September 15, 2019
The precursors of a major weather change are already under way. Mid and high level clouds are being drawn up from the southwest, resulting in what will be a partly cloudy Sunday. A strong low is now centered near Vancouver Island and will drive into the Pacific Northwest later this afternoon and evening. The marine layer along the coast is beginning to respond to falling pressures aloft. The depth has increased from 600 feet yesterday to 1,600 feet today and will rapidly deepen further from this point on.
Satellite imagery indicates the cold front that extends from southern British Columbia to off shore Oregon is not overly impressive at this time. Models indicate this is a tad weaker. As the front moves through Monday night and early Tuesday, there may be enough dynamics for showers from Fresno County northward and a sprinkle or two further south. Rainfall amounts, if any, will be mainly just trace amounts to possibly isolated locations recording a few hundredths, generally north of Fresno. This will be a quick mover as models show it moving into the Rocky Mountains by Tuesday.
We will then turn our attention to low pressure system two. It also has its makings in the Gulf of Alaska. It will follow a similar path. This will result in a continuation of well below average temperatures with readings possibly not reaching 80 degrees Thursday. One model portrays a 25% chance of rain from Fresno County north Thursday with lesser chances further south. Other models, however, show all shower activity in northern California. With this in mind, we’ll go with a dry forecast for that time frame, but will monitor it closely.
This system will also be a quick mover, moving into the Great Basin Friday. A large high over the eastern Pacific will take over next this coming weekend for dry conditions and a warming trend. Interestingly enough, the two week model this morning shows possible moisture moving into the southwest and maybe California from the subtropics. The two week model is always shaky, at best, but it does show we are definitely moving out of the summer months and into a time of year that can be changeable.
Forecast:
Partly cloudy today. Mostly cloudy, breezy, and much cooler later tonight through Tuesday morning. There will be a slight chance of sprinkles or isolated light showers from mainly Fresno County north late Monday afternoon into early Tuesday morning. Partly cloudy Tuesday afternoon and evening. Mostly clear Tuesday night and Wednesday. increasing cloudiness late Wednesday night. variable clouds Thursday through Friday. Mostly clear Friday night through Sunday.
Temperatures:
Highs today will range in the upper 90s. lows tonight will range from the upper 50s north of Kern County to the low to mid 60s in Kern County. Highs Monday will warm into the low to mid 80s. lows Monday night will cool into the low to mid 50s north of Kern County, ranging in the upper 50s to the lower 60s in Kern County. Highs Tuesday will warm into the low 80s. readings Wednesday through Friday will range in the low to mid 80s, climbing into the upper 80s to the mid 90s over the weekend.