October 19, 2017
Summary: The first phase of a major pattern change is already underway over central California. As pressures fall over the west, pressure gradients tighten up, allowing the marine layer to rapidly deepen and surge inland. The marine layer itself was about 500 feet deep yesterday and this morning has jumped up to 2,200 feet. It’s already leaking over the Coast Range and into the valley. Temperatures will be somewhat cooler today and much cooler Friday and Saturday as a trough of low pressure that originated in the Gulf of Alaska moves through.
A rapidly moving cold front will scoot down the valley late tonight and Friday morning with a chance of light showers just about anywhere, although some locations will definitely remain dry. As a strong northwest flow aloft comes in contact with the Kern County mountains, the air will be lifted, creating upslope clouds mainly in Kern County Friday night and Saturday. Light showers are possible in the extreme south valley near the base of the mountains through Friday night.
Temperatures will plummet into the mid to upper 60s Friday and possibly the upper 60s to near 70 Saturday. This change will be very temporary, however, as all of the short and medium range models indicate a large and strong upper level high pressure system will build northward and eastward from off the southern California coast. Temperatures will respond accordingly as readings will climb back to near seasonal averages by Sunday. They’ll rise into the mid to possibly upper 80s Tuesday on. All the longer range models are pointing to persistent high pressure with dry conditions.
Forecast: Mostly clear skies today. Increasing cloudiness tonight with a slight chance of showers late tonight. A chance of light showers Friday, extending into Friday night in the extreme south valley. Partly cloudy Saturday but remaining mostly cloudy in Kern County and possibly Tulare County through Saturday afternoon. Clearing Saturday afternoon. Becoming mostly clear Saturday night through Thursday with a warming trend.
Short Term:
| Madera 78/49/67/39/69 | Reedley 80/50/67/39/68 | Dinuba 80/50/68/38/68 | |
| Porterville 81/49/67/40/68 | Lindsay 81/48/67/39/69 | Delano 80/53/68/42/69 | |
| Bakersfield 81/55/66/47/69 | Arvin 82/53/66/44/70 | Taft 81/57/69/50/69 | |
| Lamont 82/53/67/46/68 | Pixley 80/50/67/41/69 | Tulare 79/48/67/39/68 | |
| Woodlake 80/50/67/38/69 | Hanford 80/52/68/38/68 | Orosi 79/50/67/40/69 | |
Seven Day Forecast:
| Sunday
Mostly clear 42/78 |
Monday
Mostly clear 46/82 |
Tuesday
Mostly clear 52/86 |
Wednesday
Mostly clear 53/86 |
Thursday
Mostly clear 53/85 |
Two Week Outlook: October 24 through October 30: The storm track will mostly remain in the Pacific Northwest as a zonal, or westerly, flow continues. Most of California will be south of the active weather pattern, so dry conditions will continue. With a flat zone of high pressure above us, temperatures will warm to at least marginally above average.
October: The month of October, according to the latest models, will have generally or at least marginally above average temperatures as high pressure remains over the Desert Southwest. The Pacific Northwest will have above average precipitation and above average temperatures. Central California will be squeezed between these two systems, so it appears we’ll have an equal chance of rain for the month, which shouldn’t range too far from average.
October, November, December: Looking out to October through December, models show marginally above average temperatures for central and southern California. Models also indicate precipitation will be near average with the main storm track moving through the Pacific Northwest.
Winds: Winds will be out of the northwest at 10 to 20 MPH later this afternoon with stronger gusts, continuing this afternoon. Winds Friday will increase for a time out of the northwest to 15 to 25 MPH with gusts to 35 MPH possible along the west side. Winds Friday night will be mainly out of the northwest at 10 to 15 MPH, becoming generally less than 10 MPH Saturday through Sunday with periods of near calm conditions.
Rain: We do have a small shot at measurable precipitation, mainly late tonight and Friday morning. A rapidly moving cold front will be moving down the valley. Most of the modeling info this morning shows the bulk of the precipitation over northern California, but some models are indicating a narrow band of showers will move through Friday morning. These showers, if they occur, will be fast moving so a tenth of an inch or less would be my best guess with some locations remaining dry. The chance of showers will end Friday night with the possible exception of the extreme south valley where upsloping against the mountains could generate some drizzle or light rain against the mountain bases. Dry weather will be with us Saturday and through at least the middle of next week and, if medium range models are correct, for the next ten days..
Afternoon Dew Points Today: Visalia, Upper 30s to the mid 40s. Bakersfield, Upper 30s to the lower 40s.
Relative Humidity Forecast: Hanford, 25%/95% Bakersfield, 25%/75%
Actual Humidity October 17, 2017: Delano, 91%/23%, Porterville, 88%/19%
Percentage of Sunshine Today/Tomorrow: Visalia: Today 80% tomorrow 20%, Bakersfield: Today 80% tomorrow 10%.
ET Rates Over the Past Seven Days October 17, 2017: Stratford 1.16, Parlier .84, Blackwell 1.09, Lindcove .89, Arvin 1.05, Orange Cove 1.02, Porterville .83, Delano .88., Madera Two .82. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 61, Parlier 67, Blackwell 70, Lindcove 67, Arvin 71, Orange Cove 66, Porterville 69, Delano 65, Madera Two 68
Mean Temperatures for September Month So Far: 62.7 -3.5
Record Temperatures: 95/36. Average Temperatures: 79/49
Cooling Degree Days This Season: 2150, +513 Courtesy of the NWS
Precipitation: Seasonal total/average/above or below average:
Since October 17, 2017 Fresno: .00 season. or -.25. Month to Date: .00
Since October 17, 2017, Bakersfield: .00, or -.11, Month to Date: .00
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove, Parlier, Arvin, Shafter, , Stratford, Madera two, Alpaugh, Delano, Lindcove, Porterville, Hours at 45 or below 45.
Sunrise: 7:10 am Sunset: 6:18 pm. Hours of Daylight: 11:09
Yesterday’s Weather:
FAT : Fresno Airport 333 : DH1700 / 82 / 53 / 0.00 /
HJO : Hanford Airport 242 : DH1700 / 84 / 53 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1700 / M / 54 / 0.00 /
BFL : Bakersfield Airport 496 : DH1700 / 85 / 64 / 0.00 /
VIS : Visalia Airport 292 : DH1700 / 83 / 58 / 0.00 /
ATEC1 : Avenal 787 : DH1653 / 83 / 58 / 0.00 /
PTV : Porterville Airport 442 : DH1700 / 84 / 60 / 0.00 /
TFTC1 : Taft 759 : DH1652 / 84 / 66 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / M / 52 / 0.00 /
Rainfall: 24 hour Season % Last year % Average Yearly Ave.
STOCKTON 0.00 0.00 0 1.02 291 0.35 14.06
MODESTO 0.00 0.00 0 0.23 74 0.31 13.11
MERCED 0.00 0.00 0 0.21 75 0.28 12.50
MADERA 0.00 0.00 0 0.04 13 0.30 12.02
FRESNO 0.00 0.00 0 0.01 4 0.27 11.50
HANFORD 0.00 0.00 0 T 0 0.18 10.10
BAKERSFIELD 0.00 T 0 0.05 42 0.12 6.47
BISHOP 0.00 0.00 0 0.00 0 0.16 5.18
SALINAS 0.00 T 0 0.16 59 0.27 12.83
PASO ROBLES T T 0 0.15 56 0.27 12.78
SANTA MARIA 0.00 T 0 0.21 88 0.24 13.95
Next Report: Friday, October 20