May 13, 2019
Summary: Short term, a weak ridge of upper level high pressure resides almost right overhead this morning. Temperatures will warm accordingly with the hottest locations pushing the 90 degree mark this afternoon. The high will begin to weaken and shift slowly towards the east in response to a deepening eastern Pacific trough of low pressure which will already be off shore Wednesday. The pattern that will evolve beginning Wednesday is more reminiscent of a later winter/early spring pattern as the southern flank of the trough increases in strength and moves into northern and central California late Wednesday night and Thursday.
Precipitation will become likely with the heaviest precipitation from Fresno County northward. However the dynamics even in the south valley are actually quite impressive for this time of year. For now, it appears precipitation will be likely throughout the valley. This is only the first of possibly three storm systems to affect central California over the next 8 or 9 days. A weak ridge will briefly fill in Friday afternoon through Saturday, but models are amazingly consistent in depicting an impressive low pressure system again for this time of year, moving into northern and central California Saturday night and Sunday.
This far out, it’s somewhat of a difficult decision in trying to discern the southern limit of precipitation. It looks like rain will be likely from Fresno County northward with at least a possibility of rain spreading into the south valley.
Where models begin to separate is the possible development of a third low about Tuesday of next week. Again, theoretically, it would spread precipitation over northern and central California. Some models keep the precipitation shield north of the central and south valley while others show a similar pattern in moving showers over the entire region. The air mass associated with all these systems is chilly for this time of year with snow over the Sierra Nevada and temperatures likely falling to 10 to 15 degrees below average Thursday and Friday. Some warming will occur over the weekend but will still be below average. It’s not until after the middle of next week when upper level high pressure begins to deflect the storm track north of central California for a return to a dry pattern.
Forecast: Other than occasional high clouds, it will be mostly clear through Tuesday. Partly cloudy Tuesday night. increasing cloudiness Wednesday. Showers becoming likely later Wednesday night, possibly lasting into Friday morning. There will be a chance of isolated thunderstorms Thursday afternoon and evening. Partly cloudy Friday afternoon through Saturday. Increasing cloudiness Saturday night with a chance of showers after midnight. Showers likely Sunday with a chance of thunderstorms. A chance of showers Sunday night. becoming partly cloudy Monday.
Short Term:
| Madera 88/56/87/56/79 | Reedley 88/57/87/57/80 | Dinuba 87/55/87/54/79 | |
| Porterville 89/56/87/56/81 | Lindsay 88/55/87/55/80 | Delano 80/57/88/57/82 | |
| Bakersfield 89/62/88/62/83 | Taft 88/63/87/63/83 | Arvin 90/58/89/63/83 | |
| Lamont 90/59/87/58/82 | Pixley 88/56/87/56/80 | Tulare 87/55/87/55/80 | |
| Woodlake 88/55/87/55/80 | Hanford 88/56/87/57/81 | Orosi 88/54/87/54/79 | |
Seven Day Forecast:
| Thursday
Showers likely 59/68 |
Friday
AM showers 49/71 |
Saturday
Partly cloudy 48/79 |
Sunday
Showers likely 55/74 |
Monday
Partly cloudy 49/74 |
Two Week Outlook: May 20 through May 27: The main signature on this model is a rather high risk of precipitation over the interior west with a lesser chance over central California, but a chance nonetheless. With predominately low pressure over the western states, temperatures will be generally below average.
May: As we now enter the dry season, precipitation chances, according to this model, will be that of most Mays, in other words, near seasonal. Nothing too dramatic shows up as far as temperatures are concerned with readings near to marginally above average.
May, June, July: As we move through the late spring through mid summer, precipitation opportunities will be typical, in other words, not very high and that’s especially true for June and July. For this 90 day period, temperatures are projected to run somewhat above seasonal values.
Winds: Winds will be generally at or less than 15 MPH through tonight. Winds Tuesday will begin to increase out of the northwest during the afternoon and evening at 10 to 20 MPH with stronger gusts, mainly along the west side. Winds Wednesday through Thursday will periodically be mainly out of the west or northwest at 10 to 20 MPH with local gusts to 30 MPH, especially in the vicinity of showers.
Rain: Considering the time of year, this will be an active weather week. Dry weather will continue through Wednesday, but an unusually deep low pressure system for this time of year will spread precipitation over all of northern and central California later Wednesday night, possibly lasting into Friday morning. For now, I must emphasize that for this late in the season, this shows the characteristics of a major winter storm with widespread showers over the valley and isolated thunderstorms possible, mainly Thursday afternoon and evening. Rainfall amounts could exceed .33 from Fresno County north and locally elsewhere. If thunderstorms develop, more could locally fall. The highest threat of precipitation will be from after midnight Wednesday night through Friday morning.
Dry weather should return Friday afternoon, continuing through Saturday. Models are amazingly agreeable on the potential of a second storm of equal strength engulfing northern and central California Saturday night into early Monday.
Yet a third system shows up on some models with possibly more rain around Tuesday of next week. At least with this system there are other models which show the precip being diverted north of the growing area. The bottom line is, it’s not until Wednesday or Thursday of next week before we get out from this pattern, although the two week model is showing above average precipitation between the 20 and 26.
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Afternoon Dew Points Today: Low to mid 40s. Kern: Low to mid 40s. Humidity values ranging from 20%/75% at Hanford. Bakersfield 20%/60%
Actual Humidity May 12, 2019: Delano, 100%/66% Porterville, 92%/27%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 80%, tomorrow 70% Bakersfield: Today: 90% Tomorrow: 80%
ET Rates Over the Past Seven Days: Stratford 1.44, Parlier 1.54, Blackwell 1.66, Lindcove .NA, Arvin 1.48, Orange Cove 1.52, Porterville 1.55, Delano 1.48. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 70, Parlier 69, Blackwell 73, Lindcove, NA, Arvin, 70, Orange Cove 68, Porterville 75, Delano 73
Record Temperatures: 103/43. Average Temperatures: 83/54
Cooling Degree Days this Season: 123 +55
Courtesy of the NWS
Average temperature for May so far: 68.7 +2.1
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2018 Fresno: 9.49 season. or -1.39. Month to Date: .02 -.19
Since Oct 1, 2018, Bakersfield: 6.32, or +.13. Month to Date: .32 +.22
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove, Parlier, Arvin, Shafter, Stratford, Lindcove, Porterville,
Hours at 45 or below 45.
Sunrise: 5:52 am Sunset: 7:59 pm. Hours of Daylight: 14:05
Yesterday’s Weather:
MAE : Madera 253 : DH1700 / 92 / 57 / 0.00 /
FAT : Fresno Airport 333 : DH1700 / 90 / 62 / 0.00 /
HJO : Hanford Airport 242 : DH1700 / 91 / 60 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1700 / 92 / 55 / 0.00 /
BFL : Bakersfield Airport 496 : DHM / 89 / 62 / 0.00 /
VIS : Visalia Airport 292 : DHM / 78 / 58 / 0.00 /
ATEC1 : Avenal 787 : DHM / 76 / 68 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / M / 60 / 0.00 /
TFTC1 : Taft 759 : DH1656 / 90 / 65 / 0.00 /
Rainfall: Water year Oct 1st through September 30th
24hr Season % L.Y. % Ave. Ave. yearly total
STOCKTON 0.00 15.79 118 9.09 68 13.40 14.06
MODESTO 0.00 12.06 97 8.00 65 12.37 13.11
MERCED 0.00 11.87 100 6.91 58 11.82 12.50
MADERA 0.00 9.84 87 7.22 64 11.34 12.02
FRESNO 0.00 9.49 87 6.73 62 10.88 11.50
HANFORD 0.00 7.67 80 4.70 49 9.53 10.10
BAKERSFIELD 0.00 6.32 102 3.93 63 6.19 6.47
BISHOP 0.00 8.09 185 1.22 28 4.37 5.18
SALINAS 0.00 12.40 100 7.13 58 12.36 12.83
PASO ROBLES 0.00 14.12 115 9.62 78 12.31 12.78
SANTA MARIA 0.00 14.83 109 6.01 44 13.59 13.95
Next report: Tuesday morning/May 14