January 30, 2020
Summary: The fog this morning seems to be concentrated in the Lemoore/Visalia/Hanford region where visibilities are ¼ mile or less with patchy fog elsewhere. Dew points are a little lower this morning in comparison to 24 hours ago, so in spite of the high clouds over the valley, many frost stations saw temperatures in the mid 30s this morning.
In the broad picture, upper level high pressure over the eastern Pacific continues to build into California and Nevada. A significant warming trend will begin today. On Friday and Saturday, the center of circulation will be just off the central coast, putting us near the highest pressure aloft. This will result in well above average temperatures with warmest locations possibly eclipsing the 70 degree mark as early as tomorrow, but more likely Saturday. however, it’s also possible that, with an increasing warm air inversion, fog and low clouds will become more widespread, lowering temperature possibilities. The freezing level both above Vandenberg and Oakland is at 11,200 feet, an indication of that bubble of warm, subsiding air.
A radical shift in the pattern will begin Sunday as the high is suppressed southwestward out over the Pacific Ocean. This will allow a cold trough of low pressure partially over the Gulf of Alaska and partially over northwest Canada to slide rapidly southward, all the way into the Great Basin by early Monday. A cold front will move down the valley Sunday, accompanied by gusty, northwesterly winds as the leading edge of the colder air mass moves in. the fact that this system is generally traveling north to south overland will starve it of moisture. Thus, precipitation is unlikely on the valley floor with a chance of light snow showers over the Sierra Nevada and possibly even the Kern County mountains Monday.
With a massive high over the eastern Pacific and a cold trough just to our east, a pipeline of cold air will move from north to south into California Monday through Wednesday. frost appears likely as early as Monday morning. this is discussed in the frost section below. By Wednesday night, the high over the eastern Pacific will begin to shift eastward, promising a warming trend after Wednesday. however, models for next weekend are hinting at another possible cold weather pattern which will deserve watching in the coming days.
Forecast: A mix of high clouds and sunshine today after the patchy fog and low clouds burn off. Mostly clear tonight through Saturday night with occasional high clouds and areas of low clouds and fog nights and mornings. Increasing cloudiness, breezy, and cooler Sunday. Mostly to partly cloudy Sunday night and Monday morning. mostly clear to occasionally partly cloudy Monday afternoon through Wednesday. mostly clear Wednesday night through Thursday.
Short Term:
| Madera 61/38/67/40/69 | Reedley 62/37/66/42/70 | Dinuba 60/37/65/41/68 | |
| Porterville 62/38/67/42/70 | Lindsay 62/37/67/40/70 | Delano 63/40/67/43/71 | |
| Bakersfield 63/42/68/46/72 | Taft 63/45/68/47/72 | Arvin 63/40/68/42/72 | |
| Lamont 63/40/68/43/72 | Pixley 62/39/66/42/71 | Tulare 60/37/66/40/69 | |
| Woodlake 61/37/66/41/70 | Hanford 62/40/66/43/70 | Orosi 61/37/66/41/71 | |
Seven Day Forecast:
| Sunday
Increasing clouds 38/53 |
Monday
Partly cloudy 31/51 |
Tuesday
Mostly clear 28/53 |
Wednesday
Mostly clear 31/57 |
Thursday
Mostly clear 33/62 |
Two Week Outlook: February 5 through February 11: This model indicates a large high will be off the north American continent with an equally large trough of low pressure over the interior west. This will result in a northerly flow with below average temperatures. The storm track is well north so precipitation is unlikely.
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 mainly along the west side but locally elsewhere.
Rain Discussion: We’ll keep a slight chance of a few light showers in the forecast for later Sunday and Sunday night. however, the chance of measurable rain at any given location will be very low. The highest risk of measurable rain will actually be near the base of the Tehachapi Mountains Sunday night and Monday morning due to strong upslope conditions. The remainder of next week will continue to be dry.
Frost Discussion: Through Sunday morning, temperatures will be above freezing. Models are still trending towards much colder weather beginning Sunday and lasting through the middle of next week. One model places Porterville at 32 degrees Monday morning and 29 on Tuesday. This potentially could lower the very coldest unprotected locations down to the mid 20s where winds are calm and skies are generally clear. What we have is a massive high over the eastern Pacific building northward into Alaska while a trough of low pressure from northern Canada digs southward into the interior west. This will create a north/south flow over California along the eastern rim of the high, feeding modified arctic air into the western U.S. For now, I’ll stick with the premise of colder locations being in the 26 to 28 degree range Tuesday and Wednesday mornings.
On Monday, which for now is a difficult forecast due to various parameters, coldest river bottom and similar locations potentially could drop to 28 to 29 degrees with widespread lower 30s. where cloud cover is dominant, readings will remain in the mid 30s.
This is something we’ll obviously have to tweak as we move forward.
The good news is that a warming trend will begin at mid-week as upper level high pressure builds in from the west. The bad news is that at least one model is showing a pattern conducive for a freeze next weekend. Variations of this have shown up on other models as well.
Afternoon Dew Points Today: Low to mid 40s. Kern: Low to mid 40s. Humidity values ranging from 55%/100% at Hanford. Bakersfield 50%/95%
Actual Humidity range January 29, 2020: Delano, 100%/63% Porterville, 97%/66%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 70%, tomorrow 70%. Bakersfield: Today: 70% Tomorrow: 80%
ET Rates Over the Past Seven Days: Stratford .46, Parlier .30, Blackwell Corner .41, Arvin .33, Orange Cove .27, Porterville .30, Delano .3. 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: 74/25. Average Temperatures: 58/36
Heating Degree Days this Season: 1338 -370
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 -1.97. Month to Date: .65 -1.38
Since Oct 1, 2019, Bakersfield: 2.83, or -.20. Month to Date: .23 -.83
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: 7:02 Sunset: 5:23 pm. Hours of Daylight: 10:19
Yesterday’s Weather:
MCE : Merced 153 : DH1600 / 60 / 45 / 0.00 /
MAE : Madera 253 : DH1600 / 56 / 38 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 54 / 46 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 55 / 44 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1500 / 58 / 39 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 58 / 46 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 55 / 44 / 0.00 /
ATEC1 : Avenal 787 : DH1600 / 51 / 41 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 56 / 43 / 0.00 /
TFTC1 : Taft 759 : DH1553 / 58 / 44 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 62 / 43 / 0.00 /
Rainfall: Water year Oct 1st through September 30th
24hr season % last year % Ave. 365 day ave.
STOCKTON 0.00 5.27 72 7.92 109 7.28 14.06
MODESTO 0.00 3.92 60 6.39 98 6.51 13.11
MERCED 0.00 5.69 95 6.12 102 6.01 12.50
MADERA 0.00 2.90 48 4.58 75 6.08 12.02
FRESNO 0.00 3.54 64 4.42 80 5.51 11.50
HANFORD 0.00 3.12 61 3.33 65 5.09 10.10
BAKERSFIELD 0.00 2.83 93 2.27 75 3.03 6.47
BISHOP 0.00 1.16 44 3.46 132 2.62 5.18
SALINAS 0.00 5.99 95 5.80 92 6.33 12.83
PASO ROBLES 0.00 6.61 106 6.36 102 6.22 12.78
SANTA MARIA 0.00 4.79 73 6.41 97 6.60 13.95
Next report: January 30/afternoon