Winter 2023/24 - Discussions & Forecasts

[bryan629]

With some references today talking of " Water Vapour " in the strat. Im assuming this Vapour would actually be ice crystals being so high up. Do the weather ballons measure the ice crystals. 

I was also wondering about the Antarctic polar vortex and if was stronger and faster spinning than normal or slower and weaker? might give us an idea if and how all the WV may impact on our SPV this year. 

Loving the cansips update BTW ,but how come they are smoothed out to the point there is no sign anywhere of the trop PV on them? 

 

[WYorksWeather]

I think one of the difficulties with forecasting is the large variations that are likely at the sub-seasonal and even sub-monthly scale. A lot of LR forecast models are showing above average temperatures, but of course that doesn't preclude cold spells. For example, you could have a 10-day cold spell with something like a -5C anomaly, but if the rest of the month was southerly/south-westerly those periods could come out well above average, say +3C, and so the month overall would come out slightly above average.

Could be some wild swings I think - still some potential for cold given the overall setup, but equally I wouldn't be surprised if we saw one of the monthly temperature records between November and March go!

[Don]

Winter 2023/24 fifth update from Gav's Weather Vids, focusing on years with positive IOD's.  Not a great sign, particularly those years coinciding with El Ninos.  However, I think the main difference this year is the E-QBO, compared to W-QBO's during 1997/98 and 2015/16 etc which also featured positive IOD's?

 

[Don]

Latest Met Office contingency forecast and no real surprises.

https://www.metoffice.gov.uk/binaries/content/assets/metofficegovuk/pdf/business/public-sector/civil-contingency/3moutlook_ond_v2.pdf

[RJBingham]

31 minutes ago, Don said:

Latest Met Office contingency forecast and no real surprises.

https://www.metoffice.gov.uk/binaries/content/assets/metofficegovuk/pdf/business/public-sector/civil-contingency/3moutlook_ond_v2.pdf

"A mild 3-month period is more likely than a cold one" 

[Don]

8 minutes ago, RJBingham said:

"A mild 3-month period is more likely than a cold one" 

Well, I would have been surprised if it said "A colder 3-month period is more likely than a mild one"!! 

[Frigid]

12 minutes ago, RJBingham said:

"A mild 3-month period is more likely than a cold one" 

Let's be honest, that's always the case. Nothing new

[RJBingham]

3 minutes ago, Don said:

Well, I would have been surprised if it said "A colder 3-month period is more likely than a mild one"!! 

OK, I've come up with the winter forecast, A milder than average winter, with the possibility of one or two cold snaps. 

[Frigid]

3 minutes ago, RJBingham said:

OK, I've come up with the winter forecast, A milder than average winter, with the possibility of one or two cold snaps. 

You might be onto something there

[raz.org.rain]

5 minutes ago, RJBingham said:

OK, I've come up with the winter forecast, A milder than average winter, with the possibility of one or two cold snaps. 

Sounds like last December!

[RJBingham]

3 minutes ago, razorgrain said:

Sounds like last December!

Oh, you can use this forecast for any winter 

[raz.org.rain]

2 minutes ago, RJBingham said:

Oh, you can use this forecast for any winter 

With the battle going on between signals for colder and signals for milder, and the Met Office going for milder than average, I wonder if it'll be a season of contrasts. Record warm spells between cold snaps.

[RJBingham]

4 minutes ago, razorgrain said:

With the battle going on between signals for colder and signals for milder, and the Met Office going for milder than average, I wonder if it'll be a season of contrasts. Record warm spells between cold snaps.

Time will tell I guess, I'm interested to see what happens to all this northern blocking that is being forecast. 

[Summer Sun]

ECMWF going for below average snowfall this winter as a whole

However, the monthly breakdown shows a slowly improving picture for Jan and Feb

https://www.severe-weather.eu/long-range-2/winter-2023-2024-seasonal-snowfall-predictions-forecast-update-united-states-canada-europe-fa/

 

[MattStoke]

2 minutes ago, Summer Sun said:

ECMWF going for below average snowfall this winter as a whole

However, the monthly breakdown shows a slowly improving picture for Jan and Feb

https://www.severe-weather.eu/long-range-2/winter-2023-2024-seasonal-snowfall-predictions-forecast-update-united-states-canada-europe-fa/

 

Above average anomaly overall for the Midlands, though. Nice.

[CryoraptorA303]

16 hours ago, razorgrain said:

With the battle going on between signals for colder and signals for milder, and the Met Office going for milder than average, I wonder if it'll be a season of contrasts. Record warm spells between cold snaps.

Looks like it. I'd bet on an overall dry winter that becomes increasingly dry into the second half, with quite a few cold nights and the odd cold spell but a good percentage of high daily maxima nationwide. I would keep the second >20C winter spell on the cards at this point, especially if things do go increasingly dry over the winter, although I'm not sure how much that helps anything at this point of the year.

Definitely looks like this could be hinting at the classical dry El Nino spring-summer at this point, although so far out, you can interpret these early seasonals to mean almost anything you want. A dry winter followed by a really dry and sunny spring, followed by a dry summer would be setting the stage for something truly catastrophic next year, were the synoptics attempting to bring extremely high temps to us come summer...

Edited October 2, 2023 by CryoraptorA303

[SqueakheartLW]

3 hours ago, CryoraptorA303 said:

Looks like it. I'd bet on an overall dry winter that becomes increasingly dry into the second half, with quite a few cold nights and the odd cold spell but a good percentage of high daily maxima nationwide. I would keep the second >20C winter spell on the cards at this point, especially if things do go increasingly dry over the winter, although I'm not sure how much that helps anything at this point of the year.

Definitely looks like this could be hinting at the classical dry El Nino spring-summer at this point, although so far out, you can interpret these early seasonals to mean almost anything you want. A dry winter followed by a really dry and sunny spring, followed by a dry summer would be setting the stage for something truly catastrophic next year, were the synoptics attempting to bring extremely high temps to us come summer...

I wouldn't bank on this if we quickly switch from El Nino to La Nina next year. Those springs and especially summers tend to go downhill very quickly, 2007 is a classic example of this situation as well as 1998.

[swfc]

Looking into october i really like the projected look at the nhp especially to our nne. Granted 7 days is a long time on thevMo but nor really your bog standard west to east patterns

[bluearmy]

11 hours ago, Summer Sun said:

ECMWF going for below average snowfall this winter as a whole

However, the monthly breakdown shows a slowly improving picture for Jan and Feb

https://www.severe-weather.eu/long-range-2/winter-2023-2024-seasonal-snowfall-predictions-forecast-update-united-states-canada-europe-fa/

 

That must be derived from the September update. October isn’t usually out until 5th of the month 

[northwestsnow]

41 minutes ago, bluearmy said:

That must be derived from the September update. October isn’t usually out until 5th of the month 

Yup.

Just checked ,Oct update not available yet.

[Frostbite80]

Just leave this here. Interesting for so early into winter.

u 60N 10 hPa

WWW.WEATHERISCOOL.COM

 

[SqueakheartLW]

1 hour ago, Frostbite80 said:

Just leave this here. Interesting for so early into winter.

u 60N 10 hPa

WWW.WEATHERISCOOL.COM

 

Also interesting is how we are already seeing weakening of the vortex predicted high up.

[Catacol]

On 01/10/2023 at 17:27, Don said:

Latest Met Office contingency forecast and no real surprises.

https://www.metoffice.gov.uk/binaries/content/assets/metofficegovuk/pdf/business/public-sector/civil-contingency/3moutlook_ond_v2.pdf

As you say - as expected. Nino to get a grip of autumn particularly if AAM rises and produces a more positive GWO orbit. Chances of a stormy autumn season higher than in recent years, maybe December also.

Edited October 3, 2023 by Catacol

[Catacol]

6 hours ago, Frostbite80 said:

Just leave this here. Interesting for so early into winter.

u 60N 10 hPa

WWW.WEATHERISCOOL.COM

 

That really would be a cracker. A proper December event leading to a disrupted January pattern given 2-4 week lead times for impact. It is the sort of thing those looking for a properly cold season would dream of.

But....it is the CFS and it is only October 3. But good eye candy at this very early stage I agree. One day these sorts of things will happen again. Dec 1962 saw a Canadian Warming

[Downburst]

17 hours ago, bluearmy said:

That must be derived from the September update. October isn’t usually out until 5th of the month 

What is the index? Is it MM, CM or days?