José Grilo

Storm #Charles Situation Update • 12:30 PM It appears that Charles’ secondary/weaker core is making a last-minute attempt at becoming better organized before moving inland right around Lisbon this afternoon. I’ve personally noticed an increase in rainfall intensity over the past 10-15 minutes in the Lisbon area, with only a slight change in wind speed. I’d like to emphasize that this does NOT mean we are trending back towards previous forecasts for destructive wind, this simply means that some gusty winds may still arrive this afternoon. This is nothing out of the ordinary for autumn and winter storms. Charles’ main circulation is south of Portugal, and has continued defying weather model guidance. It should make landfall somewhere in southern Spain or even northern Morocco later today with heavy rain and strong gusts. Remain alert for flash flooding.

Storm #Charles Update: Changes and Revised Model Guidance Conditions have gradually started to degrade in Madeira this evening. The worst conditions arrive late tonight into early Wednesday morning due to heavy and persistent rain and wind gusts over 100 km/h. Much higher gusts are possible especially in exposed and mountainous areas. Then our attention turns to Iberia, especially Portugal as Charles makes its final approach during the morning. Weather model guidance has continued to struggle with the development of the storm up until landfall, not only in terms of intensity but also trajectory and structure. I have attached two graphics which show the effect of Charles’ path on the risk of strong to damaging wind. As I’ve mentioned in my previous updates, there is generally a higher risk of severe wind in Lisbon if Charles takes a more northerly path directly over or north of the city. This could allow Charles to interact more with the jet stream and therefore become better organized, which is also why the term “sting jet” has been mentioned. Sting jets are unpredictable and extreme wind phenomena that can sometimes arise in rapidly-intensifying extratropical cyclones. The more southern trajectory, with a landfall somewhere south of Lisbon, has generally gained some model support today. This would significantly reduce the risk of destructive wind in Lisbon and central Portugal, but the wind threat would remain in the south. For these reasons I still think there’s a possibility some areas will be spared from the worst conditions. Portugal will not be “destroyed” tomorrow, even though damage is likely in the hardest-hit regions. Despite the ongoing uncertainty with the wind aspect, I think the more certain danger will be excessive rainfall. Lisbon has already experienced some flooding issues this morning after several intense downpours, and with the rich subtropical moisture arriving tomorrow with Charles, flooding is likely. ❗️NOTE: The IPMA has issued red warnings for heavy rainfall mainly in central Portugal, in addition to red wind warnings which are being maintained. These wind warnings may be adjusted tomorrow depending on the behavior of Charles. Thank you all for the incredible support today and yesterday as I’ve tried to navigate this complicated forecast, more updates are coming soon!