Daan van den Broek
@daanvandenbroek
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
🥶 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.
I had the privilege of visiting in December last year - then with a rather balmy -31.3°C in the summer. ☀️
Wow, -84.1°C! 🥶 Concordia🇦🇶 measures a temperature only half a degree above its all-time cold record (August 2010). According to @pinturicchio60.bsky.social, this is the lowest temperature recorded on Earth since 2012.
The first precipitation is now arriving from the southwest.👇🏼
3. Moisture convergence and persistent ascent along the frontal zone 4. The rain band moves largely parallel to the flow, continuously feeding moisture into the same area and leading to causing sustained rainfall Result: 30–60 mm widely, locally 70–110 mm.
Why so much rain this weekend? 🌧️ 1. A deepening cyclone moving into southwestern Finland strengthens the low-level southerly flow. 2. An atmospheric-river-like setup transports very warm, humid air into Finland.
A large area from southwestern to central and eastern Finland will see large sums of rain this weekend, regionally up to 70-100 mm.
🫗 The Rhine at Lobith has now reached its lowest discharge ever recorded *in the entire summer* (June–August).
🌍 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.
🫗 Yesterday, the Rhine at Lobith reached its lowest level ever recorded in July. And we’re only halfway through the month.
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 📉
Convection is initiating in southern Finland again. Thunderstorms and torrential rain are possible.
Very intense thunderstorms moving inland in/from the capital area right now. Take caution!
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)
☀️ 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.
At times, daily mean temperatures have hovered near 10°C (!), or 3-4 standard deviations from the long term daily climatology.
Longyearbyen (Svalbard) measured it's warmest June on record. 🌡️ Monthly mean temperature: 6.4°C Already surpassing the June of the record summer 2024 (6.1°C)
So called 'tropical days' (Tx ≥ 30°C) are becoming much more frequent. Until 1993, years without tropical days were quite common. We haven't had a year without one since. This year, we're already at 7 tropical days. Statistically, the warmest months are still to come. (4/5)
De Bilt also saw, by far, the highest June minimum temperature on record. The temperature didn't drop below 21.3°C, compared to 19.8°C during the previous record. (3/5)
And even if it doesn't get any hotter later this summer it's already the 2nd highest yearly maximum temperature. Only July 2019 saw a higher maximum temperature: 37.5°C. Most commonly, yearly maximum temperatures are set in July or August. (2/5)
About last week: De Bilt - the Netherlands' main weather station - measured the highest June temperature on record: 36.8°C compared to 36.1°C in June 1947. (1/5)
⚡️ A new record for lightning strikes in the Netherlands🇳🇱 : 301.137 discharges in a single day! Measurements started in 2004. Widespread damage occurred due to strong winds and large hail associated with the numerous extreme thunderstorms.
Final maximum temperatures on Friday. 🌡️39.4°C. Fifth warmest day on record in the Netherlands. In June. Normally heat records are set in July and August. Heat index (measure for humidity and temperature combined) was the highest on record.
🇳🇱 The Netherlands has just broken its national June temperature record. 🌡️ 38.2°C was just measured in Eindhoven. The old record was 37.9°C in Venlo, set on 27 June 1947. The temperatures are still rising. 📈
🚨 The Dutch Royal Meteorological Institute (KNMI) issues a red warning for extreme heat tomorrow, Friday 25th of June. Warning for the combination of high temperatures (35°C-40°C) and humidity.
🇩🇪 Germany is next. 🔥 The German ICON model projects maximum temperatures well above 40°C in Eastern parts of Germany. Locally, up to 43°C is possible according to ICON. 🚨 Germany's current all-time record is 41.2°C (Duisburg-Baerl/Tönnisvors on 25 July 2019). #EuropeHeatwave
The Harmonie weather model is now forecasting widespread >40°C in the Netherlands for Friday, likely the warmest day of this heatwave. 🔥 ECMWF slightly less warm. In any case, there will be 4 consecutive days with max temp >35°C in many places, which is bad enough.