December 15, 2017
Summary: Strong upper level high pressure remains just off the California coast with a weak trough of low pressure moving through Oregon. That trough will enter northern California later today before moving through central California later tonight and Saturday morning. The inversion will remain tight through this evening, but with some luck, we will have an air mass exchange late tonight and Saturday as a northerly push of air moves in aloft and colder air begins to mix down to the valley floor. It may also be somewhat breezy Saturday, especially along the west side.
High clouds are already increasing from Fresno County northward and they will spread southward later today. Temperatures tonight may actually be above freezing at many locations due to cloud cover and the mixing of the atmosphere as the trough moves through. That will last exactly one night as upper level high pressure becomes reestablished Sunday through Tuesday with a northerly flow aloft and with at least a brief off shore flow Sunday and Monday.
By Wednesday, another weak trough passage will occur with no rain, but it will increase cloud cover again temporarily. Guess what? Strong upper level high pressure will rebound right back Thursday and on through next weekend.
We’ve been looking at a possible cold weather episode beginning the 23. So far, this is looking less likely. Some of this morning’s models show the upper high further east into California with cold air plunging southward into the Rockies and Midwest. If this occurs, potentially dangerous cold would not happen with the coldest air remaining well east of the Sierra Nevada.
Forecast: Slowly increasing high clouds today. Variable high clouds tonight and Saturday morning. Becoming mostly clear Saturday afternoon through Tuesday night. partly cloudy Wednesday and Wednesday night. becoming mostly clear Thursday and Friday.
Short Term:
| Madera 66/37/60/29/61 | Reedley 67/37/61/28/61 | Dinuba 66/36/60/28/60 | |
| Porterville 67/37/60/28/61 | Lindsay 67/35/61/27/61 | Delano 68/38/62/30/60 | |
| Bakersfield 69/41/60/33/63 | Arvin 71/38/62/32/63 | Taft 70/43/61/32/63 | |
| Lamont 70/40/61/33/62 | Pixley 68/37/61/28/61 | Tulare 66/37/60/27/60 | |
| Woodlake 66/37/59/27/59 | Hanford 67/38/60/28/61 | Orosi 66/35/60/28/60 | |
Seven Day Forecast:
| Monday
Mostly clear 27/60 |
Tuesday
Mostly clear 28/64 |
Wednesday
Partly cloudy 31/65 |
Thursday
Mostly clear 28/60 |
Friday
Mostly clear 29/64 |
Two Week Outlook: December 22 through December 28: This model is showing colder than average temperatures through the entire period as a colder air mass could potentially invade the area. It does not look encouraging for rainfall as upper level high pressure will remain along the west coast.
December: This model is indicating a better than even chance of above average temperatures for central and southern California all the way to the southeast with near to below average temperatures in the Pacific Northwest. As far as precipitation is concerned, this model does show better than average precip over Washington and Oregon and near average rainfall over central and northern California.
December, January, February: If this model is to be believed, winter this year will experience somewhat above average temperatures from California, stretching eastward and southward. Below average temperatures would prevail from the northern Rockies through the Plains states. As far as California is concerned, precipitation would be near to marginally below average with temperatures marginally above average, but take all this with a grain of salt.
Winds: Winds will be generally less than 10 MPH today through this evening with periods of near calm conditions. Winds late tonight and Saturday will be out of the northwest at 10 to 15 MPH with possible gusts to 25 MPH along the west side. Winds will diminish Saturday night with light winds Sunday and Monday.
Rain: Expect dry conditions for at least the next 7 to 10 days.
Frost: Temperatures at most locations were a degree or two warmer than 24 hours ago. As of 6:00am, the coldest locations were down to 26 to 27 but most other locations ranged between 28 and 32. Low to mid 30s were the norm in Kern County. Tonight, most if not all locations will be above freezing as a rapidly moving trough of low pressure moves through late tonight and Saturday morning. The combination of increasing mid and high level clouds and mixing of the atmosphere should keep temperatures up. This will be a one night stand, however, as a northerly flow will develop behind the trough, mixing colder air down to the valley floor. This will create below freezing conditions once again beginning Sunday, but more so Monday and Tuesday as readings again fall into the mid to upper 20s at many locations.
Wednesday morning is a bit up in the air at this time. We may or may not see cloud cover from another trough passage.
Skies will clear Thursday and Friday with coldest locations below freezing.
The inversion tonight will be strong with temperatures at 34 feet being 5 to 8 degrees warmer, though that may weaken after midnight.
Medium range outlooks are a bit more encouraging this morning as far as a potential freeze pattern from the 23 on. Some models are showing strong upper level high pressure over the western one-third of the country with arctic air plunging into the Rockies and Midwest instead of over the west coast. If it happens this way, we would avoid a dangerous situation. There’s still a long way to go and models could flip flop back to a colder solution, but for now it gives me a bit more hope.
Lows Tonight:
| Terra Bella
AF |
Porterville
AF |
Ivanhoe
AF |
Woodlake
AF |
| Strathmore
AF |
McFarland
32 |
Ducor
AF |
Tea Pot Dome
AF |
| Lindsay
31 |
Exeter
32 |
Famoso
AF |
Madera
AF |
| Belridge
AF |
Delano
AF |
North Bakersfield
AF |
Orosi
32 |
| Orange Cove
AF |
Lindcove
31 |
Lindcove Hillside
AF |
Sanger River Bottom
30 |
| Root Creek
30 |
Venice Hill
AF |
Rosedale
AF |
Jasmine
AF |
| Arvin
AF |
Lamont
AF |
Plainview
32 |
Mettler
AF |
| Edison
AF |
Maricopa
AF |
Holland Creek
AF |
Tivy Valley
AF |
| Kite Road South
AF |
Kite Road North
AF |
AF=Above Freezing
Afternoon Dew Points Today: Mid to upper 30s. Bakersfield, low to mid 30s.
Relative Humidity Forecast: Hanford, 35%/95% Bakersfield, 30%/70%
Actual Humidity December 13, 2017: Delano, NA, Porterville, 97%/32%
Percentage of Sunshine Today/Tomorrow: Visalia: Today 60% tomorrow 80%, Bakersfield: Today 70% tomorrow 70%.
ET Rates Over the Past Seven Days December 13, 2017: Stratford .43, Parlier .37, Blackwell, .51 Lindcove .43, Arvin .50, Orange Cove .43, Porterville .36, Delano .NA., Madera Two .36. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 50, Parlier 50, Blackwell 53, Lindcove, 55, Arvin, 53, Orange Cove 49, Porterville 50, Delano NA, Madera Two 51
Mean Temperatures for December. Month So Far: 47.2 +1.8
Record Temperatures: 74/21. Average Temperatures: 55/35
Heating Degree Days this Season: 532, -219 Courtesy of the NWS
Precipitation: Seasonal total/average/above or below average:
Since December 13, 2017 Fresno: .37 season. or -1.94. Month to Date: T
Since December 13, 2017, Bakersfield: .03, or -1.28, Month to Date: ..00
Water year season is from October 1st through September.
Chilling ours November 1st through February 28: Orange Cove, 266, Parlier, 285, Arvin, 223, Shafter, 322, Stratford, 286, Madera two, 429, Alpaugh, NA, Delano, NA, Lindcove, 256, Porterville, 406. Hours at 45 or below 45.
Sunrise: 7:04 am Sunset: 4:44 pm. Hours of Daylight: 9:39
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 65 / 30 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 63 / 33 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 63 / 28 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / M / M / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 64 / 35 / 0.00 /
VIS : Visalia Airport 292 : DH1500 / M / 30 / 0.00 /
ATEC1 : Avenal 787 : DH1558 / 67 / 32 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 64 / 31 / 0.00 /
TFTC1 : Taft 759 : DH1559 / 61 / 34 / 0.00 /
Rainfall: Season % Last y. % Ave. Annual Ave.
STOCKTON 0.00 0.91 27 4.66 137 3.41 14.06
MODESTO 0.00 0.98 35 3.65 129 2.84 13.11
MERCED 0.00 1.03 42 3.08 125 2.47 12.50
MADERA 0.00 0.32 12 2.67 103 2.60 12.02
FRESNO 0.00 0.37 16 2.46 104 2.36 11.50
HANFORD 0.00 0.37 20 1.09 58 1.89 10.10
BAKERSFIELD 0.00 0.03 2 0.66 49 1.34 6.47
BISHOP 0.00 0.16 15 0.09 8 1.10 5.18
SALINAS 0.00 0.75 27 3.00 109 2.76 12.83
PASO ROBLES 0.00 0.25 10 2.68 112 2.39 12.78
SANTA MARIA 0.00 0.09 3 3.09 112 2.75 13.95
Next Report: Friday, December 15/pm