March 14, 2021
Clouds are increasing ahead of a very cold low pressure system which extends from its center over the Yukon Territory of Canada southward to off the northern California coast. Showers are already spreading over northern California and will advance quickly into central California tonight and Monday morning. There are models that place the center of this cold core low near Sacramento Monday morning and over the high deserts of Kern County Monday evening. With the center of circulation advancing right over us, the coldest air will be moving through central California with the freezing level anticipated to drop to 3,000 feet. This will knock the snow level down to 2,000 feet in heavier showers.
The main concern is the potential for subfreezing temperatures Tuesday and Wednesday mornings. A strong north/northwest jet stream will be overhead Monday night, which is favorable for generating upslope cloud cover against the north facing slopes of the Kern County mountains and the southern Sierra Nevada, mainly in Tulare County. The potential for lows dropping to 27 to 29 degrees in the coldest low lying frog pond is there for Tuesday and Wednesday mornings. Where cloud cover prevails, and winds stay up, readings will generally run in the low to mid 30s.
How Tuesday morning goes is anybody’s guess due to the various parameters. My feeling is most locations will range between 30 and 35 with readings in the mid to upper 30s where cloud cover is dominant. Even though the atmosphere will begin moderating as early as Tuesday afternoon, expect low to mid 30s again Wednesday morning with the chance of coldest locations dropping into the upper 20s.
Cloud cover will increase Thursday ahead of the next weather system. That system isn’t as cold, either. The chance of showers will again increase Thursday night and Friday. In fact, some models are now hinting at a broad trough of low pressure over the eastern Pacific and California with periods of unsettled weather from time to time from Thursday through the early part of next week.
Next report: March 15/am