A storm to remember—25 years ago, powerful tempest pounded Bay Area

CONTRA COSTA COUNTY—This weekend, East Bay residents woke up to the long-awaited sound of raindrops tapping on our roofs.  Twenty-five years ago, Dec. 12, 1995, we woke up to the sounds of trees and power lines falling. The damage occurred under the pressure of record breaking winds. That weather front ranks as strongest winter storm of the last 70 years in the Bay Area.

I certainly won’t forget that day. At that time I provided weather forecasting support to the PG&E’s newly created emergency response group at PG&E. We knew a large storm was brewing in the Gulf of Alaska. But it turned out to be stronger and more destructive than any weather system in recent history.

PG&E’s service area had been hit with two storm events in early 1990 that caused widespread customer outages. When the California Public Utilities Commission reviewed the company’s communications and outage response activity, it ordered PG&E to come up with a better way to prepare for and respond to damaging winter storms.

Communication between emergency response headquarters at PG&E’s San Francisco and field offices that stretched from Eureka to Bakersfield took key priority. During windstorms, phone lines are as susceptible to outages as power lines, so communications between home office and field support was always problematic. We needed better communications technology.

Fail Safe Communication

In the late 1980s portable text pagers were developed as a ‘fail safe’ method of communication. These inch-thick credit card sized devices had a small LED screen that could relay short messages (under 100 characters) sent via wireless transmitters. Our PG&E team decided to set up a system that communicated storm timing and intensity forecasts to the field offices.

As it turned out, it was quite a task to boil down a complicated forecast into a short text message. We decided to quantify upcoming storms in three categories, divide the service area into nine districts, and use the hour of expected highest winds as the storm time.

During the first week of December 1990, we tested the communications system for the first time. An example text message would read; 1400 SUN DEC 1::STORM WARNING-EAST BAY REGION; SEVERITY=MODERATE; TIME=0400 MON DEC  2.

Highest storm category

Less than two weeks after that test, the brewing storm of 25 years ago became the first operational use of our paging system. Even with the highest storm category forecast several days in advance, nothing could have prepared crews for the damage that occurred. Downed trees and power poles resulted in over one million Northern California residents losing power that morning!

Peak winds reached over 80 mph at several sites in the Bay Area. The highest reported was 134 mph at Kreiger Peak (near Mt. Diablo). A gust of 103 mph was recorded at Angel Island and SF State University had wind gusts of 85 mph. It is no wonder that nearly 1000 trees were downed in Golden Gate Park.

I was the lead storm forecaster on that December day. At 5 a.m., as I entered the PG&E parking garage, scaffolding flew off the sides of a building under construction across the street and smashed into parked cars. I knew it was going to be a long day.

The long day turned into a long several weeks for PG&E and its customers. When mother nature delivers record-breaking weather events, man made systems will likely fail–and they did.

In retrospect, our efforts to improve storm communications seemed to have limped out of the starting gate. However, that event provided the basis for the state-of-the-art storm outage modeling system that is currently used by PG&E.

It all started with the record-breaking windstorm that swept through the Bay Area 25 years ago.

Woody Whitlatch retired after working as a meteorologist for PG&E. Email your questions or comments to clayton_909@yahoo.com