January 31, 2019
Summary: The center of circulation of our coastal hugger is roughly 100 miles to the west of Santa Maria at this hour and is moving rather quickly southeastward. A swath of rain extends along the eastern flank of the low right into central and northern portions of southern California. Heavy rain and thunderstorms have been reported over the coast range. Santa Barbara recorded .58 between 6:00 and 7:00 this morning during a thunderstorm. Moderate rain is occurring over the valley portion of Kern County northward through Kings County. Since the low is moving pretty quickly, the rain will taper off this afternoon and will be replaced by a very temporary ridge of high pressure tonight and early Friday.
We then turn our attention to a very intense low digging its way southward from the Gulf of Alaska. Models place the center of circulation further south than previously suggested. In fact, the center of the low, both at the surface and aloft, will be just west of San Francisco Saturday morning. This will increase the chance of a high wind event over the Kern County portion of the valley and along the west side as very steep differences in pressure develop between roughly San Francisco and southern California. This could potentially squeeze strong winds downslope off the Tehachapi Mountains and down to the valley floor. This is discussed in detail in the wind section below.
Models are also indicating very impressive amounts of rain for the valley and snow for the Sierra Nevada as a 110 knot jet stream sweeps in from the southwest perpendicular to the Sierra Nevada. As much as 5 feet of new snow is certainly plausible above 7,500 feet from Friday night through Saturday night. big time rain shadows will develop along the west side and, of course, in Kern County which will play havoc with rainfall totals there. Even so, upwards of an inch of precipitation is possible north of Kern County along the east side, especially in Fresno and Madera Counties.
The low will move inland Saturday afternoon but not before dragging a strong cold front down the valley. Later Saturday afternoon, the rain will turn to showers with a small chance of isolated thunderstorms. Showers will taper off briefly later Saturday night and early Sunday. A new, colder low will dig southward along the British Columbia coast and will dive into northern and central California from roughly late morning Sunday through Monday night. this system will not be carrying nearly as much moisture however periods of showers can be expected through at least late Monday evening.
The trough will then begin to move northeastward away from our region, allowing high pressure to build into California. Even so, the flow aloft will be out of the north/northwest so expect below average temperatures beginning Sunday and at least through the middle of next week.
Forecast: Rain this morning, possibly locally heavy, with a slight chance of thunderstorms. Rain ending from north to south this afternoon. Mostly to partly cloudy tonight and Friday morning. The chance of rain will increase rapidly later Friday afternoon through Saturday morning with strong, gusty south to southeast winds. Showers Saturday afternoon with a small chance of isolated thunderstorms. Showers Saturday night, tapering off during the early morning hours. Showers again by late Sunday morning, continuing well into Monday night. mostly to partly cloudy Tuesday. Becoming mostly clear Tuesday night through Thursday with areas of night and morning fog.
Short Term:
| Madera 62/45/62/53/58 | Reedley 63/45/62/52/57 | Dinuba 61/45/61/52/57 | |
| Porterville 63/45/63/51/58 | Lindsay 63/44/63/51/59 | Delano 60/47/62/53/59 | |
| Bakersfield 59/48/67/54/59 | Taft59/50/64/54/60 | Arvin 59/47/67/55/61 | |
| Lamont 60/46/66/45/51 | Pixley 61/45/62/52/58 | Tulare 61/44/62/51/59 | |
| Woodlake 62/44/62/52/58 | Hanford 62/46/62/53/59 | Orosi 63/45/61/52/58 | |
Seven Day Forecast:
| Sunday
Showers likely 44/59 |
Monday
Showers likely 42/55 |
Tuesday
Mostly cloudy 40/52 |
Wednesday
Patchy fog/mostly clear 33/56 |
Thursday
Patchy fog/mostly clear 34/60 |
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 variable at 5 to 15 MPH with stronger gusts. Winds tonight and for a time Friday morning will be generally light to near calm. Winds will begin to pick up out of the south or southeast Friday afternoon and by evening will be averaging 15 to 25 MPH. winds Friday night and Saturday morning will become interesting. An impressive difference in pressure will set up between San Francisco and the deserts of southern California. It does now appear that the squeeze play of strong winds blowing downslope off the Tehachapi Mountains is likely in Kern County. Near the base of the mountains, wind gusts exceeding 50 to 60 MPH can be expected with possible gusts to 45 to 50 as far north as Bakersfield. Along the west side of the valley, gusts between 30 and 40 MPH are possible with the possibility of gusts approaching 50 MPH. in Tulare County, eastern Fresno County, and Madera County, winds will be out of the southeast at 15 to 30 MPH with local gusts to 40 MPH. as the low moves inland Saturday afternoon, pressure differences will quickly slacken, and winds will begin to die off. From Saturday afternoon through Sunday winds will generally be in the 10 to 15 MPH range with stronger gusts.
Rain: Light to moderate rain is currently falling in Kings, Fresno, Tulare, and Kern Counties. Locally heavy amounts are showing up on radar in western Kern County. Santa Barbara has had more than .50 in the last hour and a half. Here on the valley floor, rainfall amounts are ranging from a few hundredths along the east side of the valley to as much as .33 along the west side where rain continues. The center of the low will track rather quickly southeastward today so the precipitation will end from north to south as the day wears on. Dry weather will prevail tonight and Friday morning before a very intense system begins to pound all of California Friday afternoon.
Rain will be likely Friday afternoon through Saturday morning, possibly heavy at times though a significant rain shadow is expected to form along the west side and in Kern County due to the jet stream aloft and strong winds on the valley floor. Heaviest rain will be along the east side with the least amount over the valley portion of Kern County, which is certainly not unusual. Even so, high resolution models are indicating as much as .25 to .50 in Kern County with as much as an inch being possible along the east side. The west side could pick up more than .50, though I do have doubts due to rain shadows.
The rain will turn to showers Saturday afternoon with a small chance of isolated thunderstorms. Showers will taper off later Saturday night with possibly a brief break Saturday night into Sunday morning. By late Sunday morning, the chance of showers will increase again, becoming likely Sunday afternoon through Monday evening. Showers will taper off late Monday evening with dry weather returning by Tuesday. It appears dry weather will continue for at least three or four days. After that, there are too many model differences to nail down a particular pattern.
Frost Discussion: All locations will be above freezing tonight and each night through Tuesday morning. A cold low pressure system will provide active weather Sunday through Monday night. as that low pulls off to the east, a brief northerly flow will slide down the back side of the system and into California. Low to mid 30s are a distinct possibility next Wednesday and Thursday mornings with a small chance of upper 20s in riverbottom and like locations. This is by no means a critical situation, but it appears to be one of those typical cold air masses that can frequent California from time to time in February. Medium range models for late next week and beyond are calling for below average temperatures, but at this time I don’t see a pattern that would result in critically low temperatures.
Afternoon Dew Points Today: Low to mid 50s. Kern, low to mid 50s.
Humidity: Hanford: 80%/100%, Bakersfield: 75%/95%
Actual Humidity January 30, 2019: Delano, NA Porterville, 98%/43%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 10%, tomorrow 20% Bakersfield: Today: 0% Tomorrow: 30%
ET Rates Over the Past Seven Days: Stratford .36, Parlier .44, Blackwell .46, Lindcove .39, Arvin .52, Orange Cove .44, Porterville .38, Delano .42 Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 53, Parlier 52, Blackwell 53, Lindcove, 56, Arvin, 52, Orange Cove NA, Porterville 51, Delano 50
Record Temperatures: 75/26. Average Temperatures: 58/37
Heating Degree Days this Season: 1268 -458
Courtesy of the NWS
Average temperature for January so far: 50.0 +4.8
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2018 Fresno: 4.42 season. or -1.16, Month to Date: 2.09 -.02
Since Oct 1, 2018, Bakersfield: 2.27, or -.81. Month to Date: .97 -.15
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove, 608, Parlier, 610 , Arvin, 535 Shafter, 616 Stratford, 613, Delano 613, Lindcove, 901, Porterville, 1234
Hours at 45 or below 45.
Sunrise: 7:01 am Sunset: 5:24 pm. Hours of Daylight: 10:19
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 69 / 47 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 67 / 49 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 67 / 43 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 66 / 39 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 72 / 56 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 68 / 45 / 0.00 /
ATEC1 : Avenal 787 : DH1553 / 69 / 43 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 71 / 45 / 0.00 /
TFTC1 : Taft 759 : DHM / M / M / M /
LOSC1 : Los Banos 120 : DH1600 / 66 / 47 / 0.00 /
Rainfall: Water year Oct 1st through September 30th
24hr Season % L.Y. % Ave. Ave. yearly total
STOCKTON 0.00 7.92 107 3.99 54 7.37 14.06
MODESTO 0.00 6.39 97 3.55 54 6.60 13.11
MERCED 0.00 6.12 101 2.29 38 6.07 12.50
MADERA 0.00 4.58 75 1.55 25 6.13 12.02
FRESNO 0.00 4.42 79 1.64 29 5.58 11.50
HANFORD 0.00 3.33 65 1.78 35 5.13 10.10
BAKERSFIELD 0.00 2.27 74 1.10 36 3.08 6.47
BISHOP 0.00 3.46 131 0.20 8 2.64 5.18
SALINAS 0.00 5.80 90 2.51 39 6.42 12.83
PASO ROBLES 0.00 6.36 101 2.30 36 6.32 12.78
SANTA MARIA 0.00 6.41 96 2.02 30 6.70 13.95
Next report: Thursday afternoon/January 31