Because of my research on western U.S. wildfires, I keep close tabs on the weather in southern California.
So I was more than a little interested in the extreme warnings made by the National Weather Service for densely populated portions of southern California (see below).
They call this a LIFE THREATENING AND DESTRUCTIVE WINDSTORM. An EXTREME RISK demanding immediate action. Folks are warned to stay away from windows.
Specifically, tomorrow and Wednesday morning, the NWS is predicting north to northeast winds of 30-45 mph, with gusts as high as 80 mph. They suggest the winds will blow down many trees and powerlines and that travel will be difficult. Loose objects could be blown down and fires can be started and rapidly spread.
So what is going on? The large-scale models (such as the GFS forecast of sea-level pressure and surface winds shown below for 10 PM Tuesday) predict strong high pressure over Nevada and unusually low pressure over southern Arizona, producing unusually strong northeasterly winds between them (wind speeds indicated by color shading).
To better check out the forecast, the best place to turn is the high-resolution NOAA/NWS HRRR model.
By tomorrow (Tuesday) morning the HRRR model predicts 50-60 mph winds over the mountains north of LA
These winds strengthen during the day, reaching 70 mph over the hills by 4 PM.
Ominously, the crazy strong NE winds are predicted to descend to lower elevations overnight, particularly near Malibu, where the fires occurred several weeks ago (4 AM Wednesday is shown).
And the situation remains very serious at 8 AM Wednesday.
Folks, this wind event has the potential to produce major wildfires, and as a result, Southern California Edison is planning massive power shut-offs the next day (see map below). The yellow circles with the bell symbols are where they plan on having Public Safety Power Shutoffs (PSPSs). Tens of thousands of customers will lose electricity in the hope of preventing powerlines from starting fires.
Finally, let me note that this event is very, very unusual for this time of the year.
I can show this by displaying the heights and winds at 925 hPa (about 780 meters above sea level). You can see the low over southeast Arizona. The shading is something called the standardized anomaly from climatology (sorry). All you need to know is that the light gray areas indicated the winds were essentially unprecedented.
