long to wait, should you be of a cold Winter disposition and is another signal to grasp while we can. By which time, during early next week I anticipate the outputs will inevitably increase wintry potential further South with D4 through to D7 charts, i.e mid-January and beyond providing more hope for widespread wintriness than at any time during the season so far, although I would expect transient snowfall/wintry showers to be the main theme of the weather when it does arrive."

 

 

 

Let's hope the ECM and the next few day's 12z outputs and of course the ensemble spreads continue the theme. 

Edited January 8, 2015 by gottolovethisweather

[SE Blizzards]

or BUST!   

 

I've seen it, and believe me, it's Boom!! 

[Mucka]

GFS Op not going with the explosive cyclogenesis of  its Brother or UKMO and if the low develops less and tracks further South there could be a very big snowfall on its Northern flank.

 

Much rather the big snow event than a more dangerous storm event though I guess they both carry risk. For a weather enthusiast it is very interesting period weather either way.

Edited January 8, 2015 by Mucka