January 21, 2021
The cut off low off of northern Baja is now shifting into northwest Mexico while the first in a series of cold weather systems drops southward from the Gulf of Alaska. The first in the series has dropped to a position west of Washington and will move into north central California by midday Friday. Light showers will spread over the valley, mainly Friday afternoon through midday Saturday with the snow level lowering to 3,500 to 4,000 feet. A weak wedge of high pressure will give us a brief period of dry weather Saturday night and Sunday morning. Then a very cold elongated low will stretch from British Columbia to southern California Monday through Tuesday with periods of showers and snow possibly as low as 2,000 feet in the surrounding mountains.
The storm I’m most focused on will arrive Wednesday through Thursday. On paper, this is the strongest storm of the season to date. A powerful low will center off the Oregon coast with a rich feed of moisture moving from southwest to northeast into northern and central California. This type of system can be a tremendous precipitation producer, however with strong wind energy coming in from the southwest, strong rain shadows will develop along the southern and western sides of the valley. Models continue to show a pineapple connection which will hopefully produce heavy amounts of snow in the high Sierra and significant amounts of rain on the valley floor.
Surface models also show tightly wound isobars, or lines of equal pressure between the northwest coast and southern California. This could produce a high wind event in the south valley with gusty winds along the west side. This system will finally shift eastward Friday with another possibly weaker system next weekend.
Forecast: Mostly clear skies through this evening. Increasing cloudiness after midnight. A chance of light showers Friday morning. light showers are likely Friday afternoon through midday Saturday. a chance of light showers Saturday afternoon and evening. Partly to mostly cloudy Saturday night through Sunday morning. a chance of showers Sunday afternoon. Periods of showers Sunday night and at times through Tuesday with snow in the foothills. A chance of showers Tuesday night. rain likely at times Wednesday through Thursday with possibly some strong, gusty southeast winds.
Short Term:
| Madera 65/37/57/39/54 | Reedley 66/36/58/39/55 | Dinuba 65/34/57/40/54 |
| Porterville 67/36/58/40/55 | Lindsay 66/34/58/39/54 | Delano 68/37/59/40/55 |
| Bakersfield 68/41/59/41/54 | Taft 65/50/57/44/50 | Arvin 68/38/59/40/54 |
| Lamont 68/39/59/40/54 | Pixley 67/37/58/39/55 | Tulare 65/35/56/39/55 |
| Woodlake 65/36/57/39/55 | Hanford 66/37/58/40/55 | Orosi 65/34/57/39/53 |
Seven Day Forecast:
| Sunday
PM showers’ 37/55 |
Monday’
Showers likely 39/50 |
Tuesday
Showers likely’ 37/51 |
Wednesday
Rain/gusty winds 41/58 |
Thursday’
Rain at times 45/59 |
Two Week Outlook: January 28 through February 3: This model is reverting back to a pattern favorable for below average temperatures with storms moving out of the Gulf of Alaska, resulting in above average precipitation.
February: Both the 30 and 90 day outlooks reflect a La Nina pattern with below average precipitation over the southern 2/3 of California and above average precip over parts of the Pacific Northwest and northern California. Temperatures should be close to seasonal averages.
February, March, April: Precipitation will continue to be above average over the Pacific Northwest and roughly the northern ¼ of California with the southern 2/ 3 of California having below average precipitation. Temperatures should be marginally above average.
Winds Discussion: Winds will be light and variable today and tonight. Winds Friday through Saturday will be mainly out of the southeast at 5 to 12 MPH with stronger gusts, mainly from Fresno County north. Winds Saturday night and Sunday will continue to be mainly out of the southeast at 5 to 15 MPH with stronger gusts. I still have concerns about the potential of a high wind event in the extreme south valley about the middle of next week. Models continue to show strong differences in surface pressure between the northwest coast and southern Californian, potentially squeezing strong winds downslope off the Tehachapi Mountains and onto the valley floor.
Rain Discussion: The chance for light showers will begin Friday morning and become likely Friday afternoon through midday Saturday, falling off to just a chance of light shower Saturday afternoon and evening. This first system is moisture starved with most locations recording no more than .10 to .20. A dry slot of weather will set up Saturday night through Sunday morning then storm number two will arrive late Sunday through Tuesday with periods of showers. This is a very cold system which will lower snow levels down into the lower foothills. My main concern is what appears to be the strongest storm of the season so far in the form of a powerful low off the Oregon coast. There will be a rich feed of moisture stretching from well out over the Pacific initially into northern California Wednesday, sagging south into central California late Wednesday into Thursday. These types of systems generally create strong rain shadows along the west side and in Kern County. But on the flipside, lift could generate very heavy snow over the high Sierra with significant rain on the east side. Models show a weaker system possibly affecting central California next weekend.
Frost Discussion: The coldest locations as of 6:30 were Lindsay at 27 with Lindcoe and Orange Cove both at 28. Most other locations were between 29 and 32. All locations tonight will be above freezing, but only slightly above in the coldest locations. Above freezing conditions can be expected Saturday morning with local frost possible Sunday, depending on cloud cover. Monday through Friday, despite a cold pattern setting gup, will be an active period with above freezing conditions.
Afternoon Dew Points Today: Low to mid 30s.. Low to mid 30s.
Actual Humidity Range Yesterday: Delano, NA Porterville, NA
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 80%, tomorrow 20%. Bakersfield: Today: 90% Tomorrow: 40%
ET Rates Over the Past Seven Days: ET information has been unavailable for the past ten days. Seventy two hours. Stratford .NA, Parlier .NA, Blackwell Corners .NA, Arvin .NA, Orange Cove .NA, Porterville .NA, Delano .NA. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 53, Parlier 50, Blackwell 53, Arvin, 52, Orange Cove 52, Porterville NA, Delano 46
Record Temperatures: 72/19. Average Temperatures: 55/35
Heating Degree Days This Season: 1250. Varies widely from location to location. courtesy of the NWS
Average Temperature for this month So Far: 49.4 +4.8 courtesy of the NWS
Precipitation: Seasonal total for Fresno, 1.42, or -3.48 or 29% of average. Month to Date: .T or -1.43
Precipitation for Bakersfield, Season, .74, +or- -1.96, or 27% of average. Month to date .00, or -.74
Water year season is from October 1st through September 30.
Chilling Hours November 1st through February 28: Orange Cove, 701, Parlier, 834, Arvin, 675, Belridge, 779, Shafter, 785, Stratford, 796, Delano, 859, Porterville, NA
Hours at 45 or below 45. Courtesy UC Davis
Sunrise: 7:07 am Sunset: 5:14 pm Hours of Daylight: 10:05
Yesterday’s Weather
MCE : Merced 153 : DH1600 / 67 / 31 / 0.00 /
MAE : Madera 253 : DH1600 / 66 / 29 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 65 / 37 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 66 / 32 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 67 / 34 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 67 / 41 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 64 / 31 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 68 / 33 / 0.00 /
TFTC1 : Taft 759 : DH1600 / 64 / 47 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 66 / 37 / 0.00 /
Rainfall: 24hr W.Y. % Last Y. % Ave. Year ave.
STOCKTON 0.00 2.09 32 5.14 79 6.47 14.06
MODESTO 0.00 1.54 27 3.85 67 5.74 13.11
MERCED 0.00 2.28 42 0.00 0 5.48 12.50
MADERA 0.00 0.77 14 0.00 0 5.59 12.02
FRESNO 0.00 1.42 29 0.00 0 4.90 11.50
HANFORD 0.00 0.67 14 0.00 0 4.75 10.10
BAKERSFIELD 0.00 0.74 27 0.00 0 2.70 6.47
BISHOP 0.00 0.21 9 1.16 48 2.40 5.18
SALINAS 0.00 0.96 17 5.88 106 5.57 12.83
PASO ROBLES 0.00 0.99 18 6.61 122 5.44 12.78
SANTA MARIA 0.00 1.77 31 4.79 83 5.80 13.95
Next report: January 21/pm