Model Output Discussion

[Milhouse]

HP rules as far as the eye can see but again will it be another case this year of seeing such a setup in Spring and Autumn when its incapable of delivering the significant warmth that we would get in Summer. The most HP dominated months of the past 3 years have disappointingly not occurred in Summer. What a week we would have next week if it was July.

Edited March 3, 2010 by Milhouse

[LomondSnowstorm]

HP rules as far as the eye can see but again will it be another case this year of seeing such a setup in Spring and Autumn when its incapable of delivering the significant warmth that we would get in Summer. The most HP dominated months of the past 3 years have disappointingly not occurred in Summer. What a week we would have next week if it was July.

Is this not usually the case though? May,June and September tend to be more high pressure dominated with July and August generally seeing slightly more active/interesting weather.

[Thundery wintry showers]

Looks like we can virtually write off this snow event for the weekend now- I think the Euro models are seriously backtracking now and the GFS appears uninterested, but nonetheless it will turn somewhat colder in eastern and southern areas, with highs probably between 4 and 6C by day, and some sharp night frosts. It looks like being cloudy in the east for a time when the low slides down the North Sea, but otherwise a pretty sunny dry outlook.

[NorthantsSnow]

I don't think a snow event was ever really likely for this weekend. The GFS has been very consistent, and with this model if there was even the remotest possibility of a snow event, it would have flagged it up at some point. It didn't.

[karyo]

No posts here this morning, which says it all really!

At least the ECM is showing some interest in the later stages, with a slack northerly flow and a block developing in Greenland! It could get tasty if that low from the Atlantic drops southeast!

However, the ECM keeps changing in FI with every output so more runs needed.

Personally, I'd rather not see a wintry shot from the 13th-20th March as I will be away on holiday then.

Karyo

Ps Happy days, we've started our posts with the same phrase! lol

I think there might be some interest before November but if not, see you then.

Edited March 4, 2010 by karyo

[Thundery wintry showers]

High pressure looks like hanging around in the right places to keep the sunshine going for the foreseeable future, so sunshine totals look like getting a very good "head start" on the average as we head towards mid March. Many places may also see out the period without any rain/snow at all.

With cold air trapped within the high temperatures should remain below average mainly due to the low minima. If the high sticks around for most of the month I would expect the second half to be rather warmer, similar to what happened in March 2003.

Still an outside chance of some sleet/snow showers coming into the SE over the coming days if the high sets up far north enough but I doubt that it will come to fruition.

[snowmadchrisuk]

Well anybody in Scotland and Northern England could see quite a bit of Snow tomorrow morning according to the 6z and with the Higher pressure further South it will likely stall over somewhere. I know it's dry for most of England but lets not forget our friends up North .

It is just a case now of monitoring the High pressure as it decides where it wants to head k, If it Sinks then Spring could be on the cards , if it moves North or West another Cold shot likely , either way I can not see it being stuck over the Uk for more than a week or so .

Chris

[Thundery wintry showers]

I think if the high retreats eastwards it will indeed bring plenty of warm sunshine (again 2003 was a good example) but if it sinks southwards it is more likely to allow those cloudy damp tropical maritime airmasses in from the south-west.

[TEITS]

Au contraire, Rodney. The sun is streaming into my house and the thermostatic radiator valves in those sunny rooms are turning off, one by one. I'm saving on my fuel bills.

Mmmmmmmmmm. Solar gain. Way to go.

Unfortunately large trees block the sunlight in my flat. I should really contact my local council because I believe by law you have a right to light!

Thankfully the ECM extended ensembles suggest a warm up with the mean rising to 9C.

http://www.knmi.nl/exp/pluim/vijftiendaagse/Data/15DAAGSE_06260_NWT.png

Have to say im now looking for either two things in the model output. I would be happy with a nice warm S,ly flow or a cold N,ly flow with plenty of convection. At this time of year a cold N,ly with heavy showers allows a great opportunity to take stunning photos of Cumulonimbus clouds.

[snowmadchrisuk]

I think if the high retreats eastwards it will indeed bring plenty of warm sunshine (again 2003 was a good example) but if it sinks southwards it is more likely to allow those cloudy damp tropical maritime airmasses in from the south-west.

Possibly but remember Europe is getting our missed Cold Shot so will take a while to get them warmer temps over the UK . Saying that the GFS is quite a good run for the Uk and brings Snow showers into the SE and possibly the Midlands next week Tuesday looks like it would be interesting .

[TEITS]

Possibly but remember Europe is getting our missed Cold Shot so will take a while to get them warmer temps over the UK . Saying that the GFS is quite a good run for the Uk and brings Snow showers into the SE and possibly the Midlands next week Tuesday looks like it would be interesting .

I wouldn't get excited as the precip is predicted to be very weak. Note the 0mm on the link below.

http://www.wetterzentrale.de/pics/Rmgfs1203.gif

Upper temps -7C, surface temps 6C, DPs 1C means nothing worth getting excited about im afraid.

[summer blizzard]

http://www.wetterzentrale.de/pics/Rtavn1441.png

The important modelling point comes around wednesday, 144 hours out, this is because the high over the UK joins with a developing ridge over the Azores and this is where modeling differes.

The options that arise from this setup are as follows:

1)High does not connect and becomes quite shallow as per ECWMF and GEM

2)High connects but stays south west of the UK allowing the Atlantic in, classic wet north/dry south setup

These are the favoured outcomes however the other two options available are the high being pushed east resulting in a warm up, or the Atlantic High results in a northerly.

[SP1986]

Having looked at the NAO and AO, it seems they are trying to head towards a more Atlantic idea with both trying to push for positive anomalies. It's probably one of those model outputs where it looks settled, but it could change in 48 hours scenario.

But then again I'll most likely be told talking rubbish so what of it

[Eugene]

No posts here this morning, which says it all really!

Yes it says people are tired of cold because that is what the outlook shows.

http://www.wetterzen..._London_ens.png

Looks like the HP position next week is critical to whether we get sunshine or cloudy ENE'lys like on GFS 06Z, afterwards a slack cool pattern or atlantic rushing in seems likely.

UKMO 6 to 15 dayer mentions it staying cold with night frosts, what they dont mention is there is the chance of some very low dewpoints early next week, UKMO now do a 16 to 30 dayer and says rain will be way above average away from the north and east.

UK Outlook for Tuesday 9 Mar 2010 to Thursday 18 Mar 2010:

Through next week settled weather is expected to continue with a good deal of fine and dry weather for most. There will be variable amounts of cloud though, which is likely to be thickest across eastern coastal areas at times where a few showers are likely, perhaps turning wintry over hills. Temperatures will be mostly rather cold with overnight frosts and also some fog patches. Winds should be mainly light although may be strong around English Channel coasts and the far north at first. Around next weekend a change in the weather pattern looks likely with more changeable conditions moving across the northwest bringing a return to near-normal temperatures. Then towards the end of the period more unsettled weather is likely to gradually spread across the bulk of the UK.

Updated: 1140 on Thu 4 Mar 2010

Edited March 4, 2010 by Eugene

[Thundery wintry showers]

So in a nutshell the Met Office are going for the high gradually sinking SE allowing cloudier wetter warmer weather in from the Atlantic, which is increasingly looking like a major possibility- although not yet a certainty.

[karyo]

So in a nutshell the Met Office are going for the high gradually sinking SE allowing cloudier wetter warmer weather in from the Atlantic, which is increasingly looking like a major possibility- although not yet a certainty.

Are you reading between the lines re:warmer conditions? Because the further outlook doesn't mention anything like that!

Karyo

[Ian Fergusson]

Are you reading between the lines re:warmer conditions? Because the further outlook doesn't mention anything like that!

Karyo

Their 10-15d briefing does talk of a return to milder (i.e. average) temperatures; this transition to a westerly cyclonic influence occurring around or between 15-17th. So the final departure of the cold easterly / NE influence can be fairly described as 'warmer' (especially after this winter!!)

[Frosty.]

Not a bad GFS 06z run, a settled first half with lots of frost and sunny days before the high sinks southeast allowing the atlantic lows to attack from the northwest which would mean a much more mobile pattern with spells of mild, wet & windy weather with colder more showery intervals after the cold front sweeps through, a more typical early spring pattern. I am very disappointed that the models have not developed as they promised to do last sunday, a very poor model performance from all concerned IMO but the anticyclonic spell is fairly nailed on now in one form or another.

[Eugene]

http://www.wetterzentrale.de/pics/Rtavn7210.png

[Thundery wintry showers]

Looks to me like there's a glitch on that chart- there's no way we'll have 06-12Z maxima that low!

[Eugene]

http://www.wetterzen...s/Rtavn9610.png - WTF surely an error those dewpoints in north wales especially are phenomenal in March, easily freeze still water those kind of dewpoints would.

Edited March 4, 2010 by Eugene

[cooling climate]

I for one certainly do not think that northern blocking is done with us yet and we

may yet see some quite wintry weather to come this month but of course the further

we go into March the less potent this will likely be if it occurs at all.

I was always told never count your chickens until March is out.

[Ian Fergusson]

Looks to me like there's a glitch on that chart- there's no way we'll have 06-12Z maxima that low!

Interesting..... in a med-range briefing, UKMO Ops Centre advised us earlier today about some corruption to the overnight GFS ensemble products online (not sure if it's still an issue??), as follows:

"00z model comments: .....EC ensemble has 29 out of the 51 ensemble members with a cyclonic circulation in the trend period, while MOGREPS 15 has a more anticyclonic theme, but still establishes a westerly in the trend period. Unfortunately GFS ensemble data is corrupt on websites, but on the few frames visible seems to support EC."

[Eugene]

After that initial cold blast we start to pick up a milder/moister easterly flow but unfortunately a very cloudy one at that.

[Thundery wintry showers]

Agree there- the cold upper air gets mixed out as the easterly establishes over southern areas, so I can see cloud cover being extensive and precipitation minimal over East Anglia and the SE if that scenario materialises- the GFS temperature projections also support this. Scotland and N England would remain sunny.

Re. GFS the Wetterzentrale 2m temperature outputs that I can see, both on here and on WZ itself, don't match up with what Eugene is showing:

http://www.wetterzentrale.de/pics/Rtavn725.png