January 25, 2018
Summary: A fast moving cold front is currently moving through the southern San Joaquin Valley and will be clearing the Sierra Nevada over the next few hours. The southern limit of the precipitation appears to be the Kern County mountains as no shower activity is visible off the southern California coast. Once the front moves through, there will be a chance of scattered showers this afternoon lasting into the early evening hours as a cold upper trough moves in behind the front. The rain will end by early this evening with upslope clouds no doubt developing against the southern Sierra Nevada and the valley facing slopes of the Tehachapi Mountains. It’s possible light showers could occur near the base of the Tehachapi Mountains well into the night with cloud cover possibly lasting through Friday morning in Kern County and locally further north.
The air mass diving in behind the front is cold, but fairly typical of air masses behind cold fronts this time of year. Local frost will be possible tonight in areas that have clear skies and little to no wind during the early morning hours. More in the frost discussion below.
An extended period of dry weather will begin Friday as upper level high pressure sets up shop over the eastern Pacific Ocean. The next Pacific low pressure system will ride over the top of the high and into the Pacific Northwest. Eventually, a warm air inversion will develop over the valley and with additional moisture from our current system, the result will be fog and low clouds beginning Saturday morning but more so Sunday morning. The high will flatten out over its northern flank Monday and Tuesday but will hold firm over California with generally a westerly flow aloft. It does not appear this will disturb the warm air inversion so even though we’re getting late in the fog season, extensive fog and low clouds nights and mornings would not be a surprise, possibly even lasting into the afternoon in some areas. That will be the biggest challenge next week…temperature forecasting around fog and low clouds and the effect they have on overnight lows and daytime highs.
On medium range models, there’s still no indication of a pattern that would be conducive for rain for central California through at least the first several days in February.
Forecast: Light showers from Visalia southward for a time this morning. A chance of showers later this morning through early this evening. Mostly to partly cloudy skies along the east side tonight and Friday morning, mainly in Tulare and Kern Counties, with clearing skies elsewhere. Clearing in all areas Friday afternoon with mostly clear skies Friday night through Sunday with increasing night and morning fog beginning Saturday. Mostly clear to occasionally partly cloudy Monday through Thursday with widespread fog and low clouds during the mornings, possibly lasting through the afternoons, mainly in the central part of the valley north of Kern County.
Short Term:
Madera 58/32/60/30/61 | Reedley 58/33/59/31/60 | Dinuba 58/31/60/30/59 | |
Porterville 58/32/59/31/61 | Lindsay 58/31/59/30/60 | Delano 59/34/59/33/60 | |
Bakersfield 58/36/58/35/61 | Arvin 57/34/59/33/61 | Taft 59/38/59/37/60 | |
Lamont 58/33/59/32/60 | Pixley 59/32/60/30/60 | Tulare 58/31/60/30/60 | |
Woodlake 59/32/59/30/59 | Hanford 58/32/59/30/61 | Orosi 58/32/59/30/59 |
Seven Day Forecast:
Sunday
AM fog/PM sun 32/58 |
Monday
AM fog/PM sun 34/62 |
Tuesday
AM fog/PM sun 36/63 |
Wednesday
AM fog/PM sun 39/58 |
Thursday
AM fog/PM sun 39/58 |
Two Week Outlook: January 31 through February 5: This model now indicates a blocking ridge of upper level high pressure will be over and off the west coast. This pattern would drive the storm track well north. Temperatures would rise to marginally above average values, assuming the fog doesn’t take over, with very little chance of precipitation.
February: This model doesn’t really grasp at any particular pattern through the month. In fact, central California, if you believe this model, should have temperatures close to seasonal values with near average precipitation, as well.
February, March, April: This model goes all the way through April and it is calling for a ridge of upper level high pressure off the southern California coast to be the most dominant, but not the only, feature during the spring months. If this model has any credence at all, temperatures should be marginally above average with below average precipitation.
Winds: Winds will be mainly out of the northwest today at 5 to 15 MPH, diminishing this evening. Winds later tonight through Sunday will be generally less than 10 MPH with periods of near calm conditions.
Rain: As of the time of this writing, light showers were still occurring over much of Tulare County, eastern Kings County, and southern Kern County. Rainfall amounts so far have generally tallied up to about a tenth of an inch at most locations. The front is currently moving into the Kern County mountains and the southern Sierra Nevada and will be out of here in the next few hours. A cold upper trough of low pressure will follow later this morning through the afternoon hours for a relatively small chance of scattered showers which will be over by this evening.
Amounts of rain from this point on will be generally less than a tenth of an inch.
Dry weather will begin tonight and will be the beginning of a long dry spell that will not only last through the end of the month, but more than likely through at least the first week of February.
Frost: A colder air mass is sweeping in from the west/northwest behind a cold front currently moving into the Sierra Nevada and the Kern County mountains. This air mass is certainly not critically cold, but fairly typical of air masses that move in behind cold fronts this time of year. Low to mid 30s are certainly possible tonight with isolated upper 20s in colder locales being a possibility.
Upslope clouds will no doubt form along the west facing slopes of the southern Sierra Nevada and the north facing slopes of the Kern County mountains. These clouds may persist into Friday morning. Where these clouds do persist, lows will only chill into the mid to upper 30s.
There is a greater risk of more locations being in the lower 30s Saturday and Sunday mornings with a few low spots possibly briefly dipping into the upper 20s. from Monday on, lows may be mostly governed by fog and/or low clouds. A warm air inversion will no doubt form this weekend which should be ideal for a fog regime even though we’re getting late in the traditional fog season. If fog does not become as widespread as expected, low to mid 30s would certainly be possible Monday through Wednesday unless higher clouds move in from Pacific storms moving in to our northwest.
There is still no pattern showing up that would result in a cold air mass moving into California. So, it appears safe conditions will last through at least the first week in February.
Lows Tonight:
Terra Bella
31 |
Porterville
32 |
Ivanhoe
31 |
Woodlake
31 |
Strathmore
30 |
McFarland
30 |
Ducor
32 |
Tea Pot Dome
31 |
Lindsay
30 |
Exeter
30 |
Famoso
33 |
Madera
32 |
Belridge
33 |
Delano
33 |
North Bakersfield
32 |
Orosi
31 |
Orange Cove
31 |
Lindcove
31 |
Lindcove Hillside
AF |
Sanger River Bottom
29 |
Root Creek
30 |
Venice Hill
31 |
Rosedale
33 |
Jasmine
32 |
Arvin
34 |
Lamont
32 |
Plainview
31 |
Mettler
AF |
Edison
34 |
Maricopa
32 |
Holland Creek
AF |
Tivy Valley
30 |
Kite Road South
33 |
Kite Road North
30 |
AF=Above Freezing
Afternoon Dew Points Today: Low to mid 40s. Mid 40s to the lower 50s.
Humidity: Visalia, 51%/100% Bakersfield, 40%.90%
Actual Humidity January 23, 2018: Porterville, 98%/47%
Percentage of Sunshine Today/Tomorrow: Visalia: Today 50% tomorrow 10%, Bakersfield: Today 60% tomorrow 0%.
ET Rates Over the Past Seven Days January 23, 2018: Stratford .28, Parlier .32, Blackwell, .NA Lindcove .28, Arvin .27, Orange Cove .36, Porterville .26, Delano .NA., Madera Two 27. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 53, Parlier 51, Blackwell 55, Lindcove, 56, Arvin, 54, Orange Cove 48, Porterville 52, Delano NA, Madera Two 52
7.2
Record Temperatures: 78/24. Average Temperatures: 56/36
Heating Degree Days this Season: 1170, -427 Courtesy of the NWS
Average temperatures for January so far, 51.6 +6.8
Precipitation: Seasonal total/average/above or below average:
Since October 1, 2017 Fresno: 1.36 season. or -3.74. Month to Date: .95
Since October 1, 2017, Bakersfield: 1.03, or -1.78, Month to Date: .96
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove, 609, Parlier, 637, Arvin, 602, Shafter, 700, Stratford, 630, Madera two, 1030, Lindcove, 755, Porterville, 989. Hours at 45 or below 45.
Sunrise: 7:06 am Sunset: 5:16 pm. Hours of Daylight: 10:09
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 65 / 32 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 66 / 38 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 66 / 34 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 67 / 35 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 73 / 36 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 66 / 34 / T /
ATEC1 : Avenal 787 : DH1558 / 70 / 36 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 70 / 32 / 0.00 /
TFTC1 : Taft 759 : DH1558 / 71 / 33 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 59 / 40 / 0.00 /
Rainfall: Season % Last y. % Ave. Annual Ave.
STOCKTON 0.00 3.73 55 12.49 183 6.82 14.06
MODESTO 0.00 3.41 56 10.55 174 6.07 13.11
MERCED 0.00 2.17 38 9.84 171 5.77 12.50
MADERA 0.00 1.43 24 9.24 158 5.86 12.02
FRESNO 0.00 1.36 26 10.06 195 5.16 11.50
HANFORD 0.00 1.72 35 6.24 126 4.94 10.10
BAKERSFIELD 0.00 1.03 36 5.79 203 2.85 6.47
BISHOP 0.00 0.20 8 5.59 224 2.50 5.18
SALINAS 0.00 2.24 38 9.86 167 5.90 12.83
PASO ROBLES 0.00 2.20 38 10.59 183 5.79 12.78
SANTA MARIA 0.00 1.97 32 10.64 173 6.14 13.95
Next Report: Thursday afternoon, January 2