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

[joggs]

Would really appreciate it Fergieweather if you could keep us posted from a MO point of view where the worse of the weather gonna be.Im in West Yorks but wife n kids travelling to Manchester fri eve, kind regards.Sorry for off topic modrp but worried.

[snowking]

I don't see NAE further south

Or am I looking at the wrong one again???? Like twenty odd people did last night

It is certainly no further south HC, to my eye I think whats happening is the colder dew points are undercutting further south quicker than previously modelled, and so people are perhaps seeing the pink area extended southwards, and assuming the whole band moves south, when in reality the northern extent of the precipitation is still heading up towards Scotland during Friday, its just that some more southern districts are looking better for snow at the same time

SK

[fergieweather]

I don't see NAE further south

Or am I looking at the wrong one again???? Like twenty odd people did last night

It's not further south. UKMO models consistent now since yesterday eve on snow issues / accumulations of note being - by 09z Sat - effectively north of a line from N Essex to Hereford, so M40 also a rough delineation. Latest EURO4 output enhances threat E Anglia and uplands NI.... ones to watch, but totals here way below the 30-40cm progged for upland central England. Meanwhile, the latest GM agrees with GFS on snow potential running into Kent later in the weekend, but more continuity required on this.

Rainfall in S continues to look alarming in places. HIgh-res model spot totals of, e.g., 100mm S Dorset can't be easily dismissed at this juncture.

[TwisterGirl81]

You don't how lucky you guys are that live in the North, send some snow down to Exeter, all we've had this winter is a brief snow shower for an hour and it didn't settle....Anything that's ever been forecast for us like a '30 year' storm and snow possibilities is always downgraded so we've gotten used to it but it would be nice to get a good amount of snow to make up for the dissapointing winter....I guess it must not be cold enough here

What is the take for possible snow for our parts in 9 days time please?

Edited March 21, 2013 by TwisterGirl81

[johnholmes]

Staying away from the hugely interesting discussion about where the snow will fall and lie over the next 72 hours and looking further ahead.

Say 10 days and more.

Up to the last 2-3 days the 500mb anomaly charts have, from some time before the onset of the current cold spell, been showing the blocked pattern. There have been brief hiccups but overall their performance to me has been very good. Over the last 2-3 days there have been some slight changes which suggested a possible change in upper air pattern from the current mostly blocked type. This seems to be showing more and more although I still have not got the 3 days of consistency I prefer before hanging my hat on their output. Nevertheless all 3 by this morning have got a similar pattern showing.

The NOAA chart from last evening is below

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

As you can see most of the +ve areas, still showing on the 6-10 day outlook have gone and the –ve area and flow into the UK from south of west are much more in evidence. Also the heights suggested for the Channel area are now tending up rather than down as they had previously been showing.

This morning and the output from ECMWF-GFS also has little sign of any +ve heights although both show a suggestion of a slight ridging in the UK area. The major idea is the –ve area in the Atlantic and the flow at 500mb from south of west into the country-see below

http://www.meteo.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

Like I said it is early days but I do believe that a major pattern change is about 70% on the cards around or by the end of the month with a milder south of west upper flow taking over for the UK. Detail on actual timing, and the extent of any warming up is not possible but an idea of an overall warming up from the current fairly unusual length of cold spell at the moment looks odds on.

[fergieweather]

You don't how lucky you guys are that live in the North, send some snow down to Exeter, all we've had this winter is a brief snow shower for an hour and it didn't settle....Anything that's ever been forecast for us like a '30 year' storm and snow possibilities is always downgraded so we've gotten used to it but it would be nice to get a good amount of snow to make up for t he dissapointing winter....I guess it must not be cold enough here

What is the take for possible snow for our parts in 9 days time?

On latter point: v limited. A greater 'push' and progression is anticipated on any evolution later next week, with net result of enhanced rain likelihood across SW/S; again threat of significant snow further north... albeit very speculative at this stage, of course!

[Harsh Climate]

It's not further south. UKMO models consistent now since yesterday eve on snow issues / accumulations of note being - by 09z Sat - effectively north of a line from N Essex to Hereford, so M40 also a rough delineation. Latest EURO4 output enhances threat E Anglia and uplands NI.... ones to watch, but totals here way below the 30-40cm progged for upland central England. Meanwhile, the latest GM agrees with GFS on snow potential running into Kent later in the weekend, but more continuity required on this.

Rainfall in S continues to look alarming in places. HIgh-res model spot totals of, e.g., 100mm S Dorset can't be easily dismissed at this juncture.

Ian I'm noticing some very high snowfall totals progged for parts of north east wales/ north west england/ south yorkshire, away from these areas would you expect a sharp decline in snowfall with some areas like north yorkshire seeing very little snow??? Or will there still be a swathe of heavy snow but just not as heavy and dynamic as in the favoured areas?

Edited March 21, 2013 by Harsh Climate

[LeeSnowFan]

Good Morning, some trually amazing mouth watering charts

Midlands, northwards still best place to be for tomorrow and some people seeing a possible 24 hours of snowfall

Just a quick question for Ian sorry if off topic slightly, are the MO still going with upgrading to Amber this morning for some areas?

[fergieweather]

Ian I'm noticing some very high snowfall totals progged for parts of north east wales/ north west england/ south yorkshire, away from these areas would you expect a sharp decline in snowfall with some areas like north yorkshire seeing very little snow??? Or will the there still be a swathe of heavy snow just not as heavy and dynamic as the favoured areas?

This issue is PRECISELY what my colleague Paul Hudson was querying in a conference discussion with UKMO last eve. It's tricky.

[Frank Trough]

It's not further south. UKMO models consistent now since yesterday eve on snow issues / accumulations of note being - by 09z Sat - effectively north of a line from N Essex to Hereford, so M40 also a rough delineation. Latest EURO4 output enhances threat E Anglia and uplands NI.... ones to watch, but totals here way below the 30-40cm progged for upland central England. Meanwhile, the latest GM agrees with GFS on snow potential running into Kent later in the weekend, but more continuity required on this.

Rainfall in S continues to look alarming in places. HIgh-res model spot totals of, e.g., 100mm S Dorset can't be easily dismissed at this juncture.

this is quite alarming. It's already raining heavily across Dorset and the ground was beyond saturated prior to this event. Enjoy your snow those who get it....i'm going to the shed for the dinghy.

Further ahead both the GFS and the ECM eventually show the cold easing but we've been there before......and the GEM and to an extent the NAVGEM have a different view...

[Matty M]

Most intense precip over districts ajoining Irish sea at 30hrs. Amounts will be less further north and east but more likely to fall as snow

[Harsh Climate]

This issue is PRECISELY what my colleague Paul Hudson was querying in a conference discussion with UKMO last eve. It's tricky.

Yes just what I'm thinking, my worry is the boundry between very heavy snowfall and no snowfall at all could be the difference of say just 20 miles, forecasters nightmare

[Matty M]

Front then gets its act together over England giving some nice falls Saturday AM, per NAE.

[Snowmaggedon]

This issue is PRECISELY what my colleague Paul Hudson was querying in a conference discussion with UKMO last eve. It's tricky.

Morning Ian, what's it looking like for NE Eng? Is the front likely to reach us?

[TwisterGirl81]

On latter point: v limited. A greater 'push' and progression is anticipated on any evolution later next week, with net result of enhanced rain likelihood across SW/S; again threat of significant snow further north... albeit very speculative at this stage, of course!

Oh well, thankyou Ian, maybe we'll see a sparkling summer, any indications on what maybe likely this Summer? (besides rain)

I thought i'd read some people say that there was the possibility of another channel low next week (It shows in some models...apparentely)

Edited March 21, 2013 by TwisterGirl81

[A.J]

give me an 'M'.....give me an 'O'....give me a 'D'....an 'E'......a 'L'.......and add the words 'Output' & 'Discussion' after it.....add them together and what do you get?........hint hint hint!

....and no, the answer is not "Will it snow in xxxxxxx?"....lol

[DEYS(Kent)]

NAE has a good undercut for the PPN to turn to snow as early as Saturday morning for SE England. I know Ian has asked us to discount the NAE but interesting all the same given the frigid conditions just across the channel such undercutting conditions can't be ignored, surely?

:-)

[SMU]

Sorry ian i disagree with you, the northern boundary has been receeding and the southern line has been moving back towards the coast.

I fully expect the updated 06z GFS and 06z NAE to show the front stalled in the SE across WNW at 48 And be all snow.

Your line of north essex is to far north. Even the t57 euro snow accum map disagrees with that, but hey for the moment it really doesnt matter that much....

Regards

S

[shaky]

Nae has the centre of england take a battering on this run!!its has upto 20cms of snow accumulatin in the west midlands!!

[Radiating Dendrite]

Sorry ian i disagree with you, the northern boundary has been receeding and the southern line has been moving back towards the coast.

I fully expect the updated 06z GFS and 06z NAE to show the front stalled in the SE across WNW at 48 And be all snow.

Your line of north essex is to far north. Even the t57 euro snow accum map disagrees with that, but hey for the moment it really doesnt matter that much....

Regards

S

Hi Steve,

Are you seeing snow for the SE from this then?

We look to be 100 miles out of it surely?

[bobbydog]

been busy for a couple of days so not seen much of the models.

is this for real??-

[TEITS]

I feel some are misreading the situation. Based on the current output its too vague saying N England is going to be hit because as I constantly keep saying it isn't just how far N the precip manages to get but E. So with this in mind locations such as NW England will see far more precip than say NE England who at the moment appear to see very little.

The sweet zone continues to look like NE Wales, W Midlands, NW England (Maybe central and N Midlands. This risk extending further S & E during Friday night into Saturday.

[Guest pjl20101]

Oh well, thankyou Ian, maybe we'll see a sparkling summer, any indications on what maybe likely this Summer? (besides rain)

I thought i'd read some people say that there was the possibility of another channel low next week (It shows in some models...apparentely)

According to the bejing climate centre model which I am now basing my forecasting on they are going for a nw/se split of a summer season with se parts fairing better than nw parts. Also I saw a hint of even below average heights maybe towards Greenland. Its a long way off however so could all change. I don't know what the monthly output from the bejing climate centre model is for April, but would presume a better second half to first half if it makes sense.

[Herefordweather]

Gfs appears 20-30 further south west to me. Upper air temps a fair bit lower across South Wales and the Midlands too.

[Harsh Climate]

GFS again very bullish about how far north east the precipitation spreads

But then on saturday the midlands/parts of the south east remain at risk

The way I am seeing it according to the gfs is we have 2 weather fronts pushing in this weekend. The first one should track well into northern england, the second one only as far north as the north midlands. But the area that catches both of these fronts will be at primary risk of the heaviest snow (northwest england/north midlands ets...)

You can see where the two fronts are from this chart, look at the precipitation stretching from western scotland to east anglia (that is the first front), then the precipitation stretching from southern ireland through to cornwall is (front two.)

Edited March 21, 2013 by Harsh Climate