May 18, 2019
Summary: Last night, skies were generally clear and allowed many ag stations to drop into the low to mid 40s, which is about as cold as you’ll ever see it this time of year. Tonight will be on the cool side, but milder as clouds are thickening and lowering ahead of a cold front which has already spread precipitation over much of northern California. Doppler radar is currently showing virga, which is rain falling but not reaching the ground, over portions of the valley. Showers should reach into Madera and Fresno Counties during the late afternoon with widespread precipitation spreading down the valley overnight as the cold front pushes through.
The center of circulation is currently approaching the northern California coast. It’s projected to be almost right overhead late Sunday afternoon, creating the necessary environment for more showers and a fairly high risk of isolated to scattered thunderstorms. This would be similar to what we observed this past week.
Precipitation amounts both from the showers and thunderstorms and the cold front could potentially top .50 in many areas, especially towards the center and east side of the valley. Even over the valley portion of Kern County, substantial precipitation is likely, possibly adding up to .25 to .50 in some locations. This storm is moving relatively slowly so showers will continue for much of Sunday night, possibly into Monday morning. A brief lull in the action will take place Monday afternoon and night with a chance of scattered showers and thunderstorms again Tuesday and Wednesday.
Looking ahead for later in the workweek and next weekend, models still indicate a trough of low pressure will stretch from the intermountain west to off shore southern California. This will allow daily showers over the Sierra Nevada with even a small risk of showers over the valley floor. As you might expect, temperatures will remain far below the mid 80s which is average for this time of year.
Forecast: Rain spreading southward this evening, lasting into early Sunday morning. Showers Sunday with a chance of isolated to scattered thunderstorms from late Sunday morning through Sunday evening. Showers Sunday night. a chance of showers for a time Monday morning. Partly cloudy Monday afternoon and night. a renewed chance of showers Tuesday through Wednesday with a slight chance of showers Wednesday night through Saturday.
Temperatures: Lows overnight will cool into the low to mid 50s. Highs Sunday will struggle into the mid to upper 60s. Lows Sunday night will chill into the mid 40s to the lower 50s with highs Monday generally in the upper 60s.