November 15, 2017
Summary: A very moist feed of mid Pacific air better known in recent history as an atmospheric river of air continues to move into northern California this afternoon. In the meantime, in central California moisture is becoming more abundant and lift over the Sierra Nevada is already generating precipitation as far south as northern Tulare County. Over the Coast Range and along the west side of the San Joaquin Valley, standing wave clouds are clearly visible on satellite imagery. They indicate high wind energy which will create a strong rain shadow in the western and southern portions of the valley. Rainfall amounts will be seriously zapped in those areas, and especially in Kern County which will be lucky to see a tenth of an inch from this event.
As the air continues to moisten up ahead of the front, the upslope effect along the Sierra Nevada should allow rain to spread down the east side of the San Joaquin Valley, reaching Fresno County probably Thursday morning and with the slow movement of the front, Kern County will be lucky to see anything before Friday morning.
Gusty southeast winds will also occur ahead of the front Thursday into early Friday, especially from Fresno County north and along the west side.
The front will gradually dip into southern California, dissipating Friday afternoon and ending any further precipitation for California with the exception of lingering showers over the Sierra. Dry weather will return later Friday afternoon and will last through at least Sunday night before the next AR moves in from the southeast into Oregon and northern California Monday through Tuesday. Models are still showing the rain line remaining just to our north for this event, though a slight chance of showers is possible as far south as Fresno. After Tuesday night, the storm track will be active, but further north, keeping central California in a west/southwest flow aloft through the latter part of next week, at the very least.
Forecast: Slowly increasing clouds tonight. Cloudy Thursday with a chance of rain along the east side of the valley from Fresno County north by midday, spreading into Tulare County later in the afternoon with light showers possible along the west side. Periods of rain late Thursday night and Friday morning with only light showers over the valley portion of Kern County late Thursday night and Friday morning. Mostly cloudy Friday afternoon through Saturday morning with some clearing, mainly along the west side. Partly cloudy Saturday afternoon through Sunday. Increasing cloudiness Sunday night with a small chance of light rain from Fresno County northward Monday through Tuesday, but dry elsewhere. Partly cloudy Wednesday with areas of morning fog.
Short Term:
| Madera 53/70/51/63 | Reedley 54/71/50/64 | Dinuba 53/71/50/62 | |
| Porterville 54/73/52/62 | Lindsay 52/72/51/63 | Delano 54/73/52/64 | |
| Bakersfield 56/76/53/63 | Arvin 55/76/54/64 | Taft 57/75/55/64 | |
| Lamont 56/74/53/63 | Pixley 54/73/52/63 | Tulare 53/70/52/61 | |
| Woodlake 53/71/52/63 | Hanford 54/72/52/63 | Orosi 52/70/50/62 | |
Winds: Winds will be mainly out of the southeast this evening at 5 to 15 MPH with stronger gusts along the west side and from Fresno County north. Winds Thursday and Thursday night will be out of the southeast at 10 to 20 MPH with gusts to near 30 MPH possible along the west side and locally elsewhere. Winds Friday morning will be out of the northwest at 10 to 15 MPH, decreasing Friday night with light winds returning Saturday.
Rain: As expected, precipitation is spreading down the Sierra Nevada and as of the time of this writing, it had reached as far south as Kings Canyon National Park. The main feed of moisture remains in northern California and will only very slow move southward over the next 48 hours with rain spreading down mainly the east side of the valley, reaching Fresno County by late Thursday morning or around midday. Rain will spread into southeast Tulare County later Thursday afternoon or evening and will not reach Kern County until probably Friday morning.
In the meantime, a strong rain shadow will continue for the bulk of this event along the west side and in Kern County. Rainfall amounts along the west side will probably average no m ore than a tenth or two and quite possibly less than a tenth of an inch in Kern County. I wouldn’t be totally shocked to see some locations remain completely dry.
The uplift effect of the Sierra could allow for some generous rains along the east side of the valley from roughly Porterville northward where a quarter to a half an inch is possible with locally more not out of the question, especially from Fresno north.
The action should be over by early to mid afternoon Friday with dry weather Friday night through Sunday night. there’s a small chance of light rain as far south as Fresno County Monday through Tuesday, but models continue to show dry weather south of Fresno County.
Frost Information: A colder air mass will slowly trickle into the area Friday night and Saturday. I do not anticipate anything serious but where skies clear Sunday morning, mid to upper 30s are possible with a chance of lower 30s in those traditional cold spots. This should be a one night stand as clouds will begin to increase ahead of the next system for Monday morning. With a west/southwest flow aloft, a relatively mild pattern will continue for next week, as well.
Next Report: Thursday, November 16