Model Output Discussion - Heading Away From Easter

[No Balls Like Snow Balls]

06z does nothing more than re-confirm the established theme offering the hint of stronger easterlies after the weekend which really are going to be piercing especially in the south

Retrogression on the cards in FI potentially opening up the arctic floodgates again to the NE

The Scandinavians must really be freezing their collective butts off!

Goes Gavinesque right at the end of FI

But looking at the NH view heights are building into Greenland from the High Arctic so I wouldn't get the deckchairs dusted down quite yet!

Also the last 2 charts are A: FI and it is B: the GFS 06z - 'nuff said.

We shall enjoy this weekend then, as it''s not going to be very cold with temps 6c countrywide on Easter Sunday. will feel really quite pleasant in any sun. No extreme cold looks like coming back for the time being.

Even this morning the frost had nearly all melted by 8am and the sun was really quite warming on your back :-)

Edited March 28, 2013 by No balls like Snow Balls

[Tamara]

Worth looking at the different NH profiles for this year and the end of March 2007 when record warm temperatures were due to follow that April

This year

March 2007

The bottled up +AO profile of cold air over the North Pole in contrast to the expansive cold pooling this side of the arctic pushed out through the current strongly -AO profile, south and westwards into much of Northern, Central and Western Europe, including the British Isles

[Paul]

We're straying off topic (again), please can we discuss the model output in this thread - plenty of other places are available on the forums for more general chat

Edit - I've moved a number of recent posts to the model banter thread

[Weather Boy]

we could probably ignore the charts until monday and they wouldnt have changed. the only question is where exactly the blocking high just to our north will be centred, and its intensity. the option from now until the end of next week appear to be cold and sunny, cold and cloudy, but it looks predominantly dry.

depends upon whether or not you have a nagging breeze

Yes it seems to me that all of the models show a respite from the breeze over the holiday period, especially over Scotland which will more or less be under the high and therefore will have very low nighttime minima, especially where snowcover is retained and relatively high maxima (note relative!).

However, into the working week next week and we are basically back to square one with the breeze picking up, in the SW at first, but soon at least England and Wales too and probably the whole country eventually. That's due to the low to the SW attempts to move in with th eHight to the north moving only slightly, increasing the pressure gradient. It's looking dry with few if any encroachments from the Atlantic. Whether there may be convection bringing wintry showers from the west is probably too early to say at this point, but certainly it's looking like a rinse and repeat of this week to some extent, after what should be relatively bright and less breezy weather in the coming days.

[Summer Sun]

06z ensembles continue the slow rise through the next 2 weeks and get to around average by April 13th

The positive continues to be the lack of rain fall giving places a chance to dry out once again

The ECM Birmingham ensemble shows the average temperature slowly rising between April 1st and April 11th averaging from 6c to 9c by the 11th still well below the seasonal average of around 12c but better than what we've had

The Average low also rises slowly ranging from -1c on Monday to 3c by the 11th the seasonal average is 4c

As per the GFS ensembles precipitation is below average right through April 8th when it hits average the 9th to 11th it goes just 1mm above average

[-uksnow-]

06z ensembles continue the slow rise through the next 2 weeks and get to around average by April 13th

The positive continues to be the lack of rain fall giving places a chance to dry out once again

The ECM Birmingham ensemble shows the average temperature slowly rising between April 1st and April 11th averaging from 6c to 9c by the 11th still well below the seasonal average of around 12c but better than what we've had

The Average low also rises slowly ranging from -1c on Monday to 3c by the 11th the seasonal average is 4c

As per the GFS ensembles precipitation is below average right through April 8th when it hits average the 9th to 11th it goes just 1mm above average

However Gavin, a couple of days ago i noted that the mean didn't reach -5 until the 5th of April, and now it doesnt rise above it until the 7th of April, arguably even the 8th.

There's no doubt in my mind that the cold is being extended day by day, the only reason the mean really does rise is the scatter caused by FI as were never going to get strong agreement post 168 hrs imo. I just wonder how long it can really go on for...!

[Purga]

06z ensembles continue the slow rise through the next 2 weeks and get to around average by April 13th

Maybe but there is a shift to the cold side by many more members than with previous runs with virtually none getting anywhere near average until well after the first week in April. Yesterday for example the ENS were showing a split fairly soon with a significant number of runs showing mild as well as cold.

Conclusion: yes a gradual warming (to be expected as the season wears on) which has actually been shown for the last umpteen weeks! However a significant shift in support by the ENS towards a prolonged cold period in comparison to previous recent runs.

[No Balls Like Snow Balls]

Maybe but there is a shift to the cold side by many more members than with previous runs with virtually none getting anywhere near average until well after the first week in April. Yesterday for example the ENS were showing a split fairly soon with a significant number of runs showing mild as well as cold.

Conclusion: yes a gradual warming (to be expected as the season wears on) which has actually been shown for the last umpteen weeks! However a significant shift in support by the ENS towards a prolonged cold period in comparison to previous recent runs.

Cold for the time of year yes, but looking pretty dull for "weather on the ground". looks pretty benign for the foreseeable. Neither very cold nor mild, pretty much stuck in a rut, not a very exciting rut either.

Edited March 28, 2013 by No balls like Snow Balls

[Purga]

Worth looking at the different NH profiles for this year and the end of March 2007 when record warm temperatures were due to follow that April

This year

March 2007

The bottled up +AO profile of cold air over the North Pole in contrast to the expansive cold pooling this side of the arctic pushed out through the current strongly -AO profile, south and westwards into much of Northern, Central and Western Europe, including the British Isles

Interesting comparison - well illustrated Tamara, thank you.

[Tamara]

Interesting comparison

Yes it is interesting because it illustrates the stark differences we can see when the background factors are conduisive to blocking over the pole as a seemingly semi permanent pattern in the same way as back in Spring 2007 we were on the back end of a prolonged period of low heights that had been over the North Pole all winter 2006/07 with a very strong and stable polar vortex. This years stratospheric polar profile could not be more different to that

[Lincslad]

The ECM shows midlands southwards does not stay milder for long with colder 850 temps returning before the end of next week.

Indeed, but with a lack of lying snow and the strength of the sun, surface temps can actually rise quite well. This happens in tundra landscapes every spring. Will be cold nights though.

[Paul]

Latest forecast from Michael Fish - staying cold...

[Man With Beard]

A really unusual situation, one I don't think I can ever remember in the UK - widespread and highly confident agreement on one type of weather - a cold dry easterly - lasting not just for days but weeks! Michael Fish's forecast suggested we've got this for two weeks. Just now, the Beeb basically said the same. The models all seem to agree - absolutely no sign of a change in the pattern unless you search through the latter stages of the GFS ensembles and even then you're struggling.

I'm finding it hard to remember anything similar happening in recent times - perhaps August 1995 for hot weather, or Autumn 2000 for wet weather. But this pattern is the most persistent I've ever seen where there is no change at all from day to day.

This depth of blocking also suggests that the winters of 1947 and 1962/63 are still very possible - indeed, if this cold spell had come just 3 or 4 weeks earlier, I have no doubt that it would have been comparable to these famous winters. Ian F has apparently tweeted that March 1962 was the last similar March month, and this was followed by a cold year and the 1962/63 winter ...

[tinybill]

http://www.meteociel...?mode=2&ech=204

well staying cold with possible snow in parts to at least April 15 ,and im off to north Norfolk 2morrow for Easter ,cromer on the coast Saturday its cold in Summer hate to think what its like there at the moment!!,ps do i need shorts!!

Edited March 28, 2013 by tinybill

[snowking]

The ensembles are indeed promoting slightly less cold temperature as we head into next week, but it must be said they have been continually delaying/downgrading the degree of warmth as we move on.

To demonstrate this, the last 5 (0z and 12z) runs of the GFS (Black most recent, Blue the oldest)

And ECMWF:

An overall downward trend in Tmax from each ensemble run is really rather evident.

As for the suggestion of it feeling pleasant in any sunshine next week, I would disagree given the continuing windchill.

Heres next Wednesday from the 0z ECMWF:

Winds of between 25-30 knots - so lets take the lower end value, which equates to roughly 29mph.

Temperature projection from the ECMWF ensemble mean for Heathrow is 7c. Passing that through the new formula for windchill leaves us with a windchill factor making it feel more like 2c - its hardly going to have me reaching for my mankini (the public will be glad I am sure).

So yes feeling pleasant in the sunshine next week so long as you have a greenhouse. Otherwise remaining really rather chilly.

SK

[NorthNorfolkWeather]

http://www.meteociel...?mode=2&ech=204

well staying cold with possible snow in parts to at least April 15 ,and im off to north Norfolk 2morrow for Easter ,cromer on the coast Saturday its cold in Summer hate to think what its like there at the moment!!,ps do i need shorts!!

Hi TB, If you want to risk shorts, you're a brave man, it's freezing.

As far as the models are concerned, it is an amazingly persistent block. If you consider we are already 3 weeks into a pattern that looks stuck, the only hope we have is that the high will move slightly further south and we gain temperature via diurnal heating as any residual snow melts.

[Summer Sun]

This is for next Wednesday with the high to the north and the low to the south we will continue to see cool easterly winds coming our way, until the blocking eases and the jet stream moves up from north Africa we are stuck with this pattern

[johnholmes]

The ensembles are indeed promoting slightly less cold temperature as we head into next week, but it must be said they have been continually delaying/downgrading the degree of warmth as we move on.

To demonstrate this, the last 5 (0z and 12z) runs of the GFS (Black most recent, Blue the oldest)

And ECMWF:

An overall downward trend in Tmax from each ensemble run is really rather evident.

As for the suggestion of it feeling pleasant in any sunshine next week, I would disagree given the continuing windchill.

Heres next Wednesday from the 0z ECMWF:

Winds of between 25-30 knots - so lets take the lower end value, which equates to roughly 29mph.

Temperature projection from the ECMWF ensemble mean for Heathrow is 7c. Passing that through the new formula for windchill leaves us with a windchill factor making it feel more like 2c - its hardly going to have me reaching for my mankini (the public will be glad I am sure).

So yes feeling pleasant in the sunshine next week so long as you have a greenhouse. Otherwise remaining really rather chilly.

SK

Just picking you up on 1 factor in an otherwise very illuminating post

wind speeds are in fact shown as 10-15 ie 1 bar or 1.5 bars

1=10knots

1.5=15 knots

unless my eyes are up the spout again!

[snowking]

Just picking you up on 1 factor in an otherwise very illuminating post

wind speeds are in fact shown as 10-15 ie 1 bar or 1.5 bars

1=10knots

1.5=15 knots

unless my eyes are up the spout again!

Hi John,

I think this particular dataset is displayed in knots. For demonstration purposes, heres the accompanying chart showing the maximum wind gusts:

Perhaps I am reading that completely incorrectly, but from what I can make out the (kts) at the top left of the image indicates that the corresponding scale is in knots.

Kind Regards,

SK

Edited March 28, 2013 by snowking

[BLAST FROM THE PAST]

Posted Today, 00:57

I love extreme weather but how long can this go on for!?

Decades? Very much we are seeing a LIA footprint in evidence. Is it a false dawn, 5 years since change and counting and pattern becoming more extreme.

Anyway as JH has said [not many as experienced as he is, a very unusual pattern we are in [but was it unusual between 1600s and 1800s?

ECM really goes for lockin and UKMO suggests very much the same.

BFTP

Edited March 28, 2013 by BLAST FROM THE PAST

[Cheshire Freeze]

Decades? Very much we are seeing a LIA footprint in evidence. Is it a false dawn, 5 years since change and counting and pattern becoming more extreme.

Anyway as JH has said [not many as experienced as he is, a very unusual pattern we are in [but was it unusual between 1600s and 1800s?

ECM really goes for lockin and UKMO suggests very much the same.

BFTP

Get over to the LIA thread in the general weather chat Fred!

[Bristawl Si]

Get over to the LIA thread in the general weather chat Fred!

What's "LIA"?

[Cheshire Freeze]

What's "LIA"?

Little Ice Age

[johnholmes]

Hi John,

I think this particular dataset is displayed in knots. For demonstration purposes, heres the accompanying chart showing the maximum wind gusts:

Perhaps I am reading that completely incorrectly, but from what I can make out the (kts) at the top left of the image indicates that the corresponding scale is in knots.

Kind Regards,

SK

yes I'd agree with that, problem was the chart I saw had wind arrows on it of 10 and 15 knots which is why I questioned it?

[Severe Siberian icy blast]

Decades? Very much we are seeing a LIA footprint in evidence. Is it a false dawn, 5 years since change and counting and pattern becoming more extreme.

Anyway as JH has said [not many as experienced as he is, a very unusual pattern we are in [but was it unusual between 1600s and 1800s?

ECM really goes for lockin and UKMO suggests very much the same.

BFTP

I agree since 2008 we have saw a significant change in our British winters , northerly blocking is becoming more and more frequent , and I have never saw a March like this one before . I haven't had too much snow personally but lost count of the amount of times Iv saw it falling this march let alone this winter .

Been doing some research on sun spot activity and have to say the sun is behaving in a very similar way to how it did just before the Maunder Minimum , I know people debate this , but all we can do is pattern match to try and figure out where it's going and it's a perfect match to how it behaved then . It has an influence on the jet/gulf stream aswel which in my book explains why we have the jet behaving the way it is , at least affecting it in some way along with other factors . But beginning to add some "weight" to the "theories" of where we are going in the next 10 years weather wise as we build up data in the last 5 years to study and begin to understand a bit better .

And can I ask what LIA means please ?!

Edit : little ice age !! Got it . And I'm in the camp completely and have been since 2008 !!

Edited March 28, 2013 by Severe Siberian icy blast