November 17, 2019
Summary: Temperatures on the valley floor are running 3 to 4 degrees warmer than 24 hours ago with readings in the comfortable low to mid 70s as of 1:00pm. Temperatures are in the mid 70s as high as the 4,500 foot elevation. Tehachapi at 1:00pm was reporting 73 degrees and Wawona in Yosemite was at 75. The freezing level has jumped up to 14,900 feet, about 3,500 feet higher than yesterday at this time. Monday will be the warmest we’ll see possibly until next spring as strong upper level high pressure just west of the California coast is combining with a closed low off the northern Baja coastline, creating downslope heating off the west facing slopes of the Sierra Nevada and especially off the Tehachapi Mountains. Warmest locations tomorrow will be around 80 which is about as warm as you’ll ever see it this late in the season.
A complex pattern will begin to develop late Monday night as a much cooler trough of low pressure displaces the high off shore and digs rapidly southward from the Pacific Northwest into northern and central California late Tuesday afternoon and Tuesday night. showers will rapidly spread down the Sierra Nevada Tuesday afternoon with a high risk of showers over the valley floor later Tuesday night and well into Thursday. This one will be an interesting one to watch play out as that closed low off the northern Baja coast is drawn northeastward. Add to that tropical moisture from Tropical Storm Raymond being drawn into the system. Locally heavy rain is possible over southeast California and Arizona. The northern system will be diving southward a bit further west, partially off shore, adding to the moisture field. Most of the model information this afternoon is indicating as much as .25 to .33 is possible near the foothills of Madera, Fresno, and Tulare Counties. That much is also possible over the valley portion of Kern County with .10 or so possible elsewhere.
Models are still borderline on whether there will be enough bounce to the atmosphere for isolated thunderstorms Wednesday afternoon and evening. Some of that will depend on whether there are significant breaks in the cloud deck, allowing the sun to warm the ground and destabilizing the atmosphere.
The chance for showers will begin to decrease Thursday afternoon with dry weather returning Thursday night and through next weekend. Another trough will move through about Monday or Tuesday of next week, but it looks like precipitation will remain to our north. Otherwise, models show dry weather through almost the end of the month with a possible change about the first of December which could bring rain back to central California.
As far as frost is concerned, I don’t see any chance for the foreseeable future although readings could drop to just above freezing in the coldest locations next Saturday and Sunday mornings.
Forecast: Other than occasional high clouds, it will be clear through Monday night, continued hazy with patchy night and morning fog. Increasing cloudiness Tuesday. The chance of showers will increase Tuesday night with the likelihood of periods of showers Wednesday and Wednesday night and a slight chance of isolated thunderstorms Wednesday afternoon and early evening. A chance of showers Thursday, ending Thursday afternoon. Mostly to partly cloudy Thursday night and Friday morning. Becoming mostly clear Friday afternoon through Sunday.
Temperatures: Lows tonight will range in the low to mid 40s except mid 40s to near 50 in Kern County. Highs Monday will be in the upper 70s to the low 80s. Lows Monday night will cool into the low to mid 40s north of Kern County and the mid 40s to the lower 50s in Kern County. Highs Tuesday will be in the low to mid 70s.
Next report: Monday morning/November 18