Scott Duncan Profile picture
Jun 11, 2021 10 tweets 5 min read Read on X
Antarctica is ridiculously cold right now.

It is deep winter down there with the relentless night. But it is significantly colder than normal.

It is so cold, it is having an impact on the global temperature anomaly.

THREAD
A lot of heat in Northern Hemisphere across many continents over the coming days but Antarctica sticks out like a sore thumb.

Map via @khaustein
This is the jet stream. The fast river of winds encircles the deep cold. Mesmerising right?

But right now, we have a strong jet and polar vortex locking the extreme cold over the ice sheets.
I spoke to @SimonLeeWx for his take and "the Antarctic Oscillation is strongly positive and projected to remain so"

Also we have a "well coupled with stratospheric vortex".

These superb graphic are by @zd1awrence, please check out his website for more: stratobserve.com
Having this strong coupling sustained at a time of year where there is zero daylight, can allow the cold to intensify like we are seeing.

This is the anomaly for month so far and the 7 day forecast.

🔵 = colder than normal
🔴 = warmer than normal
A lot of people will have heard of the polar vortex.

The polar vortex in the southern hemisphere is much more powerful than the one we see in the north

It is a formidable beast at this time of year.
The main reasons for this intense cold:

- Strong positive Antarctic Oscillation (en.wikipedia.org/wiki/Antarctic…)
- Having a strong and well coupled stratospheric vortex
- This combination being sustained for many days during the depths of the long winter night.
But there are uncertainties. Interesting points by @khaustein

Antarctica likes to do its own thing sometimes!

Other weather extremes, climate graphics and more over on instagram

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instagram.com/scottduncanwx.…
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More from @ScottDuncanWX

Mar 3
Truly outlandish.

Some places in Europe didn't just record their warmest February on record.... They went on to beat their warmest MARCH temperature levels.

[THREAD] Image
Effectively everywhere in the dark red shading smashed warmest February record - most by large margin. Austria 🇦🇹 has over 250 years of temperature record and nothing compares to this. Not even close.

Source: zamg.ac.at/cms/de/klima/n…
Image
Wiener Neustadt in the east of Austria was so warm that temperature of February 2024 exceeded the warmest MARCH record (data here since 1949).

uwz.at/de/a/waermer-a…
Read 11 tweets
Aug 27, 2023
Heatwave going out with a bang in Europe.

Watch how the jet stream digs aggressively into Southern Europe. The atmosphere is primed for severe weather - unfolding right now...
This animation captures the transition from extreme heat (unprecedented for this late in August) to relatively cool conditions.

The variable shown here is the temperature at 850 hPa (usually around 1.5km above sea level). This can help show where our airmass is coming from.
The Mediterranean is also acting like an extra source of fuel for the storms. The sea surface temperatures are at record hot levels.

The Gulf of Lion (just south of France) is especially hot. The sea surfaces will likely cool dramatically during this breakdown.

You can access the satellite derived sea surface temperature data here:

The graph can be found here:
Read 7 tweets
Aug 10, 2023
BREAKING: Valencia 🇪🇸 has just scorched its previous heat record by a shocking +3.4°C

The new provisional record stands at 46.8°C (116.2°F). This is a huge record-break. Image
Before commenting.... please read the thread.

Historical record can be found here:

Simply select the variables you would like to check. This weather station has data since 1966. A lengthy period of observation to smash a record by such huge margin. https://t.co/JHyxNLmKZXaemet.es/es/servicioscl…
Image
The final maximum to the decimal point may still change in final daily maximum but it is a clear record by large margin.

Please read through this thread... There is a lot of detail. The temperature dropped suddenly after the maximum and can be explained.

Read 5 tweets
Jul 25, 2023
This is the hottest we have ever observed.

The Mediterranean is now completely outside all previous records. We have never measured this level of heat across the basin at any time of year.

It is only July. We usually see the annual maximum in August.
Image
Image
We could also be looking at a new world record in ocean heat from Manatee Bay (Florida). Please carefully read the excellent thread by @DrJeffMasters, there are a few uncertainties explained

You can learn more about and access the sea surface temperature data I used in the map here:

This is the link to access data in the Mediterranean: https://t.co/RcwfekQX5xncei.noaa.gov/products/optim…
ceam.es/ceamet/SST/SST…
Read 6 tweets
Jul 24, 2023
BREAKING: Palermo in Sicily has just obliterated its all-time heat record by over 2°C. The previous record was +44.8°C in August 1999.

The observatory has weather data dating back to 1791. This is a very significant record to fall by such an enormous margin. Image
It looks like Europe has also just set a new heat record for the month of July.

The heat in Southern Europe and North Africa on top of the extraordinary overnight temperatures really is astonishing. Image
A more complete list of records from today via @extremetemps

Read 7 tweets
Jul 20, 2023
Our oceans have been breaking heat records across the globe daily since March.

Excessive and sustained heat in the oceans can have enormous impact on many types of marine life. We have seen damaging marine heatwaves before, but not like this.

A short thread... Image
Let's start with the Mediterranean...

The Mediterranean Sea has never been this warm so early in the year (in modern record). The current heat is challenging some of the hottest moments which usually occur in August. Image
We know from past study that the some of the fiercest marine heatwaves (like 2003 and last year) led to mass mortality of some species in the Meditteranean

Research from 2003:

Also an article from last year: https://t.co/NUHSLkeiHDonlinelibrary.wiley.com/doi/10.1111/j.…
theguardian.com/environment/20…
Read 9 tweets

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