December 12, 2019
Summary: There are areas of dense fog out there again this morning. Lemoore, Visalia, and Hanford are each reporting ¼ mile visibility while the visibility is reasonably decent at Bakersfield, Porterville, Fresno, and Madera. Upper level high pressure is firmly ensconced several hundred miles off the Baja coast. A zonal or west to east flow rides over the top of the high and into the Pacific Northwest and northern California. There is a great amount of moisture embedded within this flow. When the air is lifted by the northern and central Sierra Nevada, light showers are a result from Yosemite northward with variable mid and high level clouds over the valley floor.
The high pressure system will buckle Friday night as a fast moving system moves out of the Gulf of Alaska and into the Pacific Northwest Friday, clipping northern California Saturday through Saturday evening. A weakening cold front will move down the valley on Saturday with what now appears to be a reasonable chance of light showers spreading all the way into the south valley. The dynamics of this system will remain to our north, so rainfall amounts will generally be .10 or less with heavier amounts in the foothills and mountains.
The air mass behind this system is colder and will spread over central California Saturday night and Sunday. It will finally lower temperatures to near seasonal values. For the first eleven days in December, temperatures have averaged 7 degrees above average. There could actually be local frost for a change Monday and Tuesday mornings, which is explained below in the frost discussion.
High pressure will dominate Sunday through Tuesday. Two of the main medium range models show a strong low just west of the Golden Gate Tuesday night and Wednesday. this could spread significant amounts of precipitation over central California if it does indeed occur. Two other models place this system considerably further off shore, which would result in dry conditions or just light rain. If the two models showing wet weather come to fruition, we could also see some strong winds.
Medium range models also indicate an active pattern from Friday the 20th through Christmas Day. There is some indication that a deep low will be off the coast of the Pacific Northwest with possibly a moist west/southwest flow into central and southern California. This typically is one of the wettest patterns we see for central California, however the predicted beginning of this pattern is still a week away.
Forecast: Areas of night and morning fog and low clouds. Otherwise, expect variable cloudiness through Friday night. mostly cloudy Saturday through Sunday morning with a chance of light showers Saturday through Saturday evening. Partly cloudy and cooler Sunday. Mostly clear to occasionally partly cloudy Sunday night through Tuesday with areas of night and morning fog and low clouds. Increasing cloudiness Tuesday night with an increasing chance of rain Wednesday and Wednesday night. partly cloudy Thursday with areas of fog and low clouds Thursday morning.
Short Term:
Madera 63/42/63/46/57 | Reedley 65/42/64/48/58 | Dinuba 64/41/63/46/57 | |
Porterville 66/42/63/46/59 | Lindsay 65/41/64/46/58 | Delano 66/43/63/48/59 | |
Bakersfield 67/50/66/53/60 | Taft 65/52/65/53/60 | Arvin 68/43/66/47/61 | |
Lamont 66/47/66/49/60 | Pixley 66/41/63/45/60 | Tulare 64/41/63/45/58 | |
Woodlake 64/41/63/44/59 | Hanford 66/43/63/46/58 | Orosi 64/40/63/43/58 |
Seven Day Forecast:
Sunday
Partly cloudy 41/55 |
Monday
Patchy fog/mostly clear 33/54 |
Tuesday
Patchy fog/partly cloudy 31/55 |
Wednesday
Chance of rain 39/57 |
Thursday
Showers possible 36/58 |
Two Week Outlook: December 19 through Christmas: 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 Friday night will be generally at or less than 6 MPH with periods of near calm conditions. Later Saturday through Sunday, winds will be out of the northwest at 8 to 15 MPH with stronger gusts, mainly along the west side. Also, there is one model showing an intense low off the northern California coast next Tuesday night and Wednesday. in theory, this could produce strong winds, especially in Kern County. Others do not show this pattern setting up, indicating winds will be much lighter.
Rain: The chance for light showers Saturday through Saturday evening appears a bit higher this morning as a weakening cold front moves down the valley. For now, it appears the highest amounts of rain would be no more than .10 with this system with most locations recording trace amounts to a few hundredths. Dry weather will return later Saturday night through Tuesday. Models are varying on the path and strength of a storm off the northern California coast Wednesday morning. Two models show a good amount of precip spreading over central California while two others show the center of the low considerably further off shore for light amounts of rain, if any falls at all. Even though there are differences on models for the 19th through the 25th, there is some indication of a significant trough of low pressure moving through during that time frame for a reasonably decent chance of rain during the week preceding Christmas.
Frost Discussion: Expect conditions to remain above freezing through Sunday morning. A somewhat colder air mass will overspread central California Saturday night and Sunday. Most models have frost stations well down into the 30s Monday and Tuesday mornings with a small chance of upper 20s in river bottom and similar locations. Northwest winds will blow down the valley Saturday into Sunday, lowering dew points, but this is more or less a typical air mass moving in. above freezing conditions can be expected Wednesday and Thursday due to increasing cloud cover with a chance of rain. For now, the pattern appears safe all the way through Christmas, although some models are showing a bitterly cold air mass diving southward into the middle of the country beginning the 27th. These air masses deserve close scrutiny, but for now so far so good.
Afternoon Dew Points Today: Upper 40s to the lower 50s. Kern: Upper 40s to the lower 50s. Humidity values ranging from 65%/100% at Hanford. Bakersfield 55%/100%
Actual Humidity range December 11, 2019: Delano, 100%/78% Porterville, 99%/71%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 40%, tomorrow 40%. Bakersfield: Today: 50% Tomorrow: 50%
ET Rates Over the Past Seven Days: Stratford .20, Parlier .22, Blackwell Corner .26, Arvin .32, Orange Cove .27, Porterville .28, Delano .28. 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: 69/18. Average Temperatures: 55/35
Heating Degree Days this Season: 512 -198
Courtesy of the NWS
Average temperature for December so far: 53.0- +7.3
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2018 Fresno: 2.47 season. or +.26. Month to Date: 1.75 +1.24
Since Oct 1, 2018, Bakersfield: 1.58, or +.33. Month to Date: .51 +.20
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove 201, Parlier 256, Arvin 146, Shafter 179, Stratford 196, Delano 219, Lindcove 232, Porterville 374
Hours at 45 or below 45.
Sunrise: 7:03 Sunset: 4:43 pm. Hours of Daylight: 9:41
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 53 / 48 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 52 / 46 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 54 / 47 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 51 / 46 / 0.00 /
BFL : Bakersfield Airport 496 : DHM / 59 / 44 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 55 / 47 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 61 / 46 / 0.00 /
TFTC1 : Taft 759 : DH1554 / 59 / 41 / 0.00 /
Rainfall: Water year Oct 1st through September 30th
24hr season % last year % Ave. 365 day ave.
STOCKTON 0.00 4.00 125 3.87 121 3.21 14.06
MODESTO 0.00 2.78 105 3.05 115 2.66 13.11
MERCED 0.00 4.52 192 2.69 114 2.35 12.50
MADERA 0.00 1.90 78 2.42 99 2.45 12.02
FRESNO 0.00 2.47 112 1.92 87 2.21 11.50
HANFORD 0.00 1.75 98 1.71 96 1.78 10.10
BAKERSFIELD 0.00 1.58 126 1.20 96 1.25 6.47
BISHOP 0.00 1.06 103 1.31 127 1.03 5.18
SALINAS 0.00 4.09 157 3.87 149 2.60 12.83
PASO ROBLES 0.00 4.70 213 2.84 129 2.21 12.78
Next report: Thursday afternoon/December 12