Tropical Storm Hilary Will Hit Southern California— the Pacific Northwest Will Get a Sample of It
Although unusual, southern California occasionally gets hit by tropical storms moving up from Baja, California, and such an event will occur during the next few days.
As shown in the satellite image this morning, Hurricane Hilary is now west of Central America and shows a well-defined eye and impressive cloud/rainbands.
The latest forecasts suggest that Hilary will move north-northwest towards southern California and greatly strengthen during the next few days, followed by a rapid weakening.
Below are the forecast tracks of several model prediction systems (left panel), as well as the predictions of the maximum wind speeds and central pressure (right panels) that I accessed from the NOAA/NWS HWRF website.
This hurricane will weaken rapidly as it approaches southern California, as they generally do.
Why?
Because hurricanes depend on warm water for their energy and sea surface temperatures cool rapidly along the U.S. West Coast (see sea surface temperatures below). Hurricanes can only be maintained and strengthened where the ocean is sufficiently warm (reds to yellow)
The latest European Center model forecast rapidly weakens the storm as it moves northward up Baja, California, ending just south of San Diego at 6 PM PDT Sunday.
But although weakening, Hilary will bring a large amount of rain to the western U.S. Below is the European Center total precipitation prediction through 11 AM Wednesday.
Wow. 2-6 inches over southern California and a deluge over southern Nevada.
Eastern Oregon gets a piece of it, as does Idaho and western Montana.
This rain is quite welcome and is very well-timed to reduce the wildfire threat over much of the western U.S.
We are now about to enter a cool-off period for the Northwest and I suspect that Puget Sound will not see another 90F day until next summer.
This has been a very benign wildfire year for Washington State, something shown by the latest wildfire statistics provided by Washington DNR.
