February 1, 2019
Summary: We are on the verge of a lot of weather over the next four and a half to five days. A huge trough of low pressure extends from the Gulf of Alaska to off the southern California coast. There are two main centers to this trough. The first is off the Washington coast. The second is roughly 500 miles west of San Francisco. That low is intensifying rapidly and will be just west of the Golden Gate Saturday. By Saturday morning, there will be an almost 16 millibar difference in pressure between the deserts of southern California and off shore northern California. Aloft, a 110 knot jet stream will be flanked from southwest to northeast across central California. This has the potential for locally hurricane force winds over the higher elevations of the Kern County mountains. The big question is whether these winds will come crashing down to the valley floor in Kern County. Current thinking is that they will, to one extent or another.
Gusts in excess of 60 MPH are possible later tonight and Saturday near the bottom of the Grapevine with strong winds stretching from near Arvin to Wheeler Ridge and westward to Taft. Winds in the 30 to 40 MPH range are certainly possible along the west side of the valley and locally elsewhere.
Satellite imagery is quite telling this morning. A huge stream of subtropical moisture is moving northeastward towards California as the low approaches with the aforementioned jet stream lifting all this moisture aloft over the Sierra Nevada. Copious amounts of rain are likely in the foothills with several feet of new snow above 7,500 feet. Four to five inches of precipitation from tonight through Saturday night would not be a surprise along the Sierra Nevada. Models are also indicating the possibility of 5 to 7 inches of rain over the mountains and foothills of southern California.
The low will not really push inland until later Saturday afternoon. Before that occurs, a strong cold front will move through with locally heavy rain on the valley floor. Showers will continue Saturday night into Sunday morning. With a little luck, there will be a few hours of dry weather Sunday then a much colder low will drop southward from western Canada and into Oregon and northern California late Sunday and well into Tuesday. Snow levels will drop into the foothills. This system won’t be nearly as wet, but showers will continue. It may be Tuesday night before we finally see an end to this very active pattern as high pressure nudges the low into the interior west.
As that occurs, a north/northeast flow will develop on the back side of the exiting storm, pumping cold and relatively dry air into the region for possibly below freezing temperatures. That is detailed in the frost discussion below.
Medium range models show below average temperatures continuing, but it does look like dry conditions will prevail from Wednesday through next weekend, at least.
Forecast: Patchy fog this morning. Otherwise, expect increasing cloudiness today. Periods of rain beginning this evening and continuing through Saturday. Locally heavy rain is possible, mainly along the eastern flank of the valley north of Kern County. Showers Saturday night, tapering off for a time Sunday. The chance of showers will again increase late Sunday afternoon with showers possible Sunday evening through Tuesday. Mostly to partly cloudy Tuesday night and Wednesday morning. Clearing Wednesday afternoon. Mostly clear Wednesday night through Friday with patchy fog.
Short Term:
| Madera 63/54/60/51/60 | Reedley 63/55/60/51/61 | Dinuba 61/53/59/50/59 | |
| Porterville 65/55/62/51/60 | Lindsay 63/54/61/49/59 | Delano 64/55/61/52/60 | |
| Bakersfield 67/57/64/52/64 | Taft 66/58/64/53/64 | Arvin 68/55/63/51/64 | |
| Lamont 66/56/64/52/64 | Pixley 64/55/62/51/61 | Tulare 62/53/60/50/60 | |
| Woodlake 63/54/60/50/60 | Hanford 64/55/61/51/60 | Orosi 63/53/61/50/59 | |
Seven Day Forecast:
| Monday
Showers likely 46/59 |
Tuesday
Showers likely 41/57 |
Wednesday
Partly cloudy 36/53 |
Thursday
Mostly clear 32/53 |
Friday
Mostly clear 32/59 |
Two Week Outlook: February 7 through February 13: This model continues to show the trend of below average temperatures during this period. Interestingly enough, the greatest risk of rain on this model is central California.
February: This model indicates the eastern Pacific high will be the most dominant feature during the month of February. There will be the usual exceptions, but overall this would result in above average temperatures and drier than average precipitation over much of the west and colder than average temperatures east of the Rockies.
February, March, April: At least this model projects about equal chances for either above or below average precipitation. There is actually a greater possibility of below average rain over the Pacific Northwest. Generally speaking, temperatures should remain at least marginally above average.
Winds: Winds this morning will be generally less than 10 MPH. later this afternoon, winds will be out of the southeast at 5 to 15 MPH. Winds later tonight will increase out of the southeast at 15 to 35 MPH with gusts to 45 MPH possible along the west side and possibly from Fresno County northward. In Kern County, winds should begin to pick up before midnight to 25 to 35 MPH with local gusts near 50 MPH possible. Near the base of the Tehachapi, local gusts to 60 to 70 MPH cannot be ruled out. The potential for the strongest winds will be near the bottom of the Grapevine and near Wheeler Ridge and, to a lesser extent, from Edison/Arvin on the east to Taft on the west. The potential for strong winds will not end until possibly late afternoon Saturday. Winds Saturday night through Tuesday will be generally out of the southeast at 15 to 25 MPH with stronger gusts. Light winds will return Tuesday night and beyond.
Rain: There will be a small chance of light showers during the late afternoon and early evening hours then the chance of rain will begin to increase rapidly after roughly 9:00 with periods of rain, possibly locally heavy at times, along the east side north of Kern County. The rain will turn to showers Saturday night. rainfall amounts tonight through Saturday night are going to be really difficult to pin down which is not uncommon with major storms. With a strong southwest to northeast jet stream above us late tonight and Saturday and the potential for very strong surface winds, strong rain shadows will develop. It’s possible that there’s so much tropical moisture moving in from the southwest that these rain shadows could be overcome by the sheer volume of moisture for possibly significant rains elsewhere, as well. Some models actually project as much as an inch to an inch and a half along the east side of the valley and more than ¾ of an inch along the west side. Half inch plus totals could fall over the valley portion of Kern County.
The showers will taper off for a time Sunday as this first system finally moves inland then a much colder low will drop southward from western Canada and into Oregon and northern California. This will renew periods of lighter showers later Sunday through Tuesday with the snow level coming down into the foothills.
Dry weather will return Tuesday night and last through next weekend for several days of dry conditions.
Frost Discussion: All locations will be above freezing through at least Tuesday and possibly Wednesday mornings. A very cold low will drop into the region Monday and Tuesday. As the low finally pulls off to the east, a north/northeast flow will develop over California, pushing cold and drier air into the valley. Low to mid 30s appears imminent for Thursday and Friday mornings with the potential for some of the coldest low lying locations down to 27 to 39 or so. We are still more than 5 days out so obviously we’ll tweak this as we go.
Afternoon Dew Points Today: Low to mid 50s. Kern, low to mid 50s.
Humidity: Hanford: 70%/100%, Bakersfield: 50%/85%
Actual Humidity January 31, 2019: Delano, NA Porterville, 96%/68%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 0%, tomorrow 0% Bakersfield: Today: 0% Tomorrow: 0%
ET Rates Over the Past Seven Days: Stratford .35, Parlier .44, Blackwell .45, Lindcove .39, Arvin .46, Orange Cove .45, Porterville .35, Delano .NA Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 53, Parlier 52, Blackwell 53, Lindcove, 56, Arvin, 53, Orange Cove NA, Porterville 52, Delano NA
Record Temperatures: 73/25. Average Temperatures: 58/37
Heating Degree Days this Season: 1278 -465
Courtesy of the NWS
Average temperature for January so far: 50.2 +4.8
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2018 Fresno: 4.56 season. or -1.10, Month to Date: 2.23 +.04
Since Oct 1, 2018, Bakersfield: 2.68, or -.44. Month to Date: 1.38 +.22
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove, 608, Parlier, 610 , Arvin, 536 Shafter, 616 Stratford, 613, Delano 613, Lindcove, 901, Porterville, 1244
Hours at 45 or below 45.
Sunrise: 7:00 am Sunset: 5:25 pm. Hours of Daylight: 10:21
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 67 / 54 / 0.18 /
FAT : Fresno Airport 333 : DH1600 / 64 / 53 / 0.14 /
HJO : Hanford Airport 242 : DH1600 / 61 / 52 / 0.33 /
NLC : Lemoore Naval AS 234 : DH1600 / 63 / 49 / 0.19 /
BFL : Bakersfield Airport 496 : DH1600 / 61 / 51 / 0.41 /
VIS : Visalia Airport 292 : DH1600 / 61 / 52 / M /
ATEC1 : Avenal 787 : DH1555 / 65 / 52 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 63 / 48 / 0.05 /
TFTC1 : Taft 759 : DHM / M / M / M /
LOSC1 : Los Banos 120 : DH1600 / 62 / 47 / M /
Rainfall: Water year Oct 1st through September 30th
24hr Season % L.Y. % Ave. Ave. yearly total
STOCKTON T 7.92 106 3.99 53 7.47 14.06
MODESTO 0.05 6.44 96 3.55 53 6.69 13.11
MERCED 0.09 6.21 101 2.29 37 6.12 12.50
MADERA 0.18 4.76 77 1.55 25 6.18 12.02
FRESNO 0.14 4.56 81 1.64 29 5.66 11.50
HANFORD 0.33 3.66 71 1.78 34 5.17 10.10
BAKERSFIELD 0.41 2.68 86 1.10 35 3.12 6.47
BISHOP 0.00 3.46 130 0.20 7 2.67 5.18
SALINAS 0.47 6.30 97 2.51 39 6.51 12.83
PASO ROBLES 0.56 6.92 108 2.30 36 6.41 12.78
SANTA MARIA 1.06 7.47 110 2.02 30 6.80 13.95
Next report: Friday afternoon/February 1