December 12, 2017
Summary: A strong warm air inversion continues to seal the valley under strong high pressure aloft. A surface high remains over the Great Basin but has weakened, so the easterly winds over the mountains have dropped off considerably. Rather than being parked over northern California, the high will begin to back up beginning Wednesday. In other words, it will move off shore. Models show a ridge building into the Pacific Northwest. Once again, it will turn the winds out of the northeast and yet another easterly flow at the surface will increase the Santa Ana winds over southern California. This minor change will not break the back of the inversion, so mild days and cold nights will continue as strong radiational cooling continues under clear skies.
Models for Tuesday and Wednesday of next week are quite interesting. One model shows a fairly strong trough of low pressure moving through northern and central California for even a chance of rain. Another places a closed low just off shore which could also result in precipitation. Since this is the first sign of a break in the pattern, we’ll view it with skepticism, but it sure looks nice on paper.
Also, a high may build Wednesday and Thursday into western Canada, resulting in colder air plunging into California. That pattern will have to be watched closely for the potential for subfreezing weather.
Forecast: Mostly clear through Friday. mostly clear skies will continue Friday night through Tuesday.
Short Term:
| Madera 64/29/65/29/66 | Reedley 64/28/65/29/65 | Dinuba 63/28/64/28/64 | |
| Porterville 65/29/64/29/66 | Lindsay 65/27/65/28/65 | Delano 66/29/65/30/67 | |
| Bakersfield 66/36/67/37/68 | Arvin 68/34/66/34/68 | Taft 67/43/67/44/68 | |
| Lamont 68/35/66/35/69 | Pixley 66/28/67/29/68 | Tulare 63/27/64/28/65 | |
| Woodlake 64/29/64/29/65 | Hanford 64/29/65/30/66 | Orosi 65/28/64/28/65 | |
Seven Day Forecast:
| Friday
Mostly clear 29/65 |
Saturday
Mostly clear 30/64 |
Sunday
Mostly clear 30/65 |
Monday
Mostly clear 31/65 |
Tuesday
Mostly clear 33/66 |
Two Week Outlook: December 19 through Christmas: This model continues to show a big ridge over the west and a big cold trough east of the Rockies. This pattern is very unfavorable for rain, but it is favorable for above average temperatures and areas of night and morning fog along with sub-freezing overnight lows.
December: This model is indicating a better than even chance of above average temperatures for central and southern California all the way to the southeast with near to below average temperatures in the Pacific Northwest. As far as precipitation is concerned, this model does show better than average precip over Washington and Oregon and near average rainfall over central and northern California.
December, January, February: If this model is to be believed, winter this year will experience somewhat above average temperatures from California, stretching eastward and southward. Below average temperatures would prevail from the northern Rockies through the Plains states. As far as California is concerned, precipitation would be near to marginally below average with temperatures marginally above average, but take all this with a grain of salt.
Winds: Winds will be generally less than 10 MPH with periods of near calm conditions through Friday.
Rain: Dry weather will continue through Tuesday, at least. Two models are showing a major shift in the pattern for Tuesday night and Wednesday which may bring showers to the area. One model shows a cold trough of low pressure moving through, spreading rain over northern and possibly central California. Another shows a closed low developing just off shore which could also bring a chance of showers. This is the first day either scenario has shown up, so for now we’ll take it with a grain of salt, but it sure looks pretty. We’ll keep you posted on developments.
Frost: Seemingly a permanent strong warm air inversion remains in place as the valley is capped by strong upper level high pressure. This will continue to allow daytime highs to be very pleasant with cold overnight lows as strong radiational cooling will continue.
Coldest overnight lows tonight will range between 26 and 28 with many other locations between 28 and 32, especially from Tulare County northward, while most locations in Kern County will see lows in the low to mid 30s.
The inversion tonight will be strong with temperatures at 34 feet anywhere from 5 to 9 degrees warmer.
There will not be much change through the weekend as the valley will continue to be controlled by that high.
A couple of models show some change about next Tuesday and Wednesday. One shows a strong trough moving through with at least a chance at rain while another indicates a closed low will develop just off shore. At least one model indicates a high will build into northern Canada with cold air driving south/southeast into the western U.S. I’m not calling for a cold weather episode yet because no trends have developed, but we’ll certainly be watching this.
Lows Tonight:
| Terra Bella
27 |
Porterville
29 |
Ivanhoe
28 |
Woodlake
28 |
| Strathmore
29 |
McFarland
29 |
Ducor
29 |
Tea Pot Dome
29 |
| Lindsay
27 |
Exeter
28 |
Famoso
30 |
Madera
29 |
| Belridge
28 |
Delano
30 |
North Bakersfield
32 |
Orosi
27 |
| Orange Cove
28 |
Lindcove
27 |
Lindcove Hillside
AF |
Sanger River Bottom
26 |
| Root Creek
27 |
Venice Hill
28 |
Rosedale
AF |
Jasmine
29 |
| Arvin
34 |
Lamont
34 |
Plainview
28 |
Mettler
AF |
| Edison
32 |
Maricopa
AF |
Holland Creek
33 |
Tivy Valley
29 |
| Kite Road South
33 |
Kite Road North
29 |
AF=Above Freezing
Afternoon Dew Points Today: Mid to lower 40s. Bakersfield, low to mid 30s.
Relative Humidity Forecast: Hanford, 35%/95% Bakersfield, mid to upper 30s
Actual Humidity December 10, 2017: Delano, NA, Porterville, 96%/33%
Percentage of Sunshine Today/Tomorrow: Visalia: Today 100% tomorrow 100%, Bakersfield: Today 100% tomorrow 100%.
ET Rates Over the Past Seven Days December 10, 2017: Stratford .48, Parlier .38, Blackwell, .52 Lindcove .42, Arvin .50, Orange Cove .44, Porterville .37, Delano .NA., Madera Two .36. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 51, Parlier 51, Blackwell 54, Lindcove, 57, Arvin, 54, Orange Cove 50, Porterville 51, Delano NA, Madera Two 52
Mean Temperatures for December. Month So Far: 47.6 +1.9
Record Temperatures: 69/29. Average Temperatures: 56/35
Heating Degree Days this Season: 476, -214 Courtesy of the NWS
Precipitation: Seasonal total/average/above or below average:
Since December 10, 2017 Fresno: .37 season. or -1.69. Month to Date: T
Since December 10, 2017, Bakersfield: .03, or -1.22, Month to Date: ..00
Water year season is from October 1st through September.
Chilling ours November 1st through February 28: Orange Cove, 221, Parlier, 241, Arvin, 181, Shafter, 276, Stratford, 241, Madera two, 382, Alpaugh, 269, Delano, NA, Lindcove, 211, Porterville, 361. Hours at 45 or below 45.
Sunrise: 7:02 am Sunset: 4:43 pm. Hours of Daylight: 9:41
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 63 / 30 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 62 / 32 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 63 / 30 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / M / M / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 61 / 30 / 0.00 /
ATEC1 : Avenal 787 : DH1558 / 66 / 34 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 65 / 32 / 0.00 /
TFTC1 : Taft 759 : DH1557 / 64 / 43 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 61 / 34 / 0.00 /
Rainfall: Season % Last y. % Ave. Annual Ave.
STOCKTON 0.00 0.91 28 4.64 145 3.21 14.06
MODESTO 0.00 0.98 37 3.65 137 2.66 13.11
MERCED 0.00 1.03 44 3.08 131 2.35 12.50
MADERA 0.00 0.32 13 2.67 109 2.45 12.02
FRESNO 0.00 0.37 17 2.46 111 2.21 11.50
HANFORD 0.00 0.37 21 1.09 61 1.78 10.10
BAKERSFIELD 0.00 0.03 2 0.66 53 1.25 6.47
BISHOP 0.00 0.16 16 0.09 9 1.03 5.18
SALINAS 0.00 0.75 29 3.00 115 2.60 12.83
PASO ROBLES 0.00 0.25 11 2.68 121 2.21 12.78
SANTA MARIA 0.00 0.09 4 3.09 121 2.56 13.95
PASO ROBLES 0.00 0.25 13 2.65 134 1.98 12.78
SANTA MARIA 0.00 0.09 4 2.58 111 2.32 13.95
Next Report: Tuesday, December 12/pm