E.N.S.O. Discussion

[Don]

8 hours ago, karyo said:

CFSv2 is keen on developing La Nina by the time we get to July.

The other models generally less keen on that but still with neutral/negative enso values by July or August.

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

I think this planet needs a La Nina!

[Kirkcaldy Weather]

 

[karyo]

On 25/02/2020 at 22:27, Don said:

I think this planet needs a La Nina!

Yes that's true. We are breaking heat records with enso neutral so imagine what a strong el nino would do.

[summer blizzard]

2 hours ago, karyo said:

Yes that's true. We are breaking heat records with enso neutral so imagine what a strong el nino would do.

Values for the last three months are actually close to weak nino, we need a Nina to scrub the atmosphere.

[summer blizzard]

Cold water west of the dateline is now close to surfacing, likely in the next month.

Glosea5 (Met Office) has now joined the Cansips and CFS on board the Niña train by summer.

-PDO is already on board so the atmosphere is unlikely to display confusion.

Fun and games on the way.

 

 

[B87]

A disastrous summer on the cards, then?

[damianslaw]

Correct if wrong but a La Nina summer usually means high pressure through mid atlantic and cool NW airstreams?

[summer blizzard]

98

00

01

05

Those are the best matches since 79 for Q3 -ENSO, -PDO, -QBO. They are all poor solar analogues though.

4 hours ago, B87 said:

A disastrous summer on the cards, then?

 

 

 

 

 

[B87]

10 minutes ago, summer blizzard said:

98

00

01

05

Those are the best matches since 79 for Q3 -ENSO, -PDO, -QBO. They are all poor solar analogues though.

1998 and 2000 were dreadful summers. 2001 was quite good and 2005 was fairly average, so 50% chance of it being a bad one based on those analogues.

[summer blizzard]

8 hours ago, B87 said:

1998 and 2000 were dreadful summers. 2001 was quite good and 2005 was fairly average, so 50% chance of it being a bad one based on those analogues.

Unfortunately they were all close to solar Maxima with it being on 01.

2012 and 2007 ticked two boxes. 2012 got the PDO and QBO but ENSO held on the positive side until Q4. 2007 had the ENSO and QBO but the PDO held up until Q4 too.

[karyo]

Possibly an active Atlantic Hurricane season then. Currently the SSTs in tropical Atlantic are generally above average so something to monitor in the coming months.

[Summer Sun]

 

[Singularity]

If we do go the way of the Nina, strength will be important with respect to the UK summer pattern.

 

A weak Nina still leaves a lot of wiggle room, with a big role for stratospheric events this month & next.

If there was no big single warming with subsequent downward propagation of positive height anomalies across the Arctic, then low heights up there could bring about a decent summer overall, especially the 1st half (like 2018 but not necessarily as impressive), depending on tropical cycles which may be more active than usual for a La Nina due to the eQBO.

In the SSW/strong final warming scenario, there could be trouble with a propensity for high-latitude blocking and lows trundling across the UK. Generally cool by day, mild by night. The last thing we need after such a soggy winter!

 

A moderate or strong Nina would make having a warm summer very difficult but could actually reduce the chances of it being a wet one, thanks to increased mid-Atlantic ridging regardless of how much HLB there is. I wouldn't mind that too much actually - we've had a fair bit of hot weather in the past few summers and odds are we'll have one of the elusive weak El Nino / positively skewed neutral ENSO summers sooner or later (which are generally the hottest for the UK, though with a few exceptions as usual).

[Kirkcaldy Weather]

 

[summer blizzard]

Strong easterlies over the ENSO region and two months with a PDO value less than -1.

[Singularity]

On 11/03/2020 at 17:05, Kirkcaldy Weather said:

 

 

A trend toward La Nina is a big factor behind the signal here:

 

[karyo]

Accuweather is forecasting an above average hurricane season for the Atlantic. They mention the above average SSTs in the Caribbean. 

AccuWeather forecasts above-normal 2020 Atlantic hurricane season – EyeWitness News

EWNEWS.COM

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NASSAU, BAHAMAS — AccuWeather meteorologists are forecasting another busy year with at least three major hurricanes when the 2020 Atlantic season officially gets underway in another two...

 

As for the tropical Pacific, some cooling is currently underway in regions 3.4 and 4. The CFSv2 is keen to bring La Nina conditions by July but other models are less keen. NOOA forecasts an enso neutral season but importantly the values are expected to turn slightly negative as the summer progresses.

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

[karyo]

Colorado state University is also expecting an above average Atlantic hurricane season.

Are You Ready for This? 2020 Hurricane Forecast: Above Average Intensity

WWW.FORBES.COM

---

Four major hurricanes, with winds at least 111 miles per hour, are possible during the season that begins June 1.

 

[summer blizzard]

[Don]

3 hours ago, summer blizzard said:

Starting to follow the CFSv2, albeit more a signal for a weak La Niña?

[summer blizzard]

1 hour ago, Don said:

Starting to follow the CFSv2, albeit more a signal for a weak La Niña?

Models rarely tend to get the peak amplitudes correct because they they don't have relative tendency built in sufficiently. They are better in situation like recent months where we have stayed about the same and thus they only need predict relatively slow movement. 

[B87]

On 12/04/2020 at 12:45, summer blizzard said:

Summer over before it has even begun? A repeat of 1998, 2002 or 2007 on the way?

[damianslaw]

Reading posts above, a la Nina tends to mean mid atlantic heights and a generally cool showery summer pattern, not necessarily a washout, but preety disappointing with poorly positioned heights stopping any continental influence from gaining a foothold, the azores high tends to align all wrongly.

Don't want to speak too soon, but I'm always wary of Aprils that bring lots of dry sunny warm conditions, the last three warmest Aprils 1987, 2007 and 2011 were all followed by poor summers. Much rather have the warm weather come in May. 

[damianslaw]

Welcome more thoughts on ensor and general prospects for summer as we enter latter half of spring.

[Cheshire Freeze]

My thoughts have been pretty clear since February-ish with regards to summer. I think we'll see a mean -ve pressure anomaly limpeted close to the UK across the 3 summer months. 

This isn't based solely on ENSO state but also the fact we're just emerging from solar min.

The latest GLOSEA flip to unsettled is telling IMO and last time I checked, the averaged CFS model was also going for a UK trough.

As time goes on, I'm also becoming more confident that winter 20/21 will be a big one.

Edited April 17, 2020 by CreweCold