December 19, 2019
Summary: Lows this morning are mostly in the low to mid 30s with a spattering of upper 20s in Tulare County. A flat zone of upper level high pressure stretches from off the southern California coast east/northeast into central and southern California. The storm track is running over the top of the high with most of the energy running into the Pacific Northwest and the northern 1/3 of California. Some high clouds will stream overhead from time to time, but no active weather is expected until the second half of the upcoming Christmas weekend. By Saturday, a trough of low pressure will be elongated from British Columbia to off the central coast.
On Saturday night and Sunday, there will be several hours where a rather steep pressure gradient will again set up between high pressure over the Great Basin and rapidly falling pressure along the northern and central coast. We may see another round of strong, gusty winds over the Kern County portion of the valley floor, this time more south to southeast as opposed to the recent event which was more out of the east to east/southeast. Highest risk area will be near the bottom of the Grapevine but locally elsewhere near the base of the mountains to as far north as Bakersfield. It’s possible some gusty southerly winds may commence along the western side of the valley as the jet stream briefly lines up with the surface flow.
Short term, the high pressure system will push temperatures into the low to mid 60s. On Saturday, as downslope winds begin to push off the Kern County mountains, some locations in Kern County could approach the 70 degree mark which is quite toasty for the latter part of December.
The first phase of this trough will push inland Sunday with periods of rain. The typical issues with rain shadows along the western and southern sectors of the valley will certainly be apparent. Just as soon as the first impulse moves through, a second and potentially stronger one is projected by models to move southward right along the northern and central coast on Monday and into Christmas Eve. Some models are showing dry conditions for Christmas Day, however that’s low confidence at this point as yet another wave of low pressure will move through on Christmas Day. The only challenge will be to see whether it has enough dynamics to sustain precipitation.
Some models are back to a cold, northwest flow between the 26th and the 29th. This would still be safe for citrus. Models have been hinting that, towards the end of the year, an upper low may be centered over southern California or thereabouts. Theoretically, this could pull colder air in aloft from the northeast and create a strong off shore flow. However, that’s eons away when you’re talking weather, so we’ll cross that bridge later.
Forecast: A mix of high clouds and sunshine today. Mostly clear tonight through Friday with patchy morning fog Friday. Mostly clear Friday night with areas of fog after midnight. Increasing cloudiness Saturday. mostly cloudy Saturday night with periods of rain Sunday through Monday. A fairly high risk of showers Christmas Eve through Christmas Day and a slight chance of showers Thursday.
Short Term:
| Madera 60/32/61/34/63 | Reedley 60/32/61/35/63 | Dinuba 59/32/61/34/62 | |
| Porterville 62/32/60/34/63 | Lindsay 61/31/60/33/63 | Delano 62/33/63/37/65 | |
| Bakersfield 63/39/64/40/67 | Taft 62/40/63/41/67 | Arvin 63/36/63/41/67 | |
| Lamont 62/34/63/41/66 | Pixley 61/32/60/35/63 | Tulare 60/31/60/34/62 | |
| Woodlake 61/32/60/34/63 | Hanford 61/34/60/37/62 | Orosi 60/31/60/34/62 | |
Seven Day Forecast:
| Sunday
Periods of rain 43/55 |
Monday
Periods of rain 40/53 |
Christmas Eve
Chance of showers 37/52 |
Christmas Day
Chance of showers 39/53 |
Thursday
Slight chance of showers 35/52 |
Two Week Outlook: December 27 through January 2: This model shows a cold weather pattern setting up with above average precipitation over southern California and the Desert Southwest. Temperatures under this regime will sink to below average values.
December: NOAA always projects warmer than average temperatures during the winter months and has a fairly low batting average. This model follows suit with a projection of above average temperatures, especially over the western U.S. The latest projection for precipitation is near average rainfall will prevail.
January, February, March: This model indicates above average temperatures this winter, but what’s new, especially over the western one-third of the U.S. There are two small notations for below average precipitation. The first is over Louisiana. The second is over northern and central California. Let’s hope this projection is inaccurate, but that’s the official prognosis from NOAA.
Winds: Winds will be generally at or less than 7 MPH with periods of near calm conditions through Friday night. Winds Saturday will be mainly out of the southeast at 8 to 15 MPH. Winds Saturday night and Sunday morning in Kern County could be strong and gusty as pressure differences between the interior and off shore tighten up for several hours. Areas of highest risk this time around will be at the bottom of the Grapevine and potentially other locations near the base of the Tehachapi Mountains. Winds in excess of 50 MPH will again be possible with winds possibly in excess of 40 MPH as far north as Bakersfield. There is also a risk of some strong winds along the far west side of the valley, possibly gusting to 45 MPH. These winds should begin to diminish by late Sunday. Elsewhere, winds Saturday night and Sunday will be out of the east/southeast at 10 to 20 MPH with stronger gusts.
Rain: The next chance of rain will begin Sunday as the first low pressure system races along a trough along the west coast and into central California. On paper, anyway, a much stronger low shows up just off shore for Monday for the likelihood of rain. Initially, strong rain shadows will really zap precipitation amounts along the west side and in Kern County. From Tuesday through Christmas Day, the flow will become more northwesterly, reducing the rain shadow effect. There is a slight chance of showers the day after Christmas then possibly three or four days of dry weather thereafter.
Frost Discussion: Ivanhoe dropped to 28 degrees overnight while Exeter and Nevalencia each fell to 29 for the coldest frost stations. All other reporting stations were in the low to mid 30s. temperatures tonight should be a degree or two milder due to daytime highs climbing into the 60s and temperatures will have a longer way to go to reach the freezing mark. Also, dew points will slowly be climbing out of the bottom that developed during the recent off shore flow.
Most if not all locations will be above freezing Saturday morning. we may begin to see higher clouds in advance of a developing off shore trough of low pressure. Even under clear skies, most locations will only drop into the mid to upper 30s.
From Sunday morning through Christmas morning, above freezing conditions can be expected due to a cold but active pattern. This is still a week away, but there is a chance of frost next Friday through Sunday. However, day to day modeling flip flops make it difficult to pin down. But, if there’s any trend at all, either a northerly or northwesterly flow will move in behind low pressure moving into the interior west. For now, there’s no pattern which would result in a major freeze event.
Lows Tonight:
| Terra Bella
32 |
Porterville
32 |
Ivanhoe
30 |
Woodlake
31 |
| Strathmore
32 |
Mcfarland
31 |
Ducor
33 |
Tea Pot Dome
32 |
| Lindsay
31 |
Exeter
30 |
Famoso
33 |
Madera
32 |
| Belridge
31 |
Delano
33 |
North Bakersfield
AF |
Orosi
31 |
| Orange Cove
31 |
Lindcove
31 |
Lindcove Hillside | Sanger River Bottom
29 |
| Root Creek
30 |
Venice Hill
31 |
Rosedale
AF |
Jasmine
33 |
| Arvin
AF |
Lamong
AF |
Plainview
32 |
Mettler
AF |
| Edison
AF |
Maricopa
AF |
Holland Creek
34 |
Tivy Valley
31 |
| Kite Road South
34 |
Kite Road North
31 |
AF=Above Freezing
Afternoon Dew Points Today: Upper 30s to the lower 40s. Kern: Mid to upper 30s. Humidity values ranging from 50%/100% at Hanford. Bakersfield 45%/75%
Actual Humidity range December 18, 2019: Delano, 98%/26% Porterville, 98%/30%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 70%, tomorrow 80%. Bakersfield: Today: 80% Tomorrow: 80%
ET Rates Over the Past Seven Days: Stratford .37, Parlier .35, Blackwell Corner .37, Arvin .NA, Orange Cove .39, Porterville .32, Delano .35. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 56, Parlier 52, Blackwell 55, Arvin, NA, Orange Cove 54, Porterville 53, Delano 49
Record Temperatures: 74/25. Average Temperatures: 54/35
Heating Degree Days this Season: 619 -237
Courtesy of the NWS
Average temperature for December so far: 51.6- +6.6
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2018 Fresno: 2.50 season. or -.09. Month to Date: 1.78 +.89
Since Oct 1, 2018, Bakersfield: 1.61, or +.13. Month to Date: .53 +.00
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove 247, Parlier 319, Arvin 198, Shafter 238, Stratford 261, Delano 294, Lindcove 316, Porterville 474
Hours at 45 or below 45.
Sunrise: 7:07 Sunset: 4:46 pm. Hours of Daylight: 9:39
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 61 / 42 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 60 / 41 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 61 / 37 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 60 / 35 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 61 / 46 / T /
VIS : Visalia Airport 292 : DH1600 / 60 / 37 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 59 / 34 / 0.00 /
TFTC1 : Taft 759 : DH1600 / 58 / 42 / 0.00 /
LOSC1 : Los Banos 120 : DH1600 / 62 / 37 / 0.00 /
Rainfall: Water year Oct 1st through September 30th
24hr season % last year % Ave. 365 day ave.
STOCKTON 0.05 4.10 111 5.00 135 3.70 14.06
MODESTO T 2.79 90 4.20 135 3.11 13.11
MERCED 0.02 4.55 170 3.56 133 2.68 12.50
MADERA 0.00 1.91 67 2.85 100 2.85 12.02
FRESNO 0.00 2.50 97 2.27 88 2.59 11.50
HANFORD 0.00 1.77 84 1.80 85 2.11 10.10
BAKERSFIELD T 1.60 109 1.20 82 1.47 6.47
BISHOP 0.00 1.06 89 1.31 110 1.19 5.18
SALINAS T 4.12 137 4.47 149 3.01 12.83
PASO ROBLES 0.03 4.73 178 3.52 132 2.66 12.78
SANTA MARIA 0.04 2.72 90 2.29 76 3.02 13.95
Next report: Thursday afternoon/December 19