May 14, 2019
Summary: Already this afternoon, mid and high level clouds are increasing ahead of a rapidly intensifying eastern Pacific trough of low pressure. Doppler radar is showing a considerable amount of virga, (which is rain falling but not reaching the ground), over northern California. Roughly 400 miles west of the northern California coast, a secondary low is developing. That is the feature which will result in very active weather beginning Wednesday afternoon and lasting through Thursday and much of Thursday night. a strong cold front will move down the valley Wednesday night and early Thursday with widespread precipitation. The post-frontal environment behind the front appears very conducive to the formation of scattered thunderstorms from late Thursday morning through Thursday evening. These storms will be significant precipitation producers and some may be accompanied by small hail. An isolated funnel cloud or two would not be a total shock.
Snow will fall over the Sierra Nevada by the bucket load with possibly more than two feet over the higher elevations from Tulare County north with one to two inches of rain possible in the foothills areas. Rainfall amounts from Wednesday afternoon through Thursday night could exceed one-half inch north of Kern County with a quarter to a third of an inch possible over the valley portion of Kern County.
Where thunderstorms develop, very significant precipitation will occur, which will really increase totals in scattered locations.
Showers will begin to wind down by late Thursday night with possibly a few lingering showers, mainly near the foothills, early Friday morning. Most of Friday will be dry, though, with the chance of showers again increasing Saturday night through Sunday. Models are not quite as bullish on precip totals as they were earlier. Actually, model information shows a greater risk of precipitation Tuesday through Wednesday of next week rather than the earlier mentioned Sunday system. One model shows a very intense winter type storm just west of San Francisco Wednesday morning, which would in theory, result in heavy precipitation, and possibly even a winter type strong wind event in the south valley. Much will change over the next week, but it sure looks peculiar at this point when you consider the time of year.
Forecast: Increasing cloudiness tonight. An increasing chance of rain Wednesday afternoon north of Kern County. Periods of rain Wednesday night and Thursday morning. Showers and scattered thunderstorms late Thursday morning through Thursday evening. Showers Thursday night, tapering off during the early morning hours. Mostly to partly cloudy Friday. Partly cloudy Friday night and Saturday morning. Increasing cloudiness Saturday afternoon. A chance of showers and a slight chance of thunderstorms Saturday night and Sunday. Mostly to partly cloudy Sunday night and Monday. Increasing cloudiness Monday night. showers likely Tuesday with a chance of thunderstorms.
Temperatures: Lows tonight will range in the upper 50s to the lower 60s. Highs Wednesday will warm into the upper 70s to the lower 80s. Lows Wednesday night will cool into the mid 50s to the lower 60s with highs Thursday ranging only in the mid to upper 60s.
Next report: May 15/AM