February 13, 2019
Summary: Remember the past couple of days when freezing levels were between 3,000 and 4,000 feet? The latest freezing level over Oakland is now 10,900 feet and 11,200 feet over Vandenberg. To find the cold air, we go to Medford, Oregon where the freezing level is 3,200 feet.
So far, models have way overdone predictions of three or four inches of precipitation in the Sierra Nevada today. In fact, measurements have not come close. Low pressure, however, is developing off the northern California coast and will begin to push a rather fragmented looking atmospheric river of air into central California tonight and Thursday morning with periods of rain. The wind potential, though, has lived up to its billing in Kern County. Lamont and Buttonwillow have reported gusts to 29 MPH. Meadows Field at Bakersfield reported a gust of 46 MPH, Taft 58 MPH, and the CHP office at the bottom of the Grapevine has had a gust of 73 MPH. High winds will continue in these areas well into Thursday morning.
The reason rainfall has been much lighter than anticipated so far is in part due to a big rain shadow along the west side. On satellite imagery, standing lenticular clouds are visible, meaning strong winds up higher in the atmosphere are sweeping in from the southwest. As long as these winds continue, rainfall amounts will be zapped, possibly all the way into the east side.
By Thursday evening, the colder sector of the storm will arrive with widespread shower activity which will taper off later Thursday night and for a time Friday morning. That will be short lived, however as the first of three modified arctic systems drives southward, partially overland and partially over water. Each will be carrying modified arctic air which will result in periods of mainly light showers Friday all the way through Monday morning.
Most of the action should be over by Monday afternoon. However, a dry north to south flow will dive into California behind the exiting trough of low pressure. By Tuesday and Wednesday, the flow will be more northwest to southeast which will still maintain below average temperatures. Models are still indicating dry weather Monday afternoon through next weekend with the possibility of another cold low moving out of the Gulf of Alaska about Sunday the 24th and Monday the 25th.
Forecast: Periods of rain tonight and Thursday morning. Showers Thursday afternoon and evening. A chance of showers later Thursday night and Friday morning. The likelihood of showers will return Friday afternoon and last off and on through Monday morning. Partly cloudy Monday afternoon and Monday night. becoming mostly clear Tuesday through Wednesday with cold nights.
Short Term:
| Madera 56/62/45/54 | Reedley 56/62/44/56 | Dinuba 54/61/44/55 | |
| Porterville 56/64/44/57 | Lindsay 54/63/44/56 | Delano 57/64/44/56 | |
| Bakersfield 59/65/46/56 | Taft 60/65/47/57 | Arvin 58/65/46/57 | |
| Lamont 58/65/46/58 | Pixley 55/63/44/56 | Tulare 55/62/44/55 | |
| Woodlake 54/62/44/55 | Hanford 56/63/43/55 | Orosi 54/63/43/55 | |
Winds: Winds on the east side north of Kern County and south of Fresno County will be out of the southeast at 10 to 20 MPH with stronger gusts through Thursday morning. From Fresno County northward, and along the west side, winds will be out of the southeast at 15 to 30 MPH with local gusts to 40 MPH possible. Over the valley portion of Kern County, winds will be out of the south to southeast at 20 to 35 MPH with local gusts to 50 MPH and possible gusts to near 70 near the bottom of the Grapevine. Winds Thursday afternoon and Thursday night will be mainly out of the west to northwest at 10 to 20 MPH with stronger gusts. Winds Friday night through Sunday will periodically be out of the southeast at 10 to 20 MPH with local gusts to 25.
Rain: I must say, the atmospheric river off shore is not nearly as impressive looking this afternoon. Even so, along the Sierra Nevada, heavy amounts of precipitation can be expected tonight and through much of the day Thursday with periods of rain on the valley floor. Big time rain shadows have developed along the lee side of the Coast Range, encompassing the west side of the valley though in reality they’ve covering most of the valley at this hour. These rain shadows will continue until sometime Thursday afternoon after the cold front moves through which will be followed by dropping temperatures and periods of showers.
The showers will taper off later Thursday evening and for a time early Friday, but will increase again Friday afternoon with periods of showers likely Friday afternoon through to Monday morning. These waves of low pressure moving in from the north will be quite cold and generally light with snow levels lowering to between 2,000 and 3,000 feet Friday through Monday. Dry weather should arrive by Monday afternoon and will likely last through all of next week.
Frost Discussion: All locations will be well above 32 degrees tonight with above freezing conditions continuing through Monday morning. From Tuesday through Thursday of next week, I expect cold conditions, but not quite as cold as early projections had portrayed. If this model output were for tonight, we’d be calling for upper 20s to mid 30s. Instead, lows tonight will be in the upper 50s to even the lower 60s in Kern County.
A northerly flow will prevail Monday and Tuesday behind a very cold trough over the interior west. It will take another few days to nail down the Tuesday through Thursday time frame, but at least I’m a little more comfortable with it than I was even this morning.
Next report: Thursday morning/February 14