February 29, 2020
Summary: The southern fringe of a cold trough of low pressure is now entering the northern ¼ of California. It will dive over central California late tonight through the late evening hours Sunday. There will be a chance of showers, mainly near the Sierra Nevada foothills, after about 3:00am or so, with a continuing chance of showers into Sunday night. models continue to look marginal on the chance for isolated thunderstorms Sunday afternoon and evening. Even though the risk looks to be low, I do believe isolated thunderstorms should remain in the forecast. Of course, any storms that do develop will be joined by brief heavy rain and small hail.
The trough will form a closed low circulation over south central California Sunday afternoon with the center of circulation just west of Vandenberg AFB. By early Monday morning, the low will have progressed to near San Diego then will swing inland through northwest Mexico Monday afternoon and Monday night. the pool of air associated with the low is very cold and will drop snow levels in the surrounding mountains down to 3,000 to 3,500 feet by Sunday afternoon. The main challenge for Monday and Tuesday will be overnight low temperatures, which is discussed below.
Temperatures which this afternoon are 2 to 5 degrees lower than yesterday, will really tank Sunday with January type highs in the mid to upper 50s. by early Tuesday, high pressure off shore will begin to build inland, creating a northeast flow. Surface high pressure will also result in a strong off shore flow. By Tuesday afternoon, the high will have pushed far enough inland for the beginning of a warming trend which will continue through Thursday as a weak westerly flow will be prevalent for much of the work week.
Models appear to be trending towards a low pressure system moving through the Pacific Northwest and northern California Friday night and Saturday for a chance of showers, mainly north of Kern County. We’ll study this and see if a trend develops. The new two week model is also adamant about there being a high risk of precipitation week after next.
Forecast: Increasing cloudiness tonight with a slight chance of light showers, mainly near the Sierra Nevada foothills after about 3:00am. A chance of light showers Sunday through the late evening hours Sunday night. there is a small chance of isolated thunderstorms from late Friday morning through early Sunday evening. Thunderstorms would be accompanied by brief heavy rain and small hail. Partly to mostly cloudy later Sunday night and early Monday morning. mostly clear Monday afternoon through Friday. Increasing cloudiness Friday night with a slight chance of showers from mainly Fresno County northward, continuing Saturday.
Short Term:
| Madera 41/56/33/61 | Reedley 42/57/33/61 | Dinuba 41/55/32/60 | |
| Porterville 42/57/32/62 | Lindsay 41/56/31/61 | Delano 43/57/33/61 | |
| Bakersfield 46/57/36/61 | Taft 45/55/38/61 | Arvin 42/56/34/61 | |
| Lamont 42/56/34/61 | Pixley 41/56/32/62 | Tulare 40/55/31/61 | |
| Woodlake 41/57/32/62 | Hanford 43/56/33/61 | Orosi 40/56/31/61 | |
Winds: Winds will increase out of the northwest at 10 to 20 MPH tonight through Sunday evening with gusts as high as 35 MPH along the west side of the valley. Later Sunday night and on Monday, winds will be generally at or less than 12 MPH. however, along the far west side, winds out of the north or northeast are possible at 15 to 35 MPH with stronger gusts. Winds Monday night and Tuesday will be generally at or less than 10 to 15 MPH with periods of near calm conditions.
Rain: There is a small chance of light showers, mainly against the Sierra Nevada foothills, after around 3:00am. The chance for scattered showers will continue Sunday through the late evening hours Sunday night. isolated thunderstorms cannot be ruled out from late Sunday morning through the early evening hours. All of the action should be over by late evening Sunday. Precipitation amounts will be widely scattered. Locations that do receive measurable rain will generally pick up no more than .10 unless thunderstorms break out. In this case, .25 is possible along with small hail in those areas that are hit. From later Sunday night through Friday, dry weather will prevail. I’m going to add a slight chance of showers to the forecast for Friday night and Saturday.
Frost Discussion: All locations will be above freezing tonight. I see no reason to change the forecast of widespread low to mid 30s Monday and Tuesday mornings. There is a chance of lows down to 27 to 29 degrees in wind sheltered low lying situations. Most flat terrain locations will generally range from 30 to 36. Temperatures will be quite chaotic Monday morning due to wind conditions, significant mixing, and the possibility of upslope clouds generating against the valley facing slopes of the Kern County mountains and, to a lesser extent, the foothills of the southern Sierra Nevada. Tuesday morning will be more ideal for more of a widespread low to mid 30s event as skies will be generally clear and winds will have slacked off. By Wednesday morning, only the typically cold regions will dip into the lower 30s with most other locations being above freezing. Expect above freezing conditions Thursday and beyond. At this time, there’s nothing on medium or long range models suggesting a cold pattern.
Next report: March 1/morning