December 2, 2017
Summary: You can certainly tell where the pool of cold air is this afternoon. The freezing level over Medford, Oregon has plummeted to 2,600 feet while in our neck of the woods, VAFB reported a freezing level of 12,600 feet. The center of the cold low is now just west of Portland, Oregon and it will begin to swing inland tonight, spreading precipitation over parts of northern California and the Sierra Nevada possibly as far south as Yosemite. However, the path of this storm will take it through the northern Great Basin and northern Rockies.
Interestingly enough, at the tail end of this trough, a secondary low will develop Monday over the Great Basin then retrograde Monday night and Tuesday to a position right over central California. This will tug colder and very dry air into northern and central California, setting the stage for a possible hard freeze. By Tuesday night and Wednesday, the low will drift southeastward off shore, creating a north/northeast flow aloft over California. A surface high will build over the Great Basin, creating a rather robust off shore flow which will aid in drying out the lower level of the atmosphere.
By Wednesday, a massive upper high will cover the eastern Pacific off shore and the western one-third of the U.S. This high will ridge northward all the way into the Yukon Territory of Canada, creating a massive blockade which will prevent any precipitation from reach California and even the Pacific Northwest. This high will be a semi-permanent fixture for at least the next week but even medium range models are maintaining that the high will be over the west for a continuation of dry weather.
Forecast: Mostly clear to occasionally partly cloudy tonight with variable high clouds Sunday. Becoming mostly clear Sunday night. mostly clear to occasionally partly cloudy Monday. Clearing Monday night. mostly clear Tuesday through Saturday.
Short Term:
| Madera 37/61/30/56 | Reedley 38/63/31/57 | Dinuba 36/62/29/56 | |
| Porterville 38/63/30/57 | Lindsay 35/62/29/56 | Delano 39/63/31/57 | |
| Bakersfield 42/62/36/58 | Arvin 36/63/33/56 | Taft 45/62/37/58 | |
| Lamont 42/64/39/58 | Pixley 38/63/31/58 | Tulare 38/62/30/57 | |
| Woodlake 37/61/30/57 | Hanford 38/63/30/57 | Orosi 36/62/29/56 | |
Winds: Winds will be less than 10 MPH tonight with periods of near calm conditions. Winds will increase Sunday afternoon out of the northwest at 10 to 20 MPH with local gusts to 30 MPH possible along the west side. Winds will decrease Sunday night, becoming light and variable Monday with some possible northerly winds of 5 to 15 MPH along the I5 corridor. Expect winds of less than 10 MPH Monday night through midweek.
Rain: Expect dry weather for at least the next seven to ten days.
Frost Information: Forecast models this afternoon are showing some minor changes to the overall pattern which will send temperatures into freeze conditions Tuesday morning, if these changes hold, with below freezing temperatures possible as early as Monday morning. Currently, the cold upper low is off the Oregon coast and will rapidly shift eastward into the northern Rockies and the northern Great Basin. A secondary low is now projected to form over the Great Basin Monday then retrograde westward right over central California Monday night and Tuesday then off shore Tuesday night. this low will bring a cold, dry pool of air over central California, aiding the overnight low temperatures. Dew points will fall to possibly dangerous levels Tuesday and Wednesday, allowing for a hard freeze. One model places Porterville at 26 degrees Tuesday morning while others were only slightly warmer. This could place low lying frost pockets down to 22 to 25 with most other locations between 26 and 30. I do look for a string of cold nights as a shallow layer of dry air will be trapped on the valley floor under a strong upper high.
Daytime highs will begin to moderate at midweek, but with the air being so dry, overnight lows will continue to be well below freezing right into the coming weekend. In fact, this high will remain in place for the next week and some models indicate for the next ten days, allowing very dry weather with strong radiational cooling each night to continue.
Lows Tonight:
| Terra Bella
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Porterville
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Ivanhoe
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Woodlake
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| Strathmore
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McFarland
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Ducor
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Tea Pot Dome
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| Lindsay
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Exeter
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Famoso
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Madera
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| Belridge
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Delano
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North Bakersfield
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Orosi
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| Orange Cove
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Lindcove
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Lindcove hillside
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Sanger River Bottom
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| Root Creek
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Venice Hill
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Rosedale
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Jasmine
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| Arvin
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Lamont
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Plainview
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Mettler
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| Edison
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Maricopa
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Holland Creek
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Tivy Valley
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| Kite Road South
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Kite Road North
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Next Report: Sunday morning, December 3