February 18, 2018
Summary: The center of circulation of a very cold, moisture starved upper low is over western Washington this morning. The low center will begin to carve out a bitterly cold modified Arctic weather system over the Great Basin. California will be on the western rim of the low, sandwiched between the low and a strong upper high off shore which ridges into southern Alaska. The squeeze play between the low to our east and the high to our west will create a north/south flow from western Canada through the Pacific Northwest and right down into California. The leading edge of this system will be in the form of a cold front which will arrive late this afternoon or this evening. The front will be accompanied by gusty northwesterly winds with gusts over 40 MPH possible along the west side. No doubt there will be areas of blowing dust.
Models this morning are a little more optimistic about light showers over the Sierra and the Kern County mountains. If they do occur, there would be snow at places like Mariposa, Oakhurst, Springville, and all locations over the Kern County mountains. Light snow could fall as low as 1,000 feet.
Skies will begin to clear Monday afternoon with mostly clear skies Monday night through Wednesday. Initially, these winds will begin to drive down dew points, possibly as low as the low to mid 20s, which should lead to a significant hard freeze event. Much more in the frost discussion below.
Through the remainder of the week, and even into next week, waves of low pressure originating in western Canada will continue to dive north to south into California. There’s even a chance of light showers Thursday with snow again down into the foothills. This may drive temperatures below freezing again Thursday through Saturday.
Longer range models are still trying to point to a low pressure system moving out of the Gulf of Alaska and into California about the 26 or 27. Hopefully, this would break the spine of this dismal rainfall season.
Forecast: Mostly clear this morning. Becoming partly cloudy later this afternoon. Variable cloudiness tonight through Monday morning with a small chance of a few light showers. Clearing Monday afternoon. Mostly clear Tuesday through Wednesday and cold. Partly cloudy Wednesday night and Thursday with a slight chance of light showers. Mostly clear to occasionally partly cloudy Friday through Sunday.
Short Term:
| Madera 66/37/52/26/53 | Reedley 67/36/53/26/53 | Dinuba 67/36/52/25/53 | |
| Porterville 68/36/52/26/54 | Lindsay 68/35/53/25/54 | Delano 69/38/52/27/54 | |
| Bakersfield 69/40/51/30/54 | Arvin 70/40/51/27/54 | Taft 68/41/51/29/53 | |
| Lamont 68/39/52/27/53 | Pixley 68/36/53/25/53 | Tulare 67/35/52/24/52` | |
| Woodlake 67/36/53/26/52 | Hanford 68/36/53/25/54 | Orosi 67/35/53/26/53 | |
Seven Day Forecast:
| Wednesday
Mostly clear 27/57 |
Thursday
Slight chance of showers 32/54 |
Friday
Slight chance of showers 30/55 |
Saturday
Mostly clear 31/60 |
Sunday
Mostly clear 33/61 |
Two Week Outlook: February 20 through February 27 This model indicates a possibly broad area of low pressure will be over and along the west coast. There is a chance that Pacific storms may move into California from the Gulf of Alaska. Temperatures should range somewhat below seasonal norms.
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 generally light this morning, becoming out of the northwest at 10 to 20 MPH this afternoon, increasing to 15 to 25 MPH tonight through Monday with gusts over 40 MPH possible along the west side. Winds will diminish Monday evening with generally light winds later Monday night through Wednesday.
Rain: Models this morning are a tad more optimistic for the chance of light showers over the Sierra and the Kern County mountains with snow down to roughly 1,000 feet. Even though this system is moisture starved, it has strong jet stream dynamics which could be enough to create a few light showers over the valley floor tonight and Monday. I would put the chance at any given location at roughly 30% or so. Dry weather will return Monday afternoon and will continue through Wednesday.
Another very cold low will drop into central California late Wednesday night into Friday morning. For now, we’ll put the chance at no more than 20%. Dry weather will prevail over the weekend and well into next week. Medium range models continue to suggest a chance of precipitation exists from the 26 through the 27.
Frost: I keep looking for a way to get out of this but unfortunately, models this morning continue to show a high risk of a hard freeze Tuesday and Wednesday mornings, and possibly Thursday morning. The leading edge of the cold air mass will be along a rapidly moving cold front which will move through this evening along with gusty winds out of the north/northwest. These winds will continue through Monday, driving down dew points. For now, it appears dew points will fall into the low to mid 20s later Monday and Tuesday. With very cold air aloft settling eventually onto the valley floor, conditions will be ripe to send many locations Tuesday morning into the mid to upper 20s. Even urban areas will be below freezing with this event. That would put frost pockets down to as low as 22 to 23 with durations possibly lasting more than 8 hours in the very coldest, unprotected locations.
It’s now looking like most locations, outside of the frost pockets, will be in the mid to upper 30s. since Tuesday will be the first day after a storm system moves through, we could see mixing and even possibly wind conditions which would nudge temperatures higher.
The air mass will be so dry that cloud cover will be doubtful, even in Kern County.
Wednesday morning will shape up to be only a degree or two warmer at best as clear skies continue with little to no wind. Thursday’s conditions are uncertain at this time as a new, very cold upper low will race southward into central California. Clouds may increase enough to moderate the situation some, but on the flip side, this system will drag more of that modified Arctic air in to the valley which means we could see below freezing temperatures through the weekend with only slow moderation.
Temperatures next week will continue to be well below average as this same basic pattern with a north to south jet stream will continue.
Lows Tonight:
All locations will be above freezing tonight.
Afternoon Dew Points Today: Low to mid 30s. Kern, Low to mid 30s.
Humidity: Visalia, 25%/90% Bakersfield, 25%/80%
Actual Humidity February 15, 2018: Delano, 81%/39%. Porterville, 88%/34%
Percentage of Sunshine Today/Tomorrow: Visalia: Today 100% tomorrow 80%, Bakersfield: Today 100% tomorrow 90%.
ET Rates Over the Past Seven Days February 15, 2018: Stratford .76, Parlier .61, Blackwell .72 Lindcove .58, Arvin .75, Orange Cove .69, Porterville .62, Delano .67., Madera Two NA. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 54, Parlier 55, Blackwell 57, Lindcove, 57, Arvin, 58, Orange Cove 53, Porterville 55, Delano 54, Madera Two 54
7.2
Record Temperatures: 80/27. Average Temperatures: 62/39
Heating Degree Days this Season: 1457, -558 Courtesy of the NWS
Average temperatures for February so far, 55.7 +6.7
Precipitation: Seasonal total/average/above or below average:
Since October 1, 2017 Fresno: 1.64 season. or -5.10. Month to Date: .00
Since October 1, 2017, Bakersfield: 1.10, or -2.68, Month to Date: .00
Water year season is from October 1st through September.
Chilling hours November 1st through February 28: Orange Cove, 782, Parlier, 806, Arvin, 705, Shafter, 863, Stratford, 804, Madera two, 1303, Lindcove, 932, Porterville, 1256. Hours at 45 or below 45.
Sunrise: 6:45 am Sunset: 5:41 pm. Hours of Daylight: 10:54
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 71 / 36 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 71 / 41 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 71 / 33 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 72 / 32 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 72 / 41 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 70 / 37 / 0.00 /
ATEC1 : Avenal 787 : DH1555 / 73 / 38 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 71 / 36 / 0.00 /
TFTC1 : Taft 759 : DH1553 / 70 / 45 / 0.00 /
Rainfall: Season % Last y. % Ave. Annual Ave.
STOCKTON 0.00 3.99 45 15.53 175 8.86 14.06
MODESTO 0.00 3.55 44 12.52 157 7.99 13.11
MERCED 0.00 2.29 31 12.21 167 7.30 12.50
MADERA 0.00 1.55 22 11.74 163 7.20 12.02
FRESNO 0.00 1.64 24 11.11 165 6.74 11.50
HANFORD 0.00 1.78 30 7.76 129 6.02 10.10
BAKERSFIELD 0.00 1.10 29 6.59 174 3.78 6.47
BISHOP 0.00 0.20 6 6.65 214 3.11 5.18
SALINAS 0.00 2.51 32 11.31 144 7.84 12.83
PASO ROBLES 0.00 2.30 30 12.84 166 7.74 12.78
SANTA MARIA 0.00 2.02 24 12.88 154 8.36 13.95
Next Report: Sunday, February 18/pm