November 7, 2018
Summary: A trough of low pressure will dive southward through the interior west tonight and Thursday followed quickly by building surface high pressure which will peak Thursday night and Friday morning. In the meantime, upper level high pressure will build farther north, eventually into the Yukon Territory of Canada over the weekend. This will turn the winds aloft out of the north/northeast. It will also enhance the off shore flow. Gusty Santa Ana winds will blow through the Tehachapi Mountains Thursday afternoon through Friday, possibly reaching the valley floor. The best chance of this occurring will be Thursday afternoon through Friday morning when the off shore flow will be at its pinnacle. This could warm things up over the Kern County portion of the valley floor, possibly lowering dewpoints down into the 20s south of the Tulare County line.
Further north, that cooler and much drier air will begin to mix down, causing dewpoints to possibly lower into the upper 20s and lower 30s by Saturday morning. With very dry air, the atmosphere will have an excellent ability to radiate its heat skyward, thus quite chilly overnight low temperatures will occur over the weekend. Even Friday morning, if this air mass arrives in time, could be quite chilly.
Over the weekend, a massive ridge will build off the Pacific coast, jutting northward into the Yukon Territory of Canada. This will allow a winter type blast of cold air east of the Rockies and into the Midwest where winter will make an early start. We may get a recharge of dry air Sunday into Monday as the winds aloft again tilt off shore.
Daytime temperatures will be very pleasant, however, as that high will be right overhead next week, allowing at least warmer locations to see temperatures into the mid 70s. medium range models again do not show much hope of a raindrop or two falling out of the sky, so for now we’ll maintain a dry forecast longer term, as well.
Forecast: Outside of occasional high, thin clouds, it will be clear through Saturday. Generally clear skies will continue Saturday night through Wednesday.
Short Term:
| Madera 40/70/34/70 | Reedley 39/71/34/71 | Dinuba 39/70/33/71 | |
| Porterville 40/72/34/70 | Lindsay 38/72/33/71 | Delano 43/71/35/71 | |
| Bakersfield 49/72/40/73 | Arvin 46/72/41/75 | Taft 52/72/45/73 | |
| Lamont 47/72/41/74 | Pixley 40/72/34/71 | Tulare 38/70/33/71 | |
| Woodlake 40/71/35/71 | Hanford 40/70/34/72 | Orosi 39/71/33/71 | |
Winds: Winds tonight and through at least midmorning Thursday will be generally less than 10 MPH with long periods of near calm conditions. Later in the day Thursday through Friday, there is a chance of Santa Ana type winds moving downslope and possibly reaching the valley floor. Wind gusts in excess of 40 MPH will be possible near the base of the Tehachapi Mountains. On some occasions, these winds can reach as far north as Oildale with near calm conditions north of that line. These winds always play an interesting cat and mouse game, so I put the chance of these winds reaching the valley floor at 30% to 40% or so. The time of greatest risk will be Thursday afternoon through Friday morning with decreasing winds Friday night and light winds returning over the weekend. North of Kern County, winds will remain generally less than 10 MPH with periods of near calm conditions tonight through the weekend.
Rain: Expect dry conditions for at least the next week to ten days.
Frost Information: The first tricky frost forecast of this winter season is now upon us. A colder and very dry air mass will invade much of the western U.S. Thursday and Friday. There’s a chance these very dry winds could reach the valley floor in Kern County, meaning dew points could fall into the teens and twenties, but that’s only if these Santa Ana winds reach the valley floor. Further north, the change of air masses will be very subtle with dry air aloft beginning to mix down to the valley floor due to strong easterly winds blowing above central California. Dew points could drop into the mid 20s to the mid 30s. It’s always difficult to determine just what Mother Nature has in store, however. A few locations could tease with the 30 degree mark as early as Friday morning. One model places Porterville at 35 while another says 34. If this occurs, riverbottom and similar locations would be in the 29 to 31 degree range, especially Saturday and Sunday mornings. I must emphasize this is no great freeze threat. In fact, the first frost of the season generally occurs about this time, so nothing out of the ordinary here.
Daytime temperatures will recover into the mid 70s by Monday as a strong ridge builds overhead, but with dry air trapped on the valley floor, overnight lows in colder locations will still dip into the 30s. If by some miracle we have precipitation preceding this air mass, temperatures would probably be two to four degrees warmer.
Lows Tonight:
All locations will be above freezing tonight.
Next Report: Thursday morning, November 8