Summary: The time could not be more appropriate to issue in the coldest air mass of the season so far. Winter officially begins at 8:28 this morning, so here we are with the longest nights of the year.
The low pressure system which resulted in scant amounts of precipitation at most locations yesterday has already barreled eastward and is centered over Utah this morning.
In the meantime, upper level high pressure has become reestablished over and along the west coast, creating a temporary northerly flow aloft. Dew points fell all night and are generally in the mid 20s to the lower 30s.
With low dew points and a now cold air mass on the valley floor, very cold temperatures can be expected for the next few nights, especially tonight and Friday night/Saturday morning. Widespread low to mid 20s are likely both nights with only minor modification Christmas Eve and Christmas Day. Interestingly enough, one model shows another fast moving cold front moving down the valley about the middle of next week with another blast of modified Arctic air moving into California. Another projection places strong upper level high pressure over the region with no Arctic air moving in.
The model favoring that cold front moving through has been fairly accurate of late, so for now I’ll take it seriously.
Overall, through the first few days of January, models show a blocking pattern along the west coast with little, if any, chance of rain. The two week model is out this morning and is calling for temperatures to rise to above average values with only a low chance of precipitation.
Forecast: Mostly clear skies through Christmas Day with cold nights. Mostly clear skies will continue Christmas night through Thursday.
Short Term:
| Madera 52/23/55/24/59 | Reedley 53/23/55/23/57 | Dinuba 52/22/55/23/57 | |
| Porterville 53/24/56/24/58 | Lindsay 53/22/56/23/58 | Delano 54/25/56/25/58 | |
| Bakersfield 54/28/59/28/60 | Arvin 54/24/58/24/60 | Taft 55/27/59/29/60 | |
| Lamont 54/24/59/24/59 | Pixley 53/23/55/24/58 | Tulare 52/22/55/23/57 | |
| Woodlake 52/23/56/23/59 | Hanford 53/23/56/24/58 | Orosi 52/22/56/23/59 | |
Seven Day Forecast:
| Sunday
Mostly clear 27/62 |
Christmas Day
Mostly clear 28/62 |
Tuesday
Mostly clear 29/64 |
Wednesday
Mostly clear 29/64 |
Thursday
Mostly clear 26/57 |
Two Week Outlook: December 28 through January 3: This model indicates a ridge of upper level high pressure will be off shore and over the western states with daytime temperatures reaching above average values. Overnight lows may still chill to below average. The chance of precipitation during this period appears quite low.
January: Overall during January this season, temperatures should range somewhat above average. This model also shows equal chances of near average precipitation over the northern half of the state but below average precip over the southern half of California. We remain between these two forecasts, so hopefully precipitation will be near seasonal levels.
January, February, March: This model is not hopeful for above average precipitation, or even average precipitation. Overall, upper level high pressure is projected to be the most dominant feature for the next three months, resulting in average temperatures.
Winds: Winds will be generally less than 10 MPH with periods of near calm conditions through Sunday.
Rain: Expect dry conditions for at least the next seven to ten days.
Frost: As of 6:00am, the coldest temperature I could find was 26 at Sanger with most other locations in the upper 20s and lower 30s. As expected, local wind conditions and mixing played a large role last night. the upslope clouds evident in Kern County have now dissipated with the only cloud cover as of the time of this writing being in eastern Fresno County. Even that will dissipate during the course of the morning.
So, here we have it. The first day of winter and the coldest air mass of the season now in place. Dew points really tumbled during the course of the night and will likely end up in the upper 20s to the lower 30s by mid afternoon. With clear skies and little or no wind, strong radiational cooling will occur tonight and again Friday night.
Coldest overnight lows tonight will range between 21 and 23 with most flatland locations ranging from 23 to 27 degrees. Hillsides will be a bit warmer as a warm air inversion slowly begins to develop. The inversion tonight will be a bit better with temperatures at 34 feet ranging from 3 to 6 degrees warmer. Coldest unprotected locations will reach 32 degrees by 8:00 or 9:00 pm and not rise above freezing until about 8:00 or 9:00 Friday morning. I would anticipate the timing Friday night to be similar.
Slight moderation will occur Christmas Eve and Christmas Morning, but even so I’m anticipating widespread mid to upper 20s with low to mid 30s on the hillside locations.
Something new has shown up on models this morning. One solution for the period of Wednesday through Friday of next week is another fast moving dry cold front moving down the valley Wednesday with another strong north to northeast flow behind the front. This would bring another shot of modified Arctic air.
Others show strong upper level high pressure over the region, maintaining above average daytime temperatures. However, the main model which has been the most accurate the past few weeks is one of the ones showing another possible Arctic outbreak, again that’s beginning next Wednesday. Since review on models vary considerably, this is by no means a given, but considering the trend of the season and the accuracy of this model in the past, I definitely want to keep a close eye on it.
Lows Tonight:
| Terra Bella
22 |
Porterville
24 |
Ivanhoe
23 |
Woodlake
24 |
| Strathmore
24 |
McFarland
23 |
Ducor
25 |
Tea Pot Dome
24 |
| Lindsay
23 |
Exeter
22 |
Famoso
25 |
Madera
23 |
| Belridge
24 |
Delano
25 |
North Bakersfield
25 |
Orosi
23 |
| Orange Cove
24 |
Lindcove
22 |
Lindcove Hillside
30 |
Sanger River Bottom
21 |
| Root Creek
23 |
Venice Hill
24 |
Rosedale
25 |
Jasmine
24 |
| Arvin
24 |
Lamont
24 |
Plainview
23 |
Mettler
26 |
| Edison
25 |
Maricopa
25 |
Holland Creek
26 |
Tivy Valley
24 |
| Kite Road South
27 |
Kite Road North
24 |
AF=Above Freezing
Afternoon Dew Points Today: Mid 20s to the lower 30s. Kern, mid to upper 20s
Humidity, Visalia, 45%/95% Bakersfield, 40%/75%
Actual Humidity December 19, 2017: Delano, NA, Porterville, 90%/24%
Percentage of Sunshine Today/Tomorrow: Visalia: Today 30% tomorrow 80%, Bakersfield: Today 10% tomorrow 70%.
ET Rates Over the Past Seven Days December 19, 2017: Stratford .45, Parlier .36, Blackwell, .53 Lindcove .38, Arvin .49, Orange Cove .43, Porterville .36, Delano .NA., Madera Two .36. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 49, Parlier 49, Blackwell 53, Lindcove, 54, Arvin, 52, Orange Cove 49, Porterville 49, Delano NA, Madera Two 51
Mean Temperatures for December. Month So Far: 47.1 +2.1
Record Temperatures: 70/24. Average Temperatures: 54/35
Heating Degree Days this Season: 640, -237 Courtesy of the NWS
Precipitation: Seasonal total/average/above or below average:
Since December 19, 2017 Fresno: .37 season. or -2.28. Month to Date: T
Since December 19, 2017, Bakersfield: .03, or -1.48, Month to Date: ..00
Water year season is from October 1st through September.
Chilling ours November 1st through February 28: Orange Cove, 334, Parlier, 363, Arvin, 298, Shafter, 411, Stratford, 365, Madera two, 512, Alpaugh, NA, Delano, NA, Lindcove, 342, Porterville, 496. Hours at 45 or below 45.
Sunrise: 7:08 am Sunset: 4:46 pm. Hours of Daylight: 9:37
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 55 / 46 / 0.09 /
FAT : Fresno Airport 333 : DH1600 / 54 / 44 / 0.04 /
HJO : Hanford Airport 242 : DH1600 / 55 / 39 / 0.04 /
NLC : Lemoore Naval AS 234 : DH1600 / 56 / 39 / 0.04 /
BFL : Bakersfield Airport 496 : DH1600 / 58 / 41 / 0.04 /
VIS : Visalia Airport 292 : DH1600 / 52 / 41 / 0.10 /
ATEC1 : Avenal 787 : DH1548 / 55 / 40 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 51 / 36 / 0.01 /
TFTC1 : Taft 759 : DH1549 / 58 / 37 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 55 / 37 / M /
Rainfall: Season % Last y. % Ave. Annual Ave.
STOCKTON 0.05 0.96 25 5.46 142 3.85 14.06
MODESTO 0.05 1.03 32 4.30 132 3.25 13.11
MERCED 0.08 1.11 40 3.72 133 2.80 12.50
MADERA 0.09 0.41 14 3.62 121 2.98 12.02
FRESNO 0.04 0.41 15 4.08 151 2.71 11.50
HANFORD 0.04 0.41 18 2.00 89 2.25 10.10
BAKERSFIELD 0.04 0.07 5 1.02 66 1.54 6.47
BISHOP T 0.16 13 0.15 12 1.24 5.18
SALINAS 0.03 0.78 25 3.82 122 3.14 12.83
PASO ROBLES 0.02 0.27 10 3.40 121 2.80 12.78
SANTA MARIA 0.03 0.12 4 4.02 127 3.16 13.95
Next Report: Thursday, December 21/pm