December 11, 2019
Summary: Despite a weak trough of low pressure that went through overnight, fog had no problem reforming on the ground. All locations from Merced southward in the valley are reporting a visibility of ¼ mile or less with the exception of the Lemoore Naval Air Station which is reporting a low overcast based at just 200 feet. Now that the trough has moved through, a mild westerly flow will set up across the Pacific over the top of a flat zone of high pressure which is centered several hundred miles to the west of the central California coast. The storm track will steer Pacific storms into the Pacific Northwest, affecting about the northern 1/3 of California from time to time through Friday night. the widespread fog this morning will be slow to burn off and may hang in there all day in some areas, especially towards the center of the valley north of Kern County.
The off shore high will begin to buckle late Friday night and Saturday as a low pressure system moves into northern California. A weakening cold front will move down the valley sometime Saturday or Saturday night with a chance of light showers. Models still indicate most of the precipitation will be confined to the Sierra Nevada.
The air mass behind the front will be colder with origins in the Gulf of Alaska. Temperatures will return to more seasonal values beginning Sunday. We could even see local areas of frost Monday and Tuesday, however much of the frost potential will be determined by the amount of cloud cover left in the San Joaquin Valley.
Some models show a low pressure system off the central coast about next Wednesday which could spread precipitation into central California. That is certainly a low confidence call for now as models are all over the place. Models continue to trend towards an active pattern between the 21 and 25 with cold storms possibly moving out of the Gulf of Alaska and into California.
Forecast: Widespread dense fog through mid morning, lifting into a low overcast by midday with partial afternoon clearing. Partly cloudy skies will prevail above the fog. Expect widespread low clouds and fog during the night and morning hours Thursday through Friday with partial afternoon clearing and partly cloudy skies above the fog. Increasing higher clouds Friday night leading to a chance of light showers Saturday into early Sunday. Mostly to partly cloudy Sunday night and early Monday. Partly cloudy Monday afternoon through Tuesday night with areas of night and morning fog and low clouds. Increasing cloudiness Wednesday with a slight chance of showers.
Short Term:
| Madera 59/42/64/43/62 | Reedley 58/42/61/43/62 | Dinuba 58/43/63/43/62 | |
| Porterville 62/41/63/44/63 | Lindsay 61/41/62/43/63 | Delano 61/44/63/45/63 | |
| Bakersfield 62/46/64/48/64 | Taft 63/48/66/50/64 | Arvin 64/44/66/46/65 | |
| Lamont 63/44/64/46/63 | Pixley 61/41/64/43/63 | Tulare 59/40/62/43/62 | |
| Woodlake 60/40/63/43/62 | Hanford 61/41/62/43/62 | Orosi 60/40/64/43/63 | |
Seven Day Forecast:
| Saturday
Chance of showers 48/61 |
Sunday
AM showers possible 42/56 |
Monday
AM fog/pm sun 34/53 |
Tuesday
AM fog/partly cloudy 32/56 |
Wednesday
Slight chance of showers 39/56 |
Two Week Outlook: December 16 through December 22: This model is indicating an increasing chance of precipitation will occur during this period. Evidently, a storm or storm systems could arrive from the Gulf of Alaska, resulting in below average temperatures.
December: NOAA always projects warmer than average temperatures during the winter months and has a fairly low batting average. This model follows suit with a projection of above average temperatures, especially over the western U.S. The latest projection for precipitation is near average rainfall will prevail.
January, February, March: This model indicates above average temperatures this winter, but what’s new, especially over the western one-third of the U.S. There are two small notations for below average precipitation. The first is over Louisiana. The second is over northern and central California. Let’s hope this projection is inaccurate, but that’s the official prognosis from NOAA.
Winds: Winds will be at or less than 6 MPH with periods of near calm conditions through Saturday.
Rain: A weakening cold front will move through central California Saturday and Saturday night. most models indicate the bulk of the light precipitation will be over the Sierra Nevada with no more than a few hundredths on the valley floor, at the most. Dry weather will return by Sunday morning and continue through at least Tuesday night. some models are indicating an upper low will be off the central coast Wednesday for the next chance of showers with dry weather for a few days thereafter. Models show an active pattern continuing with storms moving out of the Gulf of Alaska and into central California from the 21 through Christmas Day.
Frost Discussion: All locations will continue to be above freezing through Sunday morning. A colder air mass will follow a weak frontal system which will move through sometime Sunday or Sunday evening. Temperatures may be in the low to mid 30s Monday and Tuesday mornings with a slight chance of upper 20s in the typical low spots, but no freeze threat is expected. One model indicates a fairly dangerous pattern shaping up around Christmas Day. This model shows a polar air mass diving south into the interior west, possibly affecting California. This is only one model and perhaps I’m superstitious, but we’ve all spent many a Christmas with subfreezing temperatures. Not to scare you, this is just one model. We’ll study this as we continue through the month.
Afternoon Dew Points Today: Upper 40s to the lower 50s. Kern: Upper 40s to the lower 50s. Humidity values ranging from 75%/100% at Hanford. Bakersfield 65%/100%
Actual Humidity range December 10, 2019: Delano, 100%/100% Porterville, NA
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 20%, tomorrow 20%. Bakersfield: Today: 10% Tomorrow: 20%
ET Rates Over the Past Seven Days: Stratford .22, Parlier .21, Blackwell Corner .25, Arvin .33, Orange Cove .27, Porterville .26, Delano .27. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 57, Parlier 54, Blackwell 57, Arvin, 56, Orange Cove 55, Porterville 57, Delano 52
Record Temperatures: 69/25. Average Temperatures: 56/35
Heating Degree Days this Season: 497 -193
Courtesy of the NWS
Average temperature for December so far: 53.3- +7.6
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2018 Fresno: 2.47 season. or +.31. Month to Date: 1.75 +1.29
Since Oct 1, 2018, Bakersfield: 1.58, or +.36. Month to Date: .51 +.23
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove 189, Parlier 247, Arvin 130, Shafter 170, Stratford 186, Delano 210, Lindcove 200, Porterville 339
Hours at 45 or below 45.
Sunrise: 7:02 Sunset: 4:43 pm. Hours of Daylight: 9:42
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 57 / 42 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 55 / 44 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 53 / 42 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 53 / 41 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 55 / 43 / 0.00 /
VIS : Visalia Airport 292 : DH1526 / 52 / 41 / 0.00 /
ATEC1 : Avenal 787 : DH1547 / 59 / M / 0.00 /
PTV : Porterville Airport 442 : DH1500 / 57 / 40 / 0.00 /
TFTC1 : Taft 759 : DH1551 / 58 / M / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 57 / 45 / 0.00 /
Rainfall: Water year Oct 1st through September 30th
24hr season % last year % Ave. 365 day ave.
STOCKTON 0.00 3.90 124 3.87 123 3.14 14.06
MODESTO 0.00 1.78 68 3.05 117 2.60 13.11
MERCED 0.00 4.52 196 2.69 116 2.31 12.50
MADERA 0.00 1.90 79 2.42 100 2.41 12.02
FRESNO 0.00 2.47 114 1.92 89 2.16 11.50
HANFORD 0.00 1.75 100 1.71 98 1.75 10.10
BAKERSFIELD 0.00 1.58 130 1.20 98 1.22 6.47
BISHOP 0.00 1.06 105 1.31 130 1.01 5.18
SALINAS 0.00 4.09 161 3.87 152 2.54 12.83
PASO ROBLES 0.00 4.70 219 2.84 132 2.15 12.78
SANTA MARIA 0.00 2.68 107 1.95 78 2.50 13.95
Next report: Wednesday afternoon/December 11