Unusual Heat and Dry Weather Triggers Forest Fires (Photo Credit: Tropical Tidbits)

In midst of some of the worst California fires in recent memories, our friends from across the Atlantic have been dealing with similar conditions recently and throughout the summer. Portugal has a very similar climate to California, they are both coastal landmasses, influenced by large oceans, and typically have a wet and dry season. The problem this summer in Portugal has been the extreme heat and the aridity accompanied with high winds which create the fire conditions we so often see and hear about along the western United States.

The beginning of October in Portugal featured above normal temperatures and dry conditions, a “loaded gun” setup for fires to develop. The only thing missing was breezy winds. Unfortunately, hurricane Ophelia decided to spin up in the Atlantic at this time and track close enough to bring stiff sustained winds to the region without the benefit of moisture, making for a worst-case scenario. A country that went through the deadliest forest fire in its history four months ago, with 64 losing their life, are mourning as around 40 more met their demise this October.

Some relief developed after Ophelia’s passing, as a cold front moved through the country providing some moisture and cooler temperatures. This pattern has not lasted as the recent trend features more of the same, a summer type pattern with a ridge over head for the next few days, drier than normal conditions (PWAT anomalies), and temperatures well above average (temperature anomalies), all arranged in order chronologically above. The first image presents the 500mb height pattern on November 1st, which keeps warm dry weather in western Europe throughout this time. The next image is for the same time period, November 1st, which shows the precipitable water anomalies, a measure of how dry the air is compared to average with brown colors meaning below average. The third photo presented is the temperature anomalies, red being well above normal temperatures for this time. All of these ingredients will continue to present a forest fire risk across Portugal.

This pattern will be watched by GWCC throughout the rest of October and beyond. Stay up to the date on the latest fire weather news here!

©Forecaster Joe DeLizio