So I want to talk about the upcoming fire season. I've been out here in California for years forecasting and there are a few things I need to put out there. THREAD 1/

There are LOTS of headlines proclaiming that this fire season is basically going to be the worst ever. Will it? I don't know...and they don't either. Every year is different BUT there are worrying trends that will make this fire season have a lot of potential. 2/

1. It's very dry. We are in a growing drought with two years of poor rain/snow for the state. Once the grasses dry out and we warm up....the fire season will really start. A wet year can delay these conditions by a few months...but we expect to be there soon. 3/

2. It's probably going to be warmer/hotter than normal. This has been the base trend for a long time. We see this globally and we see it in California as well. Most months/years trend warmer than average based on last 30 years. So we have the combo...DRY and WARM/HOT 4/

There are other metrics like soil moisture, vegetation dryness etc...but it's more of the same...it's dry and warm and fires grow easily when it's like this. But the MAIN thing that drives the big destructive fires is WIND and we don't really know how that will go 5/

The windy days with low humidity are the days that fires really break out and become dangerous. Climate wise...it doesn't really matter what happens in the winter...by July in CA we know it will be hot and dry...by fall VERY dry and often windy. 6/

People forget the Bay Area fires started in October after a very wet 2016-17 rainy season...but it was during a very strong, dry wind event at the end of our long hot summer. These base conditions are present each and every year...but the wind is not a guarantee. 7/

The other thing that changes year to year is the random origin of fire starts. Lately powerlines have made headlines and mitigation and planned power outages. Those are known issues and being addressed but there are more ways to start a fire. 8/

Did you know the main start for the historic fire season was lightning? There is not plan to stop lightning. The other factor that is impossible to stop...accidents. The Carr fire was a blown tire and Mendocino Cmplx was a spark from a metal stake getting hammered 9/

Let's just say the lightning storm didn't happen last summer...the fire season might not have even cracked the top 10. So these random/known fire starts can make or break a season even if the base conditions are extreme. 10/

The unpredictable origin of fire starts on the critical windy/dry days makes broad fire season in California forecasts very tricky. They are still worthwhile to warn public and staff properly but again there is an element of randomness that makes it hard. END