September 6, 2017
Summary: Monsoonal moisture continues to move in from the southeast via southern California. Most of the latest batch of the monsoon is moving up the east side of the Sierra Nevada with mid level clouds over portions of the San Joaquin Valley. The same upper level low we’ve been talking about for the past week is the remains of former tropical storm Lidia which is roughly 400 miles to the west of San Francisco now. It is close enough to the coast to allow pressures to weaken over California for considerably cooler weather. this system will have to be closely watched as models show it moving northeastward into northern California towards the weekend as it is picked up by an incoming trough of low pressure.
Finally, over the weekend upper level high pressure will temporarily build over the interior west while a cut off low develops off the central coast. Models differ widely on the placement of this low, but it may very well turn the winds aloft out of the southeast, again dragging monsoonal moisture northward or northwestward for an increasing chance of thunderstorms over the Sierra Nevada and possibly over the Kern County mountains.
With all the model disparity, we’ll simply have to tweak this forecast. For now, though, I’ll keep the weekend forecast dry and monitor the situation.
Also, with that building high, we’ll again see above average temperatures with warmer locations possibly topping the century mark. This shouldn’t last too long, however, as a new trough of low pressure will move inland about Tuesday or Wednesday, possibly bringing temperatures down into the low 90s.
Forecast: Mostly clear with occasional cloudiness through Friday. partly cloudy Friday night through Sunday. Becoming mostly clear Monday through Wednesday.
Short Term:
| Madera 92/63/89/61/89 | Reedley 93/63/91/62/88 | Dinuba 93/62/91/61/89 | |
| Porterville 93/63/90/62/89 | Lindsay 93/63/90/61/88 | Delano 94/65/90/65/90 | |
| Bakersfield 95/68/91/66/90 | Arvin 95/65/91/64/91 | Taft 94/73/90/69/89 | |
| Lamont 95/66/91/64/90 | Pixley 93/63/89/62/89 | Tulare 92/63/89/61/88 | |
| Woodlake 93/63/90/62/89 | Hanford 93/63/89/62/89 | Orosi 93/63/89/62/88 | |
Seven Day Forecast:
| Saturday,
Partly cloudy 64/91 |
Sunday
Partly cloudy 67/100 |
Monday
Mostly clear 68/100 |
Tuesday
Mostly clear 67/97 |
Wednesday
Mostly clear 66/91 |
Two Week Outlook: September 13 through September 19: This model indicates another regime of above average temperatures will be at hand. Persistent upper level high pressure is the dominant feature, allowing the chance of afternoon and evening storms over the mountains during this period. For now, we’ll keep the chance of precipitation out of the forecast for the valley floor while strictly monitoring conditions.
September: This model shows upper level high pressure more dominant over the western U.S. There’s no clear indicator of above or below average rainfall as we move into the fall season. With that in mind, we’ll call for near average precipitation for the month.
September, October, November: It appears temperatures overall will rise to above average values for the bulk of this time frame. Upper level high pressure is also more dominant with precipitation, believe it or not, predicted to be somewhat near average.
Winds: Winds will be generally less than 15 MPH through Saturday and mainly out of the northwest afternoons and evenings.
Rain: The same old low pressure system is centered roughly 400 miles west of San Francisco this morning. The low is forecast to pretty much stay in place through Thursday then begin to move northeastward into northern California Friday and Saturday. The combination of building high pressure over the Great Basin and the low may cause winds over the weekend to be out of the northeast for more thunderstorms over the Sierra Nevada and the Kern County mountains.
There are many differences between models on where the low will eventually be placed, therefore the weekend forecast is a bit low confidence. For now, I’ll keep the forecast dry while watching for more uniformity over the next couple of days.
Afternoon Dew Points Today: Low to mid 60s. Kern: Low to mid 60s
Relative Humidity Forecast: Hanford, 30%/75% Bakersfield, 30%/60%
Actual Humidity September 4, 2017: Delano, 93%/31%, Porterville, 85%/27%
Percentage of Sunshine Today/Tomorrow: Visalia: Today 70% tomorrow 80%, Bakersfield: Today 70% tomorrow 80%.
ET Rates Over the Past Seven Days September 4, 2017: Stratford 1.84, Parlier 1.46, Blackwell 1.99, Lindcove 1.50, Arvin 1.73, Orange Cove 1.73, Porterville 1.50, Delano 1.61, Madera Two 1.65 Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 78, Parlier 84, Blackwell 84, Lindcove 80, Arvin 1.89, Orange Cove 83, Porterville 87, Delano 84, Madera Two 83
Mean Temperatures for September Month So Far: 88.1.5. +12.1
Record Temperatures: 105/47. Average Temperatures: 94/62
Cooling Degree Days This Season: 1910, +535 Courtesy of the NWS
Precipitation: Seasonal total/average/above or below average:
Since September 4, 2017, Fresno: 17.20 season / +5.86 or +5.87, Month to Date: T
Since September 4, 2017, Bakersfield: 7.88, or 1.43, Month to Date: T
Water year season is from October 1st through September 30.
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: 6:34 am Sunset: 7:19 Hours of Daylight: 12:41
Yesterday’s Weather
MAE : Madera 253 : DH1700 / 96 / 73 / 0.00 /
FAT : Fresno Airport 333 : DH1700 / 98 / 75 / 0.00 /
HJO : Hanford Airport 242 : DH1700 / 97 / 71 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1700 / M / 77 / 0.00 /
BFL : Bakersfield Airport 496 : DH1700 / 98 / 77 / 0.00 /
VIS : Visalia Airport 292 : DH1700 / 94 / 71 / 0.00 /
ATEC1 : Avenal 787 : DH1654 / 98 / 71 / 0.00 /
PTV : Porterville Airport 442 : DH1700 / 97 / 72 / 0.00 /
TFTC1 : Taft 759 : DH1651 / 95 / 74 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 93 / 71 / 0.00 /
Rainfall:
To date Last year Average Annual ave
STOCKTON 0.00 21.79 158 16.69 121 13.78 14.06
MODESTO 0.00 16.93 132 15.61 121 12.86 13.11
MERCED 0.00 16.03 131 14.66 120 12.22 12.50
MADERA 0.00 14.18 120 12.96 110 11.78 12.02
FRESNO T 17.20 152 14.29 126 11.34 11.50
HANFORD 0.00 11.05 111 8.26 83 9.93 10.10
BAKERSFIELD T 7.83 122 5.43 85 6.40 6.47
BISHOP 0.00 9.18 184 3.88 78 4.99 5.18
SALINAS T 16.45 130 13.47 106 12.66 12.83
PASO ROBLES T 16.16 129 8.06 64 12.56 12.78
SANTA MARIA 0.06 18.69 135 9.00 65 13.82 13.95
Rainfall season from October 1st through September 30th
Next Report: Thursday, September 7