December 21, 2018
Summary: There are two to four layers of clouds over the valley this morning. There is fog and low clouds based at very low elevations and a thick mass of mid and high clouds, mainly from Fresno County south, with a few sprinkles even occurring. All these subtropical clouds are ahead of a weak wave of low pressure which will move through later this afternoon. The higher cloud deck will slowly break off to the east, leading to mostly to partly cloudy skies this afternoon. A northwest push of air will move down the valley tonight, possibly breaking up the inversion. This would result in cloudiness against the valley facing slopes of the Sierra and Tehachapi Mountains, which may very well last through Saturday morning.
From Saturday through Monday, a west/northwest flow across the Pacific will continue with weak disturbances cutting through from time to time, none of which will have enough energy for precipitation with the possible exception of the Sierra Nevada from Yosemite north.
We are still on for our Christmas storm. The arrival time of the precipitation is a few hours later than previously indicated. The chance of light rain will arrive in Madera and Fresno Counties north about midnight or after with light showers spreading south over the valley later in the morning hours. There will be a chance of light showers Christmas afternoon, ending by early evening.
A strong northwesterly push of air will follow with plenty of upsloping occurring against the Sierra and the Kern County mountains with very slow clearing. A second system will follow about a day and a half later but it will be dry though a tad colder than the Christmas system.
Some modeling this morning concerns me for the last few days of this month and the first few days of January. This is a different scenario than we’ve been looking at. A massive high is shown building over the eastern Pacific and ridging northward into Alaska while a low carves itself out over southern California or the Desert Southwest. This, in theory, would create a north/south overland flow into California for a possible freeze threat. This is the first model run that has come up with this pattern so confidence this far out is low. Nevertheless, it is a freeze pattern and traditionally cause us all kinds of problems. Let’s hope this changes so 2019 gets off to a better start. By the way, this is the winter solstice today, the shortest day of the year. The solstice officially occurs at 2:23 this afternoon. Only nine hours and thirty eight minutes of possible sunshine. Beginning tomorrow, the days get very slowly longer.
Forecast: Widespread fog and/or low clouds this morning. Partly to mostly cloudy this afternoon through Saturday morning. Variable cloudiness at times Saturday through Monday morning with areas of night and morning fog possible. Increasing cloudiness Monday afternoon. Light rain spreading as far south as Madera and Fresno Counties beginning about midnight, making for a chillier ride for Santa. Light rain or showers through Christmas morning with a chance of light showers for a time during the afternoon. Mostly cloudy Christmas night through Wednesday morning. Partly cloudy Wednesday afternoon through Friday with areas of night and morning fog.
Short Term:
Madera 57/41/56/39/57 | Reedley 57/40/56/41/57 | Dinuba 56/42/56/39/56 | |
Porterville 59/41/56/38/58 | Lindsay 58/39/57/37/58 | Delano 58/43/56/41/58 | |
Bakersfield 60/46/58/44/57 | Taft 60/48/58/46/58 | Arvin 61/44/56/43/58 | |
Lamont 59/44/59/44/58 | Pixley 58/43/58/44/58 | Tulare 56/42/56/38/56 | |
Woodlake 58/41/56/39/57 | Hanford 57/43/56/39/57 | Orosi 59/39/57/37/57 |
Seven Day Forecast:
Christmas Eve
PM showers 40/60 |
Christmas
Light showers 45/58 |
Wednesday
Mostly cloudy 41/55 |
Thursday
AM fog/partly cloudy 37/56 |
Friday
AM clouds/mostly cloudy 40/55 |
Two Week Outlook: Christmas Day-December 31: This model is indicating a colder weather pattern will settle in over the western 2/3 of the U.S. It also indicates there’s an equal chance of dry and wet weather. Other models show generally dry weather between the 26 and January 1. Temperatures would be below seasonal average.
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 below 6 MPH through Sunday with periods of near calm conditions. Winds Christmas Eve will be out of the southeast at 5 to 15 MPH through late evening. Winds will be out of the northwest Christmas Day at 10 to 20 MPH, diminishing during the evening hours.
Rain: There’s actually been a few sprinkles this morning from an abundance of subtropical moisture moving through in the form of thick mid and high level clouds. These clouds will slowly move southeastward out of the valley this morning, replaced by a weak wave of low pressure bringing a few sprinkles this afternoon. Expect dry weather tonight through the daylight hours Christmas Eve. The chance for light rain for Fresno and Madera Counties will increase closer to midnight with periods of light rain during the early morning hours and through the first half of the day. South of Fresno County, expect light showers during the early morning hours Christmas with a small chance during the afternoon. Conditions will again turn dry Christmas night and, unfortunately for now, appears it will be dry for the day after Christmas through the first few days of January.
Frost Discussion: All locations will be above 32 degrees each night through at least Wednesday. On Wednesday, a weak weather system will move through and carve out a low pressure system over the Desert Southwest Thursday with no precipitation in conjunction with it. After Thursday, we will be on the eastern side of upper level high pressure with a low over the Desert Southwest, creating a dry northwest flow. Once we get closer to the New Year, I have a lot to be concerned about. A massive upper high will build over the eastern Pacific and ridge far to the north into Alaska while a low center develops near southern California or possibly Arizona. If this scenario plays out as models indicate, modified polar air would drop southward into the western states and into California. This basic scenario is a freeze pattern but it is certainly a low confidence forecast as this is the first set of model runs showing this particular pattern. For now, we’ll just keep an eye on it and pray this is an aberration that hopefully changes with time.
Afternoon Dew Points Today: Upper 40s to the lower 50s. Kern: Upper 40s to the lower 50s.
Humidity: Porterville: 80%/100%, Bakersfield: 70%/95%
Actual Humidity December 20, 2018: Delano, 100%/78% Porterville, 99%/50%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 10%, tomorrow 20% Bakersfield: Today: 0% Tomorrow: 40%
ET Rates Over the Past Seven Days: Stratford .29, Parlier .29, Blackwell .36, Lindcove .26, Arvin .37, Orange Cove .30, Porterville .29, Delano .30 Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 55, Parlier 53, Blackwell 54, Lindcove, 58, Arvin, 53, Orange Cove 54, Porterville 52, Delano 51
Record Temperatures: 71/23. Average Temperatures: 54/35
Heating Degree Days this Season: 631 -267
Courtesy of the NWS
Average temperature for December so far: 49.3 +4.4
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2018 Fresno: 2.27 season. or -.44, Month to Date: .50 -.51
Since Oct 1, 2018, Bakersfield: 1.20, or -.34. Month to Date: .52 -.08
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove, 288, Parlier, 316 , Arvin, 241 Shafter, 333 Stratford, 292, Delano 309, Lindcove, 422, Porterville, 601
. Hours at 45 or below 45.
Sunrise: 7:08 am Sunset: 4:47 pm. Hours of Daylight: 9:38
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 62 / 38 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 59 / 41 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 58 / 37 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 54 / 36 / M /
BFL : Bakersfield Airport 496 : DH1500 / 56 / 42 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 58 / 36 / M /
ATEC1 : Avenal 787 : DH1541 / 63 / 38 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 63 / 36 / 0.00 /
TFTC1 : Taft 759 : DH1508 / 62 / 44 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 58 / M / M /
Rainfall: Water year Oct 1st through September 30th
24hr Season % L.Y. % Ave. Ave. yearly total
STOCKTON 0.00 5.00 130 0.96 25 3.85 14.06
MODESTO 0.00 4.20 129 1.03 32 3.25 13.11
MERCED 0.00 3.56 127 1.11 40 2.80 12.50
MADERA 0.00 2.85 96 0.41 14 2.98 12.02
FRESNO 0.00 2.27 84 0.41 15 2.71 11.50
HANFORD 0.00 1.80 80 0.41 18 2.25 10.10
BAKERSFIELD 0.00 1.20 78 0.07 5 1.54 6.47
BISHOP 0.00 1.31 106 0.16 13 1.24 5.18
SALINAS 0.00 4.47 142 0.78 25 3.14 12.83
PASO ROBLES 0.00 3.52 126 0.27 10 2.80 12.78
SANTA MARIA 0.00 2.29 72 0.12 4 3.16 13.95
Next report: Friday afternoon/December 21