Christmas Day, 2018
Summary: The bulk of the precipitation has now moved into Kern County as the low, which is now centered near Vandenberg, will move southward just off the southern California coast. Freezing levels have dropped considerably. This time yesterday, the freezing level near Vandenberg was near 12,000 feet. This morning, it was down to 6,100 feet further north over Oakland, the freezing level was pegged at 5,600 feet.
What is left of the shower activity, mainly over Kern County, will end over the next few hours. As the day wears on, clearing will occur north of Fresno county and along the west side as a colder air mass moves in on a northwesterly flow, both at the surface and aloft. Local frost is possible tonight, but generally in just a few areas. My feeling is, upslope clouds will bank up against the Kern County mountains and the Sierra Nevada, maintaining a good deal of cloud cover over the eastern and southern flanks of the valley.
A fast moving cold low will drop southeastward into the Great Basin Thursday. Behind this system, the winds both at the surface and aloft will become off shore. Aloft, the flow will be out of the northeast, pumping colder and drier air down the valley.
Frost will be likely Friday through Sunday mornings unless fog and low clouds take over. There are occasions where these off shore winds simply blow over the top of the valley, leaving the lower few thousand feet undisturbed. This would allow fog and low clouds to remain in place. Some models this morning show a low almost right over central California New Year’s Eve then dropping into southern California New Year’s Day. This could result in a chance of showers, although I don’t put too much stock in this at the moment.
It’s looking better and better that we will avoid a cold weather episode the first week in January. For the second day in a row, models show westerly winds aloft breaking in. this would block any potential arctic air masses from moving south with valley citrus remaining comfy.
Forecast: Showers the next few hours over Kern County then ending. Otherwise, it will be partly to mostly cloudy today through Wednesday morning except along the west side where skies will be mostly clear to partly cloudy with areas of ground fog. Partly cloudy Wednesday afternoon through Thursday with areas of night and morning fog and low clouds. Clearing Thursday night then mostly clear Friday through Saturday night. increasing cloudiness Sunday leading to a slight chance of showers Sunday night and Monday. Mostly cloudy Monday night and Tuesday.
Short Term:
| Madera 54/35/54/34/53 | Reedley 54/36/54/34/52 | Dinuba 55/34/53/33/53 | |
| Porterville 53/38/54/36/52 | Lindsay 53/38/54/32/52 | Delano 55/39/54/35/53 | |
| Bakersfield 53/41/54/39/54 | Taft 54/41/54/38/53 | Arvin 53/40/54/36/53 | |
| Lamont 55/40/54/37/53 | Pixley 54/36/54/34/53 | Tulare 53/35/54/32/53 | |
| Woodlake 55/36/54/32/52 | Hanford 55/37/55/34/53 | Orosi 54/35/54/34/52 | |
Seven Day Forecast:
| Friday
AM fog/PM sun 31/52 |
Saturday
AM fog/PM sun 27/53 |
Sunday
AM fog/PM sun 28/54 |
Monday
Slight chance of showers 38/55 |
Tuesday
Mostly cloudy 33/54 |
Two Week Outlook: January 1 through January 7: This model still indicates possibly well below average temperatures during the first week of January. A blocking ridge of high pressure appears anchored off the Pacific coast, so the chance of precipitation remains low.
January: This model shows generally above average temperatures for January over the western one-third of the United States while near to below average temperatures will prevail east of the Rockies. There is no firm indicator of really above or below average precipitation although it does forecast below average rain in the Pacific Northwest.
January, February, March: The western half of the United States is projected in a very general sense to have above average temperatures for the next 90 days. Like the 30 day outlook, it seems to want to project near average precipitation, which would be nice.
Winds: Winds later today will be out of the northwest at 10 to 15 MPH with stronger gusts possible. Gusts to 25 MPH are possible in western Fresno and Kings Counties. Winds tonight will be mainly out of the northwest at 5 to 10 MPH. winds Wednesday will be generally less than 7 MPH with periods of near calm conditions. Winds Thursday through Thursday night will increase along the west side at 10 to 20 MPH out of the north with stronger gusts, continuing Friday.
Rain: The precipitation from this event is just about over. The only showers showing up on radar at this time are over Kern County and those showers will move into the mountain areas over the next hour or so. Dry weather can be expected for the remainder of the day and will continue through next Sunday. Some models are indicating a low formation dropping southward into central California New Year’s Eve into New Year’s Day with a chance of showers. Since this is the first time this has shown up, we’ll use the phrase slight chance of showers. After New Year’s Day, several days of dry weather can be expected.
Frost Discussion: All locations will be above 32 degrees tonight. A few isolated river bottom type locations may dip down to 31 or 32 where cloud cover is absent and winds are near calm. On Thursday morning, at this time I anticipate temperatures between 30 and 37. This may change, however, as a rapidly moving low pressure system will move through the Great Basin Thursday through Thursday evening, possibly spreading some cloud cover over the area. From Friday through Sunday mornings, temperatures down into the 26 to 28 degree range in coldest locations are certainly possible with 28 to 32 degree temperatures on a widespread basis.
There are two possible outcomes from Friday through Sunday. A colder, drier air mass will be moving in at the surface and aloft out of the northeast. Theoretically, this scours out the valley of its fog and low clouds, leading to radiational cooling. The other possibility is that this flow will blow over the top of the valley, leaving the lower few thousand feet unscathed and allowing for widespread fog and low clouds, thus keeping temperatures somewhat milder.
New Year’s Eve and Day may be above freezing. Some models are now projecting a low dropping south over central California with even a small chance of light showers. Models for the first week in January continue to look better and better. Instead of polar air driving southward into the western U.S., a westerly flow is shown moving across the eastern Pacific and into the British Columbia and the Pacific Northwest. This would effectively keep polar air well to our north with acceptable temperatures in the valley. Still not eliminating the possibility of an arctic air invasion, but if models continue on the path they’re currently on, it would be a great thing.
Afternoon Dew Points Today: Mid to upper 40s. Kern: Mid to upper 40s.
Humidity: Porterville: 75%/100%, Bakersfield: 70%/95%
Actual Humidity December 24, 2018: Delano, 100%/61% Porterville, 96%/65%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 30%, tomorrow 50% Bakersfield: Today: 10% Tomorrow: 40%
ET Rates Over the Past Seven Days: Stratford .21, Parlier .19, Blackwell .26, Lindcove .16, Arvin .32, Orange Cove .20, Porterville .19, Delano .25 Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 55, Parlier 54, Blackwell 55, Lindcove, 59, Arvin, 54, Orange Cove 56, Porterville 54, Delano 52
Record Temperatures: 72/20. Average Temperatures: 53/35
Heating Degree Days this Season: 683 -299
Courtesy of the NWS
Average temperature for December so far: 49.7 +5.0
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2018 Fresno: 2.33 season. or -.56, Month to Date: .56 -.73
Since Oct 1, 2018, Bakersfield: 1.20, or -.49. Month to Date: .52 -.23
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove, 288, Parlier, 316 , Arvin, 244 Shafter, 333 Stratford, 292, Delano 309, Lindcove, 465, Porterville, 654
. Hours at 45 or below 45.
Sunrise: 7:10 am Sunset: 4:49 pm. Hours of Daylight: 9:39
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 61 / 41 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 58 / 48 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 59 / 40 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 60 / 36 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 61 / 44 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 59 / 44 / 0.00 /
ATEC1 : Avenal 787 : DH1556 / 62 / 39 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 58 / 48 / 0.00 /
TFTC1 : Taft 759 : DH1546 / 60 / 43 / 0.00 /
Rainfall: Water year Oct 1st through September 30th
24hr Season % L.Y. % Ave. Ave. yearly total
STOCKTON 0.09 5.09 122 0.96 23 4.18 14.06
MODESTO 0.00 4.20 118 1.03 29 3.56 13.11
MERCED 0.00 3.56 117 1.11 37 3.03 12.50
MADERA 0.00 2.85 88 0.41 13 3.24 12.02
FRESNO 0.00 2.27 76 0.41 14 2.99 11.50
HANFORD 0.00 1.80 71 0.41 16 2.53 10.10
BAKERSFIELD 0.00 1.20 71 0.07 4 1.69 6.47
BISHOP 0.00 1.31 96 0.16 12 1.37 5.18
SALINAS 0.03 4.50 132 0.78 23 3.42 12.83
PASO ROBLES 0.00 3.52 113 0.27 9 3.11 12.78
SANTA MARIA 0.00 2.29 66 0.12 3 3.48 13.95
Next report: Christmas afternoon