December 17, 2017
Summary: Upper level high pressure is anchored off shore with a ridge building into the Pacific Northwest. In the meantime, a low is centered over northwest Mexico and is moving eastward. We have a fairly strong, but brief, off shore flow between these systems which will generate strong winds over the higher elevations of the Sierra Nevada and the Kern County mountains. Overnight lows as of 6:00am were a bit milder than expected due to wind conditions and good mixing. But I’m not anticipating those conditions tonight.
The upper high will govern our pattern through Tuesday evening then a rather robust trough of low pressure will move through Wednesday. This low is dropping southward over land, so it will be moisture starved with just a chance of sprinkles over the valley floor and light showers over the Sierra.
The air behind this system will be colder and will cause highs to drop down into the 50s with cold overnight low temperatures possibly dipping into the mid 20s and possibly lower. More in the frost discussion below.
We’ve been watching the period of the 22 through the 26 for a few days now. This morning’s models show a gigantic high reaching into northwest Canada and low pressure possibly over Arizona or northern Mexico. This will create a strong northerly flow aloft, however this cold air is now being shown moving southward a bit further east, meaning we may be able to avoid some very cold weather. It’s still not determined whether or not any of this air will filter into the valley. Models have been flip flopping for this time frame, so stay tuned.
If this air does make it into the valley, we could see low to mid 20s, so for now we’ll just bite our fingernails and tweak this forecast as additional information becomes available.
Forecast: Other than some occasional high clouds, it will be mostly clear through Tuesday evening. Mostly cloudy Wednesday with a small chance of sprinkles. Becoming mostly clear Wednesday night and on through Christmas Eve with cold overnight low temperatures.
Short Term:
| Madera 58/27/61/26/65 | Reedley 59/26/61/26/67 | Dinuba 58/26/60/26/64 | |
| Porterville 59/27/62/27/67 | Lindsay 59/26/61/26/64 | Delano 60/28/63/27/66 | |
| Bakersfield 59/31/65/30/66 | Arvin 60/27/65/27/67 | Taft 61/31/65/33/67 | |
| Lamont 60/29/65/28/67 | Pixley 59/27/64/27/65 | Tulare 58/26/62/26/65 | |
| Woodlake 59/29/63/27/65 | Hanford 59/27/62/27/66 | Orosi 58/26/61/26/65 | |
Seven Day Forecast:
| Wednesday
Mostly cloudy 37/59 |
Thursday
Mostly clear 27/55 |
Friday
Mostly clear 25/59 |
Saturday
Mostly clear 26/61 |
Sunday
Mostly clear 26/63 |
Two Week Outlook: Christmas Eve through December 30: 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 along the west side will be out of the north to northeast at 5 to 15 MPH. winds elsewhere will be variable to 10 MPH with locally stronger gusts through this afternoon. Winds tonight will be less than 10 MPH with periods of near calm conditions, continuing through Tuesday night. Winds Wednesday will increase out of the northwest at 15 to 30 MPH along the west side with stronger gusts and 10 to 15 MPH elsewhere, slowly diminishing Wednesday night.
Rain: Expect dry conditions for at least the next 7 to 10 days.
Frost: Wind conditions and good mixing kept temperatures in the upper 20s to the low to mid 30s overnight. Tonight, I don’t anticipate we’ll have those blessings as the atmosphere settles down following yesterday’s trough passage. The air mass is colder than the previous air mass and has also broken up the inversion. On the plus side, it has temporarily ridden us of the smog and poor air quality.
I’m anticipating dew points will lower into the upper 20s and lower 30s this afternoon, possibly a bit lower in Kern County. With generally clear skies, strong radiational cooling is expected, driving temperatures down to the mid 20s in the cold spots and mid 20s to the lower 30s elsewhere. Coldest lows tonight in unprotected low spots could drop down to 23 to 25 degrees. Expect similar conditions Tuesday morning.
The inversion will be fairly weak tonight with temperatures at 34 feet from 2 to 5 degrees warmer, at best.
By Wednesday, a strong but fairly trough of low pressure will barrel through. There’s even a small chance of sprinkles, but being that this low is taking an overland trajectory, moisture will be quite limited. Behind this system, the air mass will be colder yet with a hard freeze expected Thursday through Saturday, although temperatures may be held up a bit Thursday due to wind conditions. I wouldn’t rule out lower 20s in the coldest location with mid to upper 20s elsewhere.
We have been discussing possible problems for this coming Friday and beyond. Some models are a bit more encouraging this morning as they show the Arctic air barreling into the interior west, and especially the Midwest. This is yet another flip from previous projections, but does give me a bit of encouragement. However, even this pattern could filter some of this cold air into California, so I have no choice but to take a wait and see attitude as projections are changing from day to day.
Lows Tonight:
| Terra Bella
26 |
Porterville
27 |
Ivanhoe
27 |
Woodlake
26 |
| Strathmore
27 |
McFarland
26 |
Ducor
27 |
Tea Pot Dome
27 |
| Lindsay
25 |
Exeter
26 |
Famoso
27 |
Madera
26 |
| Belridge
26 |
Delano
28 |
North Bakersfield
28 |
Orosi
27 |
| Orange Cove
27 |
Lindcove
25 |
Lindcove Hillside
31 |
Sanger River Bottom
23 |
| Root Creek
25 |
Venice Hill
27 |
Rosedale
28 |
Jasmine
27 |
| Arvin
28 |
Lamont
29 |
Plainview
27 |
Mettler
29 |
| Edison
28 |
Maricopa
27 |
Holland Creek
29 |
Tivy Valley
27 |
| Kite Road South
29 |
Kite Road North
26 |
AF=Above Freezing
Afternoon Dew Points Today: Upper 20s to the lower 30s. Bakersfield, mid 20s to the lower 30s.
Relative Humidity Forecast: Hanford, 30%/95% Bakersfield, 30%/70%
Actual Humidity December 15, 2017: Delano, NA, Porterville, 96%/28%
+%
Percentage of Sunshine Today/Tomorrow: Visalia: Today 90% tomorrow 90%, Bakersfield: Today 90% tomorrow 90%.
ET Rates Over the Past Seven Days December 15, 2017: Stratford .41, Parlier .35, Blackwell, .50 Lindcove .40, Arvin .47, Orange Cove .43, Porterville .35, Delano .NA., Madera Two .35. 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 50, Delano NA, Madera Two 51
Mean Temperatures for December. Month So Far: 47.1 +1.9
Record Temperatures: 70/25. Average Temperatures: 54/35
Heating Degree Days this Season: 569, -224 Courtesy of the NWS
Precipitation: Seasonal total/average/above or below average:
Since December 15, 2017 Fresno: .37 season. or -2.04. Month to Date: T
Since December 15, 2017, Bakersfield: .03, or -1.35, Month to Date: ..00
Water year season is from October 1st through September.
Chilling ours November 1st through February 28: Orange Cove, 290, Parlier, 309, Arvin, 248, Shafter, 351, Stratford, 311, Madera two, 455, Alpaugh, NA, Delano, NA, Lindcove, 286, Porterville, 436. Hours at 45 or below 45.
Sunrise: 7:06 am Sunset: 4:45 pm. Hours of Daylight: 9:38
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 59 / 36 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 55 / 38 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 59 / 35 / 0.00 /
NLC : Lemoore Naval AS 234 : DHM / M / M / M /
BFL : Bakersfield Airport 496 : DH1600 / 59 / 42 / 0.00 /
VIS : Visalia Airport 292 : DH1500 / 48 / 36 / 0.00 /
ATEC1 : Avenal 787 : DH1553 / 60 / 39 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 57 / 39 / 0.00 /
TFTC1 : Taft 759 : DH1555 / 57 / 37 / 0.00 /
Rainfall: Season % Last y. % Ave. Annual Ave.
STOCKTON 0.00 0.91 26 5.46 154 3.55 14.06
MODESTO 0.00 0.98 33 4.30 145 2.97 13.11
MERCED 0.00 1.03 40 3.72 145 2.57 12.50
MADERA 0.00 0.32 12 3.62 133 2.73 12.02
FRESNO 0.00 0.37 15 4.08 165 2.47 11.50
HANFORD 0.00 0.37 19 2.00 101 1.99 10.10
BAKERSFIELD 0.00 0.03 2 1.02 72 1.41 6.47
BISHOP 0.00 0.16 14 0.15 13 1.14 5.18
SALINAS 0.00 0.75 26 3.82 133 2.88 12.83
PASO ROBLES 0.00 0.25 10 3.40 135 2.52 12.78
SANTA MARIA 0.00 0.09 3 4.02 140 2.88 13.95
Next Report: Sunday, December 17/pm