December 13, 2019
Summary: The fog product of GOES 17 satellite imagery is quite interesting this morning. fog and low clouds rapidly advanced southward along the western and central portions of the valley north of Kern County while another batch of low clouds developed against the north facing slopes of the Tehachapi Mountains. Interestingly enough, most of Tulare County is fog free, with the exception of a few patches here and there.
Regular infrared satellite imagery also paints an interesting picture. A swath of cloud cover runs from southwest to northeast from the Hawaiian Islands across the Pacific and into Oregon and northern California. There is a sharp dividing line between the cloud cover and clear skies over central California from roughly Modesto south. This line of moisture will be shoved southward tonight and Saturday as a weather system moves out of the Gulf of Alaska then quickly through northern California Saturday and into the Great Basin Sunday. A weakening cold front will spread light showers down the Sierra Nevada with possibly light scattered showers on the valley floor, mainly on the east side. The air mass behind the front is colder and will issue in temperatures more typical of mid December as highs Monday and Tuesday only warm into the low to mid 50s. frost will also be a possibility Monday and Tuesday mornings, which is summarized below.
Upper level high pressure will build in from the west Sunday through Tuesday then a lower latitude storm will approach the northern California coast Wednesday. models continue to have difficulty in giving this storm a particular direction. Some show it hugging the central California coast Wednesday night and Thursday for the likelihood of rain. Others, however, show the system stalling off shore for about 24 hours then show a weakening trough of low pressure moving through southern California Friday. That scenario would result in little, if any, precipitation.
Models still indicate an active pattern between the 20th and Christmas Day. A low could develop over southern California about Christmas Day, creating a cold northeast flow with modified arctic air originating in the northwest territories of Canada moving into California. That is one of several possible scenarios on paper this morning, but certainly something to keep an eye on.
Forecast: Areas of fog and low clouds this morning, otherwise it will be mostly clear to partly cloudy this afternoon. Increasing cloudiness tonight with a chance of light showers after midnight. A chance of light showers Saturday morning. partly to mostly cloudy Saturday afternoon through Sunday morning. becoming mostly clear to occasionally partly cloudy Sunday afternoon through Tuesday, but remaining mostly cloudy over southeastern Tulare County and Kern County into Monday morning. increasing cloudiness later Tuesday night. mostly cloudy Wednesday through Thursday with a chance of rain late Wednesday afternoon through Thursday. Mostly to partly cloudy Thursday night through Friday morning with areas of fog and low clouds.
Short Term:
| Madera 63/48/57/39/53 | Reedley 65/49/59/38/54 | Dinuba 63/49/58/37/53 | |
| Porterville 65/48/59/38/54 | Lindsay 65/48/58/38/53 | Delano 66/50/60/41/53 | |
| Bakersfield 67/52/59/43/53 | Taft 66/53/58/43/53 | Arvin 67/48/60/41/52 | |
| Lamont 66/50/60/41/53 | Pixley 65/48/59/38/54 | Tulare 63/47/59/37/52 | |
| Woodlake 64/49/58/38/53 | Hanford 65/48/59/39/54 | Orosi 64/47/59/38/54 | |
Seven Day Forecast:
| Monday
Patchy fog/partly cloudy 34/54 |
Tuesday
Patchy fog/mostly clear 31/55 |
Wednesday
PM rain possible 39/57 |
Thursday
Chance of rain 42/57 |
Friday
AM fog/partly cloudy 40/58 |
Two Week Outlook: December 20 through December 26: This model is showing the possibility of well above average precipitation for central and northern California. It’s possible a low center may develop off the northern California coast with a moist west or southwest flow into central California. Typically, this is a good precipitation producer. This pattern would also be conducive for 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 through tonight will be generally at or less than 7 MPH with periods of near calm conditions. Winds Saturday through Saturday night will be out of the northwest at 10 to 15 MPH with gusts to 25 MPH possible from Fresno County south and along the west side. Winds Sunday will continue mainly out of the northwest at 5 to 12 MPH, becoming generally less than 8 MPH Sunday night and Monday with periods of near calm conditions. I am still tracking the potential storm for later Wednesday through Thursday. Some localized strong, gusty winds could occur over the valley portion of Kern County out of the east or southeast. However, some model solutions show the center of circulation remaining far enough off shore to eliminate the chance of high level winds.
Rain: A weakening cold front will move down the valley Saturday. showers will spread down the Sierra Nevada tonight with the possibility of light showers on the valley floor, mainly along the east side of the valley. It’s possible some upslope showers could occur Saturday afternoon over the valley portion of Kern County, especially near the base of the mountains. Even so, what rain does occur will be quite light. It still appears likely amounts could range from just trace amounts to as much as .10. dry weather will return Saturday night and continue through at least Wednesday morning. models are still having a difficult time nailing down a particular path for a lower latitude storm Saturday morning. a couple of models show the low approaching the coast then it heads southward just off shore for an excellent chance of precip. Other models, however, show it approaching the coast, but stalling too far off shore for anything more than light precipitation, if that. So for now, we’ll simply put a chance of rain in the forecast for Wednesday through Thursday. The pattern between the 20th and Christmas Day still looks active and potentially quite cold.
Frost Discussion: All locations will be above freezing tonight and again Saturday night. finally, a colder air mass will overspread central California as a weather system clips northern California then moves into the Great Basin. The air mass by Sunday night through Tuesday will be more like mid December’s conditions rather than the unusually mild conditions we’ve enjoyed for the first half of the month. Widespread low to mid 30s are likely Monday morning with a few upper 20s in traditional cold spots. Tuesday morning may be a tad colder due to a more stable environment with most locations ranging from 30 to 34 degrees and with coldest locations down to 27 to 29. By Wednesday morning, clouds should be increasing for above freezing conditions. Another westerly flow will break through behind this system for above freezing conditions for Thursday and through next weekend. The pattern for the 20th through the 25th looks active, but turning colder. There are some configurations on some models for the period Christmas to New Year’s that could turn out to be quite cold with the possibility of a strong but very dry low developing over southern California or the Desert Southwest. A big ridge of high pressure would extend up into the Yukon and Northwest Territories of Canada. Theoretically, this would set up a northeast flow aloft with a strong off shore flow which could spread modified arctic air into California. Again, this is just one of several solutions, but I must say we’re way overdue for something like this.
Afternoon Dew Points Today: Upper 40s to the lower 50s. Kern: Upper 40s to the lower 50s. Humidity values ranging from 50%/100% at Hanford. Bakersfield 40%/95%
Actual Humidity range December 12, 2019: Delano, 100%/44% Porterville, 99%/39%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 60%, tomorrow 10%. Bakersfield: Today: 80% Tomorrow: 10%
ET Rates Over the Past Seven Days: Stratford .19, Parlier .22, Blackwell Corner .26, Arvin .32, Orange Cove .27, Porterville .28, Delano .29. 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: 72/23. Average Temperatures: 55/35
Heating Degree Days this Season: 523 -207
Courtesy of the NWS
Average temperature for December so far: 53.0- +7.5
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2018 Fresno: 2.47 season. or +.21. Month to Date: 1.75 +1.19
Since Oct 1, 2018, Bakersfield: 1.58, or +.30. Month to Date: .51 +.17
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove 201, Parlier 260, Arvin 154, Shafter 186, Stratford 204, Delano 227, Lindcove 242, Porterville 389
Hours at 45 or below 45.
Sunrise: 7:03 Sunset: 4:44 pm. Hours of Daylight: 9:41
Yesterday’s Weather:
: …Valley…
MCE : Merced 153 : DH1600 / 66 / 48 / 0.00 /
MAE : Madera 253 : DH1600 / 68 / 45 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 67 / 48 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 67 / 40 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 66 / 42 / 0.00 /
BFL : Bakersfield Airport 496 : DHM / 68 / 45 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 66 / 42 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 68 / 42 / 0.00 /
TFTC1 : Taft 759 : DH1552 / 68 / 48 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 65 / 47 / 0.00 /
Rainfall: Water year Oct 1st through September 30th
24hr season % last year % Ave. 365 day ave.
STOCKTON 0.00 4.00 122 3.87 118 3.28 14.06
MODESTO T 2.78 102 3.05 112 2.72 13.11
MERCED 0.00 4.52 189 2.69 113 2.39 12.50
MADERA 0.00 1.90 76 2.42 97 2.50 12.02
FRESNO 0.00 2.47 109 1.92 85 2.26 11.50
HANFORD 0.00 1.75 97 1.71 94 1.81 10.10
BAKERSFIELD 0.00 1.58 123 1.20 94 1.28 6.47
BISHOP 0.00 1.06 100 1.31 124 1.06 5.18
SALINAS T 4.09 154 3.87 146 2.65 12.83
PASO ROBLES 0.00 4.70 207 2.84 125 2.27 12.78
SANTA MARIA 0.00 2.68 102 1.95 74 2.62 13.95
Next report: Friday afternoon/December 13