December 15, 2019
Summary: The freezing level above the valley floor is down to 4,900 feet this morning. yesterday’s frontal passage issued in a considerably colder air mass. In fact, temperatures this morning are 12 to 16 degrees cooler than 24 hours ago. The main upper trough of low pressure is currently diving into the Great Basin with a pool of, shall we say, seasonably cold air in place. With a relatively clear sky tonight, temperatures will drop to near to below freezing in most areas. More in the frost discussion below.
A ridge of upper level high pressure will build in from the west tonight through Tuesday. The inversion over the valley floor tonight will be relatively weak so ground fog Monday morning should be fairly patchy. It should be more widespread Tuesday morning as the inversion firms up just a bit.
A weak low pressure system will approach the coast Wednesday and essentially fall apart as it moves through central and southern California. Still, I’m going to keep a slight chance of a few showers in the forecast, mainly from Fresno County northward. As that system scoots eastward, a new ridge of upper level high pressure will build in from the eastern Pacific for dry, stable weather Wednesday night through Saturday. increasing amounts of night and morning fog will be the main weather challenge.
The second half of next weekend has been a target period for some time for the possibility of a major pattern change. By Sunday of next week, a trough of low pressure will stretch from the Gulf of Alaska to off the central coast. If models have a handle on this situation, the chance for precipitation will increase late Sunday and Monday with a chance of rain at any given time from the 22nd through Christmas Day. Models are all over the place on the pattern for the period between Christmas to New Year’s, ranging from cold and stable with plenty of fog and low clouds while a fairly active pattern is also projected with colder type storms moving out of the Gulf of Alaska and into California.
Forecast: Mostly clear skies through Tuesday. Expect patchy low clouds and fog Monday morning then fog and low clouds will become somewhat more widespread Tuesday morning. increasing clouds later Tuesday night. mostly cloudy Wednesday with a chance of light showers from Fresno County north. Partly cloudy Wednesday night and Thursday morning. mostly clear to occasionally partly cloudy Thursday through Saturday with widespread fog and low clouds nights and mornings. Increasing clouds Saturday night leading to a slight chance of rain Sunday.
Short Term:
Madera 53/30/54/30/55 | Reedley 53/31/54/30/56 | Dinuba 52/30/54/29/54 | |
Porterville 52/31/54/30/55 | Lindsay 53/30/54/29/55 | Delano 53/32/54/31/57 | |
Bakersfield 52/36/56/36/59 | Taft 51/39/56/39/59 | Arvin 52/32/56/31/60 | |
Lamont 52/33/56/32/60 | Pixley 53/31/54/30/57 | Tulare 51/30/53/29/54 | |
Woodlake 52/31/54/30/55 | Hanford 53/32/54/32/56 | Orosi 52/30/54/29/55 |
Seven Day Forecast:
Wednesday
Mostly cloudy 41/59 |
Thursday
AM fog/partly cloudy 37/55 |
Friday
AM fog/PM sun 37/60 |
Saturday
AM fog/increasing clouds 40/62 |
Sunday
Slight chance of showers 42/57 |
Two Week Outlook: December 22 through December 28: This model is showing a broad, cold trough of low pressure as the dominant feature with potentially cold storms moving out of the Gulf of Alaska and into California. The chance of precipitation, especially between the 22 and Christmas, is relatively high with below average temperatures.
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 today will be mainly out of the northwest at 8 to 15 MPH with locally stronger gusts. Winds tonight through Wednesday will be generally at or less than 7 MPH with periods of near calm conditions.
Rain: The chances are excellent that dry conditions will prevail all the way through at least Saturday. there is a slight chance of a few sprinkles or isolated light showers Wednesday, but the chance at any given location appears to be at or less than 10%. Models are still pointing at the period from the 21 through Christmas Day as an active period. A broad trough of low pressure could develop from the Gulf of Alaska to southern California. The timing of all this mess is literally up in the air at this time, but suffice it to say rain is possible from late Sunday and at any time through Christmas Day.
Frost Discussion: Navalencia bottomed out at 33 degrees this morning with Lindcove at 34 as of 6:30 this morning for the coldest temperatures throughout the citrus belt. Most other locations were in the mid to upper 30s with a few low 40s in Kern County. The freezing level has now dropped to 4,900 feet, so obviously the air aloft is a bit chilly but nothing unusual for mid December. With generally clear skies tonight and again Monday night, temperatures will drop to near to below freezing throughout the citrus belt, but I do not anticipate anything really threatening.
With relatively strong radiational cooling tonight, coldest, unprotected locations will drop down to 27 to 29 degrees with most typical flatland terrain at 29 to 34. Hillsides will generally be above freezing.
The inversion tonight will be weak to moderate at most locations with temperatures ranging from 3 to 5 degrees warmer at 34 feet.
On Tuesday morning, most locations will be at or perhaps a degree or so colder. Most locations Wednesday morning should range in the mid 30s to the low 40s due to increased cloud cover during the second half of the night. if the anticipated cloud cover is later in arriving than anticipated, then lows of 30 to 35 are possible.
Most locations Thursday through Saturday will range between 32 and 38 degrees under a temporary ridge of upper level high pressure. Beginning Sunday morning, increased cloud cover and the possible beginning of an active pattern between Sunday and Christmas Day will set in. potentially cold storms will affect the region during this time. Any clear night sandwiched in there would definitely see lows of the low to mid 30s. it’s possible that, after Christmas, below freezing nights could be possible as some models are suggesting a low over southern California or the Desert Southwest and a ridge of high pressure building northward into western Canada would set up a northeast flow. However, the origins of the air mass do not appear to be of critical nature, but it is a time frame worth watching considering, climatologically speaking, we’re at the highest risk period for citrus.
Lows Tonight:
Terra Bella
31 |
Porterville
31 |
Ivanhoe
29 |
Woodlake
30 |
Strathmore
30 |
Mcfarland
30 |
Ducor
32 |
Tea Pot Dome
31 |
Lindsay
29 |
Exeter
29 |
Famoso
31 |
Madera
30 |
Belridge
29 |
Delano
32 |
North Bakersfield
31 |
Orosi
29 |
Orange Cove
30 |
Lindcove
29 |
Lindcove Hillside | Sanger River Bottom
27 |
Root Creek
29 |
Venice Hill
30 |
Rosedale
31 |
Jasmine
30 |
Arvin
32 |
Lamont
33 |
Plainview
30 |
Mettler
34 |
Edison
32 |
Maricopa
32 |
Holland Creek
32 |
Tivy Valley
31 |
Kite Road South
32 |
Kite Road North
29 |
AF=Above Freezing
Afternoon Dew Points Today: Upper 30s to the lower 40s. Kern: Upper 30s to the lower 40s. Humidity values ranging from 55%/100% at Hanford. Bakersfield 55%/100%
Actual Humidity range December 14, 2019: Delano, 100%/61% Porterville, 98%/64%
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 80%, tomorrow 70%. Bakersfield: Today: 60% Tomorrow: 80%
ET Rates Over the Past Seven Days: Stratford .22, Parlier .22, Blackwell Corner .25, Arvin .NA, Orange Cove .27, Porterville .30, Delano .29. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 57, Parlier 54, Blackwell 57, Arvin, 56, Orange Cove 55, Porterville 57, Delano 52
Record Temperatures: 76/25. Average Temperatures: 55/35
Heating Degree Days this Season: 545 -227
Courtesy of the NWS
Average temperature for December so far: 53.1- +7.8
Precipitation: Seasonal total/average/above or below average:
Since Oct 1, 2018 Fresno: 2.50 season. or +.14. Month to Date: 1.78 +1.12
Since Oct 1, 2018, Bakersfield: 1.61, or +.26. Month to Date: .53 +.13
Water year season is from October 1st through September.
Chilling Hours November 1st through February 28: Orange Cove 203, Parlier 265, Arvin 157, Shafter 189, Stratford 208, Delano 236, Lindcove 252, Porterville 405
Hours at 45 or below 45.
Sunrise: 7:05 Sunset: 4:44 pm. Hours of Daylight: 9:39
Yesterday’s Weather:
MAE : Madera 253 : DH1600 / 61 / 49 / 0.01 /
FAT : Fresno Airport 333 : DH1600 / 60 / 52 / 0.03 /
HJO : Hanford Airport 242 : DH1600 / 62 / 54 / 0.02 /
NLC : Lemoore Naval AS 234 : DH1600 / 61 / 52 / 0.10 /
BFL : Bakersfield Airport 496 : DH1600 / 59 / 54 / 0.02 /
VIS : Visalia Airport 292 : DH1600 / 61 / 50 / 0.05 /
ATEC1 : Avenal 787 : DHM / 58 / 54 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 60 / 54 / 0.12 /
TFTC1 : Taft 759 : DH1551 / 59 / 54 / 0.00 /
Rainfall: Water year Oct 1st through September 30th
24hr season % last year % Ave. 365 day ave.
STOCKTON 0.00 4.01 118 3.87 113 3.41 14.06
MODESTO 0.00 2.79 98 3.05 107 2.84 13.11
MERCED T 4.53 183 2.69 109 2.47 12.50
MADERA T 1.91 73 2.42 93 2.60 12.02
FRESNO 0.03 2.50 106 1.92 81 2.36 11.50
HANFORD 0.02 1.77 94 1.71 90 1.89 10.10
BAKERSFIELD 0.02 1.60 119 1.20 90 1.34 6.47
BISHOP 0.00 1.06 96 1.31 119 1.10 5.18
SALINAS 0.02 4.11 149 3.87 140 2.76 12.83
PASO ROBLES T 4.70 197 2.84 119 2.39 12.78
SANTA MARIA 0.00 2.68 97 1.95 71 2.75 13.95
Next report: Sunday afternoon/December 15