Winter 2025/26 - General Discussion

This is how I would interpret those Meteo-France 500mb height anomalies.

December shows a vast blocking signal for the high latitudes with no signal for southern Europe. For physics reasons, you would expect a corresponding trough beneath the blocking in this region. However, if hypothetically we said this "no signal" was average heights which the average is naturally higher heights/pressure so without a deep negative anomaly, you wouldn't anticipate that much of a cold pattern. You would get high pressure influence further south than that would entail. In much of the recent winters, we're lacking a proper Genoa low to drive home the blocking pattern and unleashing the beast from the east. Due to the blocking, you'd certainly could see a cold December of some kind but it's far from a classic and pessimism from the stereotypical modern scenario of Hadley cell expansion increasing heights in southern Europe would make me think it'd be milder than most would see initially.

January just looks mild to me to be honest. There are lower heights over Europe at the same time we have a strong positive anomaly close to the Azores. This would mean a predominantly westerly flow off the North Atlantic which would then probably dig down into Europe on the other side. This gives me winter 2011-12 vibes to an extent. Rather mild and dry with occasional Atlantic fronts.

February looks the most interesting of them all with a similar blocking signature in the high latitudes to December but little bit more of lower heights signal across Iberia. Ideally we'd have a very strong low heights signal here and towards Italy. I could easily see southerly influences with this as you got to remember that this is an anomaly from average, not where the anticyclones and troughs will be placed. So if you have a weak anomaly, you got to think back to the norm and the possibility of only a slight deviation from that. The low heights over Iberia could easily be associated with some kind of Biscay trough and the Greenland blocking to be too far west over towards Canada. We seen this as recent as March 2023 when the cold spell left Ireland.

With all the blocking, one thing's for sure that it would be a calmer than normal winter.

GFS 0z is even more bonkers.