Summary: This afternoon’s satellite imagery says it all. Just a classic powerful winter storm is centered just west of the southern Oregon coast. On visible satellite, the storm is tightly wound up like a cinnamon roll with a narrow cold front sweeping out towards the Pacific Ocean. Behind the low are numerous popcorn looking cloud cover, indicative of very cold, unstable air. Already this afternoon, winds along the northwest California coast are exceeding 60 MPH. as pressure differences tighten up between northern and southern California, gusty winds will sweep down the valley. More in the wind discussion below.
Doppler radar is depicting widespread mainly light precipitation over northern California spreading into north/central California. The freezing level over Oakland has now dropped to 5,800 feet and will continue to drop, as will snow levels. Precipitation will spread over the valley from northwest to southeast this evening with periods of rain Wednesday through Wednesday night. the jet stream will flank right underneath the low, generating excellent lift along the Sierra Nevada and western Tehachapi Mountains for heavy lower elevation rain and heavy higher elevation snow.
Thanksgiving Day, the rain will turn showery. There will also be a chance of thunderstorms with this system with the greatest risk being Wednesday and Thursday afternoons and evenings. The fact that this system is so cold means that any thunderstorms that do develop will be accompanied by localized heavy rain and small hail.
Models have slowed down the exit strategy of this storm just a bit now, so we’ll keep a small chance of showers in the forecast for Friday morning. Models are somewhat inconclusive about the behavior of a low pressure system which will be approaching the northern California coast Saturday morning. Some models keep this storm close enough to the coastline for an excellent chance of rain Saturday through Sunday night while others show it remaining far enough off shore for dry weather. For now, the best course of action will be to go with a chance of showers Saturday through Sunday night. some models show the low moving southward Sunday and Monday night for just a small chance of showers as it just kind of falls apart along the southern California coast.
After Tuesday, models show a flat zone of high pressure building in from the west. Should this happen, we could see widespread fog and low clouds later next week.
Forecast: Rain spreading southward later this evening. Periods of rain Wednesday and Wednesday night with a chance of thunderstorms Wednesday afternoon and evening accompanied by localized heavy rain and small hail. Showers Thanksgiving Day and night with a risk again of scattered thunderstorms Thursday afternoon and evening. A small chance of showers Friday morning. Becoming partly cloudy Friday afternoon and night. increasing cloudiness Saturday leading to a chance of showers, continuing through Sunday night. a slight chance of showers Monday through Tuesday.
Short Term:
| Madera 39/50/38/49 | Reedley 39/51/38/48 | Dinuba 38/49/38/48 | |
| Porterville 40/50/38/49 | Lindsay 38/51/37/49 | Delano 40/51/38/49 | |
| Bakersfield 42/52/39/50 | Taft 42/51/39/49 | Arvin 41/52/38/48 | |
| Lamont 41/52/39/49 | Pixley 39/51/38/50 | Tulare 38/49/38/48 | |
| Woodlake 38/50/38/49 | Hanford 40/50/38/48 | Orosi 37/50/37/48 | |
Winds: Winds through the evening hours will be out of the southeast at 10 to 15 MPH with stronger gusts. After midnight and through the midmorning hours, winds will increase out of the southeast to 15 to 35 MPH with stronger gusts possible, especially along the west side and from Fresno County north. In Tulare County, winds will be out of the east or southeast at 10 to 20 MPH with local gusts to 30 MPH.
Here we go with Kern County. It’s possible that late tonight and for a time Wednesday morning, winds will increase out of the south or southeast possibly exceeding 50 MPH near the base of the Tehachapi Mountains and possibly exceeding 35 MPH as far north as Oildale. Later Wednesday morning through Thanksgiving, winds will be mainly out of the southeast at 10 to 20 MPH with lighter gusts.
Winds Thursday night and Friday will be out of the northwest at 10 to 15 MPH, diminishing Friday evening.
Rain: Precipitation is advancing rapidly over northern and north central California and will spread over the valley this evening. Expect periods of rain later tonight through Wednesday night with a chance of thunderstorms Wednesday afternoon and evening which will be accompanied by localized heavy rain and hail. Showers will continue Thursday and Thursday night with a chance of thunderstorms again Thursday afternoon and evening. We’ll keep a small chance of showers in the forecast for Friday morning as the low begins to shift into the interior west.
Rainfall amounts are always a big challenge during strong winter storms. A rain shadow will develop along the lee side of the Coast Range and even more so over the valley portion of Kern County. Rainfall amounts in western Fresno and Kings Counties will probably tally up to .25 to .33 during this event. In Madera County, eastern Fresno and eastern Tulare Counties, we’ll stick with .50 to .75. over the valley portion of Kern County, about .25 is plausible. With a chance of thunderstorms Wednesday and Thursday afternoons, heavier amounts will occur on a localized basis. We should see a dry slot Friday afternoon into early Saturday. models are too inconsistent this afternoon to really feel confident regarding the chance of rain over the weekend and into the early part of next week. If we get a coastal hugger the way some models indicate, the possibility of showers will be high. However, some models show the center of the low just far enough off shore to reduce the chance of rain, especially south of Fresno County. For now, we’ll just go with a chance of showers Saturday through Sunday night with a small risk of showers Monday and Tuesday.
It spears Wednesday and for a few days thereafter, dry weather will return which no doubt will lead to fog and low clouds.
Frost Discussion: All locations will be above freezing tonight and will remain above freezing through Thursday. There is a small chance of local frost Friday if skies clear in a timely manner. For now, this appears doubtful. There may be a short window for clearing skies Friday night through Saturday morning which could lower temperatures into the upper 20s to the lower 30s. after Saturday morning, it appears cloud cover will again be on the increase. By the second half of the weekend, a westerly flow will take over, moving warmer air in aloft and keeping temperatures above 32. For now, there is no configuration indicating a troublesome pattern ahead.
Next report: Wednesday morning/November 27