Model Output Discussion 12z 10/05/13

[William of Walworth]

Right now, on recent output, a washout (or at least frequently wet) weekend, for some areas, seems likely?

One can only hope the detail alters and positioning of that low changes. What John said about becoming a deepening feature does seem a strong possibility though. Unfortunately for us outdoor bound weekenders ...

HP influence arriving just too late to save the coming weekend, but could this yet alter in future runs?

Not optimistic right now.

Edited May 13, 2013 by William of Walworth

[Frosty.]

Right now, on recent output, a washout (or at least frequently wet) weekend, for some areas, seems likely?

One can only hope the detail alters and positioning of that low changes. What John said about becoming a deepening feature does seem a strong possibility though. Unfortunately for us outdoor bound weekenders ...

HP influence arriving just too late to save the coming weekend, but could this yet alter in future runs?

Not optimistic right now.

I think the weekend low will be gradually shunted further east on future runs with the azores high taking over more and more of the uk but that is only my view. The met office update is looking a lot like the 6z for next weekend with heavy spells of rain and windy weather for the southeast of the uk with very cool temps, the north and west brighter and drier for a change with an azores ridge.

Edited May 13, 2013 by Frosty039

[Chris K]

I believe John was referencing tomorrow's Low having the possibility of considerable deepening, not next weekends.

Although I do agree that next weekend's low won't make it very pleasant either for many - if it does infact move as far West as currently modelled..

Edited May 13, 2013 by Chris K

[johnholmes]

I was and it almost certainly will be a deepish affair that is not the problem in term so forecasting.

The problem is how much rain will fall, when and where?

Take my location, amounts in the 48 hour period from 06z today to Wednesday 06Z currently vary from 2-4mm to up to 19mm.

UK Met, GFS, Extra, NMM!

Edited May 13, 2013 by johnholmes

[Chris K]

And lo and behold John you mentioned warnings -these were issued at 11:49am today but only just appeared for me. Its also worth pointing out that they mention the considerable uncertainity on the website, saying the area is likely to be refined and reduced as we approach closer to the time and it's development becomes clearer:

Warnings in force for these regions

East Midlands

East of England

London & South East England

North West England

South West England

Wales

West Midlands

Yorkshire & Humber

Below is the Yellow Warning for my area in particular in S Glos, but they are all the same (at the moment)...

Issued: 1149 on Mon 13 May 2013

Valid from: 0800 on Tue 14 May 2013

Valid to: 2359 on Tue 14 May 2013

The public should be aware that persistent and often heavy rainfall spreading from the southwest has the potential to cause some difficult driving conditions through Tuesday. Surface water flooding is likely on stretches of the road network, and in places strong winds will lead to considerable spray.

The public is advised to take extra care, further information and advice can be found here: http://www.metoffice.gov.uk/weather/uk/links.html

Edited May 13, 2013 by Chris K

[johnholmes]

yes I am not in the least surprised when you look at their latest Fax predictions and even their 00z model along with GFS showed fairly similar synoptic charts for tomorrow into Wednesday, as indeed they do at 06z.

[Frosty.]

I've had a closer look at the Gfs 06z with regard to the heavy rain spreading northeastwards across england and wales tomorrow and it looks like the rain will become very heavy and persistent with as much as 50 mm (2 inches) incredibly, even a risk it will turn to sleet and wet snow in some areas as temperatures continue to fall across southwest britain which includes the west midlands, the wet snow more likely on the welsh mountains, and higher ground in the midlands and then as this area of torrential rain spreads further northeast, the southern pennines could have a spell of wet snow before the very unsettled weather clears out into the north sea. Also some damaging frosts this week and next weekend could also be cold and wet in the southeast of the uk with max temps of 7c which would be abysmal for mid may, temperatures near average across northern and western parts of the uk by the weekend with more in the way of sunshine and lighter winds but a continuing risk of slight frosts, prospects for next week currently look better according to the latest gfs/ecm with azores ridging.

 

As for the rest of this week, cool with sunshine and showers, some heavy with hail and thunder but at least the winds becoming lighter although there is a risk that next weekend will bring strong NE'ly winds to the southeast quarter of the uk with spells of heavy rain and temperatures well below average.

Edited May 13, 2013 by Frosty039

[phil nw.]

Yes tomorrow looks a wet one indeed for central and southern areas of England and Wales in particular.Quite a spike on the precipitation charts for Warks.

 

 

As we all realised this week would be a cool and unsettled one under the persistent upper trough extending from low heights further north.

As shown for some days now the mean outputs have been consistent on an improvement during last week or so of May and again on the NAEF`s and ECM mean charts at 500hpa the warming out of this trough and rising pressure gets underway early next week-here at T192hrs.

 

 

The models then go onto a decent pressure build right across the UK by day 10 which should give much of the UK some warmer and settled conditions for a while at least.

 

 

 

[nitro_deluxe]

LOL to think I've returned to this..third or fourth hail shower stripping down the blossom from off the trees!

Tomorrow by contrast is going to be dire - stroll on next warmer slot?

Edited May 13, 2013 by triple_x1

[Frosty.]

 stroll on next warmer slot?

Let's hope the Ecm 00z is right then triple_x1.. a warmer and sunnier spell could be ours next week, it would be even better if the core of the azores high could fully envelop the uk rather than just a ridge so we avoid that chilly and cloudy NE'ly across the southeast of the uk but the ecm is very encouraging, as is the ensemble mean beyond T+168 hours.

Edited May 13, 2013 by Frosty039

[Frosty.]

Gfs 12z looks better on saturday at least with sunny spells, a few showers in the northwest and average temperatures.

[Summer Sun]

Better outlook from GFS this afternoon with the low getting kept further east

 

 

UKMO however says no to this and instead keeps the low

 

[Frosty.]

Much better gfs 12z for saturday, just by comparing the temperatures, perhaps we are seeing the first signs of the low being adjusted further east.

[ANYWEATHER]

Much better gfs 12z for saturday, just by comparing the temperatures, perhaps we are seeing the first signs of the low being adjusted further east.

Ahh, it will probably wobble all over the place , but the overall trend is still there!

[Frosty.]

Ahh, it will probably wobble all over the place , but the overall trend is still there!

Yes it's better early next week as the azores/atlantic ridge topples southeast, warmest and sunniest in the northwest on monday but cooler and cloudier in the southeast but by tuesday the best weather is across the southeast corner where it will be pleasantly warm but the rest of next week becomes cooler and unsettled from the northwest although with high pressure close to the south, the far south of the uk would be drier and brighter than elsewhere, I will be glad to see the back of these cool lows.

Edited May 13, 2013 by Frosty039

[rory o gorman]

Very nice 12z gfs , spits a strong ridge over us in Ireland by Saturday and continues mostly ridged into deep F.I with the jet well to the north and lower heights over Greenland is the 6 year curse over

[weather_it_will]

GFS is not matching the end of the 00z ECM as it's bringing in low pressure from the Arctic, where the ECM was bring in a high with more settled conditions.

 

 

 

Staying cool and wet possibly for a long while yet?  Certainly no agreement beyond the upcoming weekend.

 

Edited May 13, 2013 by Hot Wet Windy Cold No Snow

[Milhouse]

Agreement across the whole GEFS ensembles though which matters more than just one run.. ECM mean also going in the right direction.

 

[phil nw.]

GFS is not matching the end of the 00z ECM as it's bringing in low pressure from the Arctic, where the ECM was bring in a high with more settled conditions.

 

 

 

Staying cool and wet possibly for a long while yet?  Certainly no agreement beyond the upcoming weekend.

 

Have to say that`s a strange conclusion when you seem to base it on a chart over 300hrs out.

Be wary of any Operational run that far out in lower resolution (beyond T192hrs).

You are better off checking out the means and height anomaly trends beyond the HR period for guidance which are solid on a warmer and more settled trend beyond next weekend at the moment.

[Milhouse]

At this early stage the bank holiday is looking more warm and dry than cool and wet

 

[Summer Sun]

So far so good from ECM with pressure rising from the west during Sunday

 

 

 

The RHS Chelsea flower show takes place next week hopefully we'll see a pressure rise just in time for its start (21st to 25th)

Edited May 13, 2013 by Gavin.

[tinybill]

So far so good from ECM with pressure rising from the west during Sunday

 

 

 

The RHS Chelsea flower show takes place next week hopefully we'll see a pressure rise just in time for its start (21st to 25th)

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

 

 

i wish your right  but  looking  deep in to fantasy  world  its  not looking  nice  ex  when you read  the  jet stream 200miles  worse then it was last year  summer  wash  out  2!!

[Frosty.]

The Ecm 12z brings some settled, warmer and sunny weather to northwest britain for a change during next weekend and into next week as the azores high briefly links up with high pressure over scandinavia, eventually the weather improves in the wet, windy and cooler southeast and the azores/atlantic high keeps a ridge over most of the uk until the middle of next week, the ecm 00z at T+240 was much better because the jet was aligned more towards sw/ne with the azores high extending a strong ridge northeastwards but at least there is an increasing likelihood of a more settled start to next week once this unsettled week is over, this ecm run looks rather like the gfs 12z with low pressure spreading southeast from iceland being the eventual spoiler next week, high pressure is trying hard though.

Edited May 13, 2013 by Frosty039

[Purga]

Looks like a pretty wet GFS 12 z overall albeit with some drier interludes but certainly no long warm dry spell right through to FI.

I suspected there could be a potential deluge over the east / SE at the end of the week.

The mid Atlantic / Azores High seems to want to pull back west on the ECM 12z at 216h after teasing at 196h

 

Cool and showery then with a very wet potential this week a la ECM as well

 

 

 

 

 

Not forgetting UKMO of course!

 

[Milhouse]

Plenty of warm >5c runs showing up on the ensembles. Some cooler ones as well.

 

http://www.wetterzentrale.de/pics/MT8_London_ens.png?6767676767