Model output discussion 25th Jan onwards

[Summer Sun]

Snow risk still showing on the 12z

 

[Blizzardof82]

Not much love from GFS as it shows another big storm valentines day

[East_England_Stormchaser91]

Yikes! If that comes off valentines day, its beans on toast on a stove under rubble instead of champagne and oysters!

Edited February 8, 2014 by East_England_Stormchaser91

[john pike]

ukmo at 144

 

 

slight difference to gfs there

[Cheshire Freeze]

Bloody nora...

 

[Fred Sykes]

Not much love from GFS as it shows another big storm valentines day

good excuse not to go out and pay for an expensive meal!!

[Mucka]

Wintry potential still there for Tuesday afternoon through Wednesday morning across the output with possible back edge snow from the main front and wintry showers following behind.

 

 

Otherwise remaining very unsettled with further strong winds and rain at least to mid month and possibly beyond.

[stodge]

Afternoon all

 

GEM joins the St Valentine's Day Storm Party:

 

http://modeles.meteociel.fr/modeles/gem/runs/2014020812/gem-0-150.png?12

 

More severe than GFS but both concerning while UKMO at T+144 plays a different though still very unsettled tune.

 

GFS in low-res suggests the jet moving back north and drier conditions for the south but that's a long way off in model terms and may yet change.

 

The secondary feature for Monday looks to be passing well to the south on GEM but moves back NE on GFS which is obviously providing some interest.

[Man With Beard]

Bloody nora...

The good thing is that these 'super storms' aren't getting inside T120, perhaps a sign that a tendency to overplay their severity is going on. Neither GFS nor UKMO showing anything exceptionally bad for Tuesday/Wednesday now.

[karyo]

Snow risk still showing on the 12z

 

A definite downgrade on wintry potential compared to previous runs.

[OldMetMan]

Searching today for any further hints of an end to our Atlantic battering, but only minimal signs, mostly from the GFS with suggestion of a pressure rise across the south of the country.

 

Tamara's earlier post explained the current position and trends very nicely (thanks Tamara!) in her excellent post so there's not much I feel I could add to that.

 

One factor which is somewhat odd and has certainly done much to exacerbate the rainfall, especially along coastal counties, although not entirely, is the enhanced convection we have been seeing between frontal zones. Especially lately, the LPs have been embedded in pretty cold air, not that unusual for February, but convection has been widespread in the Channel for a long time, an effect that usually wears off as we head out of winter, as the sea temps drop. Clearly, those sea temps have remained high relative to the unstable air moving over it, hence the endless bands of showers that have been forming. Certainly in my location, rainfall from these has been considerable.

 

As Tamara mentioned, the extreme temperature gradient over the Canadian NE is, and has been, exceptional and continues to promote vigorous cyclogenesis, all of which heads our way. Hints from the GFS for this process to stop with the development of a deeper more slow-moving LP off the N American E coast, would be welcome, assuming it is capable of pushing some mid-Atlantic ridging and HP ahead of it.

 

I still think it possible to see heights rising to our N as the elongated upper trough spread out across the Atlantic starts to weaken - if it ever gets the chance and is not continually renewed with all the LP development. If the heights do rise, there may yet be a chance for some late winter blocking to our N but don't hold your breath!

 

I'd be interested to see what the mean surface and 500mb charts will end up looking like at the end of this winter. A pronounced vortex near or over the UK at both levels seems likely, with a corresponding considerable negative anomaly, so maybe if that is the case, it bodes well for HP in Spring and Summer. I think we all deserve that!

[Mucka]

GFS ensembles (snow risk for NW England shows at 95% Tuesday evening - highest thus far and though these are notoriously poor forecasting tools it is  a way to gauge whether chances are improving or receding, according to GFS at least)

 

NW England

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=233&y=40

 

SE England

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=289&y=122

Edited February 8, 2014 by Mucka

[Froze were the Days]

Yet another woeful GFS run to add to the list of many! - does anybody know why depressions are deepening like crazy fairly close to the UK? are the SST's abnormally high for this time of year, understand the cyclogenisis of the coast of the cold United States but this is another thing!

 

Getting quite tedious hunting for any real cold I really do believe it's game over, dire winter!

Edited February 8, 2014 by Froze were the Days

[gottolovethisweather]

GFS ensembles (snow risk for NW England shows at 95% Tuesday evening - highest thus far and though these are notoriously poor forecasting tools it is  a way to gauge whether chances are improving or receding, according to GFS at least)

 

NW England

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=233&y=40

 

SE England

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=289&y=122

 

I often like to read your analysis of things me ole Mucka  , but I'm not sure why you think they're (the ensembles spreads) notoriously poor forecasting tools when in the netweather guides, it states the following.

 

Many leading agencies now believe that ensemble forecasting is the way forward for anything beyond 5 days – and sometimes even shorter.

 

I personally use them and have done with great success in the past, as they often enable you to pick out specific dates for given weather events within the reliable timeframe. It may be that you're referring to the GFS and its more usual traits of exaggerating things such as deep lows and/or its default zonal tendencies, also the way it differs from one run to another. Anyway, moving on, no respite from the current pattern state, bar the potential back edge snow event on Tuesday evening, its a strong case of de ja vu. Perhaps eventually (mid Feb onwards) there will be a better chance of more drier interludes than actual rain days, now wouldn't that be most welcome.

Edited February 8, 2014 by gottolovethisweather

[DeKust BergenaanZee]

This situation with a strong, stable polar vortex concentrated around Hudson Bay Canada, pumping fridged air into the Central and East of the US reminds me of a very similar situation some years ago, when I lived on the US East coast.  I can't recall the exact year, it must have been early 2000's, (2001, 2002 or 2003), when this ice machine switched on around end December and lasted well into March.  It was bitterly cold then and I felt there was no end in sight to the cold. I remember I longed for temperatures to rise above freezing.  The last remnants of snow were still visible in early May. Also then, Western Europe experienced the opposite, extremely mild winter.  It might be fun to look at the archives in those years and identlfy the relevant patters and see how it evolved.  It could be very similar this year, which means, sorry, no winter, at least not in the lower lying areas..

[Eskimo]

I'm surprised no one has posted the maximum wind gust charts from the GFS, look away now! VERY dangerous storm :O

[Cheshire Freeze]

ECM 72 hr....snow risk Midlands?

 

[AWD]

ECM 72 hr....snow risk Midlands?

 

And us down south start flying around!

[Buzz]

I'm surprised no one has posted the maximum wind gust charts from the GFS, look away now! VERY dangerous storm

 

And yet the UKMO are having none of that:

 

http://www.meteociel.fr/modeles/ukmo2.php?nh=0&ech=144&carte=1021

[Blizzardof82]

ECM says sod waiting for everyone to get loved up and throws in a storm on the 13th

[skadi]

And we're getting our share too in the Low Countries...

[Buzz]

ECM says sod waiting for everyone to get loved up and throws in a storm on the 13th

UKMO is less stormy down south on the 13th:

 

http://www.meteociel.fr/modeles/ukmo2.php?nh=0&ech=120&carte=1021

 

And like the UKMO, the ECM leaves the 14th relatively wind free:

 

http://www.meteociel.fr/modeles/ecmwf.php?ech=144&mode=1&map=0&type=0&archive=0

Edited February 8, 2014 by Buzz

[OldMetMan]

Yet another woeful GFS run to add to the list of many! - does anybody know why depressions are deepening like crazy fairly close to the UK? are the SST's abnormally high for this time of year, understand the cyclogenisis of the coast of the cold United States but this is another thing!

 

Getting quite tedious hunting for any real cold I really do believe it's game over, dire winter!

I don't think there's an easy answer to why so many intense LPs. As I posted yesterday, today's low is the 7th to have a pressure below 950mb - uncommon is putting it mildly.

 

Personally, apart from the enormous temperature gradient you referred to, I think it's the location and persistence of the 500mb vortex and the trajectory of the jet that have brought so many LPS further S than usual and those two factors have been positioned such as to cause the LPs to reach maximum intensity near our shores. But it's mostly energy, the huge temperature gradients have made cyclogenesis more intense. I don't think SSTs are that important when it comes to the development of anything other than tropical systems and hurricanes.

 

Given the havoc this relentless storminess has caused, there will no doubt be many scientific inquiries into the whys and wherefors. That'll make interesting reading as and when!

[Man With Beard]

A closer look at ECM T72 - only affects a small part of the UK but - oh - my - goodness -

According to this chart, near-on hurricane force winds in the English Channel surely. Thank goodness this isn't backed-up by GFS/UKMO. Turns out forecasting a late-developing low is as hard as forecasting snow.

[cooling climate]

The vortex has been nowhere near the UK this winter and is wrong  to suggest otherwise.

The models are showing some amplification to the north and northeast but the ECM is still outside

the timeframe when this will be beneficial for the UK I think. It will be several days yet before we

see more consistent signs of a more wintry flavour to the output for the UK.

Of course these are just my thoughts on how things may develope based on the warming that is taking

place in the mid to upper stratosphere. If we are not to see a worthwhile potent wintry period either

before winters end or the first half of spring then hopefully we will see a quick transition to a very mild

and dry spring and summer.