Spring Model Discussion 18Z 6/3/13 onwards....

[A.J]

Why are you on here?? you are on your own with your thinking

It's the Model Discussion thread, a thread to discuss ALL model output......and with that in mind, back to the discussion

[Allseasons-Si]

Why are you on here?? you are on your own with your thinking

cos all members in here are not cold lovers john+he his describing what the model/s are showing.

Edited March 9, 2013 by allseasons-si

[Summer Sun]

ECM at t192 has some milder air about as far north as northern England with +4 uppers clipping the SE

T216 has cold air filtering down from the north once more but not as cold as Sunday and Monday at this stage

Edited March 9, 2013 by Gavin.

[SE Blizzards]

Not so mild now at 216h!! Spring put on hold once more??

And at 240h the whole of the UK is under -6 / -8 uppers

Edited March 9, 2013 by SE Blizzards

[SomeLikeItHot]

Just a blip of mild on the ECM really. but the216-240 bit doesn't look like it would last long. All FI anyway.

[Summer Sun]

T240 has another cold attack this time from the north though this doesn't look like lasting all that long, notice the Azores high at t240 as well its edging closer worth keeping an eye on

The past couple of days have saw the ECM ensemble trending milder (albeit for Holland we know) so tonight's update will be interesting

Edited March 9, 2013 by Gavin.

[Purga]

T240 has another cold attack this time from the north though this doesn't look like lasting all that long, notice the Azores high at t240 as well its edging closer worth keeping an eye on

The past couple of days have saw the ECM ensemble trending milder (albeit for Holland we know) so tonight's update will be interesting

I wouldn't be too cocky about it staying mild in the longer term based on the NH view from ECM

Edited March 9, 2013 by Purga

[Snowman.]

I wouldn't be too cocky about it staying mild in the longer term based on the NH view from ECM

Now that's a russian High!

[Panayiotis]

The ECM has a deeper low further north at T48hrs compared to the UKMO.

The fax charts better than expected given the UKMO raw output, the key is the T72hrs to see what the ECM does with the track of the low.

Actually we really need the in between parts and we only get a 24hrs jump with the ECM which is a shame.

We can check the ECM precipitation charts (when they are updated of course) ? http://en.vedur.is/w...ntic/#type=prec Edited March 9, 2013 by Panayiotis

[SnowObsessor90]

Is it possible that there could be further shifts in latter ECM output which could bring back that reload possibility again? or am just straw clutching?

[fergieweather]

About an hour ago, Ops Centre notified us of the following GM modifications; i.e. prior to full EC suite availability:

" T+48/60: Moved main precipitation band in the south 60 n miles further north (T+48), supported by NAE (modified) and Arpege, and 80 n miles further NW supported by GFS and Arpege.

T+72: Moved main low over continent 100 n miles further east towards Arpege solution, with GFS giving more modest support.

T+84: No modifications necessary, GFS and Arpege provide support for GM solution."

[Methuselah]

Pleased to see GFS FI is onto something once more the ensembles are going in the right direction the final 3rd could be the best part of the month if your a mildie like me

All in all we are heading in the right direction again tonight

But what if the GFS is not 'onto something'?

Edited March 9, 2013 by Rybris Ponce

[SteveB]

About an hour ago, Ops Centre notified us of the following GM modifications; i.e. prior to full EC suite availability:

" T+48/60: Moved main precipitation band in the south 60 n miles further north (T+48), supported by NAE (modified) and Arpege, and 80 n miles further NW supported by GFS and Arpege.

T+72: Moved main low over continent 100 n miles further east towards Arpege solution, with GFS giving more modest support.

T+84: No modifications necessary, GFS and Arpege provide support for GM solution."

I'm guessing that puts our region back in the snow zone Ian?

[Dave Kightley]

A lot better for the South West

[Gibby]

Good evening. Here is the report from the 12z output from GFS, UKMO and ECM for today Saturday March 9th 2013.

All models show the same synoptic pattern between now and the middle of next week. The cold NE flow already over many Northern areas will extend down to the milder South over the next 12 hours or so. The band of rain, sleet and snow over the North will slip South and die out overnight as the clearer colder conditions over Scotland become more prevalent. Snow showers will be driven into North Sea Coastal counties later in the night. Southern England will stay largely cloudy with a few showers of rain. Tomorrow all Southern counties will be markedly colder than today with a raw NE wind and a lot of cloud carrying wintry flurries into Eastern areas through the day. Late in the day the SW will see some rain turning to snow as it moves East across the area overnight Sunday and Monday. The Northwards extent of this is still uncertain and many areas may miss it but it in any event will be bitterly cold and windy with a significant windchill. Through Tuesday and Wednesday winds fall much lighter and though still very cold with harsh night frosts the brighter days will offset the feel somewhat. There will be scattered snow showers too almost anywhere through the daytimes but only near North facing coasts at night.

GFS then brings a new Low pressure into the mix, deepening it to the NW of Britain, turning winds into the SSW and steadily bringing less cold conditions across from the SW. Rain will follow, first to Western areas and then areas further East as a Low complex moves into the SW of the UK. It then fills as we start FI allowing slack winds to develop with a lot of cloud, the odd shower and near to average temperatures. Through this time pressure will be rising strongly from the SW with a large High developing close to Southern Britain to end the run with fine weather in the South while the North sees weak fronts round the top of the High and down the North sea to bring occasional rainfall here.

The GFS Ensembles show a cold spell next week steadily giving way to less cold conditions with good overall agreement between the members. The operational was a mild outlier at times and the general theme looks to be that an unsettled pattern with rain at times is the most likely outcome the week after next.

The Jet Stream shows a continuation of the Southern arm driving East over the North Atlantic and across Southern Europe. A new weaker arm develops to it's North later next week crossing East in the vicinity of the British Isles.

UKMO tonight shows the cold spell continuing through to the end of the week with winds backing West then SW later as Low pressure lies just to the NW. Scattered snow showers in the middle of the week will turn more to rain, especially in the South as milder air gradually drifts North and East over the UK with rain for most by the weekend, especially in the NW.

ECM shows a similar pattern keeping the cold till around Friday of next week before Low pressure is pulled South to the West of the UK with freshening SSW winds and rain moving steadily NE preceded by some snowfall in the North and East at the weekend. Thereafter, the Low tracks East over the UK followed by Northerly winds and a return to cold weather with wintry showers and the signs of renewed High pressure blocking to the North and NE.

In Summary the weather is entering a relatively short but potentially noteworthy cold snap over the coming days. Significant windchill is the likely most noteworthy event as near gale NE winds develop over the South tomorrow and Monday with some snowfall near the South Coast. Snow showers will affect other areas too but no great quantities are likely. Then after a bright and frosty midweek spell it looks like Low pressure developing to the West and NW will swing winds back round to the South or SW with milder weather with rain at times spreading across the UK next weekend. Through the following week we have different outcomes between GFS and ECM with milder conditions maintained via the GFS route whereas ECM drifts Low pressure away East to renew a Northerly flow with wintry showers again towards Week 2. A case of more runs needed I'm afraid before long term prognoses can be commented too confidently on.

[nick sussex]

These Channel Lows certainly milk the drama. They're like the Paris Hilton of synoptics, you know attention seeking and really quite annoying.

Constant changes every 6 hours, north/south, by the time one forecast is issued yet more drama ensues.I think we can see now why getting a direct hit for the UK is quite difficult.

Generally these come in tandem with blocking to the n/ne and so its like two opposing forces battling it out for supremacy.I do hope after all the nervous energy expended by members in here following this that the snow does land.

[No Balls Like Snow Balls]

It certainly looks like turning less cold next week, but it will probably be a slow process. There maybe some weak weather fronts crossing the country but on the whole it looks relatively dry. In FI things may turn more unsettled as we enter next weekend.

On another note there seems to be quite a few posts popping up attacking anyone that posts about mild weather.

Seriously grow up. How old are you people!!!

Edited March 9, 2013 by No balls like Snow Balls

[fergieweather]

A lot better for the South West

I've just now seen the MOGREPS-G and EC snow distribution probability mapped updates. The former continues to have a slightly more northern bias for Monday's snow in S: highest probs of 1cm plus are confined to S of line joining Lyme Bay across to Hants and up via London to S Essex.

EC squeezed further south still: 2-5cm contour just grazes S coastal counties (Hants-Sussex), with smaller amounts in other S districts on coastal fringes.

In effect, the yellow warning area looks pretty good still at this juncture. Next modified NAE update arriving by 2120hrs.

[mushymanrob]

i see tonights ecm doesnt want to follow the gfs's return to average in fi. i think the ecm is onto something although its probably overcooked the cold. id be happy with the gfs but i expect more cold/ below average spells before april.

[BLAST FROM THE PAST]

Have to say posts like this do irritate me.

I do not seek praise but I do like credit to be given when its deserved. Remember a while back the arguments with regards to the anomaly charts when some of us suggested cold weather was on its way and you disagreed.

Here is a comment I made on the 24th Feb!

"LP moving up from the S bringing a big snow event as bitterly cold E,lys spread across the UK."

This is what I said on the 2nd of March.

"Looking at this mornings output a cold E,ly continues to look favourite, how cold is still very uncertain. Appears around the 11th March is when this could occur so only 24hrs later than I suggested many days ago."

http://forum.netweat...d-march-onward/

http://www.wetterzen...cs/Rtavn541.png

Unfortunately I cannot find the post when I referred to "Many days ago" but I do recall saying in late Feb that the 10th March was a significant date.

Fully expect this to be deleted mind you!

Dave you did mention the 10th of March quite sometime ago.........of course though that must have been a lucky guess as there is no way you could 'forecast' it.

Keep it on mate...GOOD STUFF

BFTP

[Summer Sun]

But what if the GFS is not 'onto something'?

I'm thinking positive

[snowking]

ECM 12z det modelled >1 inch of snow between now and midday Thursday:

SK

[Frosty.]

The message from the models today for cold fans is enjoy the bitter cold and snow potential over the coming days, it's guaranteed to stay cold until just after midweek and snow showers are likely to affect northern and eastern areas (especially coastal) once the winds back Northerly, a cold front pushing south on tuesday looks like being followed by a trough or two so bands of snow showers pushing south once the main frontal snow zone clears the south coast early next week. It's still unclear what damage the developing low to the northwest of the uk will have on thurs/fri, perhaps a brief interruption only or maybe none at all, the way I read the meto update today it sounded like an unbroken cold spell for the next 10 days or so with wintry showers and frosty nights so we shall see.

[nick sussex]

The message from the models today for cold fans is enjoy the bitter cold and snow potential over the coming days, it's guaranteed to stay cold until just after midweek and snow showers are likely to affect northern and eastern areas (especially coastal) once the winds back Northerly, a cold front pushing south on tuesday looks like being followed by a trough or two so bands of snow showers pushing south once the main frontal snow zone clears the south coast early next week. It's still unclear what damage the developing low to the northwest of the uk will have on thurs/fri, perhaps a brief interruption only or maybe none at all, the way I read the meto update today it sounded like an unbroken cold spell for the next 10 days or so with wintry showers and frosty nights so we shall see.

To be honest Frosty I don't know what models the UKMO are looking at in terms of that update. Maybe some cold lover from netweather hacked the server!

Theres solid support for troughing to the nw of the UK and milder conditions,that update suggests a ne flow and then fronts moving in from the sw when all the output shows a breakdown from the nw.

Unless MOGREPS is completely at odds with the rest of the guidance then I really don't buy that update. Of course I'd like to see the cold continue a while longer but really have my doubts re that update.

Perhaps Ian F might give us an idea as to the UKMO thinking on the medium term if he's around.

The ECM postage stamps at 168hrs have a few colder options but really the overwhelming support is for milder conditions:

http://www.ecmwf.int/samples/d/inspect/catalog/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!168!pop!od!enfo!enplot!2009112700!!/

Even when that update was done earlier in the day those postage stamps were showing pretty much the same.So its a bit of a mystery really.

Edited March 9, 2013 by nick sussex

[bluearmy]

To be honest Frosty I don't know what models the UKMO are looking at in terms of that update. Maybe some cold lover from netweather hacked the server!

Theres solid support for troughing to the nw of the UK and milder conditions,that update suggests a ne flow and then fronts moving in from the sw when all the output shows a breakdown from the nw.

Unless MOGREPS is completely at odds with the rest of the guidance then I really don't buy that update. Of course I'd like to see the cold continue a while longer but really have my doubts re that update.

Perhaps Ian F might give us an idea as to the UKMO thinking on the medium term if he's around.

The ECM postage stamps at 168hrs have a few colder options but really the overwhelming support is for milder conditions:

http://www.ecmwf.int...t!2009112700!!/

Even when that update was done earlier in the day those postage stamps were showing pretty much the same.So its a bit of a mystery really.

maybe its more to do with this nick - the ecm ens mean has been keen to drop the trough across the uk in fi and on both the 00z and 12z its a direct hit. whilst a snow fest in dec/jan/feb, it will not be so in march. i think the 12z op is too progressive with the souwester and that the warmer uppers will pass to our se as the low heights drop in. staying cold but not quite cold enough for settling snow away from the higher ground and scotland/north england.

Edited March 9, 2013 by bluearmy