February 20, 2019
Summary: Clouds are already increasing ahead of a very cold modified arctic low which is now moving rapidly through Oregon and into northern California. Doppler radar is indicating scattered light showers are spreading down the Sierra Nevada to just north of Yosemite at this hour with light showers showing up over the eastern Sacramento Valley. This low, which is the coldest of the entire winter season, will quickly move into central California with possible light showers beginning mid to late afternoon. The actual low itself and its pool of coldest and most unstable air will be right overhead late tonight and Thursday morning. This proposes some interesting solutions.
The position of both the surface low and the upper level low have the potential of driving snow levels below 1,000 feet late tonight and Thursday morning. That could, in theory, result in light snow showers on the valley floor. Snow accumulations, if any falls at all, would be no more than a dusting on grassy type surfaces. I would put the chance of snow reaching the valley floor at about 20%, but it is a tantalizing thought.
By Friday, the low will be racing into Arizona, leaving a very cold modified arctic air mass in its wake. Friday and Saturday mornings, again, have the potential of dropping below freezing, something discussed in the frost section below.
During the second half of the weekend, a major change will occur in the overall pattern. A new cold low will drop southward into the Pacific Northwest Saturday, but unlike the pattern of the past few weeks, it will not dig southward far enough to be much of a precipitation threat. If you average models out, the southern limit of precipitation would be no further south than a Monterey/Merced/Yosemite line. Still, there’s enough model disparity to keep a small chance of showers in the forecast for Sunday and Monday, mainly from Fresno County north.
Some models for Tuesday and Wednesday show showers over northern California beneath a cold low centered over the Pacific Northwest. The flow underneath this feature will be out of the west, meaning temperatures in our neck of the woods will be much more seasonal next week. Some of the medium range models for the first week in March show the potential for more active weather coming into California. This time, however, this would be lower latitude storms with higher snow levels.
Forecast: Increasing cloudiness today leading to a chance of light showers by mid to late afternoon. Scattered light showers are likely tonight and Thursday with a small chance of light snow showers late tonight and Thursday morning. Becoming partly cloudy and cold Thursday night. mostly clear to occasionally partly cloudy Friday through Saturday night. increasing cloudiness Sunday with a small chance of light showers from Fresno County north later Sunday and on through Wednesday.
Short Term:
| Madera 51/35/50/29/54 | Reedley 51/35/51/28/54 | Dinuba 51/34/51/28/54 | |
| Porterville 52/35/51/28/55 | Lindsay 52/34/52/28/55 | Delano 53/36/51/29/55 | |
| Bakersfield 54/37/50/31/56 | Taft 52/37/51/31/55 | Arvin 54/35/50/29/56 | |
| Lamont 54/37/50/29/56 | Pixley 52/36/52/29/54 | Tulare 51/35/51/28/54 | |
| Woodlake 52/35/50/28/54 | Hanford 51/35/50/30/54 | Orosi 51/35/50/28/53 | |
Seven Day Forecast:
| Saturday
Partly cloudy 30/58 |
Sunday
Mostly cloudy 37/59 |
Monday
Slight chance of showers 43/62 |
Tuesday
Slight chance of showers |
Wednesday
Slight chance of showers 49/67 |
Two Week Outlook: February 27 through March 5: This model shows the return of an active weather pattern for central California with periodic chances of rain. The general flow pattern will be out of the west, so temperatures should range near to marginally above average.
February: This model indicates the eastern Pacific high will be the most dominant feature during the month of February. There will be the usual exceptions, but overall this would result in above average temperatures and drier than average precipitation over much of the west and colder than average temperatures east of the Rockies.
February, March, April: At least this model projects about equal chances for either above or below average precipitation. There is actually a greater possibility of below average rain over the Pacific Northwest. Generally speaking, temperatures should remain at least marginally above average.
Winds: Winds today will be generally out of the west to northwest at 5 to 10 MPH with stronger gusts in the vicinity of showers. Winds tonight through Thursday will be out of the northwest at 5 to 15 MPH with stronger gusts, diminishing Thursday night. winds Friday and Saturday will be generally at or less than 12 MPH with periods of near calm conditions, mainly during the night through midmorning hours.
Rain: The chance for scattered light showers will increase from mid to late afternoon and on through Thursday. Precipitation amounts will be generally at or less than .10 with locally more, especially along the west side. As discussed above, I’ve added a 20% chance of light snow showers late tonight and Thursday morning as extremely cold air for this time of year will be right above. Dry weather will return Thursday night through Sunday morning. There is a small chance of showers as far south as Fresno County Sunday through Wednesday of next week. Medium range models encompassing the first week in March are indicating the possibility of a return to wet weather. This time, however, the storms would be of the lower latitude variety which potentially could result in significant precipitation.
Frost Discussion: All locations will be above 32 tonight but only slightly above in the coldest areas. Friday and Saturday mornings will be below freezing in many areas. The cold pool of air in the wake of the current storm will be very cold with potential lows in the 27 to 31 degree range on each morning. Some models are projecting in and out cloud cover, especially for Saturday, which could bump temperatures up. However, that is by no means a guarantee. We should finally pull out of this unusually cold February Sunday as a westerly flow aloft develops, pumping in a much milder air mass at both the surface and aloft. For now, longer range models do not indicate a return to this persistent and cold pattern we’ve endured.
Afternoon Dew Points Today: Mid to upper 30s. Low to mid 30s. Humidity values ranging from 60%/95% at Hanford. Bakersfield 50%/90%
Actual Humidity February 19, 2019: Delano, NA Porterville, 96%/46%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 20%, tomorrow 30% Bakersfield: Today: 30% Tomorrow: 10%
ET Rates Over the Past Seven Days: Stratford .46, Parlier .41, Blackwell .54, Lindcove .34, Arvin 50, Orange Cove .36, Porterville .36, Delano .NA Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 52, Parlier 50, Blackwell 51, Lindcove, 55, Arvin, 51, Orange Cove 50, Porterville 51, Delano NA
Record Temperatures: 80/28. Average Temperatures: 63/40
Heating Degree Days this Season: 1609 -432
Courtesy of the NWS
Average temperature for February so far: 47.3 -2.1
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2018 Fresno: 7.65 season. or +.61. Month to Date: 3.09 +1.71
Since Oct 1, 2018, Bakersfield: 3.55, or -.41. Month to Date: .87 +.03
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove, 804, Parlier, 781 , Arvin, 708 Shafter, 769 Stratford, 779, Delano NA, Lindcove, 1100, Porterville, 1543
Hours at 45 or below 45.
Sunrise: 6:40 am Sunset: 5:45 pm. Hours of Daylight: 11:04
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 46 / 31 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 53 / 35 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 54 / 30 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 53 / 28 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 53 / 36 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 52 / 31 / M /
ATEC1 : Avenal 787 : DH1552 / 53 / 30 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 54 / 32 / 0.00 /
TFTC1 : Taft 759 : DH1555 / 52 / 36 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 53 / M / 0.00 /
Rainfall: Water year Oct 1st through September 30th
24hr Season % L.Y. % Ave. Ave. yearly total
STOCKTON 0.00 11.51 125 3.99 43 9.23 14.06
MODESTO 0.00 9.17 110 3.55 43 8.32 13.11
MERCED 0.00 9.47 124 2.29 30 7.64 12.50
MADERA 0.00 7.17 95 1.55 21 7.52 12.02
FRESNO 0.00 7.65 109 1.64 23 7.04 11.50
HANFORD 0.00 5.84 93 1.78 28 6.29 10.10
BAKERSFIELD 0.00 3.55 90 1.10 28 3.96 6.47
BISHOP 0.00 5.63 174 0.20 6 3.24 5.18
SALINAS 0.00 10.40 127 2.51 31 8.20 12.83
PASO ROBLES 0.00 11.28 139 2.30 28 8.11 12.78
SANTA MARIA 0.00 10.86 123 2.02 23 8.81 13.95
Next report: Wednesday afternoon/February 20