February 4, 2019
Summary: A fast moving cold front moved through the valley over the past couple of hours with a period of moderate rain at most locations. I noticed Lemoore picked up .14 between five and six this morning. The front is being followed by numerous showers and, once the daytime heating effect gets revved up, isolated to scattered thunderstorms will become likely. Unlike the past couple of afternoons where thunderstorms were generally from Madera County northward, the instability of the atmosphere is such where storms with localized heavy rain and small hail could occur just about anywhere.
The air mass behind the front is colder, but not nearly as cold as the air mass that will swing in tonight behind yet another cold front which will move through central California this evening. Behind that front is that pool of very cold air which may lower snow levels to 1,500 feet along the Sierra Nevada and 2,500 feet over the Kern County mountains. The last observation at Sandburg was reporting moderate snow with a temperature of 38. Freezing levels were also dropping over northern California as balloon soundings over Oakland last night showed a freezing level of 4,700 feet.
Showers and afternoon thunderstorms will continue through Tuesday then will begin to taper off Tuesday evening. Very cold temperatures will take over our attention Wednesday through Friday mornings. A brief northerly flow will wrap around the back side of the exiting low pressure system, reinforcing a cold air mass already in place. This northerly flow will lower dew points, allowing for frost/freeze conditions, especially Thursday and Friday mornings. All this is detailed in the frost discussion below.
Over the weekend, a broad area of cold low pressure will cover the waters off the Pacific Northwest and northern California with a chance of showers, mainly north of Kern County Friday and on through Sunday of next week. Unlike the current pattern, heavy precipitation is not expected.
Beginning Monday, models diverge somewhat. If there’s any common theme, it’s that there may be a significant low park off the coast of the Pacific Northwest and northern California for a few days with a strong westerly wind component underneath the low into central and southern California. Theoretically, this would steer more moisture into California via the jet stream. Due to the fact there’s so much model disparity, that would be low confidence for now.
Forecast: showers through Tuesday evening. There will be a reasonably decent chance of isolated to scattered thunderstorms this afternoon and again Tuesday afternoon. Any thunderstorms that do develop will include localized heavy rain and small hail. Showers will taper off later Tuesday evening with cloudy to mostly cloudy skies Tuesday night and Wednesday morning, but with some clearing, mainly towards the center and west side of the valley. Clearing Wednesday afternoon. Mostly clear and cold Wednesday night through Thursday night with patchy fog. Increasing cloudiness Thursday afternoon with a chance of light showers, mainly north of Kern County Friday night through Sunday. Partly cloudy Sunday night with increasing cloudiness again Monday.
Short Term:
| Madera 55/39/50/31/51 | Reedley 55/38/50/30/53 | Dinuba 54/38/51/30/52 | |
| Porterville 56/40/51/33/53 | Lindsay 56/38/52/31/53 | Delano 56/41/50/34/53 | |
| Bakersfield 57/42/50/34/52 | Taft 56/42/51/36/54 | Arvin 58/41/50/33/53 | |
| Lamont 57/42/51/33/52 | Pixley 55/39/51/31/52 | Tulare 55/38/50/32/51 | |
| Woodlake 56/39/50/31/51 | Hanford 56/38/50/30/52 | Orosi 55/39/50/30/51 | |
Seven Day Forecast:
| Thursday
Patchy fog/mostly clear 30/52 |
Friday
Patchy fog/increasing cloudiness 32/55 |
Saturday
Chance of showers 38/53 |
Sunday
Chance of showers 39/57 |
Monday
Increasing clouds 39/61 |
Two Week Outlook: February 11 through February 17: This model indicates a continuation of well below average temperatures as the eastern Pacific high remains several hundred miles off shore, allowing more disturbances and periodic shots of cold air to move in from the west or northwest. The chance of rain during this time frame appears relatively high.
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 will be mainly out of the southeast at 10 to 20 MPH north of Kern County with stronger gusts, especially near showers and thunderstorms, through Tuesday. Winds Tuesday night will be out of the northwest at 5 to 15 MPH. winds will be generally less than 8 MPH Wednesday and Thursday with periods of near calm conditions.
Rain: Two day rain totals north of Kern County have crept up to more than an inch in several locations. As a cold front moved through this morning, many locations received a tenth or two during the frontal passage. Expect numerous showers with a reasonably decent chance of isolated to scattered thunderstorms this afternoon and again Tuesday afternoon. Any thunderstorms that do break out will include heavy rain and/or small hail. The showers will finally taper off later Tuesday evening with dry weather after midnight Tuesday night through Friday.
Rainfall amounts from now through Tuesday evening will vary widely, ranging from a couple of tenths to well over one-half inch.
The next chance of rain will occur Friday night through Sunday as yet another cold trough of low pressure moves out of the Gulf of Alaska and carves out a cold low off the northern California/southern Oregon coast. On paper, this system looks pretty anemic so only light showers are possible, and even then mainly north of Kern County.
It’s possible next week could also be interesting. Even though models vary considerably, it is possible another strong low could move out of the Gulf of Alaska and park off the coast of the Pacific Northwest with a strong westerly wind component moving under the low and into central California. This could bring periodic storminess, though right now I put that in the chance category.
Frost Discussion: One final cold front will move through the valley this evening. Behind the front is a pool of very cold, unstable air which will lower snow levels down to 1,500 feet by Tuesday evening. On Wednesday morning, residual upslope clouds and wind conditions will probably keep temperatures in the low to mid 30s. I must emphasize, however, that any location with generally clear skies and calm winds will see readings tank into the upper 20s for a few hours before sunrise.
Thursday and Friday mornings are definitely of greater concern. With anticipated generally clear skies and calm winds, coldest unprotected locations have the potential to drop down to 26 to 28 degrees with widespread readings from 29 to 34 . it does not appear clouds will arrive in time Friday morning to hold temperatures up, so similar conditions appear likely.
Saturday through Monday, above freezing conditions can be expected. Even so, well below average temperatures will continue with lows in the 30s. our saving grace then will be increasing cloud cover from the next storm which could result in light showers over the weekend.
It’s possible a cold low will develop either over or off the coast of the Pacific Northwest next week with a west to east jet stream into California. This would favor periodic storminess, theoretically holding temperatures above freezing, however, there are many differences on models so this is a low confidence forecast.
Afternoon Dew Points Today: Low to mid 40s. Kern, low to mid 40s.
Humidity: Hanford: 75%/100%, Bakersfield: 55%/90%
Actual Humidity February 3, 2019: Delano, NA Porterville, 95%/60%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 20%, tomorrow 20% Bakersfield: Today: 20% Tomorrow: 20%
ET Rates Over the Past Seven Days: Stratford .31, Parlier .34, Blackwell .NA, Lindcove .27, Arvin .45, Orange Cove .32, Porterville .25, Delano .NA Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 54, Parlier 54, Blackwell 54, Lindcove, 58, Arvin, 54, Orange Cove NA, Porterville 55, Delano NA
Record Temperatures: 77/28. Average Temperatures: 59/38
Heating Degree Days this Season: 1309 -486
Courtesy of the NWS
Average temperature for February so far: 54.3 +6.3
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2018 Fresno: 5.13 season. or -.75, Month to Date: .57 +.35
Since Oct 1, 2018, Bakersfield: 2.92, or -.33. Month to Date: .24 +.11
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove, 610, Parlier, 613 , Arvin, 543 Shafter, 617 Stratford, 619, Delano 613, Lindcove, 906, Porterville, 1271
Hours at 45 or below 45.
Sunrise: 6:58 am Sunset: 5:29 pm. Hours of Daylight: 10:28
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 65 / 59 / 0.12 /
FAT : Fresno Airport 333 : DH1600 / 62 / 57 / 0.09 /
HJO : Hanford Airport 242 : DH1600 / 61 / 57 / 0.38 /
NLC : Lemoore Naval AS 234 : DH1600 / 62 / 49 / 0.22 /
BFL : Bakersfield Airport 496 : DH1600 / 64 / 52 / 0.13 /
VIS : Visalia Airport 292 : DH1600 / 61 / 48 / M /
ATEC1 : Avenal 787 : DH1556 / 60 / 48 / 0.73 /
PTV : Porterville Airport 442 : DH1600 / 61 / 48 / 0.21 /
Rainfall: Water year Oct 1st through September 30th
24hr Season % L.Y. % Ave. Ave. yearly total
STOCKTON 0.64 9.04 116 3.99 51 7.76 14.06
MODESTO 0.15 7.53 108 3.55 51 6.96 13.11
MERCED 0.09 7.04 112 2.29 36 6.31 12.50
MADERA 0.02 5.42 85 1.55 24 6.34 12.02
FRESNO 0.02 5.13 87 1.64 28 5.88 11.50
HANFORD 0.24 4.58 86 1.78 34 5.30 10.10
BAKERSFIELD 0.13 2.91 90 1.10 34 3.25 6.47
BISHOP 0.08 3.99 145 0.20 7 2.75 5.18
SALINAS 0.02 6.90 102 2.51 37 6.79 12.83
PASO ROBLES 0.65 8.93 134 2.30 34 6.68 12.78
SANTA MARIA 0.21 8.43 119 2.02 28 7.11 13.95
Next report: Monday afternoon/February 4