Summary: The center of circulation of a very active Pacific storm is now moving into northwest California with showers and thunderstorms over the northern portion of the state. Precipitation has been disappointing over the valley floor with no location recording more than .10 as of 1:00pm. Now that the daytime heating process is underway, a few thunderstorms may develop this afternoon and evening over the valley floor.
The coldest and most unstable air aloft will pass overhead tonight and Sunday morning with periods of showers and a slight chance of thunderstorms again Sunday afternoon. The low pressure system will actually become elongated from northeast to southwest, stretching from the northern Rockies to central California by Sunday morning. By Sunday evening, a massive ridge of upper level high pressure will build in from the west with a ridge extending as far north as eastern Alaska. This will force bitterly cold air southeastward into the Rockies and Midwest Monday and Tuesday. The Pacific Northwest and California will remain rather cozy for the time of year.
The main challenge beginning Monday and lasting through the rest of the week will be the coverage of fog and low clouds. The fog could lift into a low overcast with only local areas of afternoon clearing. Or, as in recent years, the fog could be more patchy, allowing for above average daytime temperatures.
Modeling through mid December is indicating the pattern will be dry with considerable fog and low clouds.
Forecast: Periods of showers tonight through Sunday. There is a chance of isolated thunderstorms this afternoon and evening and again Sunday afternoon and evening. Partly to mostly cloudy Sunday night and Monday morning. Becoming partly cloudy Monday through Tuesday with areas of fog and low clouds nights and mornings. Variable cloudiness Tuesday night through Wednesday with patchy night and morning fog. Mostly clear Thursday through Friday with widespread fog and low clouds. Partly cloudy Saturday with areas of morning fog.
Short Term:
| Madera 51/60/41/57 | Reedley 52/61/43/57 | Dinuba 49/60/40/56 | |
| Porterville 50/61/41/58 | Lindsay 49/61/41/57 | Delano 52/61/43/58 | |
| Bakersfield 55/61/47/58 | Taft 54/62/50/58 | Arvin 53/62/43/58 | |
| Lamont 53/61/47/58 | Pixley 52/60/41/57 | Tulare 50/60/40/57 | |
| Woodlake 50/61/41/58 | Hanford 51/61/42/57 | Orosi 50/60/40/57 | |
Winds: Winds tonight will be out of the southeast at 10 to 15 MPH with gusts to 25 MPH possible this evening from Fresno County north. Winds Sunday will be generally out of the west to northwest at 10 to 15 MPH with stronger gusts near showers. Winds will diminish by Sunday evening. Winds late Sunday night through Tuesday will be at or less than 7 MPH.
Rain: The following are the scant storm totals so far. Many locations will not be listed simply because they have not recorded measurable precipitation. Buttonwillow .10, Cal State Bakersfield .01, Porterville .01, Tulare .02, Visalia .01, Exeter .04, Hanford .05, Lemoore .03, Reedley .10, Fresno .06, Madera .02.
As you can see, rainfall amounts so far have been rather unimpressive. Periods of showers will continue through Sunday. A few thunderstorms cannot be ruled out this afternoon and evening and again Sunday afternoon and evening. Dry weather will quickly return Sunday evening as the low scoots off into Idaho and Nevada.
Rainfall amounts from this afternoon through Sunday afternoon will generally range from .10 to .25. considerably more will be recorded in locations hit by a thunderstorm.
A prolonged period of dry weather will begin Sunday evening. One weak system will move into northern California Wednesday with another one about Saturday. for now, it appears these systems will be too weak to bring rain back to central California, so get ready for fog and low clouds next week.
Frost Discussion: Models going out through the 17th of December still indicate very little chance of frost as this mild December continues. One model for the period beginning the 22nd shows a semi-freeze pattern. A ridge of high pressure is shown extending northeastward into central Canada while a big low sets up shop over southern California and Arizona. This could possibly create a strong northeast flow, pumping modified arctic air into central California enhanced by a strong off shore flow. I must emphasize this is a very long range forecast and will no doubt change over time. However, this is the first time I’ve seen a shift in the pattern suggesting colder weather. Through the middle of the month however enjoy the relatively mild conditions.
Next report: Sunday morning/December 8