The last 24 hours was a good illustration of the insulation power of the fog and low overcast. North of Kern County yesterday, temperatures were only in the mid to upper 40s. Lows this morning in that region are in the low to mid 40s. the fog is finally off the deck with visibilities generally of 1 to 2 miles. The base of the overcast is generally between 500 and 600 feet. Above Porterville, it’s just 200 feet and 2,000 feet at Bakersfield.
A strong surface off shore flow is underway as a strong surface high is now in place over the Great Basin with the center near northeast Nevada. At the upper levels of the atmosphere, a sharp high runs from the waters off the California coast northward into Alaska and northwest Canada.
In the meantime, there is a weak upper low off the southern California coast which is already moving some high clouds over the south valley. This feature will move inland through southern and central California Christmas Eve and Christmas Day. No measurable rain is anticipated, however a few sprinkles would not be a total shock.
A trough of low pressure running from west to east will move through northern and central California late Friday night and Saturday. this will not be much of an event with only light showers, mainly north of Kern County. This system will move quickly into the Great Basin Saturday night. a colder, stronger low will drop out of the Gulf of Alaska and will be centered just west of the Bay Area Monday. Most models show this system weakening as it moves into central and southern California. Even so, this system will provide a decent chance of precipitation throughout central California from later Sunday night through Monday night.
It had appeared the pattern would remain active well into the first week in January. That does not show up on projections now as the storm track is now expected to migrate back into the Pacific Northwest.
Forecast: Low overcast through Thursday morning. partial clearing will be possible afternoons. Increasing higher clouds tonight with variable cloudiness Christmas Eve through Christmas Day with a slight chance of sprinkles. Mostly cloudy Friday night with a chance of light showers after midnight. Light showers likely from Fresno County north Saturday with a chance of light showers in Kings and Tulare Counties. Partly to mostly cloudy Saturday night and Sunday. A chance of rain Sunday night, becoming likely at times Monday and Monday night. mostly to partly cloudy Tuesday with patchy morning fog. Mostly clear Tuesday night through Wednesday with increasing night and morning fog and low clouds.
Short Term:
| Madera 48/40/53/36/58 | Reedley 48/41/51/38/59 | Dinuba 47/40/53/38/58 |
| Porterville 53/37/57/38/60 | Lindsay 52/36/57/36/60 | Delano 49/40/54/38/60 |
| Bakersfield 57/42/60/41/64 | Taft 58/48/58/47/63 | Arvin 57/35/58/39/62 |
| Lamont 57/37/60/37/63 | Pixley 49/40/53/36/61 | Tulare 47/40/53/37/60 |
| Woodlake 48/38/53/35/61 | Hanford 48/40/54/38/60 | Orosi 49/39/53/35/60 |
Seven Day Forecast:
| Saturday
Light showers 44/61 |
Sunday
Mostly cloudy 41/58 |
Monday
Rain likely 42/52 |
Tuesday
Mostly cloudy 37/54 |
Wednesday
AM fog/partly cloudy 35/55 |
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 Saturday 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. Late Sunday into Monday, there remains a minimal chance of some strong, gusty, southeast winds near the base of the Kern County mountains. As significant surface pressure differences show up on models between the high deserts of southern California and off of the Bay Area.
Rain Discussion: A sprinkle or two cannot be ruled out Christmas Eve and Christmas Day as a weak low pressure system moves through. Later Friday night and Saturday, another trough of low pressure will move from west to east across central California. The dynamics of this system will really lose their punch in our region, so only light showers can be expected Saturday, mainly north of Kern County. Even from Fresno County north, no more than .10 can be anticipated.
Dry weather will return Saturday night and Sunday. A stronger, colder low will drop southeastward out of the Gulf of Alaska, moving through central California late Sunday night through Monday night. periods of rain are likely from this system throughout the entire region. Dry weather will return early Tuesday and will continue for several days thereafter.
Frost Discussion: The fog finally lifted into a low overcast due to a strong off shore flow. Most locations will not see any sunshine this afternoon with the best chance of clearing in Kern County as that off shore flow possibly mixes down some dry air. That will be my main concern tonight, to observe the low cloud deck and determine whether or not it remains locked in. For now, that’s my gut feeling but this may need to be amended in this afternoon’s report.
Also, high, thin clouds are beginning ot appear over southern California. These clouds will increase in density Thursday and Friday, hopefully keeping conditions above freezing.
An active pattern with lots of wind conditions will prevail Saturday through Monday night, keeping temperatures above 32.
Beginning Wednesday of next week, we may begin to see some local frost. It appears we will l have several days of upper level high pressure above us. We will also see increased chances of fog and low clouds, especially during the night and morning hours.
Lows Tonight:
All locations will be above freezing.
Air Quality Expectations: The San Joaquin Valley Air Pollution Control District has issued the following warning(s) for December 23, 2020:
The air quality for Fresno, Tulare, and Kern Counties is unsafe for sensitive groups. The air quality in the remainder of the region 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.
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%/99% Porterville, NA
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 0%, tomorrow 0%. Bakersfield: Today: 20% Tomorrow: 20%
ET Rates Over the Past Seven Days: Stratford .30, Parlier .27, Blackwell Corners .NA, Arvin .39, Orange Cove .25, Porterville .NA, Delano .27. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 53, Parlier 49, Blackwell 55, Arvin, 51, Orange Cove 52, Porterville 51, Delano 44
Record Temperatures: 68/18. Average Temperatures: 54/35
Heating Degree Days This Season: 778 -162 courtesy of the NWS
Average Temperature for this month So Far: 46.8 +2.0 courtesy of the NWS
Precipitation: Seasonal total for Fresno, 1.08, or -1.77, Month to Date: .80, or -.35
Precipitation for Bakersfield, Season, .40, +or- -1.22 Month to date .01, or -.67
Water year season is from October 1st through September 30.
Chilling Hours November 1st through February 28: Orange Cove, 443, Parlier, 528, Arvin, 428, Belridge, 492, Shafter, 480, Stratford, 501, Delano, 542, Porterville, 576
Hours at 45 or below 45. Courtesy UC Davis
Sunrise: 7:09 am Sunset: 4:48 pm Hours of Daylight: 9:39
Yesterday’s Weather
MCE : Merced 153 : DH1600 / 45 / 38 / 0.00 /
MAE : Madera 253 : DH1600 / 43 / 38 / 0.00 /
FAT : Fresno Airport 333 : DH1506 / 44 / 38 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 47 / 37 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 47 / 27 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 55 / 32 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 43 / 37 / 0.00 /
ATEC1 : Avenal 787 : DH1550 / 54 / 28 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 48 / 32 / 0.00 /
TFTC1 : Taft 759 : DH1600 / M / M / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 44 / 32 / 0.00 /
Rainfall: 24hr W.Y. % Last Y. % Ave. Year ave.
STOCKTON 0.00 1.70 42 4.16 103 4.02 14.06
MODESTO 0.00 1.45 43 3.19 94 3.40 13.11
MERCED 0.00 2.10 72 0.00 0 2.92 12.50
MADERA 0.00 0.69 22 0.00 0 3.11 12.02
FRESNO 0.00 1.08 38 0.00 0 2.85 11.50
HANFORD 0.00 0.49 21 0.00 0 2.39 10.10
BAKERSFIELD 0.00 0.40 25 0.00 0 1.62 6.47
BISHOP 0.00 0.01 1 1.06 82 1.30 5.18
SALINAS 0.00 0.83 25 4.31 131 3.28 12.83
PASO ROBLES 0.00 0.30 10 5.05 171 2.96 12.78
SANTA MARIA 0.00 0.31 9 3.27 98 3.32 13.95
Next report: December 23/pm