December 5, 2020
Weak upper level high pressure covers California and extends inland through the northern Rockies. A weak trough of low pressure will move into the Pacific Northwest later today. This trough will morph into a closed low circulation then will drop southward through Utah and Nevada and through southern California Monday. It will be positioned just west of the northern Baja coastline Tuesday. Behind this system, strong surface high pressure will develop over the Great Basin Monday and Tuesday. The counterclockwise circulation around the low off the northern Baja coast will turn the winds aloft over southern nand central California out of the east by Monday afternoon.
This will generate some strong easterly winds over the Kern County mountains and will crank up the Santa Anas in southern California. It will be yet another tricky call to try to discern whether these winds will slide downslope off the extreme southern Sierra Nevada and the Tehachapi Mountains, creating strong gusty winds in the extreme south valley. The best chance of this occurring appears to be Monday afternoon and night. pressure differences will begin to relax by late Tuesday. By Thursday, a trough of low pressure will move into the Pacific Northwest and northern California, generating an on shore flow for a change.
The air mass trapped on the valley floor continues to be extremely dry, considering the time of year, so there will be wide swings in temperatures between daytime highs and overnight lows.
Forecast: Other than occasional periods of high clouds, it will be mostly clear through Sunday. Mostly clear to occasionally partly cloudy Sunday night through Monday night. mostly clear Tuesday through Wednesday. Mostly clear to occasionally partly cloudy Wednesday night through Saturday.
Short Term:
| Madera 66/29/63/30/61 | Reedley 67/28/63/29/62 | Dinuba 66/28/62/29/61 |
| Porterville 67/29/62/30/62 | Lindsay 67/28/62/29/61 | Delano 68/30/62/31/62 |
| Bakersfield 69/38/62/39/61 | Taft 67/45/62/47/60 | Arvin 68/34/62/35/61 |
| Lamont 67/33/63/34/62 | Pixley 67/29/62/30/62 | Tulare 65/28/62/29/61 |
| Woodlake 66/29/62/30/62 | Hanford 66/30/62/31/62 | Orosi 65/28/62/29/61 |
Seven Day Forecast:
| Tuesday
Partly cloudy 30/60 |
Wednesday
Mostly clear 30/62 |
Thursday
Partly cloudy 33/61 |
Friday
Partly cloudy 33/58 |
Saturday
Partly cloudy 30/56 |
Two Week Outlook: December 11 through December 17: I was almost shocked by the looks of this model this morning. it actually shows temperatures near to below average. Unfortunately, it does not indicate a pattern that would bring rain back to the valley.
December: This model shows above average temperatures during the month of December. Southern California should experience below average precipitation. There is some hope for northern and central California, however, as this model spits out equal chances of above or below average rainfall. We’re hoping for the above average side of things.
December, January, February: This model definitely reflects a La Nina pattern, which is when ocean temperatures are below average through the equatorial waters off of Peru, extending into the mid Pacific. Typically, this results in above average temperatures for much of the southern half of the U.S., including California, with unfortunately below average precipitation for California including the valley.
Winds Discussion: Winds during the late morning and afternoon hours will be variable to no more than 10 MPH through Sunday. During the night and early morning hours will be no m ore than 5 MPH with periods of near calm conditions through Sunday night. very light winds will continue Monday through Tuesday north of Kern County, however in Kern County we are going to roll the dice again as there will be a chance of Santa Ana winds moving downslope off the Tehachapi Mountains and into the extreme south valley. The best chance of this occurring will be Monday afternoon and night. if it does occur, velocities will be similar to the wind event earlier this week.
Rain Discussion: Expect dry conditions for the next 7 to possibly 10 days.
Frost Discussion: Temperatures were a tad milder than expected last night due to some high clouds that developed off shore and moved over the valley during the early morning hours. As of 6:30am, Famoso was the coldest location I could find at 27 degrees while Orange Cove and Rio Bravo came in at 28.
There are more high clouds off shore at this hour from a weak system that will move through the Pacific Northwest later this afternoon. We may see enough high clouds to keep temperatures mainly in the 28-33 degree range. If these clouds are a bit more dense than anticipated, temperatures would be generally in the low to mid 30s.
For now, it appears coldest frost pockets will drop to 26-27 with most other locations between 29 and 32 with some Kern County stations being above freezing.
The forecast is also a bit muddy for Monday morning as a low will drop southward through Nevada then through southern California Monday. This may add enough mixing to help out a little with possibly even some cloud cover thrown in. when the low parks off the northern Baja coastline Tuesday, a strong easterly flow at the surface and aloft will develop. This may inject another round of dry, cold air onto the valley floor with possibly some gusty winds in Kern County Monday afternoon and night. In other words, from Monday through Thursday, forecasting will be a night by night situation as these various players work themselves out.
Air Quality Expectations: The San Joaquin Valley Air Pollution Control District has issued the following warning(s) for December 5, 2020:
Today’s air quality is listed as unsafe for sensitive groups in Fresno and Kings Counties. The air quality in the remainder of the growing area is moderate.
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.
For more information on wildfires affecting the Valley’s air, visit: http://www.valleyair.org/wildfires
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 30s. Kern, Mid to upper 20s.
Actual Humidity Range Yesterday: Delano, 98%/25% Porterville, NA
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 70%, tomorrow 90%. Bakersfield: Today: 70% Tomorrow: 80%
ET Rates Over the Past Seven Days: Stratford .52, Parlier .49, Blackwell Corners .NA, Arvin .70, Orange Cove .52, Porterville .50, Delano .50. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 54, Parlier 50, Blackwell 56, Arvin, 53, Orange Cove 55, Porterville 51, Delano NA
Record Temperatures: 72/28. Average Temperatures: 57/36
Heating Degree Days This Season: 472, -100
Courtesy of the NWS
Average Temperature for this month So Far: 49.5 +3.2
Precipitation: Seasonal total for Fresno, .28, -1.58, Month to Date: .00, -.16
Precipitation for Bakersfield, Season, .39, +or- -.65. Month to date .00, -.10
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove, 241, Parlier, 302, Arvin, 220, Shafter, 247, Stratford, 277, Delano, 288, Lindcove, 270, Porterville, 340
Hours at 45 or below 45. Courtesy UC Davis
Sunrise: 6:58 am Sunset: 4:42 pm Hours of Daylight: 9:46
Yesterday’s Weather
MCE : Merced 153 : DH1600 / 66 / 31 / 0.00 /
MAE : Madera 253 : DH1600 / 67 / 32 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 67 / 38 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 68 / 31 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 67 / 32 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 68 / 37 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 67 / 32 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 68 / 31 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 66 / 40 / 0.00 /
Rainfall: 24hr W.Y. % Last Y. % Ave. Year ave.
STOCKTON 0.00 0.09 3 3.27 119 2.75 14.06
MODESTO 0.00 0.10 4 2.45 109 2.25 13.11
MERCED 0.00 1.08 51 4.28 204 2.10 12.50
MADERA 0.00 0.16 7 1.61 75 2.15 12.02
FRESNO 0.00 0.28 15 1.82 98 1.86 11.50
HANFORD 0.00 0.13 8 1.36 86 1.58 10.10
BAKERSFIELD 0.00 0.39 38 1.27 122 1.04 6.47
BISHOP 0.00 T 0 1.04 117 0.89 5.18
SALINAS 0.00 0.37 17 3.22 147 2.19 12.83
PASO ROBLES 0.00 0.28 15 3.62 198 1.83 12.78
SANTA MARIA 0.00 0.25 12 2.32 109 2.13 13.95
Yesterday’s Weather
MCE : Merced 153 : DH1600 / 68 / 34 / 0.00 /
MAE : Madera 253 : DH1600 / 71 / 31 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 69 / 42 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 69 / 33 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 70 / 31 / 0.00 /
BFL : Bakersfield Airport 496 : DHM / 74 / 50 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 70 / 38 / 0.00 /
ATEC1 : Avenal 787 : DHM / M / 39 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 72 / 37 / 0.00 /
TFTC1 : Taft 759 : DHM / M / M / M /
LOSC1 : Los Banos 120 : DH1600 / 65 / 37 / 0.00 /
Rainfall: 24hr W.Y. % Last Y. % Ave. Year ave.
STOCKTON 0.00 0.09 3 2.64 98 2.69 14.06
MODESTO 0.00 0.10 5 1.90 86 2.20 13.11
MERCED 0.00 1.08 52 3.60 174 2.07 12.50
MADERA 0.00 0.16 8 1.48 70 2.12 12.02
FRESNO 0.00 0.28 15 1.50 82 1.82 11.50
HANFORD 0.00 0.13 8 0.94 60 1.56 10.10
BAKERSFIELD 0.00 0.39 39 1.07 106 1.01 6.47
BISHOP 0.00 T 0 0.92 106 0.87 5.18
SALINAS 0.00 0.37 17 2.72 127 2.14 12.83
PASO ROBLES 0.00 0.28 16 2.35 132 1.78 12.78
SANTA MARIA 0.00 0.25 12 2.14 103 2.08 13.95
Lows Tonight:
| Terra Bella
29 |
Porterville
29 |
Ivanhoe
28 |
Woodlake
29 |
| Strathmore
30 |
McFarland
29 |
Ducor
30 |
Tea Pot Dome
29 |
| Lindsay
29 |
Exeter
28 |
Famoso
29 |
Madera
29 |
| Belridge
28 |
Delano
30 |
North Bakersfield
30 |
Orosi
28 |
| Orange Cove
28 |
Lindcove
29 |
Lindcove Hillside
Af |
Sanger River bottom
26 |
| Root Creek
27 |
Venice Hill
29 |
Rosedale
31 |
Jasmine
31 |
| Arvin
Af |
Lamont
Af |
Plainview
29 |
Mettler
Af |
| edison
af |
Maricopa
29 |
Holland Creek
32 |
Tivy Valley
29 |
| Kite Road South
32 |
Kite Road North
29 |
AF=Above Freezing
Next report: December 5/pm