December 14, 2018
Summary: A blanket of high clouds based at between 2,000 and 2,500 feet moved in from the southwest overnight, resulting in fairly mild temperatures. Most frost stations were in the mid to upper 30s. One of those quirks of nature occurred overnight. We have a surface high centered over the Great Basin which is generating a weak off shore flow. Despite this, conditions in the upper atmosphere created very strong, gusty winds near the bottom of the Grapevine where winds peaked at 75 MPH. so far, these winds have been very localized. Edison was reporting winds out of the east at just 16 MPH and in the Maricopa area, I don’t have an anemometer to gauge wind speeds, but temperatures shot up to 61 in a short time, indicating strong downslope winds there. Winds are still gusting to 45 MPH at the bottom of the Grapevine but I do look for these winds to decrease as the days wears on.
Otherwise, the mass of high clouds currently streaming through ahead of a weak trough of low pressure should be east of the Sierra Nevada by late tonight. Weak ridging will occur Saturday into Sunday for areas of fog Sunday morning. A stronger trough will begin to bear down on central California later Sunday night and Monday. The most recent quantitative precipitation estimates on models are not impressive. Generally, less than .25 is expected in the wet spots with lesser amounts elsewhere.
This will be a one storm event as a strong upper level high centered off the southern California coast will build northward and eastward, driving the storm track northward into the Pacific Northwest. As the typical wintertime warm air inversion develops, fog will become more widespread with each passing day, more than likely lifting into a low, gray overcast with a chance of afternoon clearing at any given location.
Some models show a weak trough moving through Saturday, but with no rain. It is possible it could weaken the inversion enough to briefly break up the fog situation, but that’s tentative at best. After next weekend, dry weather will continue as a flat zone of high pressure will be dominant off the central and southern California coast as storm after storm moves into the Pacific Northwest. One model does suggest a possible change after Christmas, but that’s currently a shot in the dark.
Forecast: Mostly cloudy through about midnight. Becoming partly cloudy later Friday night through Saturday night with areas of night and morning fog. Increasing cloudiness Sunday with light rain becoming likely over Fresno and Madera Counties at times through Monday with light showers likely in the south valley. Mostly cloudy Monday night and Tuesday morning, clearing Tuesday afternoon. Widespread fog and/or low clouds developing by Wednesday morning with generally fog and/or low clouds Wednesday night through Friday with a chance of partial afternoon clearing.
Short Term:
| Madera 61/36/60/37/62 | Reedley 60/36/61/38/63 | Dinuba 59/35/59/37/62 | |
| Porterville 63/36/60/37/64 | Lindsay 62/34/60/36/63 | Delano 63/38/63/38/65 | |
| Bakersfield 65/42/63/43/68 | Taft 66/45/64/45/67 | Arvin 67/41/63/42/68 | |
| Lamont 65/40/64/39/67 | Pixley 62/36/62/38/63 | Tulare 60/35/60/37/62 | |
| Woodlake 61/35/60/37/63 | Hanford 61/37/60/38/64 | Orosi 60/34/60/35/62 | |
Seven Day Forecast:
| Monday
Light rain likely 49/59 |
Tuesday
Mostly cloudy 43/59 |
Wednesday
AM fog/PM sun 43/56 |
Thursday
AM fog/PM sun 43/54 |
Friday
AM fog/PM sun 45/52 |
Two Week Outlook: December 22 through December 28: This model now shows a blocking pattern as a high pressure system parks itself off the California coast, driving the storm track into British Columbia and the Pacific Northwest. The chance of rain will be low with temperatures above the valley floor running above average. Temperatures on the valley floor will be determined by the amount of fog and low clouds.
December: It’s been quite some time since this model has actually projected above average precipitation, but the good news is that is the case. It appears the dominant pattern for the month will maintain winds generally out of the west or northwest, which would favor above average temperatures.
December, January, February: It’s been a long time since the 90 day outlook projected above average precipitation for December through February, in other words the winter months. It also continues the better than even chance that over the next three months, temperatures will largely be above average. However, like any winter there will be below average periods as well.
Winds: Winds will be generally at or less than 6 MPH through Sunday. The only exception to that will be in the extreme south valley where seemingly a quirk of nature is occurring with strong downslope winds making it into the extreme south valley. Winds have gusted to 75 MPH overnight at the bottom of the Grapevine, but most locations are reporting light winds with the exception of Edison which has winds out of the east at 16 and some locally strong, gusty winds up in the Maricopa area. These winds will slowly decrease this morning and theoretically will end by this afternoon. Winds Sunday night and Monday will be out of the southeast at 5 to 15 MPH with locally stronger gusts, mainly from Fresno County northward.
Rain: The chance for light precipitation will begin to pick up later Sunday night with periods of light rain Monday, especially during the first half of the day. South of Fresno County, for now it appears just light showers will occur, ending by late Monday afternoon. Latest estimates from models show generally at or less than .25 over Fresno and Madera Counties, .10 in Kings and Tulare Counties and generally at or less than .10 over the valley portion of Kern County. Dry weather will return Monday night and continue for the rest of next week and well into the following week. Medium range models continue to point to dry weather, although one model is suggesting a possible change after Christmas. This could cause the storm track to migrate back further south, but we’ll take that with a grain of salt for now.
Frost Discussion: Most locations were in the mid to upper 30s this morning then the clouds arrived, ending any additional reduction in temperatures. There were some notable exceptions, however. Wind conditions at Maricopa drove the temperature to 61 degrees by 6:00am. These winds will die off over the next several hours, so locations like Maricopa will have much cooler temperatures tonight.
We should see clouds increasing Sunday morning ahead of the next Pacific storm which will drop light rain on the valley later Sunday night and Monday. Next week, all locations will remain above freezing each day, although temperatures Wednesday and Thursday could dip down to 34 to 36 or so, assuming the fog doesn’t take over.
The remainder of next week and beyond will continue to see a dominant westerly flow across the Pacific and into California, preventing polar air masses from having any impact on California.
Afternoon Dew Points Today: Low to mid 40s. Kern: Mid to upper 30s.
Humidity: Porterville: 55%/100%, Bakersfield: 55%/70%
Actual Humidity December 13, 2018: Delano, 100%/55%, Porterville, 99%/54%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 60% tomorrow 50% Bakersfield: Today: 60% Tomorrow: 60%
ET Rates Over the Past Seven Days: Stratford .15, Parlier .15, Blackwell .21, Lindcove .14, Arvin .27, Orange Cove .18, Porterville .15, Delano .18 Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 56, Parlier 54, Blackwell 55, Lindcove, 59, Arvin, 54, Orange Cove 54, Porterville 53, Delano 52
Record Temperatures: 71/21. Average Temperatures: 55/35
Heating Degree Days this Season: 528 -223
Courtesy of the NWS
Average temperature for December so far: 49.0 +3.6
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2018 Fresno: 1.92 season. or -.39, Month to Date: .15 -.46
Since Oct 1, 2018, Bakersfield: 1.20, or -.11. Month to Date: .52 +.15
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove, 238, Parlier, 262 , Arvin, 203 Shafter, 277 Stratford, 234, Delano 252, Lindcove, 362, Porterville, 507
. Hours at 45 or below 45.
Sunrise: 7:04 am Sunset: 4:44 pm. Hours of Daylight: 9:41
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 62 / 42 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 60 / 39 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 58 / 35 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 58 / 34 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 61 / 40 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 59 / 38 / 0.00 /
ATEC1 : Avenal 787 : DH1554 / 62 / 36 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 62 / 36 / 0.00 /
TFTC1 : Taft 759 : DH1533 / 58 / 41 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 58 / 36 / 0.00 /
Rainfall: Water year Oct 1st through September 30th
24hr Season % L.Y. % Ave. Ave. yearly total
STOCKTON 0.00 3.87 116 0.91 27 3.34 14.06
MODESTO 0.00 3.05 110 0.98 35 2.78 13.11
MERCED 0.00 2.69 111 1.03 42 2.43 12.50
MADERA 0.00 2.42 95 0.32 13 2.55 12.02
FRESNO 0.00 1.92 83 0.37 16 2.31 11.50
HANFORD 0.00 1.71 92 0.37 20 1.85 10.10
BAKERSFIELD 0.00 1.20 92 0.03 2 1.31 6.47
BISHOP 0.00 1.31 121 0.16 15 1.08 5.18
SALINAS 0.00 3.87 143 0.75 28 2.71 12.83
PASO ROBLES 0.00 2.84 122 0.25 11 2.33 12.78
SANTA MARIA 0.00 1.95 72 0.09 3 2.69 13.95
Next report: Friday December 14/pm