Rainstorms are in the forecast throughout the Inland Empire next week, coinciding with the official start of winter, according to the National Weather Service.
“It’s a closed (trough of) low pressure that dives south … tapping a lot of moisture,” the NWS said in a statement. “It slowly moves through SoCal and northern Baja Mexico Thursday and Friday. It looks like we have an increasing chance of rain Wednesday, and then probable rain Thursday and Friday, possibly significant rain.”
“It should also bring some mountain snow and some winds as it tracks through the region,” the agency said.
No travel advisories have been issued yet. The first day of winter is Thursday.
According to the weather service, a weak trough rolling in from the northwest will swipe Southern California on Monday and Tuesday, producing mostly sprinkles and a few isolated showers. But that deeper trough will arrive from the Gulf of Alaska midweek.
There are no firm predictions on precipitation amounts.
For the upcoming weekend, a ridge of high pressure will hold to the east, generating mild Santa Ana winds and keeping conditions dry throughout the region, meteorologists said.
The changing weather patterns start Monday, resulting in increasing cloudiness.
In the Riverside metropolitan area, daytime temperatures Saturday and Sunday will reach the upper 70s, with lows in the upper 40s. The high will peak in the low 70s Monday and mid-60s Tuesday, with overnight lows around 50. That temperature band will hold for the rest of next week.
In the Coachella Valley, the daytime mercury will hover around 80 and fall to the upper 50s overnight this weekend, with gradual cooling over the next week, during which highs will crest in the low 70s and lows will dip into the low 50s, forecasters said.
In the Temecula Valley, the temperature range will be almost identical to Riverside metro.