T
he fog and low clouds are finally mixing out as a weak southerly flow moves up the valley. It’s still a cold afternoon, however. Temperatures range from 41 at Porterville to 48 at Bakersfield. Doppler radar is showing a good size batch of energy moving from the subtropics into northern California. Showers have spread as far south as Monterey and will very slowly inch inward, reaching the northern half of the valley about sunrise. A very strong 130 knot jet stream is now over northern and central California. With this much energy in the upper atmosphere, a rain shadow will develop along the west side and in Kern County. Blended model information this afternoon shows that, from Wednesday through Christmas Day, 1.39 inches of rain should fall at Porterville. Lift over the Sierra Nevada should translate into 2 to 5 feet of new snow above 8,000 feet.
In the big picture, a large low is located off the Oregon/northern California coast with a cold front extending almost into the subtropics and with a feed of subtropical moisture moving in from the southwest. Forecast models show several waves of low pressure moving inland through northern and central California from Wednesday through Monday. Some models are showing some possible dry weather from the 28th through New Year’s Day. Once again, though, the storm machine is expected to crank up later in the first week of the new year. The two week model out this afternoon is indicating well below average temperatures from late this month through the end of next month. We’ll discuss this in the frost section below.
Forecast: Becoming cloudy overnight. Periods of rain Wednesday through Christmas day. Periods of rain will continue at times Sunday through Tuesday.
Short Term:
| Madera 40/57/48/58 | Reedley 39/56/48/58 | Dinuba 37/56/49/57 |
| Porterville 37/59/48/59 | Lindsay 36/57/47/57 | Delano 39/60/49/59 |
| Bakersfield 42/62/51/60 | Taft 45/58/53/59 | Arvin 38/62/50/60 |
| Lamont 38/61/48/59 | Pixley 39/61/49/58 | Tulare 37/57/47/58 |
| Woodlake 36/56/47/57 | Hanford 38/57/49/59 | Orosi 36/55/46/57 |
Wind Discussion: Winds will be generally out of the southeast tonight at 5 to 12 MPH. Winds Wednesday through Friday will continue out of the southeast at 8 to 15 MPH with gusts to 25 MPH.
Rain: Showers have reached as far south as Monterey along the coast. It will be a slow process, but rain should reach Fresno County by sunrise Wednesday. A rich feed of moisture is wrapped around a low located well off shore. It will move inland, giving periods of rain through the Christmas holiday weekend. There will be breaks, of course.
Medium range models are still indicating on and off precipitation. Snow levels will lower quickly Thursday as the cold front passes. Blended model projections for rain amounts in the valley indicate 1.39 inches at Porterville from Wednesday through Christmas day. This seems plausible for most of the east side of the valley north of Kern County. Typically, strong winter storms form strong rain shadows along the west side and that will be the case with this system. Even so, .75 seems likely. Kern County should pick up between .25 and .33. there are some models indicating we’ll have some dry weather between the 28th and the first day or two of January. A new round of storminess is anticipated after that.
Frost: All locations will be above freezing tonight and each night through the Christmas holiday weekend. Some models this afternoon show well below average temperatures from the 28th through January 2. The configuration is dangerously close to being a freeze pattern. What I generally look for is a big high building northward into Alaska with a low over the southwestern US. At this point, the low is projected to be off the central coast, keeping the pattern active with cold weather but not dangerously so. We’ll keep an eye on it.
Next report: December 22