Daan van den Broek

@daanvandenbroek.com

Researcher @ Finnish Meteorological Institute Freelance Writer MSc in Atmospheric Sciences, University of Helsinki www.daanvandenbroek.com Main interests: Meteorology | Climate | Polar Regions | Nature | Energy Transition Opinions & views are my own

🌡️ The warmth peaks today in Finland, with regionally 26-28°C inland. ⛈️ In the afternoon and evening, (severe) thunderstorms move from southwest to northeast over the country. ⚠️The storms can especially be severe in parts of western, central and northern Finland.

FMI warns for severe thunderstorms in the whole country. The storms can produce intense lightning, torrential rainfall, and strong wind gusts.

The yellow warnings are for wind gusts >15 m/s, in the counties with orange warning wind gusts >25 m/s are possible.
The location of the thunderstorms around 18:00 local time according to the MEPS forecast. The red arrows indicate the approximate direction of the thunderstorms.


Source: weatherinfo.fi.

🥶 Just as we're entering the climatologically warmest period of the year (late July), today will be remarkably cold. The forecast maximum temperature at Helsinki Airport today is only around 14°C - roughly 9°C below the late-July median.

Chart of daily maximum-temperature climatology at Helsinki-Vantaa Airport, Finland, from May through August. The black line shows the 1991–2020 median, red and blue lines the 90th and 10th percentiles, dashed lines the record highs and lows since 1959, and the green line observed daily maxima in 2026. Around 21 July, when the climatological median maximum is about 22-23°C, a green marker shows a forecast high of only 14°C. Potentially a record-cold day for this specific date. Data source: Finnish Meteorological Institute.

I've never seen anything like it. Salta, Argentina, has just recorded its hottest night on record during the climatologically coldest time of the year. The minimum overnight temperature did not fall below 26°C (78.8°F), pulverizing the previous monthly record by 7°C.

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🌍 NASA's CERES satellites show that Earth's energy imbalance has more than doubled since the early 2000s. The planet absorbs substantially more energy than it emits back to space. This means that warming in the coming years *could* outpace previous expectations.

Graph showing Earth's energy imbalance based on NASA CERES satellite observations (12-month moving average) from 2001 to 2025. The red curve shows absorbed solar radiation, which has increased steadily over time. The blue curve shows outgoing longwave radiation, which has also increased as Earth has warmed, but more slowly. The growing gap between the two curves represents Earth's energy imbalance, reaching about +1.24 W/m² by 2025. A positive energy imbalance means Earth is absorbing more energy than it emits, causing heat to accumulate in the climate system

A glimpse of Europe’s changing climate: 🫗 Rhine & Meuse are exceptionally low for mid-July - discharge levels normally seen in Sep/Oct. 🚢 Shipping and industry are already affected. 🌧️ Little effective rain expected, Rhine flows may fall below 1976 levels 📉

Average daily discharge of the Rhine. The red line indicates 2026's discharge, the grey lines show the other years, starting at 1901. 

Daily discharge is reaching the lowest levels on record for July, at values that are normally measured only in October or November.

The discharge is likely to become lower still, as drought continues in the upcoming perdiod. 

Source: Rijkswaterstaat/Deltares/NOS.

Majestetic Arcus clouds in Helsinki 🌩️Summer heat, thunderstorms and a exciting Norway-England football match. What more can a meteorologist wish for the summer holidays that just started? 😎

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Deaths linked to Europe’s June heatwave 🇧🇪 Belgium: 1,747 🇳🇱 Netherlands: ~480 🇫🇷 France: >2,700 🇩🇪 Germany: ~5,120 🇪🇺 Europe: ~20,000 Extreme heat kills. ⚠️

☀️ Warmth returns to Finland, but so do heavy showers and thunderstorms ⚡️ The highest risk in southern Finland: ⛈️ Saturday night into Sunday ⛈️ Sunday daytime The MEPS latest forecast loop below shows where the heaviest showers may develop. (1/2)

A warm and humid lower atmosphere causes a strongly unstable atmospheric profile, with remarkably high CAPE values for southern Finland. As a consequence, there's a risk for high lightning activity and torrential rainfall. (2/2)

MEPS forecast sounding for Helsinki on Saturday evening, showing a very warm and humid lower atmosphere, causing a strongly unstable atmospheric profile. This profile produces around 2,000–2,350 J/kg of CAPE, indicating the potential for strong thunderstorms.EPS forecast of MUCAPE on Saturday evening. CAPE measures atmospheric instability; values of roughly 2,000 J/kg and regionally higher are very high for southern Finland.MEPS forecast showing the highest lightning probabilities over southern Finland and the Gulf of Finland late Saturday evening.

☀️ Warmth returns to Finland, but so do heavy showers and thunderstorms ⚡️ The highest risk in southern Finland: ⛈️ Saturday night into Sunday ⛈️ Sunday daytime The MEPS latest forecast loop below shows where the heaviest showers may develop. (1/2)

Very intense rainfall on some embedded cells around the capital area in Finland. 🌧️⛈️ Some of those cells were seemingly triggered by (colliding) outflow boundaries from thunderstorms upstream.

🌡️ Unprecedented June heat across Svalbard, led by extreme spikes at the highest latitudes! Final monthly data shows Karl XII-øya (80.65N) shattered its June record reaching 0.8°C (prev 0.2°C), while Verlegenhuken (80.05N) crushed its 2024 record by a massive 0.8°C, hitting 3.2°C.

Data from frost.met.no, The Norwegian Meteorological Institute