Summary: A weak upper low is now moving into southern California. Light showers are showing up on Doppler radar from the Kern County mountains south. As the low moves inland, surface pressure differences will relax this evening, ending the strong Santa Ana wind event over the Kern County mountains and locally onto the valley floor in the extreme south. Winds at the CHP office at the bottom of the Grapevine are currently sustained at 26 MPH. Earlier today, they registered a peak gust of 66 MPH. A few miles from Lamont, a peak gust of 52 MPH was registered.
The valley is in two different worlds from one place to another. From roughly a Hanford/Visalia line northward, a low gray overcast remains locked in. Hanford, Visalia, Fresno, and Madera were only in the mid 40s as of 1:30pm while Bakersfield was 58 and Porterville 59. Variable amounts of cloud cover will continue to stream overhead through the late evening hours. As the low tracks out of the area later tonight, periods of partly cloudy skies will open up in areas which aren’t currently under the low cloud deck, widespread dense fog is likely. However, in Kern County, the downslope Santa Anas have lowered dew points into the 20s. it’s possible that, once these winds subside, the moist layer of air will move into the south valley, as well.
Clouds will begin to increase again later Friday as a weakening trough of low pressure will move from west to east through northern and central California. Measurable rain is unlikely south of Fresno County and even from Fresno County north, I’ll put the chance of rain in the low category.
On Saturday night and Sunday, a progressive ridge of weak high pressure will move through for a temporary dry slot. Models have been amazingly consistent in projecting a colder, more potent weather system just west of the Bay Area Sunday night. even though this storm will be weakening as it moves through central and southern California, I’m reasonably confident central California will do fairly well. As the storm moves into the interior west Monday night, a north/northwest flow will be sandwiched between the exiting low and an incoming zone of upper level high pressure off shore. This will cause upslope clouds against the valley facing slopes of the Tehachapi and the west facing slopes of the Sierra Nevada, especially in Tulare County.
From Tuesday afternoon through New Year’s Day, a zonal flow will prevail with Pacific storms generally running from west to east into the Pacific Northwest. It’s possible that, as these systems move inland, light rain could fall as far south as a Bay Area/Stockton line. However, there’s an excellent chance the southern 2/3 of the state will remain dry through the first week of January.
The main challenge from Tuesday night on will be increasing amounts of night and morning fog and low clouds, possibly leading us into the second fog regime of the season.
Forecast: Areas of low clouds and fog tonight north of Kern County with variable cloudiness above the fog through the late evening hours. Mostly clear to partly cloudy after midnight with widespread fog and low clouds north of Kern County, possibly spreading into Kern County towards sunrise. Areas of fog and low clouds Christmas morning, becoming partly cloudy in the afternoon. Mostly cloudy Friday night through Saturday evening with a chance of light showers from Fresno County north. Partly to mostly cloudy Saturday night through Sunday morning. increasing clouds Sunday afternoon with a chance of showers from Fresno County north by evening. Periods of rain at times later Sunday night into Monday evening. Mostly cloudy Monday night into Tuesday morning. mostly clear to occasionally partly cloudy Tuesday afternoon through Thursday with increasing amounts of fog and low clouds.
Short Term:
| Madera 30/60/41/59 | Reedley 30/61/42/60 | Dinuba 31/61/41/60 | |
| Porterville 29/63/42/59 | Lindsay 29/61/40/60 | Delano 30/63/42/60 | |
| Bakersfield 36/67/44/59 | Taft 46/65/48/59 | Arvin 32/64/43/58 | |
| Lamont 31/64/42/59 | Pixley 29/62/41/61 | Tulare 30/60/41/59 | |
| Woodlake 29/61/41/59 | Hanford 31/62/42/61 | Orosi 29/61/40/60 | |
Winds: The winds in the extreme south valley will end by this evening. Winds tonight through Christmas Day will be generally at or less than 7 MPH with periods of near calm conditions. Winds Friday night and Saturday will be mainly out of the southeast at 5 to 12 MPH, becoming light and variable Saturday night and Sunday morning. Winds will be mostly out of the east to southeast at 8 to 15 MPH Sunday afternoon and evening with local gusts to 25 MPH along the west side. There is a minimal chance of localized strong, gusty, southeast winds in the extreme south valley again from late Sunday afternoon through early Monday.
Rain: That weak upper low is finally moving through southern California this evening. Doppler radar shows scattered light showers from Kern County south, but they should not affect the central valley. There is only a minimal chance of light showers from Fresno County north late Friday night and Saturday. if precipitation does occur, less than .10 is anticipated with generally dry conditions south of Fresno County. That will change Sunday night through Monday evening. A colder low will drop southeastward out of the Gulf of Alaska. Most models place the center of circulation just west of the Bay Area Sunday night. the low will then weaken and track right through central California so the chance of some decent precipitation amounts is certainly there with snow possibly down to 3,500 to 4,000 feet. This far out, it appears likely many locations north of Kern County could pick up .25 to .33 with locally more and even a tenth or two is possible over the valley portion of Kern County. After Monday evening, the storm track will get nudged back into the Pacific Northwest for what appears to be the first week in January. Some models move the rain line as far south as roughly a Bay Area/Stockton line on occasion with the southern 2/3 of California remaining dry.
Frost: This Christmas Eve, as opposed to many I’ve worked, will be a piece of cake, though it will be a complex forecast. As of the time of this writing, low clouds were locked in from roughly a Visalia/Hanford line north with temperatures there only in the mid 40s. temperatures were near 60 in the south valley which cleared out due to the strong winds in the valley portion of Kern County. Dew points in Kern County are only in the low to mid 20s at this hour, however as these winds end by this evening, the moisture layer of air near the surface may very well begin to move back into Kern County. It’s possible widespread fog will form in many areas that are currently not under a low cloud deck.
With so many variables, like last night, I’m going to go with upper 20s in the coldest locations with generally low to mid 30s elsewhere. Some locations under the low cloud deck may not even drop down into the upper 30s and lower 40s. My Christmas present to you is above freezing temperatures Saturday through Tuesday mornings. After Tuesday, a relatively cold air mass will settle in behind the Monday storm system. Any night with mostly clear skies will see temperatures drop into the upper 20s and lower 30s. what I’m banking on is the soil becoming soaked by the upcoming storm which will aid in the formation of fog and low clouds, hopefully settling into another fog regime with temperatures holding in the mid 30s.
Meanwhile, a heartfelt Merry Christmas from the Hibler household!
Lows Tonight:
| Terra Bella
29 |
Porterville
29 |
Ivanhoe
28 |
Woodlake
30 |
| Strathmore
29 |
Mcfarland
29 |
Ducor
30 |
Tea Pot Dome
29 |
| Lindsay
28 |
Exeter
29 |
Famoso
31 |
Madera
30 |
| Belridge
28 |
Delano
29 |
North Bakersfield
29 |
Orosi
29 |
| Orange Cove
30 |
Lindcove
30 |
Lindcove Hillside
Af |
Sanger River Bottom
28 |
| Root Creek
28 |
Venice Hill
30 |
Rosedale
30 |
Jasmine
31 |
| Arvin
31 |
Lamont
32 |
Plainview
29 |
Mettler
Af |
| Edison
31 |
Maricopa
30 |
Holland Creek
32 |
Tivy Valley
29 |
| Kite Road South
32 |
Kite Road North
29 |
AF=Above Freezing
Next update: Christmas morning