Mario Sends Tropical Moisture to California, Flooding Possible

While the Atlantic has been relatively quiet this season, the Eastern Pacific has been more active, particularly in recent months. Early Saturday morning, Mario dissipated southwest of the Baja Peninsula, only to reemerge Sunday morning as a tropical storm. It has since lost tropical storm status but it's remnant moisture is bringing flood chances to California.

Mario weakened upon encountering cooler sea surface temperatures and enhanced shear. It became post-tropical once and for all Tuesday night. The leftover moisture from Mario is moving north across California over the next few days with an attendant flooding threat.

The rain will be a welcome sight for many in California. Downtown LA hasn't seen rain since the beginning of JUNE! Unfortunately the rain also comes with a threat for flooding, particularly in the mountains and deserts.

The Baron forecast model depicts pockets of 3-4 inches of rain through Friday, especially in the mountains around Southern California and in the Sierra.

The tropical nature of the rainfall is likely to lead to some flooding. The southern Central Valley out to the Colorado River, including much of southern California, is included in a Slight Risk (Level 2) Excessive Rainfall Outlook on Thursday, while the higher threat shifts north to the Sierra on Friday. Areas that have seen wildfire activity in recent years or this year will have a higher flood risk.