Showers add to Valley’s rainfall, help clean air
Cloudy skies with a chance of showers are expected to continue Thursday and Friday, keeping Merced chilly and wet.
Tuesday and Wednesday’s rain added about 0.66 inches, driving up Merced’s total rainfall to 2.02 inches of rain as of July. However, that’s still about 0.33 inches below average, explained David Spector, a meteorologist with the National Weather Service in Hanford.
Weather officials have not received any reports of flooding in the Valley areas. According to Spector, as of Wednesday, only a flash flood warning had been issued for some charred higher mountain areas near Yosemite, where fires burned earlier this year.
The Sierra Nevada, below 9,000 feet of elevation, has received about 2 inches of rain so far this week. Meanwhile, 15 to 25 inches of snow were reported in areas above 9,000 feet.
According to the National Park Service, waterfalls at Yosemite National Park – such as Yosemite Falls, Bridalveil Fall and Cascade Fall – are going full force again because of the significant rainfall in the Yosemite area. Snow levels remain high and Highways 140, 120 and 41 leading into Yosemite Valley are open and clear. Tioga and Glacier Point roads remain closed because of snow and icy conditions.
In Merced, wind gusts reached 15 mph Wednesday, but are expected to die down Thursday and Friday. Spector explained that in this situation, winds are being driven off a shore system that’s pushing them in the opposite direction, away from the Valley floor.
But according to San Joaquin Valley Air Pollution Control District officials, this combination of rain and winds is what’s needed to scrub off the air and cleanse fine particulate matter buildup. Wednesday’s ozone levels were recorded at a “good” standing, while fine particulate matter levels were labeled “moderate” by the Air District’s Real-Time Air Advisory Network.
Anthony Presto, an air district spokesman, said it doesn’t take long for air pollution to reach unhealthy levels in the Valley. When the rain and winds stop and temperatures begin to warm up, particulate matter will most likely build up again, Presto explained.
According to a seven-day weather forecast, that might be the case. This weekend is expected to reach above normal temperatures for this time of year, with Saturday at a high of 64 and Sunday at 63. Mostly clear and sunny skies are anticipated for early next week.
Because of the area’s susceptibility to pollution, Presto advises residents to check the air district’s website before burning firewood this season. Residents should look for one of three declarations: “no burning,” “no burning unless registered” and “burning discouraged.”
“It’s important that residents follow these rules and that they burn with a clean unit (certified fireplace insert of stove),” Presto said. “They’ll notice that with EPA-certified units, they will be allowed to burn more frequently.”
This story was originally published December 3, 2014 at 7:03 PM with the headline "Showers add to Valley’s rainfall, help clean air."