December 18, 2017
Summary: It was cold again last night with widespread mid to upper 20s and lower 30s in the warmer locations. Upper level high pressure will continue to maintain its grip on central California through Tuesday. With a dry air again in place, overnight lows will be chilly tonight, which is discussed in the frost summary below.
A strong cold front with its origins in the Gulf of Alaska will barrel through northern and central California Wednesday. The low itself will make more of an overland pass through the Pacific Northwest then dive southward with a limited amount of moisture involved. Even so, this system does have good dynamics so light showers are possible Wednesday, mainly from Fresno County northward.
Sharp pressure differences will set up between the north coast and the Desert Southwest as a new low forms over Arizona and northern New Mexico. Meanwhile, behind the front strong upper level high pressure will be ridging into western Canada. The flow between the southwestern low and the Canadian high will create a strong northeast flow aloft which will drive a colder air mass into the region with freeze conditions Thursday but more so Friday and Saturday.
Strong surface high pressure will take shape over the Great Basin for a strong off shore flow, aiding in the cold, dry air mass. Saturday through Christmas Day should be generally clear but with cold nights and chilly days.
Beyond that, models are inconclusive.
Forecast: Mostly clear today and tonight with occasional high clouds. Mostly clear Tuesday but with more high clouds mixing in. Partly cloudy Tuesday night. Mostly cloudy Wednesday with a chance of light showers, mainly from Fresno County north with gusty northwest winds moving down the valley. Clearing Thursday night. becoming mostly clear with cold nights Friday through Christmas Day.
Short Term:
| Madera 61/28/65/29/56 | Reedley 61/28/64/29/57 | Dinuba 61/27/64/29/57 | |
| Porterville 62/28/66/29/58 | Lindsay 62/27/67/28/59 | Delano 63/29/66/30/59 | |
| Bakersfield 65/36/68/37/59 | Arvin 65/29/65/31/60 | Taft 64/41/68/41/60 | |
| Lamont 65/30/68/32/61 | Pixley 64/29/68/30/59 | Tulare 62/27/67/29/58 | |
| Woodlake 61/28/64/29/57 | Hanford 61/29/65/30/57 | Orosi 62/28/64/30/58 | |
Seven Day Forecast:
| Thursday
Mostly clear 27/54 |
Friday
Mostly clear 24/57 |
Saturday
Mostly clear 24/58 |
Sunday
Mostly clear 27/62 |
Christmas Day
Mostly clear 28/63 |
Two Week Outlook: Christmas Day through December 31: 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 with periods of near calm conditions through Tuesday evening. Late Tuesday night and Wednesday, winds will be out of the northwest at 10 to 20 MPH with stronger gusts with gusts to 35 MPH possible along the west side. Winds Thursday night will eventually be in the 5 to 10 MPH range but with stronger gusts, mainly along the west side.
Rain: A strong cold front, but one with limited moisture, will barrel southward through the valley Wednesday. This system is moisture starved, but has strong dynamics and those dynamics could possibly squeeze out some light showers from mainly Fresno County northward Wednesday. Dry weather will return Wednesday night and on through Christmas Day.
Frost: Coldest locations last night, as of 6:00am, were generally in the 25 to 27 degree range with most other locations ranging from 28 to 30 with some lower 30s in Kern County. With a dry air mass and low dew points, strong radiational cooling will again occur for temperatures down to 25 to 26 in the coldest, low lying, unprotected areas and 27 to 31 in most flatland terrain. Hillsides will come in in the low to mid 30s. Temperatures at 34 feet tonight will range from 3 to 6 degrees warmer at most locations.
A rapidly moving strong cold front will move through Wednesday. This should keep temperatures above freezing Wednesday morning at most locations. A kind of compromise pattern seems to be developing on models for Thursday through the Christmas weekend. Models show a strong high building from southwest to northeast into western Canada while a low center develops over either northern Mexico or possibly over the Desert Southwest. This will create a strong northeasterly flow aloft, injecting a colder air mass into the valley with potentially some very cold temperatures Thursday, but more so Friday and Saturday mornings. Low 20s are possible in the coldest regions with 24 to 28 degree temperatures elsewhere. This is a developing situation but there does seem to be a trend developing leading to greater confidence in the projection of a hard freeze developing Thursday through Saturday.
Christmas Eve and Christmas morning will also be cold, barring any unexpected changes, with mid to upper 20s expected. This could last well into next week as another cold and dry air mass settles in.
Lows Tonight:
| Terra Bella
27 |
Porterville
28 |
Ivanhoe
28 |
Woodlake
28 |
| Strathmore
27 |
McFarland
27 |
Ducor
29 |
Tea Pot Dome
28 |
| Lindsay
26 |
Exeter
27 |
Famoso
29 |
Madera
28 |
| Belridge
27 |
Delano
29 |
North Bakersfield
29 |
Orosi
27 |
| Orange Cove
28 |
Lindcove
26 |
Lindcove Hillside
32 |
Sanger River Bottom
24 |
| Root Creek
26 |
Venice Hill
27 |
Rosedale
29 |
Jasmine
27 |
| Arvin
29 |
Lamont
31 |
Plainview
28 |
Mettler
32 |
| Edison
30 |
Maricopa
28 |
Holland Creek
30 |
Tivy Valley
28 |
| Kite Road South
31 |
Kite Road North
28 |
AF=Above Freezing
Afternoon Dew Points Today: Upper 20s to the lower 30s. Bakersfield, mid 20s to the lower 30s.
Relative Humidity Forecast: Hanford, 35%/90% Bakersfield, 30%/70%
Actual Humidity December 16, 2017: Delano, NA, Porterville, 87%/46%
Percentage of Sunshine Today/Tomorrow: Visalia: Today 90% tomorrow 70%, Bakersfield: Today 90% tomorrow 80%.
ET Rates Over the Past Seven Days December 16, 2017: Stratford .44, Parlier .34, Blackwell, .53 Lindcove .39, Arvin .48, Orange Cove .41, Porterville .35, 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 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: 587, -227 Courtesy of the NWS
Precipitation: Seasonal total/average/above or below average:
Since December 16, 2017 Fresno: .37 season. or -2.10. Month to Date: T
Since December 15, 2017, Bakersfield: .03, or -1.38, Month to Date: ..00
Water year season is from October 1st through September.
Chilling ours November 1st through February 28: Orange Cove, 302, Parlier, 321, Arvin, 256, Shafter, 366, Stratford, 321, Madera two, 470, Alpaugh, NA, Delano, NA, Lindcove, 283, Porterville, 451. 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 / 61 / 29 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 60 / 36 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 61 / 31 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / M / M / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 62 / 37 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 60 / 33 / 0.00 /
ATEC1 : Avenal 787 : DH1553 / 57 / 39 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 62 / 34 / 0.00 /
TFTC1 : Taft 759 : DH1554 / 57 / 31 / 0.00 /
Rainfall: Season % Last y. % Ave. Annual Ave.
STOCKTON 0.00 0.91 25 5.46 151 3.62 14.06
MODESTO 0.00 0.98 32 4.30 141 3.04 13.11
MERCED 0.00 1.03 39 3.72 142 2.62 12.50
MADERA 0.00 0.32 11 3.62 130 2.79 12.02
FRESNO 0.00 0.37 15 4.08 161 2.53 11.50
HANFORD 0.00 0.37 18 2.00 98 2.05 10.10
BAKERSFIELD 0.00 0.03 2 1.02 71 1.44 6.47
BISHOP 0.00 0.16 14 0.15 13 1.17 5.18
SALINAS 0.00 0.75 25 3.82 129 2.95 12.83
PASO ROBLES 0.00 0.25 10 3.40 131 2.59 12.78
SANTA MARIA 0.00 0.09 3 4.02 136 2.95 13.95
Next Report: Monday, December 18/pm