anuary 31, 2020
Summary: Strong upper level high pressure is located roughly 400 miles to the west of the central coast this morning. the center of circulation of this high is projected to be almost right overhead by midday Saturday. this will drive temperatures to near record highs Saturday afternoon. The freezing level continues to rise above us. The balloon sounding at Oakland pegged the freezing level at 13,100 feet. Blue Canyon at an elevation of 5,600 feet was 10 degrees warmer this morning than 24 hours ago with a balmy temperature of 54 degrees. This is anywhere from 10 to 15 degrees warmer than most locations on the valley floor.
The high will quickly be displaced southwestward further and further out to sea Sunday as a rapidly moving cold trough of low pressure dives southward through the Pacific Northwest and into northern and central California Sunday. A fast moving but moisture starved cold front will move through sometime during the late afternoon or evening hours, spreading light snow showers down the Sierra Nevada and rain showers will turn to snow showers over the Kern County mountains. The best chance of measurable rain on the valley floor, low as it may be, will be in Kern County where strong upsloping will occur against the Tehachapi Mountains, squeezing out light rain or drizzle Sunday night and Monday morning.
This appears to be the coldest air mass of the winter, so far, as modified arctic air plunges southward between upper level high pressure ridging northward into Alaska and a developing low over Utah. This puts California under a north/south flow/pumping modified arctic air down the valley on the wings of strong, gusty, northwesterly winds Sunday afternoon into Monday. The main forecast challenge will be overnight low temperatures. This is discussed in the frost section below. Suffice it to say, the chance of a hard freeze has risen dramatically.
By Wednesday night, upper level high pressure over the eastern Pacific will begin to build inland for the beginning of a warming trend, a trend that will continue into next weekend. Models for next weekend place a large cold low somewhere over the western U.S. by Sunday, possibly over northern California. In theory, this could be our next chance of precipitation.
Forecast: Mostly clear skies through Saturday night. increasing cloudiness, breezy, and much cooler Sunday. A small chance of light showers late Sunday afternoon and night. mostly cloudy in Kern and Tulare Counties Monday morning, partly cloudy elsewhere. Mostly clear to occasionally partly cloudy Monday afternoon through Tuesday and cold. Mostly clear and cold Tuesday night. mostly clear Wednesday through Saturday with a warming trend with patchy night and morning fog.
Short Term:
| Madera 67/40/71/44/57 | Reedley 67/40/70/43/57 | Dinuba 66/40/69/42/55 | |
| Porterville 68/41/71/44/56 | Lindsay 68/39/71/43/57 | Delano 68/41/72/44/55 | |
| Bakersfield 70/45/72/46/57 | Taft 70/46/72/47/57 | Arvin 70/41/72/45/58 | |
| Lamont 71/42/73/44/57 | Pixley 68/40/71/44/56 | Tulare 66/39/69/43/55 | |
| Woodlake 67/39/70/43/56 | Hanford 67/41/71/43/57 | Orosi 66/39/70/42/56 | |
Seven Day Forecast:
| Monday
Partly cloudy 31/51 |
Tuesday
Mostly clear 27/52 |
Wednesday
Mostly clear 28/56 |
Thursday
Mostly clear 31/60 |
Friday
Mostly clear 35/65 |
Two Week Outlook: February 7 through February 13: This model is depicting a rather chilly north to northeast flow from the Gulf of Alaska, or even west of Canada, into the western U.S. strong high pressure will be over the eastern Pacific so the chance of rain is low. Expect below average temperatures.
January: This model is rather inconclusive on precipitation and temperature trends. If anything, precipitation will be close to average with temperatures that are marginally above average. It does appear there will be potentially extended periods of dry weather, leading to episodes of fog and low clouds from time to time.
February, March, April: If this model has any kind of a grip on the situation, temperatures will run somewhat above average during the late winter/early spring period. This model would really dash the hopes of a wet winter as it does indicate below average rain for the three month period.
Winds Discussion: Winds will be generally at or less than 6 MPH with periods of near calm conditions through Saturday night. Winds Sunday will increase out of the northwest at 15 to 25 MPH with gusts to 35 MPH possible, especially in western Fresno and Kings Counties, but possibly elsewhere. Winds Sunday night and Monday will be generally out of the northwest at 10 to 20 MPH with gusts to 35 MPH, mainly along the west side.
Rain Discussion: A rapidly moving cold front will zip through central California Sunday afternoon and night. Snow showers will spread down the Sierra Nevada and over the Kern County mountains through Monday morning. there is a minimal chance of light showers, primarily in Kern County due to strong upsloping, generating strong lift against the Kern County mountains. This should squeeze some light rain or drizzle out. Otherwise, dry weather can be expected for the remainder of this coming week.
Frost Discussion: It is becoming more and more apparent that a hard freeze will occur Tuesday and Wednesday mornings. One model places Porterville at 26 degrees Tuesday morning. Even large cities are expected to drop below freezing with Bakersfield at 30 and Fresno 31. Models have been amazingly consistent the past week in illustrating a pattern that would result in modified arctic air diving southward from western Canada and into the western U.S. Currently, the threshold of this air mass could put unprotected river bottom and other cold pockets down to 24 to 26 degrees Tuesday and Wednesday mornings. Monday morning will be more chaotic as we deal with upslope clouds and wind conditions with most locations remaining in the low to mid 30s. even on Monday morning, though, if there are pockets where clear skies prevail and winds are calm, upper 20s could quickly develop.
The fine details of the air mass have yet to be determined. For example, how low will dew points ultimately fall? Models are showing strong differences in pressure between a surface low over Utah and Colorado and high pressure off shore, generating strong, gusty winds. By Monday night, the flow pattern will become off shore, allowing winds to die off and leading to that hard freeze beginning Tuesday morning. just briefly, the pattern creating this challenge is a massive high building northward along the Pacific coast and into Alaska and a rapidly intensifying but moisture starved low pressure system over the interior west. This allows for the creation of a pipeline of modified arctic air to flow into the west coast from Canada and Alaska. Some moderation will begin Thursday morning withi some locations climbing above freezing by Friday. Some cloud cover and possibly even showers next Sunday will help a lot in bringing up those temperatures.
Overall, however, the medium range forecast still calls for potentially well below average temperatures right into week after next.
Afternoon Dew Points Today: Mid to upper 40s. Mid to upper 40s. Humidity values ranging from 5%/100% at Hanford. Bakersfield 45%/85%
Actual Humidity range January 30, 2020: Delano, 100%/57% Porterville, 99%/50%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 80%, tomorrow 90%. Bakersfield: Today: 90% Tomorrow: 90%
ET Rates Over the Past Seven Days: Stratford .46, Parlier .32, Blackwell Corner .42, Arvin .38, Orange Cove .27, Porterville .32, Delano .41. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 53, Parlier 52, Blackwell 53, Arvin, 52, Orange Cove 53, Porterville 53, Delano 49
Record Temperatures: 75/26. Average Temperatures: 58/36
Heating Degree Days this Season: 1354 -372
Courtesy of the NWS
Average temperature for January so far: 47.9 +2.7
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2019 Fresno: 3.53 season. or -2.04. Month to Date: .65 -1.45
Since Oct 1, 2019, Bakersfield: 2.83, or -.25. Month to Date: .23 -.88
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove 699, Parlier 770, Arvin 594, Shafter 686, Stratford 671, Delano 755, Lindcove 893, Porterville 1201
Hours at 45 or below 45.
Sunrise: 7:01 Sunset: 5:24 pm. Hours of Daylight: 10:21
Yesterday’s Weather:
: …Valley…
MCE : Merced 153 : DH1600 / 62 / 38 / 0.00 /
MAE : Madera 253 : DH1600 / 63 / 38 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 62 / 41 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 62 / 35 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 61 / 34 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 62 / 38 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 61 / 38 / 0.00 /
ATEC1 : Avenal 787 : DH1535 / 61 / 40 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 63 / 38 / 0.00 /
TFTC1 : Taft 759 : DH1550 / 60 / 43 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 61 / 40 / 0.00 /
Rainfall: Water year Oct 1st through September 30th
24hr season % last year % Ave. 365 day ave.
STOCKTON 0.00 5.27 72 7.92 107 7.37 14.06
MODESTO 0.00 3.92 59 6.39 97 6.60 13.11
MERCED 0.00 5.69 94 6.12 101 6.07 12.50
MADERA 0.00 2.90 47 4.58 75 6.13 12.02
FRESNO 0.00 3.54 63 4.42 79 5.58 11.50
HANFORD 0.00 3.12 61 3.33 65 5.13 10.10
BAKERSFIELD 0.00 2.83 92 2.27 74 3.08 6.47
BISHOP 0.00 1.16 44 3.46 131 2.64 5.18
SALINAS 0.00 5.99 93 5.83 91 6.42 12.83
PASO ROBLES 0.00 6.61 105 6.36 101 6.32 12.78
SANTA MARIA 0.00 4.79 71 6.41 96 6.70 13.95
Next report: January 31/afternoon