Summary: We are very close to a full fledged fog regime. Kern County and areas along the foothills on both sides of the valley have generally clear skies with readings in the low to mid 50s. However, from roughly just north of Delano northward through Merced County, visibilities in many locations were still down to ¼ of a mile. Madera was reporting a temperature of 47, Visalia 43, Hanford 44, and Fresno 42. These readings are reminiscent of fog regimes from years past. To illustrate the warm air inversion, Bass Lake is reporting 66 degrees at an elevation of roughly 4,000 feet.
The upper level high will be just about right overhead tonight through Monday. It’s entirely possible many locations may not see the sun Monday and Tuesday afternoons. The best chance of clearing will be in Kern County and along the foothills on both sides of the valley. One aspect of the weather that makes the valley such an ideal citrus growing region is the fog and low clouds which act as insulators.
Tuesday is when the pattern becomes more complex. A strong weather system will move through the Pacific Northwest Monday night and into the northern Rockies Tuesday followed by a 1042.0 millibar surface high which will generate a strong off shore flow. Along the back side of that storm of the northern Rockies will be a sharp ridge of upper level high pressure stretching northward into eastern Alaska and northwest Canada. The result will be an arctic air mass plunging into the Rocky Mountain region and eventually into the Midwest Christmas Eve and Christmas Day. I’ve been watching the evolution of this pattern for the past week and fortunately I’m very confident the flow over California will remain northwesterly, keeping any arctic air to our east.
By Wednesday and Christmas Eve, a weak upper low will approach the southern California coast, moving inland to our south Christmas Day. This system will be quite weak and poses little chance of precipitation, although a sprinkle or two in the south valley would not be a total shock.
In the meantime, a strong trough of low pressure will be just off the northern California coast Christmas Day and will sweep inland later Friday night and Saturday. some models are now suggesting a possible atmospheric river of air moving through California Saturday. this means it could turn into a significant rainfall event with heavy snow over the high country. Models also continue to suggest a colder low dropping out of the Gulf of Alaska then moving through central and southern California about Sunday night and Monday, or in other words a week from now.
Forecast: Extensive fog and low clouds through Tuesday with local afternoon clearing, mainly along the foothills and in Kern County. High temperatures will only range in the 40s where the low overcast persists through the day and in the mid 50s to lower 60s where some hazy sunshine pokes through. For now, we’ll go for fog and low overcast with partial afternoon clearing Wednesday through Christmas Eve. Areas of fog and low clouds Christmas morning with increasing higher clouds during the afternoon. Cloudy Friday night with a chance of showers after midnight. Rain likely at times Saturday and Saturday night. a chance of showers for a time Sunday morning, becoming mostly cloudy in the afternoon.
Short Term:
| Madera 38/45/39/45 | Reedley 35/48/38/46 | Dinuba 36/47/38/46 | |
| Porterville 29/53/34/50 | Lindsay 28/52/35/51 | Delano 31/51/36/48 | |
| Bakersfield 36/58/37/53 | Taft 45/64/45/59 | Arvin 32/58/35/55 | |
| Lamont 32/56/35/54 | Pixley 34/50/37/48 | Tulare 39/45/40/45 | |
| Woodlake 29/49/37/48 | Hanford 39/46/40/46 | Orosi 28/51/35/50 | |
Winds: Winds through Wednesday will be generally less than 10 MPH late mornings and afternoons and at or less than 5 MPH during the night and early morning hours with extended periods of near calm conditions.
Rain: In all likelihood, dry weather will continue through Christmas Day. It’s possible during the night and morning hours some light drizzle may occur in some areas. There’s also a slight chance of sprinkles Christmas Eve through Christmas Day from a benign low moving through southern California. I’m beginning to gain more confidence that, late Friday night and Saturday, we may actually have a legitimate precipitation event in central California. A rather mild Pacific storm will move through late Friday night through Saturday night. some models are suggesting an atmospheric river of air will move into central California on Saturday which could potentially be a huge boost for the Sierra Nevada. The rain should end early Sunday morning. however, models are trending towards a second system, a colder storm, moving out of the Gulf of Alaska and into central and southern California Sunday night and Monday of next week.
Frost: We find ourselves in an almost full fledged fog regime this afternoon. North of Kern County and up through Merced County, dense fog persists with temperatures only in the low to mid 40s as of 1:30pm. Outside of the fog shrouded areas, temperatures are approaching the mid 50s. my feeling is the fog game will completely take over tonight and sock in the entire valley with fog and low clouds. I believe it will reach into the lower foothills by early sunrise. Areas under the low cloud deck will remain above freezing, however in the citrus belt in Kern County and right along the Sierra Nevada foothills, it may be fog free long enough for temperatures to drop into the upper 20s to lower 30s. For Tuesday and Wednesday mornings, there’s a better chance that even the foothill regions will remain under a low cloud deck.
A strong off shore flow will begin Tuesday night and Wednesday. We’ll have to watch closely to see if drier air mixes down to the valley floor, ridding us of low level moisture. For now, I believe that chance is low.
Christmas Eve and Christmas Day will, with some luck, see some clouds move in from a system moving in to our south. Hopefully the higher clouds along with the low cloud deck will maintain above freezing conditions. Friday through Sunday, look for above freezing conditions, which is a nice Christmas gift. We’ll have to closely watch the pattern for the last few days of this year and the first few days of January as models show a colder pattern developing over the western states.
Lows Tonight:
| Terra Bella
29 |
Porterville
29 |
Ivanhoe
28 |
Woodlake
30 |
| Strathmore
29 |
McFarland
28 |
Ducor
29 |
Tea Pot Dome
29 |
| Lindsay
28 |
Exeter
29 |
Famoso
29 |
Madera
Af |
| Belridge
28 |
Delano
30 |
North Bakersfield
29 |
Orosi
28 |
| Orange Cove
30 |
Lindcove
29 |
Lindcove Hillside
Af |
Sanger River Bottom
30 |
| Root Creek
28 |
Venice Hill
30 |
Rosedale
30 |
Jasmine
30 |
| Arvin
32 |
Lamont
32 |
Plainview
30 |
Mettler
Af |
| Edison
33 |
Maricopa
29 |
Holland Creek
33 |
Tivy Valley
29 |
| Kite Road South
33 |
Kite Road North
29 |
AF=Above Freezing
Next update: December 21/am