UPDATE, Thursday, Jan. 19, 6:30 a.m.
RIVERSIDE – Rain, wind, snow and a slight chance of thunderstorms are expected in Riverside County today as the first in a series of Pacific storms with the potential to deliver the heaviest precipitation since 2010 moves through the region.
A National Weather Service winter storm warning for the mountains will remain in effect until 6 a.m. Saturday. A wind advisory for the San Gorgonio Pass zone, which includes the cities of Banning and Desert Hot Springs, will
expire at 4 a.m. Friday and a more severe high wind watch for the same area will extend from late Thursday night though Saturday morning.
The heaviest precipitation with the first storm will likely be during the morning hours and commuters may be affected. Forecasters said the downpours would ease up some and become scattered showers during the afternoon and evening.
Isolated thunderstorms will also be possible throughout Riverside County, including in the Coachella Valley.
The next storm system, set to hit Friday, will have the potential for thunderstorms and flash flooding, forecasters said.
“On Friday, the next wave will arrive. This one is wetter and windier and lasts pretty much all day Friday into early Saturday,” according to the weather service.
Strong wind gusts capable of downing trees may also be possible Friday, as will heavy snowfall down to as low as 5,000 feet. Forecasters said more than a foot of snow could accumulate in some areas.
The snow level is expected to drop from 5,500 feet to 4,500 feet Friday night, and wind gusts in the mountains may top 65 miles per hour.
The break between storms is expected Saturday, but the next and possibly strongest in the series of storms will arrive Sunday morning. The snow level is expected to drop to around 4,000 feet Monday, forecasters said.
“A third storm will bring rain Sunday, then turn to snow Sunday night through Monday,” according to the weather service. “Strong gusty winds will occur at times as well, along with dense fog.”
Through Monday, the storms will drop heavy snowfall in the mountains, expected to range from 6 inches to a foot between 4,000 feet and 5,500 feet, 1 to 3 feet between 5,500 and 7,000 feet and 3 feet or more on higher peaks.
“Significant impacts are expected, including very hazardous travel conditions along mountain roadways,” forecasters said.
Over the same five-day period, forecasters also indicated the storms would deliver 1 to 2 of rain to the Coachella Valley, 3 to 6 inches to Riverside and the surrounding valleys and 6 inches to a foot of rain in the mountains. Flooding may be possible and residents living in flood-prone areas should take precautions.
Along the San Gorgonio Pass, southwest to west winds of 20 to 35 miles per hour with gusts of 50 mph or higher will ramp up to 25 to 45 mph with gusts topping 65 mph Friday afternoon into Saturday morning, according to the NWS.
RIVERSIDE – The first in a series of Pacific storms poised to deliver torrential rain, heavy mountain snow and gusty wind to Riverside County through early next week is expected to move into the region late tonight.
A National Weather Service winter weather advisory for the mountains will be in effect from 10 p.m. today until 4 a.m. Friday, as will a wind advisory for the San Gorgonio Pass zone, which includes the cities of Banning and Desert Hot Springs.
A winter storm watch for the mountains will extend from late Thursday night through late Friday night, and a high wind watch for the San Gorgonio Pass area will run from late Thursday night though Saturday morning.
“After a dry day today, a series of storm systems will move through the region tonight through early Tuesday,” according to the weather service. “Rain and mountain snow will be heaviest and westerly winds will be strongest
Thursday morning, Friday afternoon and Sunday night, along with a slight chance of thunderstorms Thursday and Friday.”
Mostly moderate rain, a slight chance of thunderstorms and an accumulation of up to 10 inches of mountain snow is expected with the first storm. A stronger storm on Friday will bring heavier rain, more snow, strong winds and further the possibility of thunderstorms.
Showers will taper off some before a third and warmer storm moves through the region Sunday night through Monday. The snow level with the third storm could fall to as low as 3,500 feet, according to the weather service.
From Thursday through Monday, the storms will drop heavy snowfall in the mountains, expected to range from 6 inches to a foot between 5,000 feet and 6,000 feet, 1 to 2 feet between 6,000 and 7,000 feet and 2 to 3 feet on higher peaks.
Preliminary data for the five-day period also indicated the storms would deliver three-quarters of an inch to 1.5 inches of rain to the Coachella Valley, 3 to 6 inches to Riverside and the surrounding valleys and 6 inches to a foot of rain in the mountains.
Along the San Gorgonio Pass, southwest to west winds of 20 to 35 miles per hour with gusts of 50 mph or higher overnight through Thursday will ramp up to 25 to 45 mph with gusts topping 65 mph Friday into Saturday morning, according to the NWS.
Forecasters warned that the heavy rain may cause flooding in rivers and along burn areas. Residents living in flood prone areas were urged to “take appropriate precautions.”
“Soils will very likely be saturated by this time, so the flood threat will be greatest with this third storm,” according to the weather service. “Rivers and burn areas will have to be watched closely for flooding and debris.”
The inclement weather may also lead to hazardous travel conditions such as slick roads. Fog and blowing snow in the mountains may skew visibility along mountain roadways, according to the NWS.
Forecasters said it was unlikely that fair weather would return before Tuesday.