Winter 2013/2014 Forecasts/Hopes/Discussion Thread

[Duane S.]

Worth remembering that if the vortex does start to set up later this month / November in an unfavourable location, it will be susceptible to to being broken up by eg. wave events unlike a fully fledged PV sat over 65N 18W in January which is far more robust and resilient.

[bobbydog]

Let's not forget October and November 2009 - increasingly wet and very mild at first. Then look what happened as the Atlantic gave way to blocking in December. Best not get too worried about the PV being over Greenland in late October. I'd rather that than undercutting lows with beautiful snowy synoptics too early in the season.

 

i was just thinking that myself as i'm watching the rain belting down.

 

something to think about-

 

"

The winter of 1963 - the coldest for more than 200 years

With temperatures so cold the sea froze in places, 1963 is one of the coldest winters on record. Bringing blizzards, snow drifts, blocks of ice, and temperatures lower than -20 °C, it was colder than the winter of 1947, and the coldest since 1740.

It began abruptly just before Christmas in 1962. The weeks before had been changeable and stormy, but then on 22 December a high pressure system moved to the north-east of the British Isles, dragging bitterly cold winds across the country. This situation was to last much of the winter."

 

http://www.metoffice.gov.uk/education/teens/case-studies/severe-winters

Edited October 13, 2013 by bobbydog

[Summer Sun]

3rd winter round up from Gavin P

 

 

He says its 50 / 50 between favouring cold or mild this winter

[snowking]

He says its 50 / 50 between favouring cold or mild this winter

With the best of will in the world to Gavin P who does does have some decent meteorological knowledge...that's a forecast I'm sure we could all make? :)SK Edited October 13, 2013 by snowking

[Weather-history]

With the best of will in the world to Gavin P who does does have some decent meteorological knowledge...that's a forecast I'm sure we could all make? :)SK

Lol Thinking about it there is a third option, average. Wouldn't average have a % chance?

[Methuselah]

With the best of will in the world to Gavin P who does does have some decent meteorological knowledge...that's a forecast I'm sure we could all make?

SK

But it's, arguably, all that's really possible (from a scientific perspective) this early in the season...Better being honest than ramping-up the unknown, SK? 

[cheese]

Who wants to take a trip to Finland?

 

[Summer Sun]

Who wants to take a trip to Finland?

 

 

Pass..........

[sebastiaan1973]

Lot's of discussion about OPI. http://www.centrometeotoscana.it/forum/index.php?topic=7356.0 & http://www.americanwx.com/bb/index.php/topic/41379-october-pattern-index-predicting-winter-ao-from-october-with-90-accuracy/#entry2437416

[Buriedundersnow]

nice satellite pic of the low pressure in the north sea today hopefully we see a few features like this come winter dragging seriously cold air from the continent and giving us all plenty of snow

 

[sebastiaan1973]

nice satellite pic of the low pressure in the north sea today hopefully we see a few features like this come winter dragging seriously cold air from the continent and giving us all plenty of snow

 

BWd3zsrCIAA3QXH.jpg

I hope so! Today in a large area of the Netherlands between 40-60mm of rainfall. Some stations even higher in the southwest corner even higher.

Edited October 13, 2013 by sebastiaan1973

[BornFromTheVoid]

I thought I'd try take a different approach to the CFS data, to look at the trends for blocking in the North Atlantic this Winter.

 

I chose to focus on the area within the green box below, stretching from eastern Scandinavia to Western Greenland, and bound by Svalbard and Iceland for the north and south edges.

 

 

So I started a spread sheet and for the 12z CFS each day, I looked at the monthly sea level pressure anomaly within the general area of the box and ranked it based on 11 categories, going from exceptional blocking (ranked as a 5), to neutral (ranked as a 0) down to exceptionally low pressure (ranked as a -5). The method a bit subjective, but should be ok for trends.

Below is an example of a +5 (most blocked), a 0 (neutral) and a -3 (strong low anomaly, the lowest I've come across, none have warranted a -5 so far!)

 

+5

 

0

 

-3

 

 

 

In situations where there is both a strong +ve and -ve anomaly within the box, they cancel eachother out, giving a 0 overall.

 

With the data gathered, I then was able to get some averages and trends.

 

Below are the predictions for November since September 22nd, the daily data in blue, the 5 day mean in red and the trend in black.

 

 

November has averaged +1.8 over the last 3 weeks, so pretty much in the moderate blocking category, but does show a very slight downward trend. Overall, I think it looks quite promising, with 80% of runs since the 22nd showing +ve SLP anomalies to our north, with 10% -ve and 10% neutral.

 

 

December

 

December is looking quite good, with an average over the last 3 weeks of +2.3, with 5% showing -ve pressure anomalies, 10% showing neutral and 85% of runs showing +ve pressure anomalies to our north. A good upward trend in the blocking too.

 

 

I'll try post an update of these every now and then. If anyone wants the stats for January, February or March I can post them up, though I'm not sure how reliable the CFS is at that kind of range.

Edited October 13, 2013 by BornFromTheVoid

[lorenzo]

Nice work BFTV - hats off to you for grinding through the CFS Data and making it more meaningful. Look forward to further updates.

[Summer Sun]

@BFTV

 

When you say +1.8 for November and +2.3 for December what are you referring too?

[BornFromTheVoid]

@BFTV

 

When you say +1.8 for November and +2.3 for December what are you referring too?

 

The average rankings for the pressure anomalies in the green box (first image), briefly discussed below the first image. They go from +5 for exceptional high pressure anomaly, to 0 for neutral and -5 exceptional low pressure anomaly.

 

So the average November ranking (from +5 to -5) between September 22nd and October 12th, based on the 12z CFS, is +1.8, with December averaging +2.3, both in the moderate high pressure anomaly/moderate blocking category.

 

Hope that helps.

[UV-RAY]

The average rankings for the pressure anomalies in the green box (first image), briefly discussed below the first image. They go from +5 for exceptional high pressure anomaly, to 0 for neutral and -5 exceptional low pressure anomaly.

 

So the average November ranking (from +5 to -5) between September 22nd and October 12th, based on the 12z CFS, is +1.8, with December averaging +2.3, both in the moderate high pressure anomaly/moderate blocking category.

 

Hope that helps.

Lol, I think Gavin was hoping you meant temps being above the CET average BFTV.

[Summer Sun]

The average rankings for the pressure anomalies in the green box (first image), briefly discussed below the first image. They go from +5 for exceptional high pressure anomaly, to 0 for neutral and -5 exceptional low pressure anomaly.

 

So the average November ranking (from +5 to -5) between September 22nd and October 12th, based on the 12z CFS, is +1.8, with December averaging +2.3, both in the moderate high pressure anomaly/moderate blocking category.

 

Hope that helps.

 

Thanks that helps greatly

 

Lol, I think Gavin was hoping you meant temps being above the CET average BFTV.

 

I knew it wasn't temps as these were pressure charts I just didn't know what BFTV meant by +1.8 for November and +2.3 for December

 

I do now though

[UV-RAY]

Thanks that helps greatly

 

 

I knew it wasn't temps as these were pressure charts I just didn't know what BFTV meant by +1.8 for November and +2.3 for December

 

I do now though

I know Gav, I was ribbing you.

[stewfox]

The average rankings for the pressure anomalies in the green box (first image), briefly discussed below the first image. They go from +5 for exceptional high pressure anomaly, to 0 for neutral and -5 exceptional low pressure anomaly.

 

So the average November ranking (from +5 to -5) between September 22nd and October 12th, based on the 12z CFS, is +1.8, with December averaging +2.3, both in the moderate high pressure anomaly/moderate blocking category.

 

Hope that helps.

 

Great stuff

 

Will you run the November blocking forecast from Sept 22nd to 31st Oct and see how it turns out ?

[BornFromTheVoid]

Great stuff

 

Will you run the November blocking forecast from Sept 22nd to 31st Oct and see how it turns out ?

 

Cheers.

I'll keep updating it on a daily basis and post the graphs and data up here every now and then.

Edited October 13, 2013 by BornFromTheVoid

[Skyraker]

What has happened to Ian F?

 

Has he been gagged or more likely simply had enough of us lot misquoting 'shannon entropy'?

 

 

 

You could call people like me a very hurtful person then because I pray for a Madden winter, so you could say im wishing for people to be dead in a roundabout way, but my argument is that heat kills many more people in the world than cold and people say its ok to pray for that, I remember Ian fergusson last December saying how could anyone be celebrating THAT ECM when it would almost certainly result in death, yet he likes thunderstorms!! I know there was a thread on this a long while ago.

[Skyraker]

Any danger you could re-post this in English please?

 

james madden is Accuracy is very good at points he known that a mild spell was going to happen next week.We have to wait and see we could see a winter of are lifetime+ or just a boring old hot winter.

Edited October 13, 2013 by Skyraker

[johnholmes]

Nice work BFTV - hats off to you for grinding through the CFS Data and making it more meaningful. Look forward to further updates.

 

yes agree with those comments L-thanks BFTV, trend is the only real use of these and it does illustrate this quite well.

[bluearmy]

Any danger you could re-post this in English please?

 

rather he didnt  !!

[johnholmes]

re the qu from BFTP this morning

 

It is as far as I can remember not a usual pattern with +ve heights and -ve heights underneath but maybe someone can correct me if I am wrong.

 

As to what follows-search me lad, IF it had been pursued for 3 days or more than blocking to the north and lower heights south of it, suggesting a 500mb flow from a point east of north.

However if you log on to the NOAA version this evening the 6-10 has modified this idea almost to the point of extinction! Never ever believe ANY model on ONE output. Look for trends.

Edited October 13, 2013 by johnholmes