September 9, 2017
Summary: The next 72 hours will be a bit tricky. Currently, we have an upper low which is just west of Monterey this morning with plenty of monsoonal moisture working northward from southern California into Nevada. Models show this feature drifting southward parallel to the California coast to a position off the southern California coast by Sunday. This will turn the winds aloft south and eventually southeasterly, pumping in some fairly deep tropical moisture into the entire region Sunday and Monday. The chance for measurable rain this time around is somewhat higher as the low will add convection to the atmosphere, possibly sustaining precipitation over the valley floor with Kern County being at greatest risk. Heavy thunderstorms will develop over the Kern County mountains and the Sierra Nevada. These storms will try to move over the valley floor.
This situation is one where some or possibly most locations will remain dry and where it does rain, amounts should be generally less than .10 of an inch. However, locally heavy thunderstorms are possible, mainly near the foothills, with the time of greatest risk being Sunday afternoon through Monday.
The low will move north again Tuesday and will shift inland across central California Wednesday, making for a tough forecast. As the low moves inland, a strong on shore flow will develop, pushing marine air inland for possibly mid to upper 80s Wednesday and possibly through Friday.
Medium range outlooks don’t show anything exciting. Weak high pressure will dominate with a west to southwest flow aloft, maintaining a dry forecast.
An afternoon update will be issued.
Forecast: Mostly clear skies today. Becoming partly cloudy later tonight. Variable cloudiness Sunday through Monday with a chance of isolated to scattered showers and thunderstorms. Partly cloudy Tuesday. Becoming mostly clear to occasionally partly cloudy Wednesday and Thursday. Mostly clear skies Thursday night through Saturday.
Short Term:
| Madera 92/64/97/66/98 | Reedley 93/64/97/66/97 | Dinuba 91/64/96/67/97 | |
| Porterville 93/64/97/71/97 | Lindsay 93/64/98/67/98 | Delano 93/67/98/70/97 | |
| Bakersfield 93/72/97/77/96 | Arvin 94/73/96/74/96 | Taft 92/74/96/76/96 | |
| Lamont 94/70/96/74/97 | Pixley 93/66/97/71/97 | Tulare 92/65/97/69/96 | |
| Woodlake 93/65/97/71/97 | Hanford 92/65/97/71/97 | Orosi 92/64/97/70/96 | |
Seven Day Forecast:
| Tuesday
Partly cloudy 68/92 |
Wednesday
Partly cloudy 65/88 |
Thursday
Mostly clear 61/89 |
Friday
Mostly clear 60/89 |
Saturday
Mostly clear 58/88 |
Two Week Outlook: September 15 through September 21: For a change, a trough of low pressure shows up on this model along the Pacific coast. It’s very doubtful any precipitation will occur with this trough, but it will lower temperatures to near to possibly somewhat below average.
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 Tuesday and mainly out of the northwest afternoons and evenings.
Rain: Currently, there is a considerable amount of monsoonal moisture working northward through parts of Arizona, southern California, and Nevada. We have a cut off low just to the west of Monterey which will begin to entrain the moisture around its counterclockwise circulation. The low will drift southward over the next 48 hours, meaning the winds aloft will become out of the southeast, moving that flow of monsoonal moisture into central California. Heavy thunderstorms are likely over the mountains and, with the proximity of the low nearby, enough convection will be possible to sustain scattered showers and isolated thunderstorms over the valley floor. The time of greatest risk will be Sunday afternoon through about midday Monday then will taper off by Monday evening as the low moves northward again, eventually turning the winds aloft out of the southwest.
Models indicate the low will move inland Wednesday through central California. Even though model information shows a dry system moving through, we’ll have to keep a close eye on it in case the moisture field is deeper than modeling shows.
Rainfall amounts on the valley floor will range from nothing to a tenth of an inch or so. It’s possible, especially near the east and southeast foothills, that a thunderstorm could occur with considerably more rain, however those would be isolated cases.
After Wednesday night, all of this will shift to the east as a westerly flow aloft begins for dry and mild weather through the weekend and likely through all of the following week.
Afternoon Dew Points Today: Mid to upper 50s. Kern: Mid to upper 50s
Relative Humidity Forecast: Hanford, 30%/80% Bakersfield, 30%/60%
Actual Humidity September 7, 2017: Delano, 71%/32%, Porterville, 76%/29%
Percentage of Sunshine Today/Tomorrow: Visalia: Today 80% tomorrow 50%, Bakersfield: Today 80% tomorrow 30%.
ET Rates Over the Past Seven Days September 7, 2017: Stratford 1.70, Parlier 1.37, Blackwell 1.85, Lindcove 1.39, Arvin 1.58, Orange Cove 1.60, Porterville 1.42, Delano 1.52, Madera Two 1.138 Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 78, Parlier 84, Blackwell 83, Lindcove 80, Arvin 1.89, Orange Cove 83, Porterville 87, Delano 84, Madera Two 84
Mean Temperatures for September Month So Far: 85.9+9.9
Record Temperatures: 108/49. Average Temperatures: 93/62
Cooling Degree Days This Season: 1965, +558 Courtesy of the NWS
Precipitation: Seasonal total/average/above or below average:
Since September 7, 2017, Fresno: 17.20 season. / +5.86 or +5.86 Month to Date: T
Since September 7, 2017, Bakersfield: 7.89, or 1.43, Month to Date: .01, 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: 6:37 am Sunset: 7:15 Hours of Daylight: 12:41
Yesterday’s Weather
MAE : Madera 253 : DH1700 / 90 / 62 / 0.00 /
FAT : Fresno Airport 333 : DH1700 / 91 / 64 / 0.00 /
HJO : Hanford Airport 242 : DH1700 / 92 / 63 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1700 / 94 / 63 / 0.00 /
BFL : Bakersfield Airport 496 : DH1700 / 91 / 69 / 0.00 /
VIS : Visalia Airport 292 : DH1700 / 91 / 63 / 0.00 /
ATEC1 : Avenal 787 : DH1654 / 90 / 61 / 0.00 /
PTV : Porterville Airport 442 : DH1700 / 91 / 63 / 0.00 /
TFTC1 : Taft 759 : DH1653 / 89 / 68 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 88 / 62 / 0.00 /
Rainfall:
To date Last year Average Annual ave
STOCKTON 0.00 21.79 158 16.69 121 13.79 14.06
MODESTO 0.00 16.93 132 15.61 121 12.87 13.11
MERCED 0.00 16.03 131 14.66 120 12.24 12.50
MADERA 0.00 14.18 120 12.96 110 11.79 12.02
FRESNO 0.00 17.20 152 14.29 126 11.34 11.50
HANFORD 0.00 11.05 111 8.26 83 9.94 10.10
BAKERSFIELD 0.00 7.83 122 5.43 85 6.40 6.47
BISHOP 0.00 9.18 183 3.88 77 5.01 5.18
SALINAS 0.00 16.45 130 13.47 106 12.67 12.83
PASO ROBLES 0.00 16.16 129 8.06 64 12.57 12.78
SANTA MARIA 0.00 18.69 135 9.00 65 13.83 13.95
Rainfall season from October 1st through September 30th
Next Report: Saturday, September 9 afternoon