Intense Rain Expected Monday through Wednesday

Published : Monday, January 8, 2018 | 6:21 AM

Rain

Pasadena could receive its largest rainfall in almost a year on Monday and Tuesday, according to the National Weather Service, saying rainfall rates in excess of one half to an inch per hour are possible during the peak of the storm.

The latest forecast says rain is possible starting Monday morning, with a 60 percent chance of rain mainly after 10 a.m. The rest of the day should be cloudy with a high near 67 and east southeast winds at five to 10 miles per hour.

Pasadena Fire Department spokesperson Lisa Derderian reminded the public that “we haven’t had significant rain for a while so roads can be slick so allow extra time commuting.”

The storm is forecast to deliver about one to two inches of rain to the valleys in the Southland, and two to four inches or even five inches to south-facing mountain slopes, City News Service quotes NWS meteorologist Joe Sirad.

Thunderstorms are possible after 10 p.m. Monday night. Some of the thunderstorms could produce heavy rainfall. Lows will be around 57.

The chance of rain increases to 100 percent Tuesday, with a thunderstorm possible before 10 a.m., followed by showers. Highs Tuesday should be near 60 as a southeast wind 10 to 15 mph becomes southwest in the morning. Winds could gust as high as 20 mph.

Gusty northerly winds are likely behind the system by Wednesday with a diminishing shower threat, the NWS discussion continued, adding high pressure will bring dry weather and a warming trend to the region late in the week.

After the storm, drier weather could take over in the region later Wednesday, and the only chance of showers would be up against the northern slopes of the mountains. Maximum temperatures could also be about six degrees warmer than Tuesday’s.

By Thursday, upper level ridging and offshore flows could produce mostly sunny skies along with a warming trend, says the NWS forecast.

Afternoon highs could be 10 degrees above normal by Friday and even 15 degrees above normal on Saturday, with some highs in the lower 80s.

For residents who may be thinking the rains could possibly end the 10-month drought in Pasadena, the NWS says it is very unlikely the rainfall will make a significant change. This week’s storm is not expected to be the beginning of wet weather in the region, as high pressure steps in midweek to regain control.

Derderian also said people “may use heaters for the first time so make sure no clothing items cover vents or floor heaters.”

“If it’s a trash day keep cans a few feet from the curb so water doesn’t build up around it causing flooding,” she said, and noted that it you are facing water or mudflows that sand and sandbags are available at Stations 37 (Foothill/Halstead) and 38 (Linda Vista/Salvia Canyon) for Pasadena residents only, and there is a limit of 10 bags.

“They are self-serve but if personnel are at the station they will assist,” Derderian said.

Here is a summary of the forecast:

Monday: Rain likely, mainly after 10 am. Cloudy, with a high near 67. East southeast wind 5 to 10 mph. Chance of precipitation is 60%.

Monday Night: Rain likely, then rain and possibly a thunderstorm after 10 pm. Some of the storms could produce heavy rainfall. Low around 57. Southeast wind around 10 mph, with gusts as high as 15 mph. Chance of precipitation is 100%.

Tuesday: Rain and possibly a thunderstorm before 10 am, then showers and possibly a thunderstorm, mainly after 10 am. Some of the storms could produce heavy rainfall. High near 60. Southeast wind 10 to 15 mph becoming southwest in the morning. Winds could gust as high as 20 mph. Chance of precipitation is 100%.

Tuesday Night: Showers likely and possibly a thunderstorm before 10 pm, then a chance of showers. Mostly cloudy, with a low around 50. Chance of precipitation is 60%.

Wednesday: Partly sunny, with a high near 66.

Wednesday Night: Partly cloudy, with a low around 50.

Thursday: Sunny, with a high near 74.

Thursday Night: Mostly clear, with a low around 54.

Friday: Sunny, with a high near 78.

Friday Night: Mostly clear, with a low around 56.

Saturday: Sunny, with a high near 79.