Spring Model Discussion 17/3/13 6PM onwards....

[Captain Shortwave]

Frontal snow aside

Having -14 uppers almost reaching North East Scotland is really something and this is just 3 days away

[AWD]

Rainfall also a major issue for some. In excess of 70mm by the end of Friday over Cornwall;

I remember scenes such as the Mavigessey floods a few years back. Something similiar could happen again should the NAE verify.

So both snow and rain could hit the headlines across the country over the coming days.

[Troubleatmill]

NAE is the same model that had little to no accumulative snow last week on the Northern France low.

I'm going to say it again when it comes to snow you just need the radar and your current temp and DP.

If only it was as simple as those two variables. If you look at John Holmes a-z of snow requirement its far more complicated. though if your temps were -6 and dew points the same, its unlikely anything else would fall, but ive know it snow at temps of +8 and DP of +1 and rain at -3 and DP -2, allorts in the mix for snow for our tiny island in the warm atlantic. wind direction, wet bulb temps, 850-1000hpa temps, intesity, it goes on...

[Cheshire Freeze]

GEM suggests snow central Mids north

UKMO suggestive of snow for most of the Midlands north as the 0C isotherm never makes it further north than the M4 corridor before retreating south again thereafter.

Edited March 20, 2013 by CreweCold

[shaky]

Thats now gfs midlands north gets pounded!!ukmo =midlands is the place to be for this event and gem is is pretty much the same as ukmo!!

[Captain Shortwave]

UKMO and GEM are very similar throughout (both to T144)

GFS in the midrange wants to develop a cut off high over Scandinavia which sinks into Eastern Europe.

Edited March 20, 2013 by Captain shortwave

[Harsh Climate]

IMBY the latest gfs is perfect

Heaviest snowfall north midlands up to north yorkshire!

I've noticed since yesterday the gfs esembles continually has had most of the precipitation around west yorkshire, stretching 40-50 miles south west. Be careful when looking at the gfs control/operational run at face value, keep an eye on the esembles for precipitation amounts/placement.

I think if things are the same this time tommorow the favoured areas that I've mentioned could end up with at least 9 inches of snowfall.

[Cheshire Freeze]

LOL these temps are well overdone but I think most of nature would be back in hibernation if anything close came off!

[SomeLikeItHot]

Any ideas why the GFS has a much weaker cold pool compared with the UKMO. While the 0 deg and -4 lines are similarly placed, the depth of cold within them is less on the GFS? Even at +6hrs the cold in Eastern Europe and Scandi area is about 2 degrees less for the colder regions.

Edited March 20, 2013 by SomeLikeItHot

[Guest]

Amazing for any time of year:

[Chris W]

LOL these temps are well overdone but I think most of nature would be back in hibernation if anything close came off!

-15 at Richmond in March, yes perhaps a little overdone!

Edited March 20, 2013 by Chris W

[SP1986]

Yes those temperatures are just the GFS being the GFS, it's done it for the last 3 years or so, I'm pretty sure there's an algorithm in the modelling the compensates for certain factors, temperature could be one of them.. Ive lost count of the amount of times GFS has over-exagerrated the depth of cold this winter.. recording -8C when it turns out to be -1C.

That said, I agree nature will be asleep for a very very long time.. I wonder how long trees will be bare for.. is there any known records?

Edited March 20, 2013 by SP1986

[Harsh Climate]

-15 at Richmond in March, yes perhaps a little overdone!

Possible though

[Cheshire Freeze]

This will be the next point of interest going forward, circa 192 hrs. I'd wager this chart won't look like this nearer the time and this is a possible juncture where the cold may be extended (as it has been the past few times). Experience so far tells us higher pressure to the N and low pressure going under. HP has tended to be shifted further E as time has gone on this winter/early spring.

Edited March 20, 2013 by CreweCold

[Captain Shortwave]

This will be the next point of interest going forward, circa 192 hrs. I'd wager this chart won't look like this nearer the time and this is a possible juncture where the cold may be extended (as it has been the past few times). Experience so far tells us higher pressure to the N and low pressure going under.

AKA the met's concerns (around day 9). Would be unbelievable to get 3 possible major snow events in a month (note despite us missing the worst last monday, you would call that a major snow event)

[Summer Sun]

GFS remains keen to warm things up from the 29th in the SW at first before spreading UK wide just in time for Easter

The mild, cloudy and at times wet theme continues through the Easter weekend and into April with temperatures around where they should be double figures.

For any newbies on here those temperature charts only go to 12 noon so add around 2 or 3c on to those to get a rough estimate for the afternoon peak

Edited March 20, 2013 by Gavin.

[trickydicky]

March* -21.1 °C 4 March 1947 Houghall (County Durham) April* -15.0 °C 2 April 1917

Newton Rigg (Cumbria)

They are the monthly records for minimum temperatures in England for March and April. So I would say, if the models are showing an unusually cold spring blast, with widespread deep snow in Northern England and clear skies, -15 in North Yorkshire (or any other dale/valley north of Derby) is far from unbelievable.

[mushymanrob]

. I wonder how long trees will be bare for.. is there any known records?

well the oak and ash which make up most of our countryside trees dont usually leaf until may, willow, birch, chestnut, lime, hawthorn are earlier, itll jusy delay them abit.

spring 79 was delayed due to cold, but when it happened it was spectacular, because the early blooms were delayed but the later ones were more or less on time resulting in a 'mass bloom' of flowers/blossoms that would normaly have been staggared.

[Severe Siberian icy blast]

GFS remains keen to warm things up from the 29th in the SW at first before spreading UK wide just in time for Easter

The mild, cloudy and at times wet theme continues through the Easter weekend and into April with temperatures around where they should be double figures

If it was cold at the end of every single gfs run without getting any nearer I would know its just not going to happen and certainly wouldn't post several charts every time pointing it out like its gonna happen ! I appreciate you like warm but you've been barking up the mild tree for months , surely it's more constructive to post about weather in the reliable time frame?!

[SP1986]

I don't buy the milder conditions myself, if anything it's just another potential for cold.. the GFS has consistently pushed back the mild into FI, and this seems to be a long running trend (after a few years back it was the other way around), so I would not be surprised to see any milder weather being kept in FI long into April!

well the oak and ash which make up most of our countryside trees dont usually leaf until may, willow, birch, chestnut, lime, hawthorn are earlier, itll jusy delay them abit.

spring 79 was delayed due to cold, but when it happened it was spectacular, because the early blooms were delayed but the later ones were more or less on time resulting in a 'mass bloom' of flowers/blossoms that would normaly have been staggared.

Things happena bit earlier here than that, usually trees are looking fresh with new growth by the end of April into early May (remembered from my many bus rides to uni!)

[Summer Sun]

If it was cold at the end of every single gfs run without getting any nearer I would know its just not going to happen and certainly wouldn't post several charts every time pointing it out like its gonna happen ! I appreciate you like warm but you've been barking up the mild tree for months , surely it's more constructive to post about weather in the reliable time frame?!

It goes with Exeter's latest thought's as posted by Ian this afternoon

Weds(27th)-Fri(29th) their concern period. Go for milder thereafter with EC EPSgram example to support this notion in their briefing.

Edited March 20, 2013 by Gavin.

[SP1986]

March* -21.1 °C 4 March 1947 Houghall (County Durham) April* -15.0 °C 2 April 1917

Newton Rigg (Cumbria)

They are the monthly records for minimum temperatures in England for March and April. So I would say, if the models are showing an unusually cold spring blast, with widespread deep snow in Northern England and clear skies, -15 in North Yorkshire (or any other dale/valley north of Derby) is far from unbelievable.

In that area yes, but when you move towards the coast it warms at a faster rate, for example the record for late March here is around -6C.. if that gets broken it's a new record.. so in this situation its far easier to to break records by the coast than inland.

[Cheshire Freeze]

I don't buy the milder conditions myself, if anything it's just another potential for cold.. the GFS has consistently pushed back the mild into FI, and this seems to be a long running trend (after a few years back it was the other way around), so I would not be surprised to see any milder weather being kept in FI long into April!

I'm of the same opinion Stephen. I posted above the point in the run I think we'll see the potential mild to cold transition in modelling terms.

It goes with Exeter's latest thought's as posted by Ian this afternoon

They can only hint at what the model is showing at present though. It might be the case at this moment in time but we've seen time and time again how this can all change as we get closer and the modelling sends more and more energy S instead of N.

It was only a couple of days ago that you were posting ECM ensembles which supported mild for next week (before they flipped to cold the following day).

Edited March 20, 2013 by CreweCold

[492]

was it not the case that the Atlantic was in its cold phase? I do remember that in the 70's we did have a string of cold and snowy winters. I also remember certain science journals and media predicting a slow haul back to an ice age lol

1974, 1975, 1976 and 1977 were all mild winters at least in the south. It wasn't until the winter of 1978 that things turned dramatically colder.

[Mucka]

It goes with Exeter's latest thought's as posted by Ian this afternoon

I think NAVGEM shows this up quite nicely this evening.

Still, a much more certain event coming for many before we worry about that.

Edited March 20, 2013 by Mucka