December 30, 2018
Summary: A fast moving Canadian low pressure system continues to dive southward into the interior west. The center of this storm’s circulation is currently over Idaho with the bottom side of the trough invading northern Nevada. In the meantime, upper level high pressure covers the eastern Pacific with a ridge extending into western Canada. As the low moves southward, the western side of it will slide right down the spine of the Sierra Nevada. With a strong off shore flow developing, it’s even possible Mono type winds could blow down the Sierra Nevada, mainly through canyons from Tulare County northward. As the low passes just to our east, some increase in clouds should begin to appear, especially after midnight. By sunrise, it’s possible we could see some upslope clouds against the Kern County mountains. If this occurs, those clouds will be short lived as colder and drier air surges down the valley in the form of gusty north to northwest winds along the west side.
By Monday evening, the low will be centered over Arizona with a northeast to southwest oriented flow aloft. That does not bode well for low temperatures Tuesday and Wednesday mornings. More in the frost discussion below.
Fortunately, this pattern will be short lived. As early as Wednesday night, a flat zone of upper level high pressure will extend from the eastern Pacific all the way across California and into the interior west. The storm track will be sliding over the top of the high and into the Pacific Northwest.
By Friday, a trough of low pressure will be approaching the northern California coast. At about the same time, models are still showing a subtropical batch of air moving northeastward, but mostly into Baja, Arizona, and New Mexico. Even so, as the trough moves through, we could pick up some precipitation late Saturday and Sunday.
Forecast: Mostly clear this evening. Partly cloudy after midnight. Mostly clear to partly cloudy New Year’s Eve and New Year’s Day. Mostly clear and cold Tuesday night through Thursday. Mostly clear and warmer Friday and Friday night. increasing clouds Saturday with a small chance of rain Saturday night and Sunday.
Short Term:
Madera 30/52/27/52 | Reedley 30/53/27/53 | Dinuba 28/51/26/52 | |
Porterville 30/52/27/52 | Lindsay 29/53/26/53 | Delano 31/53/27/52 | |
Bakersfield 35/52/30/53 | Taft 37/54/30/53 | Arvin 31/52/27/53 | |
Lamont 31/52/28/53 | Pixley 29/52/27/53 | Tulare 28/52/26/52 | |
Woodlake 30/52/27/53 | Hanford 31/53/28/52 | Orosi 29/52/26/52 |
Winds: Winds will be generally less than 8 MPH tonight with periods of near calm conditions. Winds Monday through Tuesday will increase, mainly along the west side, to 15 to 25 MPH with stronger gusts possible along the Interstate 5 corridor. Elsewhere, winds will generally be in the 5 to 10 MPH range except possible from Fresno north where winds may be in the 10 to 20 MPH range with stronger gusts. Winds Tuesday night and Wednesday will be generally at or less than 8 MPH with periods of near calm conditions.
Rain: Expect dry weather to continue through at least Friday night. a trough of low pressure will be moving through late Saturday and Sunday for a chance of rain. To our south, some models indicate a batch of subtropical moisture will move northeastward, but they now show it moving into Baja and then Arizona. Even so, with that trough moving through, a chance of showers is possible.
Frost Discussion: A cold trough of low pressure continues to dive southward into the interior west. The southern portion of the trough has now entered northern Nevada. Clouds are increasing over the Sierra Nevada north of Yosemite and they will spread southward during the night. in the meantime, a strong surface off shore flow will develop Monday as the winds aloft become out of the northeast. We should see winds begin to pick up along the west side, possibly even Mono winds down the west facing slopes of the Sierra. All of this will allow another marginally colder air mass to move in, resulting in subfreezing temperatures beginning Monday night and lasting through at least Wednesday night. for now, Tuesday and Wednesday mornings are of the most concern.
I do anticipate widespread mid to upper 20s. in fact, one model for Wednesday morning shows a low of 27 for Porterville while another indicates 26. That would put the coldest locations possibly down into the lower 20s. it’ll be tomorrow before we can tweak with a high degree of certainty. For now, I’ll go with temperatures down to 23 to 26 in the coldest unprotected locations with mid to upper 20s elsewhere. Winds and possibly even cloud cover could slow the process down, but for now I believe this is the most likely scenario.
I look for a few degrees of moderation Thursday morning as high pressure bursts in from the west, setting up a westerly flow through the western U.S. This will move much warmer air in aloft and, with an on shore flow, dew points will rise accordingly. Nothing on longer term models suggests cold air masses moving into California through at least the middle of the month.
The inversion tonight will be decent with temperatures at 34 feet from 4 to 7 degrees warmer at most locations.
Lows Tonight:
Terra Bella
30 |
Porterville
30 |
Ivanhoe
28 |
Woodlake
29 |
Strathmore
29 |
McFarland
28 |
Ducor
31 |
Tea Pot Dome
30 |
Lindsay
28 |
Exeter
28 |
Famoso
29 |
Madera
30 |
Belridge
29 |
Delano
30 |
North Bakersfield
32 |
Orosi
28 |
Orange Cove
29 |
Lindcove
28 |
Lindcove Hillside
Af |
Sanger River Bottom
27 |
Root Creek
28 |
Venice Hill
30 |
Rosedale
31 |
Jasmine
30 |
Arvin
32 |
Lamont
31 |
Plainview
29 |
Mettler
Af |
Edison
32 |
Maricopa
28 |
Holland Creek
33 |
Tivy Valley
29 |
Kite Road South
33 |
Kite Road North
30 |
AF=Above Freezing
Next report: Monday morning/December 31