The South Valley is expecting and preparing for the strongest storms and heaviest rainfall of the season so far through the Christmas holiday, with wind and thunderstorms forecast through at least Dec. 26.
Valley Water, the water district that serves Santa Clara County, issued an advisory and “minor flood watch” for the next incoming storm, which is expected to arrive off the coast about 10pm Dec. 23. The rain is expected to continue with a series of storms until about 10pm Dec. 26.
“Valley Water’s hydrologists are monitoring the storm, and its impacts on the creeks prone to flooding,” says a statement released by the water district. “Our teams are working to ensure that our creeks remain clear of debris and blockages.”
While a flood watch is issued through 10pm Friday, district officials are not anticipating major impacts to reservoirs and waterways in and around South County.
According to the National Weather Service, the chance of rain in Morgan Hill and Gilroy starts at 90% on Dec. 23, rising to guaranteed rainfall Dec. 24 and Christmas Day. Temperatures are forecast to reach the low 60s on Dec. 25, and drop to the mid-40s by Thursday night.
On Christmas Day, showers and a possible thunderstorm are forecast before 7am and 1pm, with another thunderstorm after 1pm, according to the NWS. Another thunderstorm could soak South County by 4am Dec. 25.
Rainfall will continue at a lighter pace on Friday and Saturday, says the NWS forecast. By Saturday, the skies could be mostly clear.
Valley Water added that rainfall from Dec. 23-26 could total up to three inches in low lying areas, and up to six inches in the mountains.
“While forecasts continue to evolve, these storms have the potential to intensify quickly, so residents—particularly those in flood-prone areas—are encouraged to stay prepared and remain alert to changing conditions,” Valley Water’s advisory said.
Chris Henry, a local weather enthusiast who runs the Facebook page “Morgan Hill Rainfall,” posted that forecasts say up to five inches of rain may fall in South County before the series of storms is over.
“In fact, instability will be so high that thunderstorms, possibly strong, will accompany the front, the showers behind the front, and along and behind the second front on Christmas Eve and Christmas Day,” Henry posted on Dec. 22. “You can thank the unusually warm ocean for the extra instability.”
He further quipped, “Rudolph’s nose might shine brighter that night if he’s hit by lightning. Downside is, all the presents will come crashing down with Santa’s sleigh!”
So far this rainy season, a total of about 8 inches of rain have fallen in South County, according to data posted by Valley Water.
