December 25, 2019
Summary: Widely scattered light showers are moving across the valley early this Christmas morning. the main focus is a cold low which is roughly 250 miles west/northwest of the Golden Gate this morning. models have been consistent in showing this storm moving southward just off the central coast late this afternoon through the evening hours with the center of circulation just to the southwest of Santa Barbara by this time tomorrow morning. models also show the precipitation shield wrapping around the low is not that large, so the best chance of precipitation will be along the western and southern flanks of the valley. This will be a major storm for southern California, including the Kern County mountains where more than a foot of snow is possible for a very white Christmas at places like Tehachapi and even the high deserts. It’s questionable whether much precipitation will actually spread into the eastern sector of the San Joaquin Valley. There may also be a period of some strong, gusty, easterly winds below the mountain passes along the valley floor from late this afternoon through early Thursday as pressure differences increase between the high deserts and falling pressure just off shore.
The low will track across southern California and northern Baja Thursday and Thursday night where unusually heavy precipitation will affect the desert regions. Upper level high pressure will begin nudging in from the eastern Pacific Thursday night and will dominate the pattern through Sunday. The main challenge during this period will be the possibility of widespread fog and low clouds nights and mornings and possible below freezing conditions, although nothing unusual is anticipated.
The next feature of note will be a low dropping southward from the Pacific Northwest, possibly into the Great Basin or possibly even into northern and central California Monday and into New Year’s Eve. Since there are model differences regarding this feature, we’ll just go with a chance of showers for Monday and Tuesday of next week.
After that, models generally point to dry weather with the storm track well to our north.
Forecast: Widely scattered light showers this morning. rain becoming likely by late afternoon, mainly along the west side of the valley and over Kern County. Rain at times tonight, mainly south of a Hanford/Visalia line with a chance of showers elsewhere. Rain likely south of a Hanford/Visalia line Thursday morning with a chance of light showers elsewhere. A chance of showers Thursday afternoon, mainly in Kern County. Mostly to partly cloudy Thursday night and Friday morning with areas of fog and low clouds possible Friday morning. mostly clear to occasionally partly cloudy Friday afternoon through Sunday night with widespread fog and low clouds developing during the night and morning hours. Increasing cloudiness Monday morning with a small chance of showers mon day afternoon through Tuesday. Partly cloudy Tuesday night and Wednesday with areas of night and morning fog and low clouds.
Short Term:
| Madera 52/38/52/32/52 | Reedley 53/40/52/31/52 | Dinuba 51/39/52/30/51 | |
| Porterville 53/39/52/32/53 | Lindsay 54/38/52/30/51 | Delano 54/41/52/32/53 | |
| Bakersfield 56/42/50/36/53 | Taft 51/38/49/35/51 | Arvin 55/42/50/35/52 | |
| Lamont 55/42/51/35/52 | Pixley 53/40/52/32/53 | Tulare 52/38/52/31/51 | |
| Woodlake 52/39/52/30/51 | Hanford 53/39/52/32/52 | Orosi 52/39/52/30/51 | |
Seven Day Forecast:
| Saturday
AM fog/PM sun 31/52 |
Sunday
AM fog/PM sun 32/53 |
Monday
Small chance of showers 40/53 |
Tuesday
Slight chance of showers 41/54 |
Wednesday
AM fog/Partly cloudy 35/53 |
Two Week Outlook: January 1 through January 7: This model is indicating high pressure will be shielding California from Pacific storms, so precipitation is unlikely. Temperatures should be pretty close to average.
January: This model is rather inconclusive on precipitation and temperature trends. If anything, precipitation will be close to average with temperatures that are marginally above average. It does appear there will be potentially extended periods of dry weather, leading to episodes of fog and low clouds from time to time.
February, March, April: If this model has any kind of a grip on the situation, temperatures will run somewhat above average during the late winter/early spring period. This model would really dash the hopes of a wet winter as it does indicate below average rain for the three month period.
Winds: Winds will be generally out of the east to southeast this morning at 5 to 10 MPH. North of the Kern County line, winds this afternoon through Thursday will be out of the east/southeast at 8 to 15 MPH with local gusts to 20 MPH possible. In Kern County from late this afternoon through early Thursday, winds will be out of the east/southeast at 15 to 30 MPH with stronger gusts. Gusts in excess of 45 MPH are possible, especially along the Highway 58 corridor into the eastern side of Bakersfield. However, locally strong, gusty winds can also be expected at places like Wheeler’s Ridge and the bottom of the Grapevine. The entire region can expect winds mainly out of the northeast Thursday at 10 to 15 MPH with stronger gusts, diminishing Thursday night with light to calm winds returning Friday and on through the weekend.
Rain: There are some bands of widely scattered showers moving across the valley this morning, but they are fairly insignificant. The rainfall pattern for later this afternoon through Thursday is a very tricky call. It’s a given that southern California will get walloped with this storm with heavy rain and snow along with strong winds. However, models show almost all the precipitation with this storm will occur from roughly a Hanford/Visalia line south. The highest risk of anything significant would be in western Fresno, Kings Counties and the valley portion of Kern County with just light showers north of that line. If the low passes just a bit further off shore than anticipated, then just light showers will occur in the south valley, as well. For now, as far as precipitation amounts are concerned from later this afternoon through Thursday, I’ll go out on a limb and call for .25 to .33 over the valley portion of Kern County, .10 to .20 in Kings and Tulare Counties, and less than a tenth in Fresno and Madera Counties. The precipitation will have ended by early Thursday evening with dry weather Thursday night and through at least Sunday night. I’ll continue to forecast a small chance of showers for Monday and Tuesday of next week. Some models show a low pressure system moving into the Great Basin while others track it into California. The period from New Year’s Day and for several days thereafter appears dry.
Frost Discussion: All locations will be above 32 degrees tonight. we should see cloud cover banked up against the west facing slopes of the Sierra Nevada and the north facing slopes of the Tehachapi Mountains Friday morning. however, where it clears, coldest river bottom and like locations could dip down to 31 to 29 degrees, though most locations will remain in the low to mid 30s.
For Saturday and Sunday mornings, the combination of a northeast flow aloft and an off shore surface flow should mix out residual cloud cover. That would set the stage for both frost and fog. With so much moisture on the valley floor, and relatively strong radiational cooling, coldest locations Saturday and Sunday mornings could dip down to 27 to 29 degrees in those unprotected natural cold spots and generally 29 to 32 degrees elsewhere.
It’s entirely possible, though, that widespread fog and low clouds could take over. If this occurs, most locations would remain in the 30s.
For Monday and Tuesday mornings, we may see increasing amounts of higher clouds in association with a new system. It’s unclear at this time, however, whether this storm will dive into the Great Basin or track further west into California. At any rate, nothing dangerous is showing up on models at this time, so we progress through November and December with generally well above average temperatures and little in the way of frost.
Afternoon Dew Points Today: Low to mid 40s. Kern: Low to mid 40s. Humidity values ranging from 70%/100% at Hanford. Bakersfield 60%/95%
Actual Humidity range December 24, 2019: Delano, 100%/70% Porterville, 98%/79%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 10%, tomorrow 10%. Bakersfield: Today: 20% Tomorrow: 0%
ET Rates Over the Past Seven Days: Stratford .28, Parlier .27, Blackwell Corner .31, Arvin .46, Orange Cove .32, Porterville .26, Delano .32. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 54, Parlier 50, Blackwell 53, Arvin, 52, Orange Cove 52, Porterville 50, Delano 46
Record Temperatures: 72/20. Average Temperatures: 53/35
Heating Degree Days this Season: 712 -270
Courtesy of the NWS
Average temperature for December so far: 51.1- +6.3
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2018 Fresno: 2.81 season. or -.18. Month to Date: 2.09 +.80
Since Oct 1, 2018, Bakersfield: 1.94, or +.25. Month to Date: .87 +.12
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove 284, Parlier 358, Arvin 238, Shafter 277, Stratford 298, Delano 337, Lindcove 374, Porterville 569
Hours at 45 or below 45.
Sunrise: 7:10 Sunset: 4:49 pm. Hours of Daylight: 9:39
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 56 / 36 / 0.01 /
FAT : Fresno Airport 333 : DH1600 / 53 / 44 / 0.06 /
HJO : Hanford Airport 242 : DH1600 / 56 / 43 / 0.04 /
NLC : Lemoore Naval AS 234 : DH1600 / 55 / 39 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 54 / 46 / 0.20 /
VIS : Visalia Airport 292 : DH1600 / 56 / 47 / 0.12 /
ATEC1 : Avenal 787 : DH1600 / 53 / 40 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 54 / 48 / 0.85 /
TFTC1 : Taft 759 : DH1551 / 53 / 41 / M /
Rainfall: Water year Oct 1st through September 30th
24hr season % last year % Ave. 365 day ave.
STOCKTON 0.00 4.16 100 5.32 127 4.18 14.06
MODESTO 0.00 3.19 90 4.33 122 3.56 13.11
MERCED 0.00 4.88 161 3.73 123 3.03 12.50
MADERA 0.00 2.15 66 2.98 92 3.24 12.02
FRESNO 0.03 2.81 94 2.33 78 2.99 11.50
HANFORD T 1.96 77 1.86 74 2.53 10.10
BAKERSFIELD 0.01 1.94 115 1.20 71 1.69 6.47
BISHOP 0.02 1.10 80 1.57 115 1.37 5.18
SALINAS 0.01 4.32 126 4.63 135 3.42 12.83
PASO ROBLES 0.00 5.08 163 3.52 113 3.11 12.78
SANTA MARIA 0.00 3.28 94 2.31 66 3.48 13.95
Next report: December 26/morning