Model Output Discussion - Into Autumn 2019.

[mb018538]

GEM going all-in on the Greenland block by day 10:



Totally different to the GFS:

[Methuselah]

The GFS 00Z OP looks interesting: plenty of warm air still to our south, and some decent cooling, further north...Let the fun-and-games commence!

   

So, on to the GEFS 00Z ensembles: mostly a tad on the warm side, WSW winds and plenty of lovely rain!

   

   

Don't worry about the cold, peeps -- that'll come. Meanwhile, cast your minds back to October 1974 and recall what a stinker that was: heavy rain (sometimes sleet) and cold temps throughout...?

I know full-well that making winter predictions based on what goes down in October, is fruitless...but I'd always take an October 1978 over a 1974!

Edited September 20, 2019 by Ed Stone

[Summer Sun]

After tomorrow low pressure is going to become the main player in our weather with spells of heavy rain and strong winds becoming more dominant

On a positive note at least it won't be cold 

[Methuselah]

Will we see a cold start to October, or a warm one? Who knows!

   

[Frosty.]

A largely settled and unseasonably warm start to october from the Gfs 6z operational with temperatures into the low / mid 20's celsius range across most of england, warmest further s / se. Next week looks unsettled and a little cooler but still on the warm side across the southeast with temps generally close to 20/21c but the main thing about next week is some welcome rain for the parched SE / East Anglia.

Edited September 20, 2019 by JON SNOW

[Methuselah]

I can't argue with that, karl; it also looks rather warm throughout next week...If the GEFS 06Z ensembles are anything to go by!

   

   

Plenty of time for the polar cold to intensify, too!

[Kirkcaldy Weather]

An interesting spell coming up over the next few weeks with a few things going on, I will start with the ensembles which show a tropical feature in the Atlantic during the first week of October with some bringing it our way and others moving it up toward Greenland / Iceland

   still some of the ensembles trying to bring in a northerly too    

Also looks like the MJO will head into phase 1 (currently phase 8         https://docs.wixstatic.com/ugd/31d9e0_3c062d439cb841d2eea3ea174256642b.pdf  https://docs.wixstatic.com/ugd/31d9e0_10ee87ce9b95595674142ec32136a6c6.pdf The majority of those charts suggest lower pressure to the west / north west possibly extending into the UK. Will be interesting to see how it pans out and if the models follow suit and lower the pressure especially to the north west where they seem keen to try and develop some blocking ATM. 

[MR EXTREMES]

8 hours ago, Summer Sun said:

After tomorrow low pressure is going to become the main player in our weather with spells of heavy rain and strong winds becoming more dominant

On a positive note at least it won't be cold 

The last chart not far of a northeasterly blast. 

Or northerly something a little interesting but then again the hurricane season is in full swing to bring us some stormy weather. From Sunday anyway. 

Edited September 20, 2019 by MR EXTREMES

[Methuselah]

We could be in for some rather exciting model-watching!

   

[Frosty.]

Two months before the meteorological winter begins the Gfs 12z operational brings the uk it's first taste of winter as Arctic air floods south, especially across scotland!!..frosts and snaw, yes snaw!!.. Frosty's limbering up for winter continues..am I really looking at wet bulb temps at the beginning of october..crazy !!!❄❄

 

 

 

Edited September 20, 2019 by JON SNOW

[Methuselah]

Indeed karl -- the warmth suggested by the 06Zs has left the building, in the 12Zs!

   

   

For the love of Gaaaaaaaaaad, maxima of only 11C!

[ICE COLD]

Stonking Greenland high on the ECM 12z . Please be there in late November early December. 

Edited September 20, 2019 by ICE COLD

[I remember Atlantic 252]

9 minutes ago, ICE COLD said:

Stonking Greenland high on the ECM 12z . Please be there in late November early December. 

think you'll find huge PV there then

[SMU]

Yes a very interesting theme that continues in the models - obviously very early days to consider that it links into winter to much however its a nice start- 

We need the slow jet to continue......

[MATTWOLVES 3]

Some nice posts above regarding the Greenland block in place from ECM. Firstly we all no next week is more unsettled, temps around average!! Blah blah.... Let's get to the interesting part.... Nice little cold pool setting up to end the run.... Perhaps a N/NEtly. And wow, some impressive heights setting up shop over Greenland..... To early for winter big ups just yet.....oh what the hell...... 

[January Snowstorm]

Great charts as others have said and long may it continue as we head further towards Winter. A line of caution though we saw something similar a couple of years back but it went pear shaped as we got towards winter proper. Still frosts by next weekend onwards look likely which if nothing else will help kill the weeds that have been rampant this Winter!!

[damianslaw]

Bang on cue - autumn is arriving in time for the equinox - very often takes until the latter part of September to get going properly, just like spring tends to set in properly after the spring equinox.

From some late summer warmth, to something increasingly distinctly chillier as we end the month, if the synoptics shown by the models this evening verify.

Always noteworthy to see heights building to the NW through autumn - not the norm, and such heights will help to maintain those warm SST values to the south of greenland - an ingredient needed to slow down the jet at a time when it wants to ramp into gear.

In the reliable timeframe, becoming wet, which will prop up the rainfall totals and prevent September from going down as a notably dry month as it has been up to now.

[Gael_Force]

Even if it does change later in autumn, it's another example of the new season replicating the pattern that closed out the previous season. This seems more apparent where the vortex has been particularly blown apart by SSW or very strong final warming. Look at the charts for early May; almost identical when you allow for difference between winter/summer arctic temperature.

[Mapantz]

A couple of posts moved to the moans/ramps/chat thread. If you're just posting a chart to ramp, please do so  in here. 

Thanks. 

[Allseasons-Si]

Ok,someone get me the Prozac

That is almost a 2010 redux in September

keep em comin.

a gif of the evolution with the cold pool coming down from svalbard but then relents later.

 

 

Edited September 21, 2019 by Allseasons-si

[Cheshire Freeze]

8 hours ago, damianslaw said:

Bang on cue - autumn is arriving in time for the equinox - very often takes until the latter part of September to get going properly, just like spring tends to set in properly after the spring equinox.

From some late summer warmth, to something increasingly distinctly chillier as we end the month, if the synoptics shown by the models this evening verify.

Always noteworthy to see heights building to the NW through autumn - not the norm, and such heights will help to maintain those warm SST values to the south of greenland - an ingredient needed to slow down the jet at a time when it wants to ramp into gear.

In the reliable timeframe, becoming wet, which will prop up the rainfall totals and prevent September from going down as a notably dry month as it has been up to now.

Interesting point about Atlantic SSTs. I suspect that we'll need the Atlantic profile fully in our favour this year to stave off the raging +PDO. interestingly, the GLOSEA (which is showing an 88/89 redux) has the cold blob in the N Atlantic re-emerging over the winter months. This Atlantic cold blob has been a common factor across our recent mild winters.

[ICE COLD]

That would be a freezing Northerly in winter . Nice charts appearing at the moment. ECM 00z T216 . 

And by the end it gets pretty chilly for the end of September. 

Edited September 21, 2019 by ICE COLD

[knocker]

The next anticyclonic wave, Aleutians/western Atlantic aided and abetted by Jerry merging with a trough on the eastern seaboard, which eventually forms a high cell over Greenland as it absorbs the cut off high cell west of Norway.

Not good news for the UK with the two energy flows

Quickly moving on and the highly amplified Atlantic

Edited September 21, 2019 by knocker

[knocker]

The better news is that according to the latest EC46 output the amplification is short lived and a more benign outlook beckons

[LRD]

12 minutes ago, knocker said:

The better news is that according to the latest EC46 output the amplification is short lived and a more benign outlook beckons

I know your preference is for a nothing, pretty boring sort of weather type (not knocking that (pardon the pun) by the way, as we all have our preferences) but I'm not quite sure why that's better news. We're desperate for rain, and a fair amount of it, in the SE. A spell of extended unsettled weather is what we need, not more high pressure influence

Although I am always doubtful that the EC46 will be near the mark in the long range, anyway, whether it's predicting warm or cold, wet or dry

Edited September 21, 2019 by LRD