August 15, 2023
Summary The main weather concern over the next 72 hours will be heat and the slight risk of an isolated thunderstorm near the foothills of the Sierra Nevada and the Kern County mountains during the afternoon and evening hours through Thursday. Strong upper level high pressure over the Desert Southwest is linked up with another high off the coast of the Pacific Northwest. A weak upper low is still parked off the central coast. This is creating a south/southeast flow over central California. Monsoonal moisture is embedded within this flow, bringing in the necessary moisture for PM showers over the mountains and periods of partly cloudy skies over the valley floor. the marine layer is only 800 feet deep at Monterey, meaning there’s no chance modified sea breezes will lower our temperatures until at least Friday.
My main concern is the tropics where a tropical wave is forming an area of low pressure southwest of Guatemala. This low should form a depression within the next 24 hours, eventually gaining hurricane strength by Friday. Models show the storm moving northwestward parallel to the Baja coastline over the weekend with the remnants of the storm being just southwest of San Diego by early next week. by this time, a large high will be parked over the middle of the country, channeling moisture northward into the southern half of California. This system is in a particularly dangerous spot for valley rain, which could arrive as early as Sunday with a greater risk Sunday night and Monday. the risk factor for measurable rain is roughly 50/50 for Kern County and 20% to 30% north of the Kern County line. We will continue to monitor this situation closely, but I do see this as a legitimate threat. Some models are projecting the possibility of more than .25 in Kern County with lesser amounts further north.
Forecast Mostly clear to occasionally partly cloudy through Thursday and continued hot. A slight chance of isolated thunderstorms near the foothills afternoons and evenings. Mostly clear to occasionally partly cloudy Friday through Saturday night. Increasing cloudiness Sunday morning leading to a chance of showers and isolated thunderstorms Sunday afternoon through Tuesday.
Temperatures:
| Madera
104/71/104/72/104 |
Reedley
105/72/105/72/104 |
Dinuba
103/70/103/71/102 |
| Porterville
105/73/105/72/104 |
Lindsay
103/70/104/71/103 |
Delano
105/74/106/75/105 |
| Bakersfield
106/80/106/79/105 |
Taft
103/80/103/79/102 |
Arvin
106/77/106/76/105 |
| Lamont
107/77/106/77/106 |
Pixley
104/72/105/72/104 |
Tulare
103/70/103/71/103 |
| Woodlake
103/70/103/72/103 |
Hanford
104/71/104/70/103 |
Orosi
103/70/103/71/102 |
Seven Day Forecast
| Friday
Mostly clear 67/100 |
Saturday
Mostly clear 66/97 |
Sunday
PM showers possible 67/93 |
Monday
Chance of showers 71/91 |
Tuesday
Slight chance of showers 72/98 |
Two Week Outlook: August 22 through August 28 This model points to hot weather over the Pacific Northwest and northern California with above average temperatures over the remainder of California. Expect a chance of isolated thunderstorms over the Sierra Nevada. Otherwise, dry conditions will prevail.
August: This model indicates temperatures over the next 30 days will be near to slightly above seasonal averages. Dry weather will continue, although we will have to keep a watchful eye to the south for possible tropical activity.
August, September, October: This model shows above average temperatures for much of the west, particularly the Desert Southwest. It also points to below average precipitation over the Desert Southwest, possibly meaning a less active monsoon season. The chance of precipitation for central California appears to be near average.
Wind Discussion: Winds today through this evening will be mainly out of the west to northwest at 8 to 15 mph at times with locally stronger gusts. During the night and morning hours winds will generally be at or less than 8 mph with periods of near calm conditions through Friday.
Rain Discussion: With that upper low just off the central coast, and monsoonal moisture caught up in that southeast flow, we’ll continue to have daily chances of afternoon and evening thunderstorms over the Sierra Nevada and the Kern County mountains. There is a slight risk of a few of these storms clipping the extreme eastern and southern San Joaquin Valley during the afternoon and evening. The chance of measurable rain at any given location remains very low.
Of much greater concern is an increasing chance of showers and thunderstorms late this weekend and early next week. a tropical system is projected to develop to the west of Guatemala. This storm will strengthen and move north/northwest, eventually moving parallel to the Baja coastline late this week and this weekend. Some models are showing the center of circulation of what’s left of this system to the southwest of San Diego. By this time, a large high will be parked over the mid section of the country. This would favor a southerly flow channeling moisture from a dying hurricane into central and southern California. You old timers can remember, I’m sure, what dying tropical systems can do.
Guessing potential rainfall totals is difficult, at best, especially from dying hurricanes. However, a few high resolution models are depicting more than .25 between Sunday night and Tuesday over the southern section of the valley with lesser amounts further north. Let me say also, most of the moisture will move northward east of the Sierra Nevada, leaving us completely alone. Friday night appears 50/50 for rain, and, of course, we’ll keep you posted.
Mid afternoon dew points: Upper 50s to the lower 60s. Kern: Mid to upper 50s.
ET for the past seven days: Stratford, 1.85, Parlier, 1.65, Arvin 1.92, Delano 1.66.
Soil temperatures: Stratford 75, Parlier 81, Arvin 82, Delano 82 *=data missing.
Average Temperatures: 97/65 Record Temperatures: 109/53
Cooling Degree Days This Season. 1394 +135 Varies widely from location to location. courtesy of the NWS
Precipitation: Seasonal total for Fresno 17.83, Monthly .T
Precipitation for Bakersfield: Season: 10.26, Monthly: T
Average Temperature this Month 80.6 +0.9 taken at NWS Hanford.
Water year season is from October 1st through September 30.
Chilling Hours November 1st through February 28: Parlier 1306, Arvin 1115, Belridge 1204, Shafter 1230, Stratford 1277, Delano 1273, Porterville 1245 courtesy UC Davis
Sunrise 6:17, Sunset, 7:49. hours of daylight, 13:34
NA=Not available
Yesterday’s Weather: H L
MCE : Merced 153 : DH1700 / 103 / 72 / 0.00 /
MAE : Madera 253 : DH1700 / 106 / 71 / 0.00 /
FAT : Fresno Airport 333 : DH1700 / 106 / 78 / 0.00 /
HJO : Hanford Airport 242 : DH1700 / 107 / 73 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1700 / 107 / 70 / 0.00 /
BFL : Bakersfield Airport 496 : DH1700 / 105 / 75 / 0.00 /
VIS : Visalia Airport 292 : DH1700 / 104 / 69 / 0.00 /
PTV : Porterville Airport 442 : DH1700 / 104 / 68 / T /
LOSC1 : Los Banos 120 : DH1600 / 102 / 74 / 0.00 /
Rainfall stats: seas % L.Y % ave. s.a.
STOCKTON 0.00 23.21 174 9.81 73 13.36 13.45
MODESTO 0.00 20.17 165 9.00 74 12.20 12.27
MERCED 0.00 20.86 178 7.44 63 11.75 11.80
MADERA 0.00 11.62 108 2.21 21 10.76 10.79
FRESNO 0.00 17.83 163 6.34 58 10.94 10.99
HANFORD 0.00 14.59 180 6.36 79 8.09 8.13
BAKERSFIELD 0.00 10.26 163 5.41 86 6.31 6.36
BISHOP 0.00 14.72 314 5.63 120 4.69 4.84
DEATH VALLEY NP 0.00 1.25 64 1.70 87 1.95 2.20
SALINAS 0.00 13.95 111 7.31 58 12.52 12.58
PASO ROBLES 0.00 20.89 173 8.70 72 12.09 12.15
SANTA MARIA 0.00 24.05 182 7.79 59 13.24 13.32
Next report: August 16 am
At John Hibler Weather Forecasting, it is our goal to provide the most accurate forecasts available. Weather forecasting, unlike any other business, invites errors. Weather, by nature, is chaotic. It is our goal to be as accurate as humanly possible.