A series of storms is lined up to bring significant rainfall with the potential for flooding through Thursday. The precipitation follows a Friday night storm that drenched the North County with up to 1.5 inches of rain.
"The cold front came through, and the intensity around the cold front was really strong, which lifted the moisture and carried over into the region," said meteorologist Tom Fisher, with the National Weather Service. "The faster the air is forced upward, the more moisture gets squeezed out, and the more intense the rainfall can be, as was on Friday night in Santa Maria."
Saturday was mostly clear and dry, but there will be lots of cloud cover as the next storm system moves in after midnight Sunday, he added.
Debris flow, flooding
There is the potential for debris flow in the Thomas, Woolsey and Hill fire burn areas when the rainfall intensifies late Sunday night into Monday morning, according to the weather service. In addition, as the ground becomes more saturated, there could be an increased threat of rock and mudslides in canyon roadways, especially near the burn areas.
"Burn areas aside, we need to keep an eye out for debris basins, which can fill up very fast with the storm systems coming so close together," Fisher said.
The National Weather Service works with the United States Geological Survey and county fire departments across the state to determine rainfall rates that might trigger a mudslide, "but we're not expecting to meet that threshold [rainfall rate] during this upcoming week, but of course, we'll continue to analyze the forecast," he added.
Due to multiple storms bringing significant rainfall to the region, conditions could approach saturation levels, with significant water flow into the rivers.
"We don't expect any large river flooding, while roadways or freeways in urban areas might experience some minor flooding and ponding in north Santa Barbara County," Fisher said.
"We're essentially keeping an eye out on three systems that'll be continuously spreading out from Monday through Thursday morning," Fisher continued, adding that the storm systems will be entering the region "every 12 hours, back to back," with little break in between.
"We have a line of low-pressure systems coming off the Central Pacific, one right after another, that are heading this way. While the three systems will be continuous, the intensity level of precipitation will change from moderate to heavy."
He added, "Throughout those four days, we'll see anything ranging from scattered showers to heavier rain. Fortunately, it's not like there's an atmospheric river where we'll just be dumped 8 inches of rainfall in a day with no break in between, so we don't believe the rainfall intensity would cause any kind of large debris flow."
Rain totals, temperatures
While officials are only estimating potential rainfall for the next several days, Fisher said the North County, including Santa Maria, Lompoc and the Santa Ynez Valley, will receive between 2 and 4 inches of rain as a result of the three storm systems.
Regional high temperatures Sunday will be in the low 60s, with winds between 5 and 15 mph and gusts up to 20 mph. Sunday night, when rain is expected to begin, temperatures will be around 50 degrees, with 15 mph winds gusting up to 25 mph.
On Monday, the high will be near 61 degrees, with 15 to 25 mph winds and gusts up to 30 mph. Monday night's low will drop to 49 degrees.
Tuesday's daytime high will reach 62 degrees, with a nighttime low around 53, and breezy conditions.
Wednesday's daytime high will be 63. Wednesday night will be cloudy with a low around 52.
Thursday's daytime high will hit 63, with a low Thursday night of 48.
Friday will be partly sunny, with only a slight chance of rain, and the high will be 63.
According to the weather service, the storm starting Sunday night has the potential of bringing a longer duration of heavy rainfall as a strong southerly flow enhances rainfall on the coastal slopes.
Santa Maria is forecast to get about 3 inches of rain, Lompoc and the Santa Ynez Valley could receive up to 4 inches and the Santa Ynez Mountains up to 5 inches.
"These amounts will change, as rainfall totals depend on the orientation and direction from where the rainfall will be coming from," Fisher said. "This is just what we see for now."
The series of storms "should be taking your area to near normal amounts of precipitation for this time of the year," Fisher said.
"It always seems like it's a really rainy pattern, but this is pretty standard for this time of the year. January's rainfall totals will make up for the lack of rainfall along the Central Coast in November and December, since the rainy season began in October."
The new rainfall "would most likely put the Central Coast above normal by the end of the week," he added.