May 21, 2018
Summary: The center of circulation of a relatively cold upper level low is now over eastern Kern County. The counterclockwise circulation around the low has the winds aloft out of the east from Yosemite northward and out of the west over Kern County. This poses a tricky forecast for both this afternoon and Tuesday afternoon as this will be a slow mover. Scattered showers and isolated thunderstorms will develop over the higher elevations of the Sierra Nevada both afternoons with some activity spilling over the foothills due to the eastern winds aloft. There will also be a small chance of an isolated shower or thunderstorm or two making it over the valley floor, especially along the east side. Isolated showers and thunderstorms may also develop along the Coast Range and over the Kern County mountains and deserts. The chance of measurable rain at any given location remains quite low with the greatest risk being along the Sierra Nevada foothills.
The combination of marine air surging into the valley and cooler air aloft will result in a temporary cooling trend today with temperatures possibly below the 80 degree mark at many locations. As the low begins to shift towards southern Nevada Tuesday, the flow will become more off shore, possibly suppressing the marine air and allowing some warming to occur.
Weak upper level high pressure will fill in from the west Wednesday and Wednesday night then we’ll have a new low to content with Friday through Sunday. Most of the data this morning indicates the main dynamics of this system will move through northern California, however one model poses a 30% to 40% chance of measurable rain Saturday and Sunday. For now, it’s the odd model out. With that in mind, we’ll continue to go with a dry forecast with the exception of the Sierra Nevada.
As soon as that system moves to the east Sunday night, the possibility of a new trough may move through about Tuesday or Wednesday of next week, holding temperatures in check as the on shore flow continues, allowing modified sea breezes to move down the valley from time to time.
Forecast: Variable cloudiness through Tuesday evening. A small chance of isolated showers or thunderstorms this afternoon or evening and again Tuesday afternoon and evening. Mostly clear to occasionally partly cloudy Tuesday night. Mostly clear Wednesday through Thursday. Variable cloudiness at times late Friday through Sunday. Mostly clear Sunday night and Monday.
Short Term:
| Madera 78/56/84/57/86 | Reedley 78/57/84/57/86 | Dinuba 77/55/86/57/85 | |
| Porterville 78/56/83/56/87 | Lindsay 78/57/85/56/86 | Delano 79/58/84/59/87 | |
| Bakersfield 79/61/85/62/85 | Arvin 77/60/84/58/87 | Taft 79/62/86/62/86 | |
| Lamont 79/59/86/59/88 | Pixley 78/57/84/57/85 | Tulare 77/56/83/57/85 | |
| Woodlake 78/57/84/57/85 | Hanford 78/58/85/57/87 | Orosi 79/57/85/57/87 | |
Seven Day Forecast:
| Thursday
Mostly clear 58/85 |
Friday
Partly cloudy 58/81 |
Saturday
Variable clouds 55/76 |
Sunday
Variable clouds 54/79 |
Monday
Mostly clear 56/85 |
Two Week Outlook: May 25 through May 31 This model is showing more ridging prevailing over the western United States and off shore. This will result in above average temperatures. The chance of precipitation will be very low.
May: This model is indicating upper level high pressure will be somewhat more dominant over the Desert Southwest, stretching into the eastern Pacific Ocean. This pattern typically means generally above average temperatures and would also result in below average precipitation.
May, June, July: Now we head into the heart of summer, which is typically dry for central California. This model is indicating even drier than average conditions will prevail. Upper level high pressure will be dominant, maintaining generally above average temperatures.
Winds: Winds will be out of the northwest at 5 to 15 MPH late mornings through early evenings through Thursday and generally light during the night and morning hours.
Rain: I cannot rule out a small chance of isolated showers or thunderstorms this afternoon and evening and again Tuesday afternoon and evening. As a rule of thumb, the closer one is to the Sierra Nevada foothills, the greater the risk will be, though even there the risk will be small. I must emphasize the vast majority of locations will remain dry. Dry weather will return Tuesday night and continue through the rest of the week though my confidence level is not that great for Friday through Sunday. Models are showing a fairly robust low off the northern California coast moving slowly inland over the weekend with the main dynamics remaining over northern California. However, the path of this storm has not been set in stone as of yet so this forecast is certainly subject to change. We’ll keep you informed of any changes as newer data becomes available. Next week appears dry.
Afternoon Dew Points Today: Mid to upper 40s. Kern: Mid to upper 40s.
Humidity: Visalia: 20%/75% Bakersfield: 20%/60%
Actual Humidity May 17, 2018: Delano, 93%/28%, Porterville, 94%/30%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 80% tomorrow 80% Bakersfield: Today: 90% Tomorrow: 90%
ET Rates Over the Past Seven Days May 17, 2018: Stratford 1.83, Parlier 1.66, Blackwell 1.97, Lindcove 1.62, Arvin 1.71, Orange Cove 1.72, Porterville 1.63, Delano 1.66, Madera Two 1.71. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 69, Parlier 70, Blackwell 76, Lindcove, 70, Arvin, 80, Orange Cove 65, Porterville 78, Delano 76, Madera Two NA
Record Temperatures: 103/42. Average Temperatures: 85/55
Cooling Degree Days this Season: 156 +55 Courtesy of the NWS
Average temperatures for May so far, 69.4 +2.2
Precipitation: Seasonal total/average/above or below average:
Since July 1, 2017 Fresno: 6.73 season. or -4.22. Month to Date: .00
Since July 1, 2017, Bakersfield: 3.93, or -2.28. Month to Date: T
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: 5:48 am Sunset: 8:03 pm. Hours of Daylight: 14.13
Yesterday’s Weather:
MAE : Madera 253 : DH1700 / 84 / 51 / 0.00 /
FAT : Fresno Airport 333 : DH1700 / 85 / 57 / 0.00 /
HJO : Hanford Airport 242 : DH1700 / 86 / 56 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1700 / 86 / 55 / 0.00 /
BFL : Bakersfield Airport 496 : DH1700 / 85 / 60 / 0.00 /
VIS : Visalia Airport 292 : DH1700 / 84 / 57 / 0.00 /
ATEC1 : Avenal 787 : DH1655 / 82 / 55 / 0.00 /
PTV : Porterville Airport 442 : DH1700 / 84 / 53 / 0.00 /
TFTC1 : Taft 759 : DH1653 / 83 / 62 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 84 / 58 / 0.00 /
Rainfall: Water year Oct 1st through September 30th
STOCKTON 0.00 9.09 67 21.68 161 13.50 14.06
MODESTO 0.00 8.00 64 16.79 134 12.50 13.11
MERCED 0.00 6.91 58 15.79 132 11.93 12.50
MADERA 0.00 7.22 63 14.17 124 11.46 12.02
FRESNO 0.00 6.73 61 17.20 157 10.96 11.50
HANFORD 0.00 4.70 49 11.04 115 9.61 10.10
BAKERSFIELD 0.00 3.93 63 7.81 126 6.22 6.47
BISHOP 0.00 1.25 28 9.16 208 4.41 5.18
SALINAS T 7.13 57 16.36 132 12.43 12.83
PASO ROBLES 0.00 9.62 78 16.14 130 12.37 12.78
SANTA MARIA 0.00 6.01 44 18.44 135 13.65 13.95
Next report: Tuesday, May 22