November 19, 2019
Summary: currently, light showers are spreading down the Sierra Nevada as far south as Tahoe while to our south, showers have spread as far north as Riverside County in southern California. This is as of 1:00pm. As of the time of this writing, a dry cold front was moving through the southern San Joaquin Valley while the center of circulation of the main cold core low is over northwest California and is moving rapidly southward. Even though skies are deceivingly mostly clear this afternoon, cloud cover will increase this evening as a colder air mass is lifted by the Sierra Nevada and Kern County mountains, spreading showers into the southern Sierra Nevada. To our south, that tropical juice associated with that low currently moving on shore near northern Baja will interact with colder air diving southward from the northern system for considerable shower activity over the Tehachapi Mountains and over all the desert regions then up through Inyo County.
The chance for measurable rain towards the center and west side of the valley isn’t that great. Models continue to paint eastern Tulare County and Kern County as the real estate most likely to record measurable rain. Some models give the Bakersfield area nearly .25 and possibly even more in the extreme southern and eastern sectors. As much as .10 is projected along the far east side from Lindsay southward through Porterville and Ducor. The best chance of this occurring will be after midnight tonight through midday Wednesday.
The center of the cold system will be near Santa Barbara Wednesday morning, creating a reverse rain shadow as the counterclockwise circulation around the low causes the winds at the mid and upper levels of the atmosphere to swing out of the northeast and then the east. By Wednesday evening, the center of circulation of the main low will be somewhere near Needles then will jet rapidly eastward into the Four Corners region Thursday.
The chance for showers will wind down by midday Wednesday, however as the system heads to the east, a new weak upper low will develop off the coast of the Pacific Northwest and will move to a position west of the central coast Saturday. this system won’t be active, but it will keep pressure patterns weak, so no big warm up is anticipated with generally mid 60s over the weekend, which is more or less typical for this time of year.
Monday and Tuesday, there will be some kind of trough of low pressure more than likely digging into the interior west. Models this afternoon show this feature as a little further east, so little if any chance of rain exists. However, another system is shown diving southward from western Canada and into the United States next Wednesday and Thursday which, theoretically, could bring rain and colder temperatures.
Forecast: Becoming mostly cloudy later tonight with a chance of showers after midnight, mainly over Tulare and Kern Counties. A good chance of showers over Kern County and southeastern Tulare County Wednesday morning with a good chance of light showers elsewhere. Partly to mostly cloudy Wednesday afternoon through Thursday morning. Mostly clear to occasionally partly cloudy Thursday afternoon through Friday. Mostly clear to occasionally partly cloudy Friday night through Monday with areas of night and morning fog and low clouds. Partly cloudy Monday night and Tuesday with patchy night and morning fog.
Short Term:
| Madera 43/57/38/63 | Reedley 43/58/40/64 | Dinuba 42/57/37/63 | |
| Porterville 42/57/38/64 | Lindsay 41/57/38/63 | Delano 43/57/40/65 | |
| Bakersfield 49/55/44/64 | Taft 50/57/47/65 | Arvin 48/55/41/65 | |
| Lamont 45/57/42/65 | Pixley 42/57/40/64 | Tulare 41/56/37/63 | |
| Woodlake 42/58/38/64 | Hanford 42/58/39/64 | Orosi 41/57/36/63 | |
Winds: Winds tonight will be generally out of the northwest at 8 to 15 MPH with local gusts to 25. Winds Wednesday will continue out of the northwest at generally 8 to 15 MPH with locally stronger gusts, diminishing Wednesday night. Winds Thursday through Friday will be generally at or less than 6 MPH with periods of near calm conditions.
Rain: Showers will continue to spread down the Sierra Nevada this evening with a chance of light showers over the valley floor, mainly along the eastern rim of the valley. The greatest potential for rain will be over eastern Tulare County and over the valley portion of Kern County. With the reverse rain shadow in play, some locations towards the center and west side from Kings County north may not pick up any measurable precipitation at all. There are short term models which are showing .25 rainfall amounts over portions of Kern County with possibly .10 or so over southeast Tulare County, but lesser amounts are expected elsewhere. This is a complex pattern with two main players, so confidence levels are pretty low. The best chance of rain will be later tonight through Wednesday morning. The center of this storm will race towards the Colorado River Valley later Wednesday afternoon, pulling any remaining shower activity east and south of the valley. Dry weather will prevail Thursday through Monday. It appears dry weather will continue through at least Tuesday of next week. Some models are suggesting a cold weather system will dive into the western states about Wednesday or Thursday of next week, just in time for Thanksgiving.
Frost Discussion: There will be a minimal chance of local frost by Tuesday morning, however models this afternoon indicate the pool of colder air will be further east than earlier projected. About Wednesday or Thursday of next week, we may see the development of a cold low dropping southward from western Canada for the possibility of showers. On paper, the jet stream is oriented straight south down the western U.S. In theory, this could drive cold enough air into the region for upper 20s and lower 30s later next week. That’s by no means in concrete as the developing patterns we’re seeing in the world of weather are fast moving and certainly subject to change.
Next report: Wednesday morning/November 20