January 24, 2021
Yesterday’s storm system is now moving into southwest Arizona, leaving California under a narrow ridge of weak high pressure which will quickly break down this afternoon, allowing a very cold low pressure system to race southward. Clouds are already increasing over northern California and will spread into central California later today. The low cloud deck along the eastern and southern flanks of the valley this morning will dissipate as a brief southerly flow moves in ahead of the upcoming event. Showers will spread as far south as Fresno County by late afternoon or early evening then will rapidly spread southward over the remainder of the valley tonight with periods of showers continuing through Monday.
The cold front will move through the valley during the early morning hours, moving into southern California by sunrise. At the surface, a relatively strong low pressure system will form over southern Nevada tonight and Monday. With the jet stream flanked from north to south and increasing pressure differences, gusty northwesterly winds will develop later tonight, continuing Monday.
Dry weather will return Monday night and Tuesday. The air behind this system is very cold, so where it clears Monday night and Tuesday morning, below freezing temperatures will be the next challenge. This is discussed below in the frost section.
This will be an extremely active weather week as a powerful low will be off the Oregon coast Tuesday night and the southern Oregon/northern California coast Wednesday through Friday. There is more and more evidence on models that a pineapple connection will develop with this storm with possibly tremendous amounts of precipitation over northern and central California. As this moist feed of air streaks in from the west/southwest, the Sierra Nevada will lift the air mass, squeezing heavy amounts of rain and snow out of the feed. I would not be surprised more than 6 inches of rain along the Sierra Nevada foothills and several feet of new snow over the higher elevations. Some models actually show this feed of moisture stalling over north/central California Wednesday night through Thursday evening then weakening and moving into southern California Friday.
A new storm will drop out of the Gulf of Alaska this coming weekend for more chances of precipitation for the northern 2/3 of California. The first half of next week also appears active.
Forecast: Mostly cloudy this morning. increasing cloudiness this afternoon with a chance of showers from Fresno County north by late afternoon. Showers likely tonight through Monday with snow down to 1,500 to 2,000 feet. Partly cloudy Tuesday night. periods of rain, possibly locally heavy at times, Wednesday through Friday. Strong, gusty, southeasterly winds are possibly Tuesday night and Wednesday. a chance of showers Friday night through Sunday.
Short Term:
| Madera 55/39/50/29/52 | Reedley 56/38/49/28/50 | Dinuba 54/38/49/27/50 |
| Porterville 56/39/49/28/52 | Lindsay 56/38/50/37/51 | Delano 56/40/49/29/52 |
| Bakersfield 57/39/47/35/49 | Taft 54/40/47/35/47 | Arvin 56/39/47/32/50 |
| Lamont 56/39/48/31/51 | Pixley 56/39/50/29/52 | Tulare 54/38/49/27/51 |
| Woodlake 55/39/48/28/51 | Hanford 55/39/51/29/52 | Orosi 55/38/50/27/51 |
Seven Day Forecast:
| Wednesday
Rain likely 40/58 |
Thursday
Rain likely 44/61 |
Friday
Rain likely 43/56 |
Saturday
Chance of showers 39/57 |
Sunday
Chance of showers 40/58 |
Two Week Outlook: January 30 through February 5: This model is reverting back to a pattern favorable for below average temperatures with storms moving out of the Gulf of Alaska, resulting in above average precipitation.
February: Both the 30 and 90 day outlooks reflect a La Nina pattern with below average precipitation over the southern 2/3 of California and above average precip over parts of the Pacific Northwest and northern California. Temperatures should be close to seasonal averages.
February, March, April: Precipitation will continue to be above average over the Pacific Northwest and roughly the northern ¼ of California with the southern 2/ 3 of California having below average precipitation. Temperatures should be marginally above average.
Winds Discussion: There will be two periods of gusty winds. The first will be from late tonight through Monday evening in the form of gusty winds out of the northwest. Winds will average 15 to 25 MPH at times. Gusts to 35 MPH will be possible, especially along the west side, but this time around, gusts to 35 MPH will be possible just about anywhere. These winds will diminish Monday night.
The next challenge will be Tuesday night through Wednesday as strong differences in pressure set up between the northwest coast of California and the high deserts of southern California. This particular configuration in the past has resulted in strong downslope winds off the Tehachapi Mountains into the extreme south valley. On some occasions these winds don’t make it all the way down to the valley floor, but other times they do. If they do this time around, gusts exceeding 50 MPH are possible near the bottom of the Grapevine and other locations south and southeast of Bakersfield. we’ll tweak this as time goes by.
Gusty southeast winds will commence on the west side of the valley Tuesday night and Wednesday as well.
Rain Discussion: Showers will spread as far south as Fresno County by late afternoon or early evening. Periods of showers will continue tonight through Monday with snow down to 1,500 to 2,000 feet in the surrounding mountains. This will be a showery event so rainfall amounts will vary widely from location to location. Any location on the valley floor could pick up between .25 and .50 with the heaviest precipitation falling between midnight and sunrise.
Dry weather will return Monday night through Tuesday. A very slow moving storm system will likely form a pineapple connection from Wednesday into Friday. I would not be surprised to see over 6 inches of rain in the foothills from Fresno County north and 2 to 4 inches further south. Very strong winter storms also create rain shadows along the west side and in Kern County which can extend as far north as southern Tulare County. At any rate, along the east side more than 2 inches of rain is possible between Wednesday and Friday with possibly as much as an inch in the south valley.
Models vary somewhat on this coming weekend but it does appear there will be a chance of rain this coming weekend and into the following week.
Frost Discussion: All locations will be above 32 degrees tonight. the air mass driving down the valley Monday is extremely cold. Where skies clear Tuesday morning, and winds die off, mid to upper 20s are certainly possible. However, it’s also possible that upslope clouds will bank up against the mountains to our south and east. Locations underneath this cloud deck will remain in the 30s. keep in mind, however, any locations observing generally clear skies and calm winds could potentially dip down to 25 to 26 in those unprotected river bottom type locations and 27 to 31 elsewhere.
For Wednesday morning and beyond, a very moist west/southwest flow will develop along with potentially heavy rain at times keeping temperatures above freezing into early next week.
Afternoon Dew Points Today: Low to mid 40s. Kern: Upper 30s to the lower 40s.
Actual Humidity Range Yesterday: Delano, NA Porterville, NA
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 20%, tomorrow 0%. Bakersfield: Today: 20% Tomorrow: 0%
ET Rates Over the Past Seven Days: ET information has been unavailable for the past thirteen days. Seventy two hours. Stratford .NA, Parlier .NA, Blackwell Corners .NA, Arvin .NA, Orange Cove .NA, Porterville .NA, Delano .NA. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 53, Parlier 50, Blackwell 53, Arvin, 52, Orange Cove 52, Porterville NA, Delano 46
Record Temperatures: 78/24. Average Temperatures: 56/36
Heating Degree Days This Season: 1300. Varies widely from location to location. courtesy of the NWS
Average Temperature for this month So Far: 49.3 +4.5 courtesy of the NWS
Precipitation: Seasonal total for Fresno, 1.96, or -3.14 or 38% of average. Month to Date: .54 or -1.09
Precipitation for Bakersfield, Season, .94, +or- -1.87 or 33% of average. Month to date .20, or -.65
Water year season is from October 1st through September 30.
Chilling Hours November 1st through February 28: Orange Cove, 726, Parlier, 863, Arvin, 694, Belridge, 803, Shafter, 804, Stratford, 829, Delano, 891, Porterville, 822
Hours at 45 or below 45. Courtesy UC Davis
Sunrise: 7:06 am Sunset: 5:17 pm Hours of Daylight: 10:10
Yesterday’s Weather
MCE : Merced 153 : DH1600 / 54 / 41 / 0.17 /
MAE : Madera 253 : DH1600 / 55 / 43 / 0.13 /
FAT : Fresno Airport 333 : DH1600 / 56 / 43 / 0.48 /
HJO : Hanford Airport 242 : DH1600 / 54 / 39 / 0.15 /
NLC : Lemoore Naval AS 234 : DH1600 / 54 / 37 / 0.09 /
BFL : Bakersfield Airport 496 : DH1600 / 54 / 46 / 0.04 /
VIS : Visalia Airport 292 : DH1600 / 56 / 41 / 0.15 /
ATEC1 : Avenal 787 : DH1600 / 51 / 35 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 53 / 42 / 0.06 /
Rainfall: 24hr W.Y. % Last Y. % Ave. Year ave.
STOCKTON 0.03 2.78 41 5.17 77 6.73 14.06
MODESTO T 1.63 27 3.86 64 5.99 13.11
MERCED 0.03 2.55 45 M M 5.71 12.50
MADERA 0.04 0.98 17 M M 5.80 12.02
FRESNO 0.41 1.96 38 M M 5.10 11.50
HANFORD 0.00 0.85 17 M M 4.90 10.10
BAKERSFIELD 0.03 0.94 33 M M 2.81 6.47
BISHOP 0.00 0.21 9 1.16 47 2.47 5.18
SALINAS 0.01 1.20 21 5.88 101 5.81 12.83
PASO ROBLES 0.05 1.04 18 6.61 116 5.70 12.78
SANTA MARIA 0.19 2.09 34 4.79 79 6.06 13.95
Next report: January 25/am