Dense fog ranging from 0 visibility to ¼ mile extends from just west of Bakersfield northward into the lower Sacramento Valley. Right along the edge of the fog bank in the citrus belt near the Sierra Nevada foothills, temperatures rocketed down into the mid to upper 20s with mid 30s towards the center of the valley. The warm air inversion is well illustrated this morning. As of 6:00am, the temperature at Sandburg at 4,100 feet was 55 degrees. The freezing level taken over Vandenburg AFB a few hours ago was at 11,700 feet. The dense fog will slowly lift into a low overcast during the late morning through afternoon hours. The best chance of seeing hazy sunshine this afternoon will be along the foothills on each side of the valley and over Kern County. Where it does not clear, highs will struggle into the mid to upper 40s. where it does clear, generally mid 50s can be expected. These types of conditions will probably last into Christmas Eve.
Upper level high pressure is overhead this morning. A trough of low pressure will race through the Pacific Northwest tonight then will turn into a major winter storm over the Rockies on Tuesday. Behind this system will be a sharp ridge of upper level high pressure which will extend all the way into Alaska. Fortunately, the flow over California will remain out of the northwest so arctic air moving southeastward will not impact our region. A 1040.0 millibar surface high will center over Idaho on Wednesday and Thursday, resulting in a sharp off shore surface flow.
The high will break down Christmas Day, allowing a trough of low pressure to move through central and southern California. Some models this morning are showing the rain line remaining further north, generally north of Kern County. The best chance of precipitation will be late Friday night and Saturday. about 36 hours later, a cold low will drop out of the Gulfof Alaska, moving th rough all of California Sunday night and Monday for the next chance of precipitation.
A relatively active pattern will continue through New Year’s Day.
Forecast: Widespread dense fog this morning, slowly lifting into a low overcast this afternoon with local afternoon clearing, mainly in Kern County and along the foothills. Fog and low overcast will continue through Christmas Eve with partial afternoon clearing. Areas of morning low clouds Christmas Day with increasing higher clouds above. A chance of showers Friday night, mainly after midnight. Rain likely Saturday, mainly north of Kern County. A chance of showers Saturday night. mostly to partly cloudy Sunday. A chance of rain Sunday night and Monday.
Short Term:
| Madera 49/31/48/34/50 | Reedley 48/33/48/35/49 | Dinuba 48/32/48/35/49 |
| Porterville 53/28/52/30/51 | Lindsay 53/27/52/29/50 | Delano 52/29/50/34/50 |
| Bakersfield 57/36/54/37/58 | Taft 57/46/58/46/59 | Arvin 57/33/57/33/58 |
| Lamont 57/33/58/34/59 | Pixley 50/30/49/35/49 | Tulare 47/35/47/36/48 |
| Woodlake 50/29/49/32/49 | Hanford 48/35/48/36/48 | Orosi 51/28/50/30/52 |
Seven Day Forecast:
| Christmas Eve
AM fog/partial clearing 37/51 |
Christmas Day
Increasing clouds 37/59 |
Saturday
Showers likely 42/57 |
Sunday
Mostly cloudy 38/56 |
Monday
Chance of showers 39/53 |
Two Week Outlook: December 28 through January 3: This model is showing a pattern resulting in below average temperatures throughout much of the western U.S., including California. It also indicates below average precipitation, though some models do show a chance of precip during the period.
January: This model doesn’t really show a trend for temperatures at all. We’ll call it near average this time around. Not surprisingly, it does indicate January will have below average precipitation, as has been the case this La Nina year.
January, February, March: This model does not really offer much hope for a decent rainy season as below average precipitation is indicated over the Golden State. Temperatures over this 90 day period will be generally above seasonal average.
Winds Discussion: Winds through Thursday 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 Discussion: Expect dry conditions through Christmas Day. There will be a chance of showers Friday night, mainly after midnight, becoming likely Saturday. Some of this morning’s models paint the wet/dry line a bit further north, mainly just north of Kern County. For now, though, that remains to be seen. A possible atmospheric river of air continues to show up, but mainly into northern California. We will have another shot at precipitation around Sunday night or Monday as a cold low drops southward out of the Gulf of Alaska and into California. There may be yet another shot around New Year’s Eve.
The timing this far out is quite tentative, but at least the northern half of the state should do pretty well from Friday night on.
Frost Discussion: A local phenomenon was evident during the early morning hours. Right along the edge of the fog bank, especially in Tulare County, temperatures rocketed down. As of 6:30, Porterville’s temp had dropped to 26 with Lindcove and Lindsay coming in at 27. Most other locations ranged between 28 and 32. Towards the center of the valley, readings were mostly in the mid 30s.
The widespread dense fog this morning will slowly lift into a low overcast this afternoon. Areas right along the foothills have a greater possibility of hazy sunshine this afternoon as does Kern County. This is the shortest day of the year and with the low sun angle, it’s difficult for the low clouds to burn off, especially towards the center of the valley. If the low overcast lifts high enough, it will move into the lower foothills regions and even Kern County, putting the citrus belt under a protective layer of low clouds. However, like last night, my numbers will reflect generally clear skies long enough for temperatures to drop into the upper 20s and lower 30s.
Coldest frost pockets tonight could drop down to 26 to 27 with most flatland locations between 28 and 33. Temperatures at 34 feet will be generally 4 to 7 degrees warmer.
Hopefully the fog will lift into a low overcast for a protective blanket Wednesday and Thursday, but that remains to be seen.
On Christmas day, we may see some moderation due to increasing higher clouds ahead of a system that will bring some showers later Friday night and Saturday. Generally, above freezing conditions can be expected over the weekend through Monday.
The air mass moving in behind Monday’s system looks to be fairly cold, but not critical.
Lows Tonight:
| Terra Bella
28 |
Porterville
28 |
Ivanhoe
27 |
Woodlake
29 |
| Strathmore
28 |
Mcfarland
28 |
Ducor
29 |
Tea Pot Dome
28 |
| Lindsay
27 |
Exeter
28 |
Famoso
29 |
Madera
31 |
| Belridge
37 |
Delano
30 |
North Bakersfield
29 |
Orosi
28 |
| Orange Cove
29 |
Lindcove
28 |
Lindcove Hillside
Af |
Sanger River Bottom
29 |
| Root Creek
28 |
Venice Hill
29 |
Rosedale
29 |
Jasmine
30 |
| Arvin
33 |
Lamont
32 |
Plainview
29 |
Mettler
Af |
| Edison
33 |
Maricopa
29 |
Holland Creek
31 |
Tivy Valley
29 |
| Kite Road South
31 |
Kite Road North
29 |
AF=Above Freezing
Air Quality Expectations: The San Joaquin Valley Air Pollution Control District has issued the following warning(s) for December 20, 2020:
The air quality for Kings and Merced Counties. The air quality for the remainder of the growing area is unsafe for sensitive groups.
The District’s Real-time Air Advisory Network (RAAN) can be used to track air quality at any Valley location by visiting myRAAN.com. The option to use a specific address is available.
In addition, anyone can follow air quality conditions by downloading the free “Valley Air” app on their mobile device
Afternoon Dew Points Today: Low to mid 40s. Kern, upper 30s to the lower 40s.
Actual Humidity Range Yesterday: Delano, 99%/71% Porterville, NA
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 0%, tomorrow 0%. Bakersfield: Today: 50% Tomorrow: 30%
ET Rates Over the Past Seven Days: Stratford .40, Parlier .30, Blackwell Corners .NA, Arvin .36, Orange Cove .29, Porterville .NA, Delano .31. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 54, Parlier 50, Blackwell 55, Arvin, 52, Orange Cove 53, Porterville 51, Delano 45
Record Temperatures: 71/23. Average Temperatures: 54/35
Heating Degree Days This Season: 732 -166 courtesy of the NWS
Average Temperature for this month So Far: 47.3 +2.4 courtesy of the NWS
Precipitation: Seasonal total for Fresno, 1.08, or -1.63, Month to Date: .80, or -.21
Precipitation for Bakersfield, Season, .40, +or- -1.14 Month to date .01, or -.59
Water year season is from October 1st through September 30.
Chilling Hours November 1st through February 28: Orange Cove, 401, Parlier, 484, Arvin, 398, Belridge, 463, Shafter, 449, Stratford, 460, Delano, 500, Porterville, 538
Hours at 45 or below 45. Courtesy UC Davis
Sunrise: 7:08 am Sunset: 4:47 pm Hours of Daylight: 9:39
Yesterday’s Weather
MCE : Merced 153 : DH1600 / 48 / 37 / 0.00 /
MAE : Madera 253 : DH1600 / 50 / 35 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 46 / 37 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 50 / 33 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 54 / M / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 57 / 34 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 49 / 30 / 0.00 /
ATEC1 : Avenal 787 : DH1600 / 59 / 35 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 56 / 29 / 0.00 /
Rainfall: 24hr W.Y. % Last Y. % Ave. Year ave.
STOCKTON 0.00 1.70 44 4.11 107 3.85 14.06
MODESTO 0.00 1.45 45 2.80 86 3.25 13.11
MERCED 0.00 2.10 75 0.00 0 2.80 12.50
MADERA 0.00 0.69 23 0.00 0 2.98 12.02
FRESNO 0.00 1.08 40 0.00 0 2.71 11.50
HANFORD 0.00 0.49 22 0.00 0 2.25 10.10
BAKERSFIELD 0.00 0.40 26 0.00 0 1.54 6.47
BISHOP 0.00 0.01 1 1.06 85 1.24 5.18
SALINAS 0.00 0.83 26 4.22 134 3.14 12.83
PASO ROBLES 0.00 0.30 11 4.73 169 2.80 12.78
SANTA MARIA 0.00 0.31 10 2.72 86 3.16 13.95
Next report: December 21/pm