September 17, 2018
Summary: The overall pattern has not changed much. A broad trough of low pressure stretches along the Pacific coast southward to central California with a southwest flow aloft. At the surface, the flow remains onshore, allowing marine air to move down the valley from time to time. This mild air mass has allowed overnight lows to fall into the mid to upper 40s at the coolest locations. Madera north, for example, registered a low of 45 as of 7:00 this morning. If you’re wondering where the upper high has gone, it is centered over Texas this morning and covers the southwest as far west as the lower deserts of southern California.
The trough will begin to migrate northward Wednesday, allowing the southwestern high to begin to shift back into California from the southeast. By Thursday, temperatures will warm into the lower 90s with low to mid 90s becoming the norm Friday through Saturday.
By Sunday, most models this morning are indicating a new trough will sag southward along the Pacific coast, again strengthening the onshore flow and allowing more marine air to spill into the valley via the Delta and other gaps and passes along the coast range.
The two week model is rather interesting this morning. It shows a fairly robust low off the California/Oregon coast with a chance of showers into northern California. For now, it appears central California will remain dry, however we are reaching the time of year where, on rare occasions, systems to our north have resulted in showers over central California.
Forecast: Mostly clear skies through Thursday. Mostly clear skies will continue Thursday night through Monday.
Short Term:
| Madera 86/50/84/48/86 | Reedley 87/51/85/50/87 | Dinuba 85/50/85/51/86 | |
| Porterville 87/50/85/49/87 | Lindsay 86/48/85/48/86 | Delano 87/52/85/53/87 | |
| Bakersfield 86/56/85/55/86 | Arvin 88/52/85/52/87 | Taft 86/58/85/57/86 | |
| Lamont 87/55/85/55/87 | Pixley 86/52/85/51/87 | Tulare 85/50/85/49/86 | |
| Woodlake 86/51/85/50/86 | Hanford 87/51/84/50/86 | Orosi 86/49/85/48/87 | |
Seven Day Forecast:
| Thursday
Mostly clear 56/92 |
Friday
Mostly clear 58/95 |
Saturday
Mostly clear 57/93 |
Sunday
Mostly clear 56/91 |
Monday
Mostly clear 52/88 |
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 tonight and Tuesday along the west side, especially near the Coast Range, could gust as high as 35 MPH. Winds will decrease Wednesday and Thursday to 5 to 12 MPH.
Rain: Expect dry conditions indefinitely.
Afternoon Dew Points Today: Mid to upper 40s. Kern: Low to mid 40s.
Humidity: Visalia: 25%/75% Bakersfield: 20%/65%
Actual Humidity September 16, 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 1.56, Parlier 1.39, Blackwell 1.51, Lindcove 1.40, Arvin 1.60, Orange Cove 1.56, Porterville 1.28, Delano 1.43, Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 71, Parlier 74, Blackwell 84, Lindcove, 75, Arvin, 74, Orange Cove 75, Porterville 80, Delano 73,
Record Temperatures: 105/48. Average Temperatures: 91/59
Cooling Degree Days this Season: 1932 +439
Courtesy of the NWS
Average temperature for September so far: 76.7 +1.6
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: 7:02 pm. Hours of Daylight: 12:19
Yesterday’s Weather:
MAE : Madera 253 : DH1700 / 86 / 50 / 0.00 /
FAT : Fresno Airport 333 : DH1700 / 85 / 56 / 0.00 /
HJO : Hanford Airport 242 : DH1700 / 86 / 51 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1700 / 85 / 50 / 0.00 /
BFL : Bakersfield Airport 496 : DH1700 / 83 / 59 / 0.00 /
VIS : Visalia Airport 292 : DH1700 / 84 / 50 / 0.00 /
ATEC1 : Avenal 787 : DH1658 / 83 / 51 / 0.00 /
PTV : Porterville Airport 442 : DH1700 / 84 / 50 / 0.00 /
TFTC1 : Taft 759 : DH1653 / 82 / 59 / 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 13.87 14.06
MODESTO 0.00 8.17 63 16.93 131 12.93 13.11
MERCED 0.00 7.06 57 16.03 130 12.33 12.50
MADERA 0.00 7.22 61 14.26 120 11.87 12.02
FRESNO 0.00 6.73 59 17.30 152 11.39 11.50
HANFORD 0.00 4.70 47 11.16 112 10.00 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 12.71 12.83
PASO ROBLES 0.00 9.62 76 16.17 128 12.62 12.78
SANTA MARIA 0.00 6.01 43 18.91 136 13.86 13.95
Next report: Tuesday, September 18