November 25, 2019
Summary: There is a rapidly moving wave of low pressure sliding through the interior west, resulting in tight pressure differences. As a result, strong gusty winds are occurring along the west side of the valley. Lemoore is reporting gusts to 40 MPH. even on the east side, Madera is reporting gusts to 30 MPH, Merced 32, while Fresno has sustained winds of 23 MPH. These winds will slowly die off this evening and become generally light, at least towards the center and east side of the valley, by about midnight.
A rapidly advancing low pressure system is diving southward off the coast of the Pacific Northwest. The center of circulation is currently west of Washington and by later Tuesday night and early Wednesday, most models predict the center of circulation will be somewhere near Crescent City. It seems like we’ve been talking about isobars for the past week or so, but they are certainly tightly wound around this low and will result in strong winds for northern California and, to a lesser extent, central California. The wild card for now is Kern County and whether or not they’ll experience a high wind event. This is discussed in more detail below.
This is a very dynamic winter storm which will center over Oregon and northern California. Central and southern California will be on the southern flank of the storm with a moist jet stream moving in from the Pacific. Where mountain ranges interfere with this flow, heavy precipitation will be the result. Two to three inches is expected over the higher elevations of the Sierra Nevada with possibly 3 to 5 inches over the San Gabriel and San Bernardino mountains. Strong rain shadows will be prevalent along the west side and in Kern County through at least Wednesday.
Precipitation will turn more showery Thanksgiving Day before this storm winds down on Friday. A pool of very cold air aloft will move in overhead Wednesday and Thanksgiving Day, so if any breaks in the overcast occur, isolated thunderstorms with their heavy rain and small hail will be possible.
Models had earlier projected skies would clear this coming weekend. However, the past model runs have done a complete flip flop. They now indicate a low will be off the northern California coast Saturday, spreading precipitation over northern and central California. Some models show this system doing a slow roll parallel to the California coast, moving inland through southern California but not until next Tuesday. If this turns out to be the case, active weather will begin again Saturday with the chance of precipitation all the way through Tuesday. This storm is also much milder than the event we’re expecting soon with much higher snow levels.
Forecast: mostly clear tonight. increasing cloudiness later Tuesday with a slight chance of showers from Fresno County north later Tuesday afternoon. Periods of rain Tuesday night through Wednesday night with a chance of isolated thunderstorms Wednesday afternoon and evening. Showers Thanksgiving and Thursday night with a renewed chance of isolated thunderstorms Thursday afternoon with snow possibly down into the lower foothills. A rapidly diminishing chance of showers Friday morning. Becoming partly to mostly cloudy Friday afternoon into Saturday morning. The chance of showers will again increase Saturday afternoon, becoming likely again Saturday night and at times through Monday.
Short Term:
| Madera 30/56/40/52 | Reedley 31/56/41/52 | Dinuba 29/55/39/51 | |
| Porterville 31/56/41/52 | Lindsay 30/55/40/53 | Delano 33/56/42/52 | |
| Bakersfield 35/56/43/54 | Taft 40/56/43/54 | Arvin 33/57/42/54 | |
| Lamont 33/56/43/55 | Pixley 31/56/40/52 | Tulare 30/54/40/51 | |
| Woodlake 31/56/41/53 | Hanford 32/55/40/53 | Orosi 30/55/40/53 | |
Winds: As of 1:00pm, winds were gusting to between 30 and 40 MPH along the west side and anywhere from 20 to 32 MPH in eastern Fresno and Madera Counties. Even Porterville and Bakersfield had sustained winds between 10 and 20 MPH. These winds will slowly diminish this evening and will become generally light after midnight, especially along the east side and up the center of the valley. In Kings County and western Fresno County, winds will be generally out of the northwest between 5 and 12 MPH.
Beginning Tuesday afternoon, winds will completely reverse and will be out of the southeast at 10 to 20 MPH with stronger gusts, increasing to 15 to 35 MPH Tuesday night and Wednesday morning along the west side and from Fresno County northward. In Tulare County during that time frame, winds will be out of the east or southeast at 10 to 20 MPH with stronger gusts. In Kern County, this will definitely be a teaser. If the center of the low were 200 to 300 miles further south, a high wind event would be almost assured. However, this time it appears the center of circulation will be somewhere near Crescent City for definite wind challenges over northern California. Even so, there is still the possibility out of the south or southeast potentially eclipsing 50 MPH near the base of the Tehachapi Mountains, possibly eclipsing 30 MPH as far north as Oildale.
Winds Wednesday afternoon through Thanksgiving Day will be generally out of the southeast at 10 to 20 MPH at times with stronger gusts near showers and on Thursday night and Friday, winds will be mainly out of the northwest at 10 to 20 MPH.
Rain: The chance for rain will begin to increase from Fresno County north by late Tuesday afternoon, spreading rapidly southward during the evening. Periods of rain are likely Tuesday night through Wednesday night. with strong, gusty winds and strong west/southwest winds aloft, rain shadows will definitely develop along the west side and in the southernmost portion of the valley. The rain will turn to showers Thanksgiving Day with very low snow levels, possibly down into the lower foothills with a rapidly diminishing chance of showers Friday morning.
Rainfall amounts in Madera County, eastern Fresno County and eastern Tulare County from roughly Porterville northward should be between .50 and .75. On the west side, due to rain shadows, only upwards of about .25 is likely. Over the valley portion of Kern County, about the same amount can be expected.
Models this afternoon are continuing the trend of a low pressure system off the northern California coast Saturday night and Sunday, spreading precipitation over northern and central California and renewing the likelihood of rain. Some models show this low moving just off the central California coast then indicate it will move in through southern California but not until Tuesday of next week. This means we could see rain any day from Saturday through late Tuesday of next week.
Frost Discussion: Winds this afternoon towards the center and west side of the valley have been gusting to between 30 and 40 MPH.As a result, dew points have fallen into the mid to upper 20s on the west side of the valley. As of 1:00pm, the dew point at Fresno had fallen to 31 while dew points are still in the lower 40s over much of Tulare and Kern Counties. Frost prediction tonight will be a chaotic challenge as wind conditions and mixing will play large roles. Where winds stay up for most of the night, especially along the center and west side, most locations will remain above freezing. However, in those traditionally cold low spots, where winds become calm, strong radiational cooling will set up with readings down to 28 to 30 MPH. When all is said and done, most locations should bottom out in the 30 to 35 degree range, possibly near 40 where winds stay up.
As it turns out, this may be the only frost challenge of the week. The pattern from Tuesday night through Friday morning will be very active with periodic rain and snow down to very low elevations. On Friday morning, it’s possible breaks could occur in the cloud cover, in which case upper 20s and lower 30s would be possible in colder locations. However just as quickly as the clouds move eastward, a new low will be approaching the northern California coast, spreading clouds over northern and central California Saturday afternoon. Some models show the low moving right along the California coast, eventually moving inland through southern California, but not until Tuesday of next week. So, with storm number two resulting in cloud cover and rain, plus the fact it will be a milder system anyway, after tonight, frost can almost be eliminated for a time from the forecast.
Lows Tonight:
| Terra Bella
31 |
Porterville
30 |
Ivanhoe
29 |
Woodlake
30 |
| Strathmore
30 |
Mcfarland
31 |
Ducor
33 |
Tea Pot Dome
31 |
| Lindsay
30 |
Exeter
30 |
Famoso
32 |
Madera
30 |
| Belridge
31 |
Delano
33 |
North Bakersfield
32 |
Orosi
30 |
| Orange cove
30 |
Lindcove
30 |
Lindcove Hillside
35 |
Sanger River Bottom
28 |
| Root Creek
28 |
Venice Hill
30 |
Rosedale
33 |
Jasmine
31 |
| Arvin
AF |
Lamont
AF |
Plainview
30 |
Mettler
AF |
| Edison
AF |
Maricopa
32 |
Holland Creek
AF |
Tivy Valley
31 |
| Kite Road South
Af |
Kite Road North
32 |
AF=Above Freezing
Next report: Tuesday morning/November 26