Model Output Discussion 31/03/14 onwards.

[Summer Sun]

The Easter weekend is now in the reach of GFS, you can guess what it has... yes low pressure, cooler temperatures and some wintery precipitation

 

Good Friday

 

 

Saturday

 

 

Easter Sunday

 

 

Easter Monday (only available to 06:00)

 

 

Personally I preferred the 00z run more settled and slowly turning warmer

 

Edited April 5, 2014 by Summer Sun

[Skyraker]

Nailed on then SS?

[damianslaw]

Mmmm GFS might be latching on to my suggested thoughts i.e. retreat of the PV from its resident home, thanks to a kicking due to strat warming which is very strong at present for time of year and you would expect a time lag for change in about 2 weeks time.. I wouldn't discard what GFS is showing today as we hit easter - it is often the first model to pick up on a change when that change is coming from the NW. Indeed it should raise a few eyebrows, especially given how late April/early May is notorious for seeing northerly and easterly airstreams - they reach their peak at that time of year.

[Summer Sun]

Nailed on then SS?

 

Not much difference between the 00z and 06z it has to be said.....

[Polar Maritime]

A fantastic PM Flow towards end to the run by the GFS, and in line with meto further outlook.. We could end up with a very traditional Spring set-up, cool wintry and unsettled. with the vortex being bottled up for so long over Greenland during Winter it finally looks like it's weakening giving more scope for lows to swing further South, in turn taking the Jet with it.

 

Edited April 5, 2014 by Polar Maritime

[knocker]

Mmmm GFS might be latching on to my suggested thoughts i.e. retreat of the PV from its resident home, thanks to a kicking due to strat warming which is very strong at present for time of year and you would expect a time lag for change in about 2 weeks time.. I wouldn't discard what GFS is showing today as we hit easter - it is often the first model to pick up on a change when that change is coming from the NW. Indeed it should raise a few eyebrows, especially given how late April/early May is notorious for seeing northerly and easterly airstreams - they reach their peak at that time of year.

 

I was under the impression that the PV does not create new modes of variability in the troposphere, It stimulates preexisting modes that are fundamental to the dynamics of the lower atmosphere. If this is the case how is it effecting the tropospheric dynamics at the moment? Am I wrong in thinking this or is it, as I suspect, far too simplistic?

Edited April 5, 2014 by knocker

[johnholmes]

Looking at the mid term and further into April; extended ecm indicates days 10-15, will be average with a fairly neutral temp anomaly with broadly westerly's/NW flow. CFS ens go negative, with days 15-25 below for all. Whether it pans out like this, who knows.

ecm 10/15 temp anom. Cfs 15/25 temp anom.

 

yet only 4 days ago the temperature anomaly showed quite a marked -ve bias for the country!

Edited April 5, 2014 by johnholmes

[Summer Sun]

A fantastic PM Flow towards end to the run by the GFS, and in line with meto further outlook.. We could end up with a very traditional Spring set-up, cool wintry and unsettled. with the vortex being bottled up for so long over Greenland during Winter it finally looks like it's weakening giving more scope for lows to swing further South, in turn taking the Jet with it.

 

 

Not quite this is what they say for the 14th to 19th

 

Into the following week, there are signals for southern parts to see more settled and drier weather, with the most unsettled and windiest conditions further north. Temperatures should be mainly near normal, perhaps rather warm at times over central and southern parts, and maybe a little below average in the far north.

[049balt]

Not quite this is what they say for the 14th to 19th

 

Into the following week, there are signals for southern parts to see more settled and drier weather, with the most unsettled and windiest conditions further north. Temperatures should be mainly near normal, perhaps rather warm at times over central and southern parts, and maybe a little below average in the far north.

The weight of evidence is still favouring a more settled second half for April

[Summer Sun]

ECM ensemble shows high pressure is never far away from the south once it gets in next week the further south you are the better chance you have of seeing the best weather

 

[draztik]

yet only 4 days ago the temperature anomaly chwed quite a marked -ve bias for the country!

if your point is to suggest we are dealing with an unreliable timeframe, then yes? That's a given! But i tend to lean towards the latest trends and analysis than those of 4 days ago.

[knocker]

It is a long way off  so quite unreliable but the ECM Ens Control has a deep trough mid-Atlantic developing beginning of the Easter week resulting in:

Edited April 5, 2014 by knocker

[Summer Sun]

Gibby has posted an update on his website

 

Due to a terminal personal family health issue regarding my close family I am unable to supply the forecast pages for the time being. I will try and maintain the live weather feeds when able but apologize for the short term interruption to this service too at times. While my focus must remain entirely focused on family welfare currently I am unable to predict a time when normal updates resume and this applies to my Model Output Summary service too.

 

http://www.norton-radstockweather.co.uk/

 

My thoughts are with Gibby and his family at this difficult time

[DR(S)NO]

Gibby has posted an update on his website Due to a terminal personal family health issue regarding my close family I am unable to supply the forecast pages for the time being. I will try and maintain the live weather feeds when able but apologize for the short term interruption to this service too at times. While my focus must remain entirely focused on family welfare currently I am unable to predict a time when normal updates resume and this applies to my Model Output Summary service too. http://www.norton-radstockweather.co.uk/ My thoughts are with Gibby and his family at this difficult time

Indeed Gavin,there are more important things than the weather......thoughts are with Gibby and his family.

[Summer Sun]

UKMO continuing to show pressure building during Tuesday and more extensively on Wednesday though northern Scotland could be more unsettled this unsettled weather pushes south by Thursday where as GFS keeps pressure higher by Friday UKMO shows high pressure starting to move back in from the west

 

 

Little change from GFS so far

 

 

Out in FI GFS has its deep lows back with a northerly as well

 

Edited April 5, 2014 by Summer Sun

[Winter Cold]

Come on GFS, a white Easter would make up (slightly) for the total crap we had in winter!!! 

Hopefully when it gets closer, ECM will do same. Its encouraging that CFS and extended ECM look to be on board for now too, from the post a bit above

[049balt]

http://wxmaps.org/pix/prec4.html

 

Grim outlook for week two from GFS.

 

Week two looks horrific but if might only last a few days.

Edited April 5, 2014 by 049balt

[Methuselah]

I have followed the met in the past and they are generally poor beyond a week, this has been the best place for picking up trends, remember last July's heat wave, it was picked up here first !

Not to mention all those upcoming snow-events, heatwaves and dartboard lows that are 'picked up here first', but almost always fail to materialize?

[Captain Shortwave]

So the two model forecasts seen today are a blowtorch southerly and a snowy northerly. I don't need to think anymore about it.

Nothing really swinging away from near average conditions on the GFS ensembles even out to day 15. Given the other ensembles show similar to that time-frame I would expect the first half of April to come out drier and milder than average, but nothing extreme compared to the seasonal norm.

Edited April 5, 2014 by Captain shortwave

[Summer Sun]

First signs of the pressure rise on Tuesday from ECM

 

 

More widespread by Wednesday

 

 

By Thursday low pressure moves into Scotland but the high holds on in the south

 

 

Friday sees the high moving back in

 

 

Becomes unsettled just in time for the weekend away from the far south

 

Edited April 5, 2014 by Summer Sun

[johnholmes]

if your point is to suggest we are dealing with an unreliable timeframe, then yes? That's a given! But i tend to lean towards the latest trends and analysis than those of 4 days ago.

 

My point was that any forecast is just that, and subsequent runs may well show a difference, just as in this case.

The clever bit is being able to pick the right output in any time scale, be it 24 hours or 24 days ahead. Never ever believe one model no matter where it comes from.

[knocker]

The ECM ENS Control 500 hPa geopotential five day mean for Easter week at 12z is similar to the 00z which is no big surprise. The GFS is edging that way looking at a few days but still some significant differences. So need to keep the powder dry for the moment with low confidence.

 

 

Edited April 5, 2014 by knocker

[Milhouse]

ECM 12z looks like delivering some very average Springlike conditions with temperatures fluctuating from a couple of degrees above average under high pressure to average/slightly below under cooler northwesterlies. Rainfall looks to be highest in the NW, but nowhere looks like being especially wet over the next 10 days going by this run.

[DAVID SNOW]

ECM 12z looks like delivering some very average Springlike conditions with temperatures fluctuating from a couple of degrees above average under high pressure to average/slightly below under cooler northwesterlies. Rainfall looks to be highest in the NW, but nowhere looks like being especially wet over the next 10 days going by this run.

 

Average spring conditions; thank the lord we are saved....

[Polar Maritime]

GFS is showing a lovely Northerly,  in keeping with this mornings run.

 

Edited April 5, 2014 by Polar Maritime