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Model output discussion - proper cold spell inbound?

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Am I the only person who finds ukmo day 5 to be implausible on both meteociel and wz?

looks like sub 520dam surface thickness across the uk from a westerly flow ??

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6 minutes ago, Stormeh said:

That’s not just rain, there is plenty of PM shots coming up over the next week or so. A lot of this precipitation will be falling as snow in many areas in NW of the UK.

Yes you're absolutely right, there is plenty of cold zonality on the 12z runs covering the next 7-10 days so I expect  widespread frosts / ice and wintry showers, some snow at times..it's certainly not just rain..it would be misleading to say it was just wet and windy weather ahead !:)

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It looks like it's all falling into place for our little island,........ BUT we've been burned too many times before for me to get hyped up about this.

Yes there's a SSW but it's no guarantee we'll be in the best location for it. Until these amazing charts are at +6 I'm not allowing myself to get carried away.

having said that, it's gotta happen one of these times, no?

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Major cold developing over the continent on the control run, not for a while have I seen uppers that low (-24) close to the UK! 

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2 minutes ago, MattTarrant said:

Major cold developing over the continent on the control run, not for a while have I seen uppers that low (-24) close to the UK! 

but note the 'shortwave' features develop as it heads towards the 'warm' north sea. we don't want uppers that low headed this way because im not sure they have a chance to make it past the Scandinavian coastline and the flow gets cut off. ironically, you don't want lower than -15 uppers headed west out of scandi

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10 minutes ago, MattTarrant said:

Major cold developing over the continent on the control run, not for a while have I seen uppers that low (-24) close to the UK! 

Are you referring to the -24 core some 400 miles east of Moscow?! (just checking!) :-)

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20 minutes ago, Frosty. said:

Yes you're absolutely right, there is plenty of cold zonality on the 12z runs covering the next 7-10 days so I expect  widespread frosts / ice and wintry showers, some snow at times..it's certainly not just rain..it would be misleading to say it was just wet and windy weather ahead !:)

It can be very good for the northwest but tbf cold zonal is usually a poor airmass snow-wise for my area on the south coast of Wales. For example BBC suggests Swansea temperatures will range between 7-9C max to 3-5C min throughout next week (with frequent rain showers or longer spells of rain.) Average high in Feb is only around 7C so quite disappointing really. 

Edited by Jonathan Rhodri Roberts

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8 minutes ago, bluearmy said:

but note the 'shortwave' features develop as it heads towards the 'warm' north sea. we don't want uppers that low headed this way because im not sure they have a chance to make it past the Scandinavian coastline and the flow gets cut off. ironically, you don't want lower than -15 uppers headed west out of scandi

I am merely talking in terms of a possible trend to keep an eye on, I merely mentioned the uppers because I couldn't be bothered to copy the image. I agree with your statement that it would cause a series of complications. Just something to observe to see whether the Extended EPS or GEFS Ensembles develop deeper cold across the European continent, instead of the cold being pooled over Northern Canada for the majority of winter. 

Edited by MattTarrant

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4 minutes ago, MattTarrant said:

I am merely talking in terms of a possible trend to keep an eye on, I merely mentioned the uppers because I couldn't be bothered to copy the image. I agree with your statement that it would cause a series of complications. Just something to observe to see whether the Extended EPS or GEFS Ensembles develop deeper cold across the European continent, instead of the cold being pooled over Northern Canada for the majority of winter. 

yes matt - just making a point that extremely low uppers can be a poisoned chalice if they attempt to cross the north sea (the channel is ok)

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Looking good so far with the SSW at play almost anything can happen however past few runs have been good! 

Still the next few days will be interesting hence why I've joined this community... 

 

6BF66E3D-0584-486F-AC62-D3D1BD508589.png.053012182bbb842a0c6aa18d35d9f48f.png

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probably echoing other's posts, but I can't help but noticing how quickly the effect of a SSW is having on the model output....I thought the lag time was 14 days min...Even though it's FI, the GFS is churning out some very good runs in the past 24 hours, also even in the semi-reliable, long may it continue!

I'm not normally a ramper as such, but the outputs, the mood in here, and the trend towards a possible late winter to remember has got me a bit excited....no, it's got me considerably excited, so much so, I think a little bit of wee just came out.....lol !

Edited by ajpoolshark

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41 minutes ago, bluearmy said:

but note the 'shortwave' features develop as it heads towards the 'warm' north sea. we don't want uppers that low headed this way because im not sure they have a chance to make it past the Scandinavian coastline and the flow gets cut off. ironically, you don't want lower than -15 uppers headed west out of scandi

Can I ask as a novice why would this be the case?

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ECH1-120.GIF?07-0ECH1-144.GIF?07-0

I still think the period 12/13 could be quite snowy for some - even if a transient affair.

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12 minutes ago, ajpoolshark said:

probably echoing other's posts, but I can't help but noticing how quickly the effect of a SSW is having on the model output....I thought the lag time was 14 days min...Even though it's FI, the GFS is churning out some very good runs in the past 24 hours, also even in the semi-reliable, long may it continue!

I'm not normally a ramper as such, but the outputs, the mood in here, and the trend towards a possible late winter to remember has got me a bit excited....no, it's got me considerably excited, so much so, I think a little bit of wee just came out.....lol !

Yes all the pieces may at last fall into place. Good output today so far, looking for a decent 9/10 day ECM now. And in response to your last sentence I think you need a QTR. (that's quicker todger response)

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Seems to be some unequivocal, momentum based ramping going on. 

So we have easterly's down 13+ days from now? How often is this the case? (<rhetorical question)

Can this be attributed to the forecast SSW event upcoming? Possibly, but then again, possibly not?

Not all SSW events are followed by persistently and unusually cold weather. Especially if the vortex fails to split.

Cold weather is certainly favourable but dramatic winter weather is still the least likely scenario. 

 

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8 minutes ago, SN0W SN0W SN0W said:

Can I ask as a novice why would this be the case?

I assume its to do with the contrast between the temp of the upper air and that of the sea. when frigid uppers leave the eastern seaboard you see systems generated as they reach warmer waters. (waters muddied here by the gulf stream meeting the Labrador current). I imagine its the same atmospheric physics at work.

Edited by bluearmy

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4 minutes ago, Mucka said:

ECH1-120.GIF?07-0ECH1-144.GIF?07-0

I still think the period 12/13 could be quite snowy for some - even if a transient affair.

Really good output this evening gota say!!ecm looks cold aswell up to 144 hours!!

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not a big difference to our east and northeast gfs/ecm by day 7. clearly to our west there is a debate on how strong that low will be. I don't think the ssw response will affect that feature so soon after its occurred. have to see what ukmo makes of that later on its extended

EDIT: the strength of that system makes a big change by day 8. not that we should be paying too much attention to ops at day 8 but given their higher resolution, I'm interested to see their evolution with the ssw in play

Edited by bluearmy

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42 minutes ago, bluearmy said:

yes matt - just making a point that extremely low uppers can be a poisoned chalice if they attempt to cross the north sea (the channel is ok)

t's not always a problem though is it Nick

image.thumb.png.e99f7257d7693753f9b95630991c0832.png

image.thumb.png.28a094259e791e1f0fe7507f3c2ff6c7.png

:D

 

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Looks like some snow from the system that moves across UK between 120 and 144 on latest ECM. Really is quite a cold westerly air mass that we have coming up prior to any SSW influence. 

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3 minutes ago, Purga said:

t's not always a problem though is it Nick

image.thumb.png.e99f7257d7693753f9b95630991c0832.png

image.thumb.png.28a094259e791e1f0fe7507f3c2ff6c7.png

:D

 

yes I knew someone would pick that one out !

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There's growing support for a February freeze within the GEFS 12z..hope it keeps growing..think it will!!:D:cold:

0_384_850tmp.png

1_384_850tmp.png

2_384_850tmp.png

5_384_850tmp.png

15_384_850tmp.png

 

18_384_850tmp.png

20_384_850tmp.png

21_384_850tmp.png

Edited by Frosty.

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@Optimus Prime has a point take Feb 1999 SSW for example.

5a7b4a42c312a_ScreenShot2018-02-07at18_46_13.thumb.png.82f686b39fa0fa88d34e596867dd3974.png  Pick out the Feb 1999 SSW from the chart and notice The ENSO states...La Nina. Also an East QBO. Both same as now.

Next MJO phase 7.....5a7b4a4da0e8a_ScreenShot2018-02-07at18_47_28.thumb.png.e7cbe8663f8b508de672c76a668e8849.png .....as we are now.    Dramatic wind reversal 5a7b4a55caa45_ScreenShot2018-02-07at18_48_03.thumb.png.da68f38529f650662f2a3e897b1fa0d9.png similar to what we are about to see and is forecast obviously.

Net result...5a7b4a63c64d8_ScreenShot2018-02-07at18_47_18.thumb.png.89522a6bed2d6a29007dc16cbdd04ee7.png not a great looking snow anomaly map for the uk. 

Just trying to keep things in perspective. 

Note the saving grace for snow lovers might be that this SSW happened 10 days later than the one we are about to see. May just be about enough of winter left to see a difference. Fingers crossed.

Edit...ok Steve Murr's post after this trumps mine in more ways than one, epic post. In that this 1999 split was a wave 1 split and we are about to see a wave 2 split so be interesting to see how it plays out. 

Edited by ghoneym
.

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