Model Discussion 12Z 25/02/13

[bluearmy]

anyone who cannot see the general fall off in temps post the 10th of the month is not looking properly. however, the likelihood is that this will not bring widespread snowfall. what is also true is that there no chance of any snowfall anywhere without the fall off in temps. at least you can win the raffle if you buy a ticket!

there were hints on yesterdays nwp that this colder spell was being dispensed with. however, if anything, the anomolys and means are more bullish 24 hours later.

[mushymanrob]

but after the higher temps expected next week of course there will be a drop. but atm theres nothing to suggest theres anything exceptionally cold, not in the current model outputs anyway. whether they change or not is anybodies guess, be clear, im not sayingtheres no more cold, and people like gp who suggest there might be must be heeded.

ps ten days time is well into fi.

Edited March 1, 2013 by mushymanrob

[nick sussex]

GFS 18hrs run so far is the best of the day in terms of cold potential, shortwave runs west, gap opens up to the north allowing more forcing on the pattern.

If this doesn't deliver some cold interest I will be very surprised.

[Snowman.]

but after the higher temps expected next week of course there will be a drop. but atm theres nothing to suggest theres anything exceptionally cold, not in the current model outputs anyway. whether they change or not is anybodies guess, be clear, im not sayingtheres no more cold, and people like gp who suggest there might be must be heeded.

ps ten days time is well into fi.

Agree here. The pattern changes constantly and usually gets cooler or warmer and at 10 day range many things can change between that time.

I am a coldie but as soon as we hit march I get fed up of the cold.

But a do Disagree on the colder period. The OPs are currently outliers or very much on the mild side I do believe we will see a bit of cold here and there but nothing; This can change much like it can get alot warmer too.

[Panayiotis]

GFS 18hrs run so far is the best of the day in terms of cold potential, shortwave runs west, gap opens up to the north allowing more forcing on the pattern.

If this doesn't deliver some cold interest I will be very surprised.

That shortwave needs watching! If it doesnt move and remains there eg UKMO it will probably scupper our chances of getting possible cold once again.

Edited March 1, 2013 by Panayiotis

[Frank Trough]

anyone who cannot see the general fall off in temps post the 10th of the month is not looking properly. however, the likelihood is that this will not bring widespread snowfall. what is also true is that there no chance of any snowfall anywhere without the fall off in temps. at least you can win the raffle if you buy a ticket!

there were hints on yesterdays nwp that this colder spell was being dispensed with. however, if anything, the anomolys and means are more bullish 24 hours later.

we can see it, we just aren't sure it will happen. It was all going to happen at day 9 two days ago.

[Cloud 10]

GFS 18hrs run so far is the best of the day in terms of cold potential, shortwave runs west, gap opens up to the north allowing more forcing on the pattern.

If this doesn't deliver some cold interest I will be very surprised.

Indeed,this could be a pub run special with its arctic mega high!

[Panayiotis]

Indeed,this could be a pub run special with its arctic mega high!

Yes we havent seen any epic Fi pub runs this winter however last winter we saw them everyday! Will it regain its name?

[Frank Trough]

Agree here. The pattern changes constantly and usually gets cooler or warmer and at 10 day range many things can change between that time.

I am a coldie but as soon as we hit march I get fed up of the cold.

But a do Disagree on the colder period. The OPs are currently outliers or very much on the mild side I do believe we will see a bit of cold here and there but nothing; This can change much like it can get alot warmer too.

but this simply comes back to the pointless argument of whether the ops should be believed or the ensembles. People pick and choose whether the ops should be followed or, suddenly, if the ensembles trend cold in winter then we should follow them.

where are the stats that back the idea that we should follow the ensembles in this situation?

[bradymk]

Yes we havent seen any epic Fi pub runs this winter however last winter we saw them everyday! Will it regain its name?

I could show you plenty of epic pub runs that have occured this winter, there have been a fair few i think!

[Panayiotis]

I could show you plenty of epic pub runs that have occured this winter, there have been a fair few i think!

Not many from the pub run, I remember last year where we nearly had an epic chart on the 18z everyday!

[nick sussex]

Indeed,this could be a pub run special with its arctic mega high!

Its a good trend so far but that shortwave to the nw takes too long to weaken and is too far north which means the angle of the high to the ne doesn't ridge down in a more favourable manner. It could get complicated when that shortwave energy phases with that eastern USA low.

Better early but still dragging its heels, but does give some interest if this trend continues but the models still having problems with what to do with that shortwave energy to the north.

[swfc]

First day of spring and look at the 850s running into scan in fi on the 18z

[Cloud 10]

Blizzards at 360 hrs from the pub run,its definitely off the wagon now.

[bluearmy]

dont you just love march? +20 uppers trying to get into spain whilst -20 sitting over norway.

[Panayiotis]

I find it funny how by the 16th on this run winds switch to a more south/southeasterly with v.cold uppers. Now the MO's take on things:

UK Outlook for Saturday 16 Mar 2013 to Saturday 30 Mar 2013:

Most areas are likely to be colder than average during the end of March with an east or southeasterly influence most probable. Generally, there are no strong signals regarding precipitation, but taking the period as a whole, in an east or southeasterly regime, some western and northwestern areas of the UK are most likely to be drier and sunnier than normal.

Will this be too late however?

[TEITS]

sorry, i know im a mildy, but a big freeze?or remarkable cold spell?c,mon guys until theres one being shown consistently within a reliable timeframe the chances are incrdibly remote

Posts like this really get on my nerves. What is even more irritating is looking at who liked your post.

Did I say in my post when I highlighted the JMA that a big freeze is on its way? No I said the JMA would show this at +240. Furthermore I did say I wish the JMA was more reliable.

Let me say this is the model discussion thread and I was discussing what the JMA was showing.

Edited March 1, 2013 by chionomaniac
removed unnecessary comment

[nick sussex]

I've decided to delay my spring/summer hibernation to see how the current model tease plays out! As founder member of NWMAS Net Weather Members Against Slush! I'll be interested to see if that deep cold to the ne can make a direct hit on the UK and so reducing the slush factor!

Realistically this late into the season you need some very good synoptics and a bit of luck to see something special, its happened before so why not now.

I think we've had many last chance saloons in here but this is IMO the final last chance saloon to get something a bit more widespread before the battle with the increasing solar energy is lost. Thereafter we have to lower expectations but anyway theres a chance for the UK but theres still quite a few hurdles.

[TEITS]

Last post.

Looking at the ECM mean and anyone saying we have no chance of cold really isn't looking at the charts correctly.

Very similar to the 12Z GEFS mean.

So at +240 I think its fair to say the chance of an E,ly flow has alot of support. Now this isn't me saying snow is on its way because the reason for the widespread scatter in the ensembles is due to how far SW the bitter cold upper temps manage to get. However regardless of upper temps a E,ly flow off the N Sea would bring cold conditions especially to E areas due to the N Sea being at its coldest at this time of year.

At the moment there is far more support for a colder outlook than a mild one. Again I stress this isn't me forecasting snow because obviously the time of year has to be taken into account.

[Thundery wintry showers]

The main issue with any possible cold solution is that most of the signals that I'm seeing keep low pressure close by to the SW. To get something snowy we really need to tap into that cold Arctic air- so a shift of the low pressure towards southern Europe bringing in an east to north-easterly, or a total shift in the pattern bringing us a northerly.

From what I can see, the two most likely options are a warm, moist south to south-easterly (moist because of Atlantic weather systems pushing in from the west, rather than the continental air), and a cool grey east to south-easterly. The former looks odds-on to happen during the early part of the second week of March while the latter is more likely IMHO towards midmonth, but I think snowy options are odds against this side of mid-March.

Edited March 1, 2013 by Thundery wintry showers

[Jason M]

GFS 18Z not untypical of recent days ensembles tbh.

I still think on balance a full on easterly is odds against but this one has its origins in the high res part of the run so worth a slight eyebrow raise IMO

It would be amusing though if a freeze pops up (as is possible) in view of the unjustified pops at posters who are simply pointing out that the possibility is there. Some portions of humble pie may need to be distributed amongst some fairly senior posters . As the weather cares little for reputations a little end of season poetic justice would round things off nicely

Jason

Edit - the 12z control run wasn't exactly toasty either!!

Edited March 1, 2013 by Jason M

[bradymk]

Yes a few people getting turning colder and snow mixed up here I think. There is support for it to turn colder after next week. Both GEFS and ECM Ens show this, but turning colder does not mean ice days/snow. It seems a few people think because there is not widespread snow showing, that the outlook is mild longer term. Incorrect, cool to cold longer term looks about right, how cold and how wintry remains the very uncertain part. But personally, I am up for some v cold or v mild weather now

Edited March 1, 2013 by bradythemole

[TEITS]

Following on from my post its worth highlighting the current temps in the N Sea.

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

Let me put its this way I wouldn't fancy a swim in Cromer!

Have to be honest if we do see an E,ly I would much rather see very cold upper temps involved otherwise it will be cold, overcast, miserable in my location and many others. Infact I would then prefer a very mild SW,ly.

[SMU]

Going on from posting over the last few days Im expecting a significant swing towards cold in the 144/168 timeframes of modellling in the next 24 hours.

S

Edited March 1, 2013 by Steve Murr

[bradymk]

Following on from my post its worth highlighting the current temps in the N Sea.

http://www.wetterzen...ics/Reursst.gif

Let me put its this way I wouldn't fancy a swim in Cromer!

Have to be honest if we do see an E,ly I would much rather see very cold upper temps involved otherwise it will be cold, overcast, miserable in my location and many others. Infact I would then prefer a very mild SW,ly.

Brrr, North sea temps colder than avg, on 20th February which is the latest data I have show SST anomalies -1c below normal across most of the north sea with -1.5c in places. I would think SST have cooled even more the last 2 weeks. So any easterly is likely to be cool and cloudy even with poor upper temps. Like most of the winter, a large area of +ve anomaly SST to our north, particularly between Iceland and Scandi which has probably aided height rises there recently even more.

Edited March 1, 2013 by bradythemole