January 21, 2021
Summary: The next low pressure system is a cold one and is just off the Oregon coast this afternoon. High clouds are already spreading over northern California and will advance over central California tonight. this system is fairly moisture starved, but even so the chance of light showers will begin to increase by Friday afternoon, continuing on and off through the first half of the day Saturday. there will be a chance of a few lingering showers Saturday afternoon followed by dry weather Saturday night and early Sunday.
Storm number two is very cold and will stretch from British Columbia to southern California. Bands of energy will move through this low, resulting in periods of showers from late Sunday afternoon well through Tuesday. Snow will fall over the surrounding mountains to as low as 2,000 to 2,500 feet.
Storm number three is the one that most has my attention. An intensifying low will move out of the Gulf of Alaska and will form a powerful low pressure system off the Washington and Oregon coast. A moist feed of energy will set up from southwest to northeast, initially spreading heavy precipitation into northern California early Wednesday, slowly spreading south late Wednesday into Thursday. This storm will present interesting possibilities. With the jet stream flanked from southwest to northeast, perpendicular to the Sierra Nevada, strong rain shadows will develop along the west side and of course, in the south valley.
On the flip side, lift along the Sierra Nevada could potentially result in heavy snow over the high Sierra with significant rain along the east side of the valley north of Kern County. Models still show lots of surface isobars, which are lines of equal pressure, meaning strong differences in surface pressure will develop between the northwest coast and southern California. This could potentially result in high winds in the extreme south valley and along the west side. This system will shift eastward later Thursday night and Friday for dry weather. Most models show the next system mainly affecting northern California next weekend.
Forecast: Increasing high clouds tonight. mostly cloudy Friday with a chance of light showers, mainly in the afternoon. Scattered light showers Friday night and Saturday morning with a chance of light showers Saturday afternoon. Mostly to partly cloudy Saturday night and Sunday morning. increasing clouds later Sunday leading to periods of showers late Sunday afternoon and at times through Tuesday with snow on the foothills surrounding the valley. A slight chance of showers Tuesday night. periods of rain later Wednesday through Thursday night, possibly locally heavy at times along the east side north of Kern County with locally strong, gusty southeast winds.
Short Term:
| Madera 36/58/39/54 | Reedley 35/58/40/54 | Dinuba 34/57/39/54 | |
| Porterville 34/59/40/55 | Lindsay 33/58/39/55 | Delano 36/59/40/55 | |
| Bakersfield 41/59/42/54 | Taft 45/57/42/53 | Arvin 37/60/41/53 | |
| Lamont 37/59/40/55 | Pixley 35/58/40/55 | Tulare 33/57/39/53 | |
| Woodlake 34/57/39/55 | Hanford 37/58/40/55 | Orosi 33/57/39/54 | |
Winds: Winds through tonight will be generally at or less than 10 MPH late mornings and afternoons and at or less than 6 MPH during the later night and morning hours with periods of near calm conditions. Winds Friday will be mainly out of the southeast at 5 to 12 MPH with stronger gusts, mainly from Fresno County north. Winds Saturday through Sunday will be out of the northwest at 8 to 15 MPH. I’m still looking at the late Tuesday/Wednesday time frame for the possibility of a high wind event in the extreme south valley in the usual trouble spots.
Rain: Light showers will overspread the valley late Friday afternoon, continuing on and off through midday Saturday with only a light chance of showers later Saturday afternoon. This is shaping up to be a pretty dry system, so no more than .10 to ,20 is expected at any given location. A brief, dry slot will return Saturday night through Sunday morning then a very cold low will drop into California Sunday afternoon, spreading showers which will continue into Tuesday morning. the foothills will get a sugar coating from this storm as the snow level drops to between 2000 and 3000 feet. On Wednesday, a powerful low will be centered just west of the Oregon coast with the jet stream flanked underneath the low, running from southwest to northeast. It will spread slowly south during the day. Potentially heavy amounts of snow may accumulate in the mountains with heavy rain in the foothills and possibly significant amounts of rin along the east side of the valley north of Kern county. No doubt a strong rain shadow will develop along the west side and in Kern County, zapping rainfall amounts there. Precipitation will continue through Thursday evening with dry weather returning Friday night. another storm will affect northern California next weekend, however it’s unclear how far south precipitation will progress.
Frost: All locations will be above 32 tonight, but at or slightly above in the coldest locations. Above freezing conditions will continue for Saturday morning as well. There is a chance of local frost Sunday morning, however plenty of cloud cover may keep temperatures up. A very cold pattern will arrive Sunday night through Tuesday night, but will involve heavy cloud cover and precipitation for above freezing temperatures. A warmer, powerful storm will affect the valley Wednesday through Friday for above freezing conditions. For now, there’s nothing longer term suggesting a cold pattern is on the horizon.
Next update: January 22/am