a 90-minute drive. Accidents, fallen trees and mudslides make the trip a lot longer.
“Access can be part of the problem, especially in strong winter storms,” said Logan Johnson, the warning coordination meteorologist at the Weather Service’s Monterey office.
When it rains
So if it’s raining cats and dogs and the Mount Um radar is down, forecasters fall back on other tools.
“You bite your lip, maybe say something under your breath,” quipped KNTV’s Mayeda.
Automated rain gauges indicate how fast the rain is falling in selected locations. Weather satellites reveal approaching storm clouds. Forecasters even use eyewitness reports of downpours, hail and high winds.
With all these other tools available, some government forecasters say, the Mount Um radar location really isn’t all that bad. “You have to look at all the data sources available,” Johnson said.
And there’s some good news for the 20-year-old radar: The Weather Service has been continuously upgrading and maintaining its Doppler radars.
“We do a really rigorous preventive maintenance schedule on it,” Johnson said. “We want to prevent it from actually breaking during hazardous weather.”
The Weather Service also added a wireless connection to get data from the Mount Um radar when the main phone line goes down. And in 2012, the agency replaced several aging components. “Dual polarization” Doppler radar can now see the difference between small raindrops, large raindrops, hail and even snow.
KNTV’s Mayeda compared it to the aftermath of a trip to the eye doctor.
“It’s kind of like having blurry vision and now suddenly you’ve got a real sharp set of glasses on,” Mayeda said.
But critics point out that the upgrades do little to fix the basic problem: location, location, location.
Meteorologist Null and other forecasters think the Weather Service could have chosen a much better place than Mount Um — low enough to see most of the rain, with good views of approaching Alaskan storms, easy access and better coverage for millions of people.
“The ideal spot probably would have been Mount Tamalpais” in Marin County, Null said.