Daria’s Big Sister: the January 1884 storm
Gustave Eiffel learns a lesson
On January 19, 1884, a strong depression moving across northern Scotland marked the start of a string of storms coming in from the Atlantic. The strongest event in this series began to unfold on January 26, 1884. During the morning, barometers in northwestern Ireland started to plunge.
Figure 1 shows the track and pressure development of this event as it moved across the northern United Kingdom at a fairly moderate speed. However, due to its extremely low central pressure and associated steep pressure gradients, damaging wind speeds extended over a north-south distance of more than 1 000 kilometres. As far away as Evaux-les-Bains in central France for instance, a 50-metre steel truss from a railway bridge under construction was blown from its abutments into a ravine. The bridge’s engineer, Gustave Eiffel, no doubt bore this event in mind when constructing the Eiffel Tower in Paris five years later.
Figure 1: The minimum surface pressure track and the reconstructed peak gust footprint of the 26/27th January 1884 storm
Reconstruction of this event’s wind footprint difficult
For the British Isles, the strongest winds were observed over the north of Ireland, southern Scotland and northern England. Severe forestry damage is described for several locations, however without precise quantification of thrown timber volumes. In southern England, the winds still caused damage to individual buildings and trees across a wide area, but were clearly lower than in the north. So far, this is as expected – the further south, the lower the wind speeds. However, damage reports and meteorological observations suggest that along the coasts of northern France, peak gusts were actually higher again than in southern England.
Why the storm blew harder in France than England
Back in 1884, it was thought that a secondary depression had perhaps passed over France. Given the scarcity of observation data – often only three readings per day and none during the night in few locations across France – the existence of a shallow secondary low cannot be completely ruled out, but is considered unlikely. By the time the southwest-northeast oriented cold front of this storm had passed over northern France it was strongly elongated. Thus, it may well have produced higher gusts in Paris at 11 pm than it did when passing over London four hours earlier.
While gradually weakening in the early morning hours of January 27, stormy conditions reached far into France’s interior, with the Massif Central, Alps, Jura and Vosges mountains affecting the speed and direction of the wind. Reports do not indicate damage on a massive scale, but accounts of fallen chimneys, damaged roofs and broken windows extend far beyond Paris. Wind speed measurements in Paris, Brussels and Dunkirk indicate that this event was likely the strongest in the 1880s, but not as strong as the severest storms in the decade before and after.
Why does the 1884 storm remind us of Daria in 1990?
The descriptions above make clear that the January 26, 1884 event was not particularly severe in terms of its maximum intensity. What made the event spectacular was the tremendous reach of damaging wind speeds, which were undoubtedly driven by the exceptionally low central pressure of the storm. Figure 1 shows our best estimate of a 3-second peak gusts footprint of the January 1884 event. We estimate that the area with gusts in excess of 120 km/h spanned some 1,250 km from northern Scotland down to central France. In comparison, the January 1990 storm known as Daria or “Burn’s Day storm” – considered a storm of very large proportions – unleashed comparable wind speeds across an area of only 750 km at the most. Therefore, the January 1884 event can undoubtedly be termed Daria’s “big sister”.
1884 storm happening now would generate record insured losses
Based on the most recent European PERILS market portfolio for 2019, insured property losses alone would reach close to EUR 14 billion according to our estimates – far beyond the insured losses caused by any European winter storm in history. The table shown in Figure 2 breaks down the estimated losses per country. Again, the figures do not include losses from other lines of business nor from any loss amplification. It has to be noted that the loss estimates have not been changed compared to our loss estimates in 2014 due to exposure changes in the UK that are in favour of smaller losses for this particular event. This is a prime example showing how significant the impact of the location of the exposure on the resulting loss numbers is.
In line with the footprint is the remarkable fact that the Benelux countries and Germany have not been strongly affected, as the depression veered off sharply to the north after reaching its maximum intensity over Scotland. Had it held a more northeasterly course, the estimated losses would no doubt rise massively for these countries.
Before concluding our account, we should highlight that the storm described in detail above was both preceded and followed by another. Although smaller in size, a preceding storm on January 23/24 was almost equally strong over parts of Britain, and extended its wind footprint across Belgium and Netherlands and into Germany. Moreover, during the night of January 27 to January 28, only 24 hours after the big storm had abated, a small secondary depression passed over the southern-most portion of France, where it exceeded the wind speeds of the night before. Neither of these events is accounted for in the peak gust footprint we have presented. Given the partial overlap of areas affected, the short time between the storms and a recent trend to expand event definition clauses in reinsurance contracts, claims adjustment would no doubt be challenging if such a cluster of events took place today.