John Hibler
Weather Forecasting
johnhibler@johnhibler.com
573-776-3920
September 18, 2018
Summary: A high center over Texas covers the southern plains and the Desert Southwest. A massive low covers the Gulf of Alaska, much of western Canada, with a trough extending southward into northern and central California. Embedded within this trough is a secondary but invisible wave of low pressure which will move through central California later today and tonight. The main impact will be to continue below average temperatures through Wednesday. As pressures fall over the interior, the onshore flow will again increase with another surge of marine air arriving in the valley this afternoon and tonight, meaning temperatures will generally range in the mid 80s. this is about 5 degrees cooler than what is considered to be average. There will be locally gusty winds, especially below favored canyons along the coast range as the modified sea breeze moves inland.
A pattern change will begin to take place Thursday as the trough finally begins to migrate towards the north, allowing eastern Pacific high pressure to begin to move back in from the west. This high will not be especially strong, but nevertheless, low to mid 90s are likely from Thursday through Sunday. This really isn’t bad considering the record high for today’s date is 107.
Models differ considerably on the pattern beginning Monday. If you had to pick and choose, a trough of low pressure would be the result, extending from the Pacific Northwest down into California. This trough, on paper, anyway, does not appear to be as impressive as the one that brought the current weather pattern. Still, we should get enough marine air in here to lower temperatures back into the upper 80s to the lower 90s, possibly a tad cooler north of Fresno.
Medium range models continue to favor low pressure in one way, shape, or form along the west coast, so there’s certainly no hot weather on the horizon with possible periods of below average temperatures down the road.
Forecast: Mostly clear skies through Friday. Mostly clear skies will continue Friday night through Tuesday.
Short Term:
| Madera 86/51/85/50/90 | Reedley 86/51/85/50/89 | Dinuba 84/50/85/50/88 | |
| Porterville 86/51/86/52/91 | Lindsay 86/49/86/50/90 | Delano 86/53/86/54/91 | |
| Bakersfield 87/56/85/58/90 | Arvin 87/54/85/56/92 | Taft 86/58/86/62/92 | |
| Lamont 87/54/86/56/92 | Pixley 86/51/86/52/90 | Tulare 85/50/85/52/89 | |
| Woodlake 85/51/85/51/90 | Hanford 86/51/86/53/91` | Orosi 85/51/84/52/89 | |
Seven Day Forecast:
| Friday
Mostly clear 57/93 |
Saturday
Mostly clear 58/95 |
Sunday
Mostly clear 58/92 |
Monday
Mostly clear 54/90 |
Tuesday
Mostly clear 54/89 |
Two Week Outlook: September 24 through September 30: This model shows a rather robust low off the coast of Oregon and northern California with a chance of showers over parts of northern California. This pattern would definitely bring cooler air aloft along with a strong onshore flow, resulting in below average temperatures. The chance of precipitation would remain very low.
September: This model indicates there will be a higher than active monsoon over the Desert Southwest and possibly central and southern California. This typically does not affect the valley floor other than cloud cover but could result in a larger number of days of thunderstorms over the Sierra Nevada and possibly even the Kern County mountains. With generally high pressure over the southwest, temperatures will likely be somewhat above seasonal average.
September, October, November: The first part of this time frame will see a more active than usual monsoon in place for above average rain over the Sierra Nevada and possibly the mountains and deserts of southern California. October and November’s conditions aren’t as easy to determine. At this time we’ll call for generally average values for both rain and temperatures.
Winds: Winds, mainly in the afternoons and evenings, will be out of the northwest at 10 to 15 MPH at times with locally stronger gusts. Winds through Wednesday morning, especially near the Coast Range, could gust as high as 35 MPH. Winds will decrease Wednesday through Friday to 5 to 12 MPH.
Rain: Expect dry conditions indefinitely.
Afternoon Dew Points Today: Upper 40s to the lower 50s. Kern: Mid to upper 40s.
Humidity: Visalia: 30%/80% Bakersfield: 25%/65%
Actual Humidity September 17, 2018: Delano, 86%/31%, Porterville, 84%/26%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 100% tomorrow 100% Bakersfield: Today: 100% Tomorrow: 100%
ET Rates Over the Past Seven Days: Stratford 1.53, Parlier 1.37, Blackwell 1.47, Lindcove 1.38, Arvin 1.56, Orange Cove 1.51, Porterville 1.25, Delano 1.40, Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 70, Parlier 73, Blackwell 83, Lindcove, 74, Arvin, 73, Orange Cove 75, Porterville 79, Delano 72,
Record Temperatures: 107/48. Average Temperatures: 90/58
Cooling Degree Days this Season: 1938 +437
Courtesy of the NWS
Average temperature for September so far: 76.4 +1.4
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2017 Fresno: 6.73 season. or -4.66. Month to Date: .00
Since Oct 1, 2017, Bakersfield: 3.93, or -2.47. 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, Lindcove, Porterville, Hours at 45 or below 45.
Sunrise: 6:44 am Sunset: 7:00 pm. Hours of Daylight: 12:18
Yesterday’s Weather:
MAE : Madera 253 : DH1700 / 89 / 51 / 0.00 /
FAT : Fresno Airport 333 : DH1700 / 87 / 58 / 0.00 /
HJO : Hanford Airport 242 : DH1700 / 88 / 54 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1700 / 88 / 51 / 0.00 /
BFL : Bakersfield Airport 496 : DH1700 / 86 / 60 / 0.00 /
VIS : Visalia Airport 292 : DH1700 / 86 / 50 / 0.00 /
ATEC1 : Avenal 787 : DH1657 / 87 / 54 / 0.00 /
PTV : Porterville Airport 442 : DH1700 / 88 / 52 / 0.00 /
TFTC1 : Taft 759 : DH1656 / 90 / 57 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 85 / 55 / 0.00 /
Rainfall: Water year Oct 1st through September 30th
Year % Last Y. % Ave. Annual ave.
STOCKTON 0.00 9.22 66 21.79 157 13.88 14.06
MODESTO 0.00 8.17 63 16.93 131 12.94 13.11
MERCED 0.00 7.06 57 16.03 130 12.34 12.50
MADERA 0.00 7.22 61 14.26 120 11.88 12.02
FRESNO 0.00 6.73 59 17.30 152 11.39 11.50
HANFORD 0.00 4.70 47 11.16 111 10.01 10.10
BAKERSFIELD 0.00 3.95 62 8.33 130 6.42 6.47
BISHOP 0.00 3.08 61 9.18 181 5.06 5.18
SALINAS 0.00 7.16 56 16.49 130 12.72 12.83
PASO ROBLES 0.00 9.62 76 16.17 128 12.63 12.78
SANTA MARIA 0.00 6.01 43 18.91 136 13.87 13.95
Next report: Wednesday, September 19