[Pete Roberts]

Dave W, on 29 March 2012 - 22:34, said:

Some chilly nights next week, in fact by Thurs 5th GFS 18Z op suggests local -7 to -8C isnt out of the question.. noteworthy as the daily record low -is -9C http://www.wetterzen.../Rtavn15617.png

Despite the very high temps of previous days, sea surface temps surrounding the UK are still only average for the time of the year.

Pete

[Matt D]

Pete Roberts, on 30 March 2012 - 00:00, said:

Despite the very high temps of previous days, sea surface temps surrounding the UK are still only average for the time of the year.

Pete

Not sure about that Pete, all sources of SST that I can see suggest that SSTs around the UK are 1 to 2C above average (North Sea especially warm).

http://www.worldclim...ng/sstanom0.png
http://www.osdpd.noa...t.3.29.2012.gif

Where abouts are you sourcing your data?

This post has been edited by Matt D: 30 March 2012 - 00:36

[Matt D]

Dave W, on 29 March 2012 - 22:34, said:

Some chilly nights next week, in fact by Thurs 5th GFS 18Z op suggests local -7 to -8C isnt out of the question.. noteworthy as the daily record low -is -9C http://www.wetterzen.../Rtavn15617.png

ECMWF 12z suggests 20-30cm of wet snow accumulation across the northern Pennines/southern Scotland on Monday night! It develops an eastwards moving wave on the major cold front that pushes southwards across Scotland on Monday evening and then deepens this into a small closed circulation low with heavy, extensive precip to the north of it.

A particularly nasty variation on a theme perhaps, but many ECMWF ensemble support a covering of snow (1-3cm at least) over many northern hills/mountains by the end of Tuesday. The synoptic scale evolution through this weekend and into next week are reasonably consistent across the models but there is considerable inter/intra model run variation on smaller scale features such as this low.

Synoptic pattern (esp ECMWF), is not too disimilar to the cold plunges of early April 2008 (6th-7th) and also Jan 6th/7th 2010, both featuring an amplifying upper trough from the N, slipping southwards down the eastern flank of ridge positioned near Iceland. However, at this stage the synoptics early next week do not look quite as developmental as these two aforementioned events.

[Pete Roberts]

Matt D, on 30 March 2012 - 00:35, said:

Where abouts are you sourcing your data?

I was looking at Dave W's post:

http://www.wetterzen.../Rtavn15617.png

I use Wetterzentral's GFS temperature charts to keep an eye on SST's. I also use CEFAS' Smartbuoy map:

http://cefasmaps.def...aticMapPage.asp

but many of the original SmartBuoys seem to be offline or inactive.

Pete

[Dave W]

Those are max 2 metre temps not SSTs though.?

[Pete Roberts]

Matt D, on 30 March 2012 - 00:48, said:

ECMWF 12z suggests 20-30cm of wet snow accumulation across the northern Pennines/southern Scotland on Monday night! It develops an eastwards moving wave on the major cold front that pushes southwards across Scotland on Monday evening and then deepens this into a small closed circulation low with heavy, extensive precip to the north of it.

A particularly nasty variation on a theme perhaps, but many ECMWF ensemble support a covering of snow (1-3cm at least) over many northern hills/mountains by the end of Tuesday.

Looks more and more just like the rapid turnaround I've mentioned a couple of times: Grand National weekend at the end of March 1968. 70F on the Thursday and Friday, then heavy snow on the Monday.

Thurs 28th Mar:




and on Mon April 1st when the weather provided a classic April Fool day:


Incidentally, please forgive me if I repeat myself or post off-topic. Unfortunately my recent medical contretemps has not only trashed my lingual ablities but my short- and medium memory are badly affected. I can't remember weather events over the immediately previous 20 years or so, but clearly remember the weather over the weekend covered by my post.

Pete

This post has been edited by Pete Roberts: 30 March 2012 - 13:06

[Dave K]

It's not a total impossibility that Aboyne could go from record March warmth to points in Icebox Europe next week!

[PJB]

12Z GFS produces a fair amount of Snow for Northern Britain next week much like some earlier ECMWGF solutions.

[Dave K]

Out of "nowhere", after next week has been looking mainly dry down here the 00z GFS produced some prolonged rainfall for the 3rd/4th with up to 20mm (much needed), and the UKMO local outlook even hints at sleet as the cold front passes. Signs that the outlook is indeed unsettled and model runs could get jumpy.

[Dave W]

Notably cold 06Z GFS op run http://www.meteociel...1&ville=Londres but it was on the whole an outlier

[Chris Alder]

The retrogression of high pressure into the mid Atlantic that is present in both this evenings GFS & ECM later stages is really starting to concern me as these setups willl no doubt lead to a flabby, cold low dominating the weather for much of central and western Europe for a lengthy spell, not what I want to see when it's now only two weeks till my trip to Rome!

[Chris Alder]

While things are generally more unsettled this week GFS still only 3-6mm of precip falling across the south of England through to Saturday, given those small amounts it seems likely some places will only get 1-2mm, which is almost pointless rainfall when most places in the south are running at least an 50% YTD rainfall deficit.

[Andy Mayhew]

Aye, we're looking at around 11mm here over the next couple of days, then a mostly dry Easter now. But looks like we could see some more next week. The high in the Atlantic looks like it wants to stay put and leave us under cool north/northwesterlies. ECMWF even has a deep low sat over us by the end of next week, though at this stage doesn't seem to have much support.

[Peter H]

Andy Mayhew, on 03 April 2012 - 07:45, said:

Aye, we're looking at around 11mm here over the next couple of days, then a mostly dry Easter now. But looks like we could see some more next week. The high in the Atlantic looks like it wants to stay put and leave us under cool north/northwesterlies. ECMWF even has a deep low sat over us by the end of next week, though at this stage doesn't seem to have much support.

Indeed. And on the basis of going by where most of the pressure blobs are, and the highest pressure looks to be further west or south west, I'm just beginning to wonder if mid April might not see rain for most of us

[skanky]

Chris Alder, on 03 April 2012 - 05:46, said:

While things are generally more unsettled this week GFS still only 3-6mm of precip falling across the south of England through to Saturday, given those small amounts it seems likely some places will only get 1-2mm, which is almost pointless rainfall when most places in the south are running at least an 50% YTD rainfall deficit.

At least it will lesson demand though. It doesn't look like the sort of weather that will have people turning the sprinklers on - in those places that are still allowed, of course.
However, it could be the sort of weather where, in a month's time people will be saying that there's been plenty of rain, whereas the actual quantities aren't that large.

[Dave W]

Looking dry over next 2 weeks again looking at GFs output recently .. esp in south /SE. On recent GFS op output it seems Easter Monday looks reasonably warm in south .. 18C possible? Not great otherwise though earlier in easter period still.

[Dave W]

Very different 12Z chart from GFS op to 06Z op .. looking unsettled, potentially rather wet & windy as we go theough Easter and the following week in fact..

[Chris Alder]

Yes Dave, some pretty Awful looking charts that will, if they come off bring some beneficial rainfall from not just GFS but also this evenings ECM.

[Dave W]

GFS 12Z London ensembles- a lot of uncertainity prevails post easter but generally they're unsettled http://www.meteociel...=0&type=1&ext=1