January 20, 2021
Summary: All of the weather action today is over southern California where a cut off low located off the northern Baja coast is rotating showers and thunderstorms from the Coachella Valley southward. Flash flooding is taking place in a few locations in the Imperial Valley. The northern 2/3 of California is mostly clear. With a much drier air mass in place on the valley floor, strong radiational cooling will take place after sunset with widespread frost later tonight and Friday morning. more in the frost discussion below.
The storm west of northern Baja will begin shifting eastward later tonight in response to a cold, moisture starved low pressure system driving southward from British Columbia which will move quickly into California Friday into Saturday. like so many times this winter, models painted this system as a major event but now it looks like some locations will receive no precipitation at all with most of the activity confined to the mountain areas. This storm will race into the Desert Southwest Saturday evening, allowing a weak wedge of high pressure to fill in behind.
The next weather system appears to have much more potential with strong upper air dynamics. This storm is very cold and may lower snow levels down to around 2,900 feet or so Monday into Tuesday. The system will then track southeastward out of the area Tuesday evening. Models are showing a very intense system forming off the northern California/Oregon coast Wednesday through Thursday. Flanked underneath this low is a rich feed of moisture possibly originating from north of Hawaii. This is better known as the pineapple connection which could potentially dump lots of rain and higher elevation snow in northern California. Models show this line of moisture dropping slowly southward Wednesday night through Thursday night.
the other element of this storm that bears watching is potentially large differences in surface pressure between very low pressure off the northern California coast and much higher pressure over southern California and the Desert Southwest. This configuration favors a high wind event in the extreme south valley. It’s much too early to officially add that to the forecast, however, the time frame I’m looking at currently is Wednesday morning through Wednesday night.
Models also continue to show additional chances of rain a week from this weekend.
Forecast: Mostly clear skies tonight through Thursday evening. Partly cloudy after midnight Thursday. Variable cloudiness Friday through Saturday with only a chance of scattered light showers, mainly Friday afternoon through Saturday morning. partly to mostly cloudy Saturday night through Sunday morning. increasing cloudiness late Sunday. A chance of showers Sunday night, mainly after midnight. Showers likely Monday through Tuesday morning with snow in the surrounding foothills. Partly cloudy Tuesday night. increasing cloudiness Wednesday with a chance of strong, gusty, southeast winds.
Short Term:
| Madera 30/64/35/57 | Reedley 29/65/34/58 | Dinuba 28/64/34/57 | |
| Porterville 28/66/34/59 | Lindsay 28/65/33/57 | Delano 29/66/36/57 | |
| Bakersfield 39/68/40/59 | Taft 48/65/45/57 | Arvin 33/66/36/59 | |
| Lamont 34/65/37/58 | Pixley 29/66/34/59 | Tulare 28/64/34/57 | |
| Woodlake 29/65/34/57 | Hanford 29/66/36/58 | Orosi 28/64/34/57 | |
Winds: Winds through Thursday night 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 will be out of the northwest at 8 to 15 MPH.
Rain: Dry weather will continue through Thursday night. as has been the case so often this winter, models continue to spit out a drier weather system for Friday through Saturday morning with only a chance of scattered light showers. Most of the activity will be confined to the mountain areas. So, we’ll forget that one and turn our attention to Sunday night through at least Tuesday morning. so far, modeling shows decent cold air dynamics with this storm with a chance of showers as early as Sunday night, becoming likely at times Monday through Tuesday morning. this system is very cold, so look for snow on the surrounding foothills. This storm will exit to the southeast late Tuesday and Tuesday night.
The next storm still looks to be the strongest of the winter, so far. By Wednesday morning, a powerful low will be west of the Oregon/northwest California coast with a rich feed of moisture extending from north of Hawaii northeastward into northern California initially then sagging southward into central California late Wednesday and Thursday. These types of systems generate strong rain shadows along the west side and in the south valley, but upsloping also generates heavy amounts of precipitation along the Coast Range and the Sierra Nevada. This system will move out of here Friday, but models continue to point to the possibility of more rain next weekend.
Frost: Dew points north of Kern County are only in the mid to upper 20s. In Kern County, only lower 20s are being observed. With mostly clear skies tonight, strong radiational cooling will occur with widespread upper 20s and lower 30s.
Coldest low lying frost pockets will drop to near 26. I wouldn’t be surprised to see a 25 or two out there by sunrise. Most other locations will range from 27 to 31. South of Bakersfield, most locations will generally remain in the low to mid 30s.
The inversion tonight will initially be weak, but by sunrise will be generally 3 to 6 degrees warmer at 34 feet.
Temperatures Friday morning will in part be determined by recovering dew points and possibly cloud cover ahead of the next weather system, which will arrive later Friday. This system is cold, so readings Saturday and Sunday mornings will be mostly in the low to mid 30s, however several hours of clear skies could easily see temperatures in the upper 20s in the traditional cold spots.
A very cold storm will spread heavy cloud cover and showers over the valley Monday through Tuesday for above freezing conditions. A very strong southwesterly flow will bring above freezing conditions Wednesday through Friday.
Lows Tonight:
| Terra Bella
28 |
Porterville
28 |
Ivanhoe
27 |
Woodlake
28 |
| Strathmore
28 |
McFarland
28 |
Ducor
29 |
Tea Pot Dome
28 |
| Lindsay
27 |
Exeter
27 |
Famoso
28 |
Madera
30 |
| Belridge
27 |
Delano
28 |
North Bakersfield
29 |
Orosi
28 |
| Orange Cove
29 |
Lindcove
27 |
Lindcove Hillside
Af |
Sanger River Bottom
25 |
| Root Creek
27 |
Venice Hill
28 |
Rosedale
29 |
Jasmine
29 |
| Arvin
33 |
Lamont
33 |
Plainview
28 |
Mettler
32 |
| Edison
34 |
Maricopa
28 |
Holland Creek
31 |
Tivy Valley
28 |
| Kite Road South
31 |
Kite Road North
28 |
AF=Above Freezing
Next update: January 21/am