March CET

[Stratos Ferric]

The problem with the 'northerlies' we have had this year (today included) is unlike those you mentioned in the winter of 2005/06 they have just not had a long enough hold i.e. all been less than 24 hours and therefore the cold air has never had time to develop sufficiently, also they have not been true northerlies from the arctic, or been preceeded by cold surface temperatures.

I agree, though this presumes that northerlies ought to require a couple of days for the coldest air to get established at the surface. It wasn't always thus. In the late 70s and 80s snow would often occur at the initial front, and certainly on the back edge. When we do get northerlies nowadays there rarely seems to be a marked cold front. We're perhaps being hit by a triple whammy of warmer source air, slightly warmer sea surface, and less persistent flow, such that genuinely and extensively cold air seldom gets established in a mP flow.

As others have stated, early Feb 2007 was a candidate but featured a succession of fronts. I think 12 March 2006 is perhaps the most recent example, which blanketed much of western Britain in particular.

...

Was that widespread, or just the NW?

[chionomaniac]

A coolish day of 3.9C yesterday leaving the CET at 6.6C still 2.1C above average for this time in March! This should drop further by tomorrow.

[kold weather]

Yeah it will because despite the maxes being a little higher the mins were quite low which more then made up for the increase in the maxes.

Min average in the CET zone must have been down to -3/4C last night and maxes are only up around 8-9C so another sizeable drop likely today.

Thursday is probably going to see it rise again however with mins only down to 5-7C and maxes between 9-11C generally.

Edited March 5, 2008 by kold weather

[reef]

Yeah it will because despite the maxes being a little higher the mins were quite low which more then made up for the increase in the maxes.

Min average in the CET zone must have been down to -3/4C last night and maxes are only up around 8-9C so another sizeable drop likely today.

Thursday is probably going to see it rise again however with mins only down to 5-7C and maxes between 9-11C generally.

The min average for today came in at -2.7C:

http://hadobs.metoffice.com/hadcet/cet_min_est_2008

We should see a decent drop. I imagine we'll be at around 5.8-6.0C by tomorrow.

[Thundery wintry showers]

Was that widespread, or just the NW?

I remember 5cm of snow in Leeds from the 12 March 2006 event, there was also a dumping over W Scotland and NW England, I think parts of Wales as well, and also north-east England to a lesser extent. It certainly wasn't countrywide (I recall most of the SE missed it) but I think well over half of the country was affected.

Agree on your assessment re. northerlies by the way. I think one factor in both this and the 1st Feb northerly was that there was a lot of mixing to our N between Atlantic LP cores and ex-Arctic air, and so when the northerly started up, we got that heavily modified airmass. In that case you do need a N'ly to establish for a couple of days to get a largely unmodified flow from the Arctic. To me, it confirms the notion that to expect much from a northerly it helps if the jet is tracking south so that we don't get such modification of Arctic airmasses to the N.

I imagine the CET should be around par by the middle of the month as temperatures look like being mostly close to average during the upcoming zonal spell, at least in CET land, maybe milder in the south and colder in Scotland.

[eddie]

The Hadley CET is now 5.9C. Yesterday's CET was 3.1C.

[BLAST FROM THE PAST]

Fred-- Thought you were going for a CET nearer 4c

S

Hi Steve

Yes you got me!!! Late March can produce some impressive warmth and I do expect a solid easterly with good blocking to be in place from or just after mid month. If it is in the wrong place a big warm up will occur but as you can see I'm hedging my bets. I do expect a very solid and prolonged 5-7 day cold spell this month but the way this winter has gone there will probably be a switch to warm temps too afterwards. If it doesn't then 4c is on the cards....and aren't the modles liking that at the mo!

Fred

[eddie]

The Hadley CET is now 6.0C. Yesterday was 6.4C.

Looking at the GFS I can't see the CET deviating much from 6C over the next week.

[mountain shadow]

The Hadley CET is now 6.0C. Yesterday was 6.4C.

Looking at the GFS I can't see the CET deviating much from 6C over the next week.

It's the two weeks after that where it will take a tumble. 4 degree maxes and sub zero lows. My 4.4 bid could be looking good.

Is there a prize for the best guess?

[BLAST FROM THE PAST]

At this early stage a below average March looks the bet. I was going to go close to 4C but to achieve that we need prolonged cold for the time of year and these occur generally after decently cold winters. However, we are in for a chilly spring and the set up potentially could deliver something of notable cold and the warm up may not arrive until well into April. My punt could be conservatively high.

BFTP

[Kentish Man]

Hadley is at 6.1C today, a small 0.1C increase from yesterday.

The chances of a sustained colder spell mid to late month seem to have receded going by the models this morning.

Edited March 8, 2008 by Kentish Man

[eddie]

Since 1772 there have been 77 Marches that were warmer by this point in the month.

The warmest March up to the 7th was 1834 which was 9.7C.

The the coldest was 1786 at -1.7C. March 1947 was also -1.7C by the 7th. I just can't imagine seeing numbers like that these days. It almost seems like another country.

[Scorcher]

I disagree that a below average March looks on the cards. It's 0.9C above average at the moment and is not going to be dented much in the next week I don't think. There just doesn't seem to be enough frost on offer at the moment to take it below average and I am backing a warmish spell in the last week which I think will leave it around average or maybe marginally above.

[Stu_London]

GFS 12z has the CET remaining remarkably steady for the next 10-11 days fluctuating within a 0.2C range and ending up at 6.0 after the 18th.

Thereafter one would normally be looking at temps rising in the last third of the month, however if the northern blocking materialises and manifests itself to give colder conditions to our shores then a below average month is also possible.

[kold weather]

What is interesting with regards to the CET is the way the models have slowly been toning down the milder stuff and instead perfering to have the jet dominated WNW type flow, indeed the euro models decide to give a breif northerly shot next weekend as a weak high pressure cell develops in the Atlantic.

I think below average is the best bet but probably not much below unless a marked cold spell does develop in the last 10 days of the month which is possible. For the next 5-7 days I agree with Stu there probably won't be much movement, milder days balanced out with slightly colder ones.

[Norrance]

I remember 5cm of snow in Leeds from the 12 March 2006 event, there was also a dumping over W Scotland and NW England, I think parts of Wales as well, and also north-east England to a lesser extent. It certainly wasn't countrywide (I recall most of the SE missed it) but I think well over half of the country was affected.

Agree on your assessment re. northerlies by the way. I think one factor in both this and the 1st Feb northerly was that there was a lot of mixing to our N between Atlantic LP cores and ex-Arctic air, and so when the northerly started up, we got that heavily modified airmass. In that case you do need a N'ly to establish for a couple of days to get a largely unmodified flow from the Arctic. To me, it confirms the notion that to expect much from a northerly it helps if the jet is tracking south so that we don't get such modification of Arctic airmasses to the N.

I imagine the CET should be around par by the middle of the month as temperatures look like being mostly close to average during the upcoming zonal spell, at least in CET land, maybe milder in the south and colder in Scotland.

Re the 12th March 2006 I had a look at the snow reports on here for that day. I think that it could trully be said to be widespread with only the South / South East missing out. These reports came from as far apart as Inverness and Aberdeen in the North to the Midlands, Central England & Wales in the South. There was even a report from the Isle of Mann. [both yourself and SF, several times reported snow on the 12th.] Depths from the Met O and Torro included 25 cms in Glasgow [caused chaos on the Saturday night with three thousand people staying the night in Night Clubs due to public transport being totally disrupted], 22cms in West Fife, 28 cms in Ayrshire and Dumfries & Galloway. Cumbria and inland parts of Northumberland also had 20-30 cms and there were drifts in North Wales of 30- 40 cms. The deepest official report of level snow came from Artalnaig [Loch Tay] in Highland Perthshire where there was 39 cms of level snow. Was this the last trully widespread fall in the UK?

As for this March I still think that a just over average is possible though if the Northern blocking comes off I for one may have pitched too high.

[chionomaniac]

Hadley CET up to 6.3ºC today. I reckon it will hover around the low 6s until mid month.

[The PIT]

I'm beginning to wonder if Sheffield will record a below average month. If it does it'll be due to low mins. Max's are slightly above but the min about a degree below at the moment.

[chionomaniac]

Hadley still 6.3C after yesterday came in at 6.3C.

Edited March 10, 2008 by chionomaniac

[Thundery wintry showers]

I feel that my 6.4C is looking good, as while it may well turn colder for a time later in the month, it's unlikely that there won't be the odd warmer incursion in there as well to keep the CET up.

[Weather-history]

The "March colder than January" possibility still remains. Last occasion was 1983.

[BLAST FROM THE PAST]

The "March colder than January" possibility still remains. Last occasion was 1983.

Very much stays largely in the frame

BFTP

[The PIT]

MMm my 7.4C is looking rather silly right now.

[Duncan McAlister]

To the end of the GFS would take the CET to around 5.0, as has been the case for some days now. However it almost always underestimates temperatures so at the moment I'd say 5.4-5.9 the landing zone.

[Stu_London]

The "March colder than January" possibility still remains. Last occasion was 1983.

I'd say that whilst the trend to negative NAO/AO continues for the second half of the month, it is odds on.