December 22, 2018
Summary: The valley is blanketed with fog and/or low clouds with visibilities ranging from generally .5 to 1 mile. Drizzle is also occurring in some areas. This low cloud deck is a thick one and it extends well into the foothills, spilling over into the coastal valleys on the west side. We know the top of the cloud deck is at least 4,000 feet as Tehachapi is reporting dense fog at this hour. The chance for clearing is quite low for this afternoon due to the thickness of the cloud deck and it could possibly hang in there all the way through Monday morning with possibly some afternoon clearing. Above the fog, there will be periods of high clouds from time to time intermixed with plenty of sunshine. For a low cloud and fog event, it’s a very warm one with temperatures in some cases above 50 degrees this morning. A west/northwest flow will prevail Christmas Eve into California. This flow will begin to buckle on Christmas Eve day as a low center and its associated cold front move out of the Gulf of Alaska and into northern California Monday. From there, it will move into central California Christmas Eve night and Christmas Day. Most of the precipitation should end later Christmas afternoon.
The air mass behind this system is colder, but not critically so as a north/south flow works around the back side of the system. This will no doubt cause clouds to stack up against the Sierra Nevada and the Kern County mountains. That flow will generally continue through about Friday for colder temperatures, both for highs and lows.
It’s the periods of December 31 and beyond that concerns me. For the third day in a row, some models are projecting a massive high over the eastern Pacific Ocean, eventually stretching up into Alaska and the western Yukon. In the meantime, a low center will develop over southern California or possibly somewhere over the Desert Southwest. Models for this morning show the bulk of the air moving to the east of the Sierra Nevada or winter conditions over the interior west. It is certainly possible some of this air could arrive in two waves. The first would be to filter downslope off the Sierra Nevada and the second would be down the Sacramento Valley and the west side of the San Joaquin Valley, eventually filling in the entire valley. There is still plenty of time for this pattern to change in our favor, so I’m definitely just discussing possibilities here and for now, that’s all I’ll call it: A possible freeze situation coming up after the first of the year.
Forecast: Low overcast and fog this morning with areas of drizzle. Low overcast this afternoon with only a chance of afternoon clearing. Fog and/or low overcast tonight through Sunday with partial clearing in the afternoon. Increasing cloudiness Sunday night. mostly cloudy Christmas Eve with rain becoming likely as we approach midnight. South of Fresno County, the precipitation will be more showery. Showers Christmas morning with a chance of showers during the afternoon. Cloudy to mostly cloudy Christmas afternoon and Wednesday morning. Variable cloudiness Wednesday afternoon through Thursday with patchy night and morning fog. Mostly clear Thursday through Saturday with areas of night and morning fog.
Short Term:
| Madera 56/49/56/42/58 | Reedley 55/48/56/42/58 | Dinuba 54/49/55/41/57 | |
| Porterville 54/50/56/41/59 | Lindsay 55/49/56/41/59 | Delano 56/50/56/42/60 | |
| Bakersfield 54/50/57/45/60 | Taft 57/50/57/46/61 | Arvin 54/50.55/47/61 | |
| Lamont 56/50/57/44/60 | Pixley 55/49/56/42/59 | Tulare 54/49/56/41/57 | |
| Woodlake 56/48/56/42/58 | Hanford 55/49/56/41/59 | Orosi 55/47/56/41/58 | |
Seven Day Forecast:
| Christmas Day
Showers likely 45/52 |
Wednesday
Mostly cloudy 34/53 |
Thursday
Patchy fog/partly cloudy 32/53 |
Friday
Patchy fog/mostly clear 31/52 |
Saturday
Patchy fog/mostly clear 30/52 |
Two Week Outlook: December 29 through January 4: This model is indicating below average temperatures from California all the way into the Midwest, especially after the first of the year. With a blocking ridge of upper level pressure just off shore, the chance for precipitation appears low.
January: This model shows generally above average temperatures for January over the western one-third of the United States while near to below average temperatures will prevail east of the Rockies. There is no firm indicator of really above or below average precipitation although it does forecast below average rain in the Pacific Northwest.
January, February, March: The western half of the United States is projected in a very general sense to have above average temperatures for the next 90 days. Like the 30 day outlook, it seems to want to project near average precipitation, which would be nice.
Winds: Winds will be at or less than 7 MPH through Sunday night with periods of calm conditions. Winds Monday will be generally out of the southeast at 5 to 15 MPH, continuing Christmas Eve night. Later Christmas Day, winds will be out of the northwest at 10 to 20 MPH with stronger gusts along the west side, diminishing Tuesday night.
Rain: Dry weather will continue through Christmas Eve day. On Christmas Eve night and Christmas Day, precipitation will spread over the area. Models are a bit more bullish this morning on amounts which may total as much as .25 to .33 in Fresno and Madera Counties, possibly as much as .25 in portions of Tulare and Kings Counties, but it still appears Kern County will only pick up about .10 or less. Dry weather will return Tuesday night and, if all goes as planned, will continue through the end of the year and possibly right through the first week in January.
Frost Discussion: All locations will be above freezing through Christmas morning and possibly through Wednesday morning, depending on a myriad of conditions. The air mass moving in behind the Christmas Day storm will be colder but nothing excessive is in the offing. A north/south flow will wrap around the back side of the exiting storm. This system will be followed by an inside slider about 36 hours later which will be dry for California, but the air mass behind this system is definitely colder for the interior west and possibly could lower temperatures and dew points in the valley, as well. For now, low to mid 30s are certainly possible Wednesday morning with the possibility of upper 20s Thursday through Friday.
My main focus continues to be from the 30th through the first four or five days of January. For the third day in a row now, models are showing a massive high over the eastern Pacific, ridging northward into Alaska and the northwest Yukon. While that’s developing, a low will be carving itself out over possibly southern California or Arizona. The flow between the systems will be out of the north or possibly the north/northeast, funneling modified arctic air southward into the U.S. models this morning are only slightly more hopeful as they show a little bit better chance that most of the air will slide into the Great Basin and Rocky Mountain region, but there is certainly a chance of some of this air moving down the Sacramento Valley and eventually the west side of the San Joaquin Valley, ultimately filtering into the remainder of the valley. I’ve also see occasions where it filters downslope from the Sierra Nevada.
The best possible solution would be to modify this into a northwesterly flow which would effectively steer the arctic air away from our region.
Afternoon Dew Points Today: Upper 40s to the lower 50s. Kern: Upper 40s to the lower 50s.
Humidity: Porterville: 80%/100%, Bakersfield: 75%/95%
Actual Humidity December 21, 2018: Delano, 100%/88% Porterville, 99%/89%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 10%, tomorrow 20% Bakersfield: Today: 0% Tomorrow: 40%
ET Rates Over the Past Seven Days: Stratford .28, Parlier .28, Blackwell .36, Lindcove .24, Arvin .39, Orange Cove .29, Porterville .27, Delano .30 Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 55, Parlier 53, Blackwell 55, Lindcove, 58, Arvin, 54, Orange Cove 55, Porterville 53, Delano 51
Record Temperatures: 70/19. Average Temperatures: 54/35
Heating Degree Days this Season: 646 -273
Courtesy of the NWS
Average temperature for December so far: 49.4 +4.5
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2018 Fresno: 2.27 season. or -.51, Month to Date: .50 -.58
Since Oct 1, 2018, Bakersfield: 1.20, or -.38. Month to Date: .52 -.12
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove, 288, Parlier, 316 , Arvin, 241 Shafter, 333 Stratford, 292, Delano 309, Lindcove, 426, Porterville, 625
. Hours at 45 or below 45.
Sunrise: 7:09 am Sunset: 4:47 pm. Hours of Daylight: 9:38
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 65 / 47 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 55 / 48 / T /
HJO : Hanford Airport 242 : DH1600 / 54 / 46 / T /
NLC : Lemoore Naval AS 234 : DH1600 / 55 / 44 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 60 / 48 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 53 / 46 / T /
ATEC1 : Avenal 787 : DH1549 / 60 / 46 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 54 / 46 / T /
TFTC1 : Taft 759 : DH1545 / 60 / 47 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 61 / 49 / 0.00 /
Rainfall: Water year Oct 1st through September 30th
24hr Season % L.Y. % Ave. Ave. yearly total
STOCKTON T 5.00 127 0.96 24 3.94 14.06
MODESTO T 4.20 126 1.03 31 3.33 13.11
MERCED 0.00 3.56 124 1.11 39 2.86 12.50
MADERA 0.00 2.85 94 0.41 13 3.04 12.02
FRESNO T 2.27 82 0.41 15 2.78 11.50
HANFORD T 1.80 77 0.41 18 2.33 10.10
BAKERSFIELD 0.00 1.20 76 0.07 4 1.58 6.47
BISHOP 0.00 1.31 103 0.16 13 1.27 5.18
SALINAS 0.00 4.47 139 0.78 24 3.21 12.83
PASO ROBLES 0.00 3.52 122 0.27 9 2.88 12.78
SANTA MARIA 0.00 2.29 71 0.12 4 3.24 13.95
Next report: Saturday afternoon/December 22