Model Output Discussion - Autumn 2018

[feb1991blizzard]

If ever there is a run that gets close to Nov 2010, then the CFS 0z run from today is it.

http://www.meteociel.fr/modeles/cfse_cartes.php?ech=714&mode=0&carte=1&run=0

Must just point out though in the interests of balance, wrt this possible Scandi high October, the biggest match I can find in terms of pressure patterns NEAR AND TO THE EAST OF UK (not ENSO QBO etc etc) is October 1988 where I had the coldest October night for 30 years at the time (-7c), there was also snow in November that year but rest of winter - Oh dear!

 

 

[Mike Poole]

I know it's too early for this kind of stuff, but...

I was struck by the position of the tropospheric fledgling polar vortex on the GFS at T192:

Just where we don't want it right? But at the end of the run it has turned into a naughty little blue terrier with a bobtail over the eastern US:

 

Edited September 29, 2018 by Mike Poole

[feb1991blizzard]

Another Scandi high coming up and WAA into pole.

[feb1991blizzard]

The biggest cluster is still Westerly but there is a block and the second cluster is the only one out the 5 that doesn't show some sort of blocking high. cluster 4 being the tastiest.

[mb018538]

Still a bit early to be worrying about the vortex and scandi highs! Give it another month and we will be nearer the business end of things.

We could have another nasty little low clipping the SE next weekend, just as we had a week ago. One to keep tabs on.

[Frosty.]

The Gfs 12z operational turns on the heat pump or at least the warmth pump in the run up to mid october with air sourced from way south..a recurring theme with strong height rises to the east and stalling atlantic lows...there could be more very warm weather for the time of year on the way.

[Mike Poole]

Quiet today!  

Feature worth mentioning re next weekend, GEM hits and GFS doesn't next Saturday:

GEM hits and GFS  doesn't.

Moving on, heat pump on the GFS T300, 

Similar direction to the GEFS mean 6z at T240:

Finally,it seems no post is complete without one for winter, here the CFS 18z at T2592 showing the first easterly of the season, I'd have hoped of one sooner!

Hey ho!

Edited September 30, 2018 by Mike Poole

[Bruegelian]

Hey ho indeed, I think at this time of year us weather nutters start to get impatient about winter arriving, and are totally ignorant of the Autumn weather. Hey Ho!

[Frosty.]

I don't think we're done with warm weather yet..the Ecm 12z ends potentially very warm with a long draw southerly as we see high pressure to the east and low pressure anchored out in the atlantic.

[phil nw.]

53 minutes ago, Frosty. said:

I don't think we're done with warm weather yet..the Ecm 12z ends potentially very warm with a long draw southerly as we see high pressure to the east and low pressure anchored out in the atlantic.

Indeed Frosty whilst I understand some enthusiasm from those looking at blocked Winter CFS charts that is a nice October set up for an Indian Summer.

The real indication for vortex development will come towards December when zonal winds tend to really increase.

I am quite happy to see that continental high wafting warm southerlies over us for another month until we have a better chance of Winter weather.

 

[Leo97t]

7 minutes ago, phil nw. said:

Indeed Frosty whilst I understand some enthusiasm from those looking at blocked Winter CFS charts that is a nice October set up for an Indian Summer.

The real indication for vortex development will come towards December when zonal winds tend to really increase.

I am quite happy to see that continental high wafting warm southerlies over us for another month until we have a better chance of Winter weather.

 

Well said. With regards to the vortex there is slightly more favored to be a more beefy vortex than previously  thought however there is plenty of time for that to change 

[Allseasons-Si]

@Frosty.& @phil nw.,Some nice looking charts there and i think everyone is thinking that we are at the end of Autumn and trying to usher winter in too quickly(me included)and i will repeat what has been said that if we get a nice indian summer so be it,why not cos there's plenty of time for winter to arrive and the latest means and anomoly's show a good waft from the S/SW quadrant

and here is the latest from the ecm mean at day 10 and the gefs ens mean at day 14 with the latest 6-10/8-14 day 500mb outlook from the cpc underneath reflecting the former

http://www.meteociel.fr/modeles/ecmwf.php?ech=72&mode=1&map=1&type=1&archive=0

http://www.meteociel.fr/modeles/gefs_cartes.php?code=21&ech=192&carte=1&mode=0

http://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

just looking through the 20 perturbations at 300hrs,there is quiet a few with mid-highland blocking,so there could be a good standoff between the atlantic and the Scandi block

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=6&ech=300

 

[BlueHedgehog074]

Not too much to add this morning. Therefore, just a little focus on the possible storm this weekend.

The 00Z GFS (both 135 hour and 144 hour charts used):

00Z ECMWF at 144 hours:

00Z UKMO at 144 hours:

GEM at 144 hours:

00Z ICON (like GFS, both 135 hour and 144 hour charts used):

00Z NAVGEM at 144 hours:

You can see they all show variations of a similar theme. It looks quite likely a Low Pressure system will affect the UK this weekend with some rain and showers. But it’s only really the GFS and the NAVGEM which shows the Low being a bad boy (stormy). The GFS has it affecting a wider area of the UK, particularly Eastern parts, where there could be some vicious gusts towards the East coast. The NAVGEM, on the other hand, has the Low taking a beating over Northern U.K. Most other models keep the Low Pressure system as a shallower affair and generally towards the Southern portion of the UK. Particularly the UKMO! The ICON, though, when you look at its 135 hours chart, is somewhere in between with the isobars of the Low tightly packed towards the Southern part of the little cyclone, so maybe some strong gusts towards the South coast on that chart. 

Just an example, these are what the wind speed gusts are like on the 00Z GFS during Saturday:

Could be some angry gusts down Eastern parts with high tides, so would think carefully about taking the deck chairs with you to the beach! ?

(not to mention the fact it could be chilly in those Northerly winds on the GFS). 

Obviously I imagine things will keep changing from run to run regarding the Lows track and intensity. And knowing how models like the GFS handled that pervious storm over the weekend, would be cautious of its outlook for now. Personally expect the Low to not be that moody at all with a shallower feature more likely. 

It may even be possible that the Low may not affect the U.K. at all and track well to our South. Still wouldn’t ignore the grumpy Low... just incase! 

[carinthian]

Morning all, had an interest chat this morning with our portal forecaster about the possible deep cyclone that could develop next weekend in the vicinity of Southern Britain. Feeling are that the situation becomes quite fluid in 5 days time as the Eastern Atlantic trough moves into NW Europe. A baroclinic zone becomes established towards the North Sea, not surprising really when you see the 144t 850mb forecast temperature chart below. Very cold air getting established to the North  and meeting pulses of warm air moving poleward through Eastern Europe, hence the North Sea could see fairly rapid cyclonic development. However, at this stage the positioning , deepening and potential cut off low formation is still  showing a degree of uncertainty but defo one to watch. Their own model tends to show a bit more of a southward positioning and could change very quickly over the coming days. We have a snow alert for tonight, not a lot but fine mesh model predicting 5 cm in the village as the freezing level gets down to 1750m  tomorrow morning.

[Iceaxecrampon]

Extremes for this transitional time of year - Summer clinging on in the SE

True Indian Summer after frosts

[Mike Poole]

The threat of very unsettled weather affecting the east at the weekend reduced on the 12s, UKMO and GFS at T120:

Following weekend GFS still ramping the surge of warm air from the south, look at this at T300, shown up on a fair few runs now:

Thats 14C uppers over well pretty much all of us.  Indian summer!

I'd certainly welcome this before the search for cold takes over - for me after the clocks change.

Edited October 1, 2018 by Mike Poole

[mb018538]

Models not really interested in anything majorly unsettled either, doesn’t look like the trough is going to get too close to cause any headaches in the short to mid term. Looks reasonable to me.

[ICE COLD]

1 hour ago, Mike Poole said:

The threat of very unsettled weather affecting the east at the weekend reduced on the 12s, UKMO and GFS at T120:

Following weekend GFS still ramping the surge of warm air from the south, look at this at T300, shown up on a fair few runs now:

Thats 14C uppers over well pretty much all of us.  Indian summer!

I'd certainly welcome this before the search for cold takes over - for me after the clocks change.

GFS a little on its own tho really with its high over the uk pulling up very warm uppers . Here's the ECM and GEM at day 10 . 

There pretty similar with the alantic working its way in . It ties in with the METO update really . More unsettled mid October with something more blocked towards the end of October with possible frost and fog . Proper autumn weather .

[Man With Beard]

1 hour ago, Mike Poole said:

The threat of very unsettled weather affecting the east at the weekend reduced on the 12s, UKMO and GFS at T120:

Following weekend GFS still ramping the surge of warm air from the south, look at this at T300, shown up on a fair few runs now:

Thats 14C uppers over well pretty much all of us.  Indian summer!

I'd certainly welcome this before the search for cold takes over - for me after the clocks change.

Would be threatening some records if the flow from the south isn't too slack. We've seen three days of this type of chart all over the extended ensembles. Can they hold out, unlike last month? 

[bobbydog]

Just for fun at this stage but the CFS looks interesting for Boxing day 

Even -16c uppers a few days later!

1962 anyone? 

[mulzy]

On 30/09/2018 at 20:07, Frosty. said:

I don't think we're done with warm weather yet..the Ecm 12z ends potentially very warm with a long draw southerly as we see high pressure to the east and low pressure anchored out in the atlantic.

Pure perfection for October - lets' hope it verifies Frosty!

This evening's ECM not quite as good sadly...

 

[Atmogenic]

1 hour ago, bobbydog said:

Just for fun at this stage but the CFS looks interesting for Boxing day 

Even -16c uppers a few days later!

1962 anyone? 

I'm not even a coldie but seeing those charts at the end of December would make me very excited as well

[BlueHedgehog074]

I’d love to be very greedy and have both Frosty’s/Mike Poole’s smashing warm Southerly, and bobbydog’s Boxing Day wintry paradise charts, come off!

[carinthian]

On ‎01‎/‎10‎/‎2018 at 09:58, carinthian said:

Morning all, had an interest chat this morning with our portal forecaster about the possible deep cyclone that could develop next weekend in the vicinity of Southern Britain. Feeling are that the situation becomes quite fluid in 5 days time as the Eastern Atlantic trough moves into NW Europe. A baroclinic zone becomes established towards the North Sea, not surprising really when you see the 144t 850mb forecast temperature chart below. Very cold air getting established to the North  and meeting pulses of warm air moving poleward through Eastern Europe, hence the North Sea could see fairly rapid cyclonic development. However, at this stage the positioning , deepening and potential cut off low formation is still  showing a degree of uncertainty but defo one to watch. Their own model tends to show a bit more of a southward positioning and could change very quickly over the coming days. We have a snow alert for tonight, not a lot but fine mesh model predicting 5 cm in the village as the freezing level gets down to 1750m  tomorrow morning.

Morning all , snow duly arrived overnight on time and snow cover as the computer predicted 5cm ( spot on as above post ) Snow settled at 1800m with a more widespread covering on the mountain range just to the north of Katschberg ( Obertauern) which is not unusual for these parts. Certainly a chill breeze currently with flurries. The weekends cyclonic development looks now to be downgrading with the fall in pressure is being predicted further south  across Northern France this coming weekend as our own model indicted yesterday.So may be some rain for a time in Southern Parts of England but quite a temperature differential between Britain and Eastern France, with you lot on the colder side.

C

[Jonathan Rhodri Roberts]

Saturday looks rather cold for the beginning of October on the GFS 6z highs struggling to even reach double figures for many!