Model Output Discussion - early October

[MATTWOLVES 3]

Yes indeed the ECM did go insane, the op was most definitely on the warmer side of the pack, the mean being that bit lower... But good lord I don't think it has a grasp of the SLP... its massive dips would make Thorpe Park proud. 

[knocker]

The ext EPS mean anomaly pretty much as expected. Some ridging northern Scandinavia > eastern Greenland but with he vortex/trough northern Canada pepping up a tad quite a strong westerly upper flow across the atlantic south of that, backing slightly near the UK With negative anomalies in this region it portends some unsettled weather with temps varying around the average

 

[knocker]

https://www.nhc.noaa.gov/gtwo.php?basin=atlc&fdays=2

Quote

1. Shower activity continues to become better organized in association with a small-scale low pressure area embedded within a larger extratropical low centered a few hundred miles southwest of the Azores. If current trends continue, advisories on a tropical or subtropical cyclone could be initiated later today. The low is forecast to move toward the east-northeast, and interests in the Azores should monitor the progress of this system. For more information, see High Seas Forecasts issued by Meteo France. * Formation chance through 48 hours...high...80 percent. * Formation chance through 5 days...high...80 percent.

 

[feb1991blizzard]

If you think this episode of flooding is bad, if the 18z GFS verified, it would be about to get a great deal worse - low just stalls at 204 and stays over the UK / Ireland for 36 hours (and counting)

Northern Ireland might be worst affected.

 

[feb1991blizzard]

And its still there and getting re enforcements  in the way of phasing with another incoming slider from the North West - the good news is its allowing a scandi high to develop with some frigid air waiting in the wings.

[Jordan S]

6 minutes ago, feb1991blizzard said:

If you think this episode of flooding is bad, if the 18z GFS verified, it would be about to get a great deal worse - low just stalls at 204 and stays over the UK / Ireland for 36 hours (and counting)

Northern Ireland might be worst affected.

 

That would be bad but the severity looks about the same as the situation this weekend but that would be more widespread though them big rainfall totals if that came off. It illustrates the pattern quite well with some blocking over or to the north of us slowing the progress of low pressure systems close by if the blocking is further to the north east of us Then lots more of the UK would be very wet with low pressure and there rain bearing fronts stalling over various hours that's the sort of pattern it's showing very sluggish pattern.. But that's over a week away so probably not worth worrying about.

[MATTWOLVES 3]

Pretty amazing Feb, that low which is forming around day 8, is still going strong several days later! And slowly but surely the air is cooling! I think one of the earlier ensembles highlighted this possibility, with cold air being dragged in around it... Would be Interesting for sure. 

[feb1991blizzard]

6 minutes ago, jordan smith said:

That would be bad but the severity looks about the same as the situation this weekend but that would be more widespread though them big rainfall totals if that came off. It illustrates the pattern quite well with some blocking over or to the north of us slowing the progress of low pressure systems close by if the blocking is further to the north east of us Then lots more of the UK would be very wet with low pressure and there rain bearing fronts stalling over various hours that's the sort of pattern it's showing very sluggish pattern.. But that's over a week away so probably not worth worrying about.

 

4 minutes ago, Mattwolves said:

Pretty amazing Feb, that low which is forming around day 8, is still going strong several days later! And slowly but surely the air is cooling! I think one of the earlier ensembles highlighted this possibility, with cold air being dragged in around it... Would be Interesting for sure. 

 

 

Its still centred over NI at 300, that is about 5 days of near continuous heavy rain!!

EDIT : stands a chance of verifying as its rain, you can bet your bottom dollar it would soon get shunted out the way if it was snow!

Edited October 25, 2019 by feb1991blizzard

[MATTWOLVES 3]

And like you say Feb, there is some very cold air in waiting. Long way off, but could be one to watch! Sorry mate, I've used up my quota of likes.. good stuff all the same..

Edited October 25, 2019 by Mattwolves

[Allseasons-Si]

Deary! deary! me,the 18z is a rain fest and i hope that this doesn't come off,the uk from 192 disappears under a continuous wash cycle,

we need to see further corrections south of the undercutting low in the Atlantic to get north of the pfj,this is all out of the reliable though so it's not too app hazard but we do not want a repeat of this in future runs,one thing i have noticed though in recent runs is that i am seeing lots of wedges appearing(high pressures),and these could lead to favorable conditions( if placed right ) for colder shots.

 

[Jordan S]

48 minutes ago, feb1991blizzard said:

 

Its still centred over NI at 300, that is about 5 days of near continuous heavy rain!!

EDIT : stands a chance of verifying as its rain, you can bet your bottom dollar it would soon get shunted out the way if it was snow!

5 days of relentless heavy rain in the same area believe it or not is rare for the UK though may feel like it never stops raining sometimes  does feel like snow whizzes by though typical ain't it. 

Edited October 25, 2019 by jordan smith

[ItNeverSnowsInWindsor]

Not sure about the Gfs 18z it looks a bit progressive with a bit of firework crackers before bonfire!

Edited October 25, 2019 by prolongedSnowLover

[Allseasons-Si]

The control and op are not in sync with most of the ens,so a slight relief at the beginning of the month 

the control takes the low a bit further south than the op though at 192

which leads to this favorable wedge

could be frontal snow on that.

 

[Allseasons-Si]

And a last post from me tonight goes to the trusty good old NAVGEM,two runs on the bounce for getting near on perfect synoptics to getting cold to the uk,the latter more so(18z)

 

 

[Allseasons-Si]

Ok,one last one,the jma.

[ItNeverSnowsInWindsor]

The Gfs 18z run looks like it can be discounted being a mild outlier at the start of Nov. The rest is history as they say 

 

Edit @Allseasons-si mentioned the same earlier

Edited October 26, 2019 by prolongedSnowLover

[Allseasons-Si]

8 minutes ago, prolongedSnowLover said:

The Gfs 18z run looks like it can be discounted being a mild outlier at the start of Nov. The rest is history as they say 

Yes,mentioned this above,the cluster circled is i hope the way forward.

Edited October 26, 2019 by Allseasons-si

[knocker]

Some interesting soundings at midnight. The colder air into the lower levels at Castor Bay but a frontal surface at 550mb with tropical air still around above this with a very strong thermal gradient denoted by the jet at 215mb of 270/160kts. In contrast to Lerwick which is well a truly in the colder air with the tropopause at 326MB and a 50mb temp of -30.5C as as against -15C at Castor Bay. Camborne on the other hand is still fully in the tropical air

Of coarse through today this will change somewhat as the surface front tracks slowly south east. I will not bother with any more detail as I'm sure everyone is aware of the rainfall problems associated with this. But just to note there could well be some nasty, squally weather actually on the front as it passes through and that the front trails all the way back to TS Pablo

[Seasonality]

One thing makes me happy with its absence. No horrible euro high.

[shaky]

6 hours ago, Allseasons-si said:

Yes,mentioned this above,the cluster circled is i hope the way forward.

It was not much of an outlier now was it!!nearly all members have joined the op and control this morning!!damn it!!!jus our luck happens everytime!!

[Jordan S]

The JMA output yesterday for day 7 and 8 was very interesting certainly very good if blocked and cold is what you enjoy. 

Edited October 26, 2019 by jordan smith

[mb018538]

Amazing how we quickly we can go from a blocked Atlantic with an Azores low at day 3 to full on zonal unsettled by day 6/7. I need a break from this incessant wind and rain, doesn’t look like it’s coming any time soon.

[shaky]

21 minutes ago, mb018538 said:

Amazing how we quickly we can go from a blocked Atlantic with an Azores low at day 3 to full on zonal unsettled by day 6/7. I need a break from this incessant wind and rain, doesn’t look like it’s coming any time soon.

Its the same thing year in year out!!the 18z ensembles were really cold last night but the control and op were well away from that main cold bunch and a few thought its a mild outlier but you wake up this morning and all the other members have joined the control and op and turn it much milder!!its frustrating cos if it was vice versa it would never happen lol!!so frustrating!!

[Jordan S]

Gfs Gem and Ecm have all shifted to a more Atlantic dominated pattern for the end of next week with some rather wet weather for Halloween on all 3 models have to admit that's strong agreement for a week out plus upto to day 10 looks unsettled with rainfall totals once again going up.. They all could swing back to the blocked scenario again but history tells us this ends up happening quite frequently. The 10 day accumulated rainfall from the 3 models shows the pattern pretty well.. bare in mind the rest of today's rainfall is included but still gives the general idea within the model output atm. 

GFS.. 

ECM.. 

Gem.. 

GFS ensembles paint a pretty wet end to October and start to November after a few days of drier weather temps going cold for a time but going back towards average. 

Edited October 26, 2019 by jordan smith

[IDO]

The temporary wave pattern was from a one-off event and wasn't really heralding a pattern change. It was a case how much cold could we get from it? As the pattern flattened in the Pacific region it was going to fire up the Atlantic for a while.

We are back to that en passe where there is little forcing from the lower regions and no sign of the PV getting its act together. So a period of quasi-zonality with the UK at the wrong latitude to avoid the nasty stuff. The GEFS are on a similar vein right out to the dark recesses of FI.

So we await the formation of the PV to see what sort of Nov/Dec we have in store. ATM no sign of the persistent Atlantic wave/ridge that dominated our weather for many months this year.