January 28, 2020
Summary: Skies are partly cloudy in some areas of the valley and mostly clear in others. Temperatures are generally in the upper 50s which is close to seasonal for late January. The latest freezing level over Vandenberg was 9,800 feet, which is relatively low but will begin to rise over the next 72 hours as upper level high pressure builds in from the west.
In the short term, a strong low will move through the Pacific Northwest and will carve out a new low over Utah and Arizona Wednesday and Wednesday night followed by a strong surface high. The combination of the off shore high and the low over the interior will generate a robust off shore flow beginning Wednesday and lasting through Thursday. This will crank up the Santa Anas in southern California and over the Kern County mountains. It may add enough mixing to the lower levels of the atmosphere over the valley to slow down the fog machine.
The off shore high will build inland late Thursday through Saturday with a distinct warming trend. This may allow warmest locations to approach the 70 degree mark Saturday and possibly Sunday. Late Sunday and Sunday night, a rather dynamic but moisture starved cold front and associated trough of low pressure will move through central California, resulting in gusty winds and much cooler weather next week.
This will be the first time in weeks modified arctic air has been driven into the lower 48. Current model thinking keeps the coldest air over the interior west. Still, with a north/south flow from northwest Canada down into California, frost concerns will be an issue beginning as early as Tuesday morning. this is discussed in the frost section below.
If it’s going to rain over the next 10 days it will probably be Sunday night or Monday when the cold front moves through. However, this will be an overland system so moisture will be limited. Therefore, only a slight chance of light showers exists over the valley floor with snow showers over the mountains and lowering snow levels.
Forecast: Partly cloudy tonight with areas of fog and low clouds developing after midnight. Mostly clear to occasionally partly cloudy Wednesday after the fog and low clouds burn off. Mostly clear Wednesday night through Saturday night with extensive night and morning fog and low clouds. Mostly clear Sunday morning after areas of fog and low clouds dissipate, becoming partly cloudy in the afternoon. Increasing cloudiness Sunday night with a small chance of light showers after midnight. Mostly cloudy, breezy, and cooler with a small chance of showers Monday. Partly to mostly cloudy Monday night and Tuesday morning. becoming partly cloudy Tuesday afternoon.
Short Term:
| Madera 38/56/36/62 | Reedley 38/57/36/61 | Dinuba 36/56/35/60 | |
| Porterville 37/57/36/62 | Lindsay 37/55/35/61 | Delano 38/57/36/62 | |
| Bakersfield 43/57/40/62 | Taft 44/56/42/62 | Arvin 39/56/37/62 | |
| Lamont 39/57/37/62 | Pixley 39/56/37/61 | Tulare 38/55/36/60 | |
| Woodlake 38/56/36/61 | Hanford 39/57/37/61 | Orosi 37/56/35/60 | |
Winds: Winds this evening will be mainly out of the northwest at 5 to 12 MPH. Winds tonight through Friday will be generally at or less than 6 MPH with periods of near calm conditions.
Rain: Dry weather will continue through at least Sunday. We’ll go ahead and maintain a small chance of light showers in the forecast for Sunday night and Monday as a moisture starved but rather dynamic cold front moves through. After Monday, dry weather will continue for all of next week.
Frost Discussion: All locations will be above 32 degrees tonight. On Thursday morning, the very coldest locations will dip down into the 33 to 35 degree range. However, no real frost threat is anticipated. Above freezing conditions will prevail through at least Monday morning. it does appear winter will finally return early next week. A cold front and associated trough of cold low pressure will move through Sunday night and Monday followed by a much cooler air mass. For now, it appears daytime highs will drop into the low to mid 50s Monday and Tuesday.
One of the main medium range models is spitting out a low temperature of 33 degrees both Tuesday and Wednesday mornings of next week. This is one of the more reliable models. Generally, low 30s on this model translates to lows in the 27 to 29 degree range in colder low lying and unprotected locations.
Models for much of next week show a massive upper high building along the north American coast, almost reaching into the Arctic Circle with a cold trough of low pressure digging southward into the interior west along with modified arctic air. On paper, California shows up on the far western fringe of this trough with a north/south flow aloft and a strong off shore flow. How chilly it could potentially become is very speculative at this time, but for now I would not rule out mid to upper 20s in those coldest locations by the middle of next week. For now, I put that chance at around 30% or so.
Next report: January 29/morning