December 2, 2020
Upper level high pressure covers California, the Pacific Northwest, and southern British Columbia. A low pressure system developing over Oklahoma is stretching into the Desert Southwest. This is creating an east/northeast flow aloft. In the meantime, surface strong high pressure is now centered over Idaho. Pressures are much higher over Utah and Idaho than they are off the southern California coast. For example, the pressure in Pocatello, Idaho is 30.53 inches of mercury while at LAX the current reading is 30.04. this is resulting in an off shore flow that’s more out of the east than northeast, which is more favorable in moving Santa Ana winds downslope off the Tehachapi Mountains and into the extreme south valley tonight and Thursday.
It’s looking more and more likely that these winds could possibly reach as far north as Shafter and Bakersfield. winds gusting into the mid 30s are likely in Bakersfield with gusts possibly exceeding 50 MPH at places like the bottom of the Grapevine. This will be a short lived event as pressure differences will slacken Thursday night with light winds returning Friday.
These downslope winds Thursday could push temperatures in Bakersfield and other Kern County locations to over 70 with dew points possibly lowering into the teens. Typically with this configuration, drier air mixes down into the rest of the valley, as well, so by the time we get into Saturday morning, colder temperatures can again be expected. More in the frost discussion below.
Models are very inconclusive on the pattern for Sunday through Tuesday. It’s possible a weak upper low will drop southward from the Pacific Northwest, possibly into Nevada or northern California by Monday. It would then sink southward to a position off the northern Baja coast by Tuesday. It’s unlikely this feature would bring any active weather whatsoever. In fact, once this system positions near Baja, the counterclockwise circulation around the low will create another robust off shore flow, a signature of this year’s fall and now winter season.
Just as a weather note, meteorological winter began December 1 and runs through February 28. Medium range models don’t hold out much hope for rain through the middle of the month as the blocking pattern continues.
Forecast: Mostly clear skies through Sunday with occasional high clouds. Mostly clear to occasionally partly cloudy Sunday night through Monday night. Mostly clear Tuesday through Wednesday.
Short Term:
| Madera 65/30/66/31/65 | Reedley 65/29/67/31/65 | Dinuba 65/29/66/30/64 |
| Porterville 65/30/67/31/65 | Lindsay 65/29/67/31/66 | Delano 66/30/69/32/66 |
| Bakersfield 66/43/71/40/65 | Taft 66/46/70/45/66 | Arvin 67/36/69/40/66 |
| Lamont 67/35/71/37/65 | Pixley 65/30/67/31/65 | Tulare 64/28/67/30/64 |
| Woodlake 64/30/67/31/65 | Hanford 65/31/67/32/65 | Orosi 64/28/67/30/64 |
Seven Day Forecast:
| Saturday
Mostly clear 28/62 |
Sunday
Mostly clear 29/63 |
Monday
Partly cloudy 34/61 |
Tuesday
Mostly clear 29/63 |
Wednesday
Mostly clear 29/64 |
Two Week Outlook: December 9 through December 15: This model gives absolutely no hope for precipitation. It is simply a variation of the blocking ridge pattern we’ve been under through the fall season so expect little chance of rain with above average daytime temperatures.
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 through Saturday north of Kern County will be at or less than 10 MPH late mornings and afternoons and variable in nature. Winds during the night and early morning hours will be generally at or less than 5 MPH with periods of near calm conditions. In Kern County, winds today will be light. Winds tonight through Thursday in the extreme southern portion of the valley will increase out of the southeast at 20 to 35 MPH with local gusts to near 50 MPH possible. For now, it appears these winds will make it as far north as Shafter and Bakersfield with gusts to 35 MPH possible. This will be a short lived event with light winds returning Thursday night through Saturday.
Rain Discussion: Expect dry conditions for the next 7 to possibly 10 days.
Frost Discussion: The coldest locations I could find this morning as of 6:30 were 26 at Reedley and Ivanhoe and 27 at Exeter. Most other locations north of Kern County ranged between 28 and 32 with mid 30s in portions of Kern County.
North of Kern County tonight, coldest sink hole type locations will see temperatures down to 27 to 29 degrees with most other locations between 29 and 32.
In most of Kern County, south of Delano, temperatures will be above freezing. I do anticipate increasing southeasterly winds later in the night. where these winds develop, temperatures will rise dramatically, possibly into the 50s by sunrise. These Santa Ana winds will continue through Thursday sthen decrease Thursday night.
Most locations Friday morning will drop to between 26 to 28 degrees, possibly down to 24 to 25 in wind sheltered low spots with similar conditions coming up Saturday morning. it’s conceivable that we could see some cloud cover Sunday morning from a weak upper low sliding southward from the Pacific Northwest. It’s unclear what track this system will take, but it is projected to slide south/southwest and park off the northern coast of Baja for several days. The placement of this low could result in yet another strong off shore flow Monday and Tuesday. So, at least there are some wild cards out there.
Air Quality Expectations: The San Joaquin Valley Air Pollution Control District has issued the following warning(s) for December 2, 2020:
Today’s air quality is listed as unsafe for sensitive groups in Fresno, Kern, 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: Mid to upper 30s, Kern, Low to mid 30s.
Actual Humidity Range Yesterday: Delano, 83%/31% Porterville, 96%/29%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 90%, tomorrow 90%. Bakersfield: Today: 90% Tomorrow: 90%
ET Rates Over the Past Seven Days: Stratford .53, Parlier .46, Blackwell Corners .55, Arvin .56, Orange Cove .49, Porterville .49, Delano .49. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 55, Parlier 50, Blackwell 56, Arvin, 53, Orange Cove 55, Porterville 51, Delano 43
Record Temperatures: 74/27. Average Temperatures: 58/36
Heating Degree Days This Season: 428, -87
Courtesy of the NWS
Average Temperature for this month So Far: 48.0 +1.0
Precipitation: Seasonal total for Fresno, .28, -1.46, Month to Date: .00, -.04
Precipitation for Bakersfield, Season, .39, +or- -.57. Month to date .00, -.02
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove, 218, Parlier, 262, Arvin, 196, Shafter, 207, Stratford, 242, Delano, 247, Lindcove, 256, Porterville, 304
Hours at 45 or below 45. Courtesy UC Davis
Sunrise: 6:55 am Sunset: 4:43 pm Hours of Daylight: 9:48
Yesterday’s Weather
MCE : Merced 153 : DH1600 / 64 / 29 / 0.00 /
MAE : Madera 253 : DH1600 / 65 / 32 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 64 / 40 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 65 / 31 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 64 / 27 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 65 / 39 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 64 / 32 / 0.00 /
ATEC1 : Avenal 787 : DH1551 / 63 / 36 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 66 / 34 / 0.00 /
TFTC1 : Taft 759 : DH1600 / 62 / 45 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 63 / 38 / 0.00 /
Rainfall: 24hr W.Y. % Last Y. % Ave. Year ave.
STOCKTON 0.00 0.09 4 1.97 77 2.57 14.06
MODESTO 0.00 0.10 5 1.37 66 2.09 13.11
MERCED 0.00 1.08 54 3.28 163 2.01 12.50
MADERA 0.00 0.16 8 1.48 72 2.05 12.02
FRESNO 0.00 0.28 16 1.50 86 1.74 11.50
HANFORD 0.00 0.13 9 0.94 62 1.52 10.10
BAKERSFIELD 0.00 0.39 41 1.07 111 0.96 6.47
BISHOP 0.00 T 0 0.92 110 0.84 5.18
SALINAS 0.00 0.37 18 1.49 73 2.03 12.83
PASO ROBLES 0.00 0.28 17 2.22 131 1.69 12.78
SANTA MARIA 0.00 0.25 13 1.98 100 1.98 13.95
Lows Tonight:
| Terra Bella
29 |
Porterville
30 |
Ivanhoe
28 |
Woodlake
29 |
| Strathmore
30 |
McFarland
28 |
Ducor
31 |
Tea Pot Dome
30 |
| Lindsay
29 |
Exeter
29 |
Famoso
29 |
Madera
30 |
| Belridge
29 |
Delano
30 |
North Bakersfield
32 |
Orosi
28 |
| Orange Cove
29 |
Lindcove
29 |
Lindcove Hillside
Af |
Sanger River Bottom
27 |
| Root Creek
28 |
Venice Hill
30 |
Rosedale
32 |
Jasmine
32 |
| Arvin
Af |
Lamont
Af |
Plainview
30 |
Mettler
Af |
| Edison
AF |
Maricopa
30 |
Holland Creek
Af |
Tivy Valley
30 |
| Kite Road South
Af |
Kite Road North
30 |
AF=Above Freezing
Next report: December 2/pm