November 24, 2019
Summary: Temperatures this afternoon are very close to where they’ve been the past several days and are running in the mid to upper 60s as of 1:00pm. The latest freezing level over Oakland is 12,700 feet. It will be fun to watch that plummet as the week progresses. A rapidly moving inside slider will barrel through the Pacific Northwest and into the Great Basin and Rocky Mountain region Monday, spreading snow into those regions. Currently, there is a weak ridge of high pressure over Oregon and northern California which will be displaced off shore by that system to our east.
A rapidly intensifying low pressure system will dive southward right along the British Columbia coast. It varies from model to model, but basically, the center of circulation should be perhaps 100 miles west of Medford, Oregon by Tuesday evening. Surface models continue to show tightly wound isobars, or lines of equal pressure, around the low over Oregon and northern California. Northern California should take quite a battering from strong winds Tuesday night and Wednesday morning.
Winds will also pick up out of the southeast later Tuesday night and Wednesday morning in the valley. However, since the center of circulation will remain in southern Oregon or extreme northern California, winds will not be as strong as they could have been. Still, winds in the 15 to 25 MPH range with stronger gusts are likely along the west side. The chance for a high wind event in Kern County has definitely been reduced, but we’ll keep a chance of that occurring in the forecast just in case.
The first showers could reach Fresno County sometime Tuesday night. As the pool of very cold air and strong mid and upper level dynamics settle in over the area, periods of rain will be produced Wednesday and Wednesday night. the orographics along the Sierra Nevada will be excellent as the jet stream flanks underneath the low and moves in from the southwest. The fact that the Sierras are perpendicular to this system means that moisture laden flow of air will be lifted, producing copious amounts of higher elevation snow. For that same reason, as the air descends on the west side of the valley and down in Kern County, a strong rain shadow will develop, reducing precipitation amounts.
As the coldest air begins to arrive Thanksgiving Day, we’ll see snow levels drop like a rock, possibly as low as 1,500 to 2,500 feet Thursday night and early Friday. If there are breaks in the cloud deck either Wednesday or Thursday afternoon, there will be a chance of isolated thunderstorms with localized heavy rain and small hail. Even a cold air funnel cloud would not be a total shock.
By Friday morning, the low will begin to open up with the main energy moving into the Great Basin. There will be a chance of mainly widely scattered showers Friday morning, but Friday will definitely see improvement in our weather. Dry weather should return Friday afternoon and more than likely will last through the weekend. Models are still showing the formation of a large area of low pressure off the northern California coast. Most now, however, show it far enough off shore for precipitation to not be a factor in the valley. Some models do show it moving inland about the 5th, leading to a chance of several storms moving into California. We’ll see if that pans out.
Forecast: Other than some high clouds at times and patchy late night and early morning fog, it will be mostly clear through Monday night. becoming breezy along the west side Monday afternoon and evening. Increasing cloudiness Tuesday. A chance of showers Tuesday night, mainly north of Fresno County. Periods of rain Wednesday through Thanksgiving with a chance of isolated thunderstorms either day. Showers Thursday night with very low snow levels in the surrounding mountains. A chance of showers for a time Friday morning, otherwise it will be partly cloudy for a time Friday through Saturday morning. Partly cloudy Saturday night through Sunday with areas of night and morning fog and low clouds.
Short Term:
| Madera 34/61/31/53 | Reedley 35/63/32/54 | Dinuba 36/63/31/54 | |
| Porterville 35/63/32/55 | Lindsay 35/62/31/54 | Delano 38/63/33/54 | |
| Bakersfield 41/62/38/54 | Taft 44/62/40/54 | Arvin 39/62/34/55 | |
| Lamont 38/63/34/55 | Pixley 36/63/32/54 | Tulare 34/62/31/53 | |
| Woodlake 35/63/31/54 | Hanford 37/63/32/54 | Orosi 35/63/30/54 | |
Winds: Winds tonight and for a time Monday morning will be at or less than 6 MPH with extended periods of near calm conditions. Late Monday morning through Monday evening, winds in Kings County and western Fresno County will increase out of the northwest to 10 to 20 MPH and 5 to 15 elsewhere. Winds Tuesday morning will be out of the southeast at 8 to 15 MPH, increasing to 15 ot 25 MPH later Tuesday evening and 15 to 30 MPH with stronger gusts after midnight Tuesday night through Wednesday morning. Strongest gusts will be along the west side. It’s possible later Tuesday night and Wednesday morning gusts in excess of 50 MPH are possible near the base of the Tehachapi Mountains and 35 MPH as far north as Bakersfield. Winds Wednesday afternoon through Thursday will be mainly out of the southeast at 10 to 20 MPH with stronger gusts at times.
Rain: There will be a chance of rain after midnight Tuesday night from Fresno County north. Periods of rain will be likely Wednesday through Thanksgiving Day with showers Thursday night and snow down into the lower foothills. There will be a chance of showers for a time Friday morning, becoming partly to mostly cloudy Friday afternoon through Saturday morning. Partly cloudy skies Saturday afternoon through early Sunday with areas of low clouds and fog are likely.
It still appears rainfall amounts from late Tuesday night through Friday morning could be between .50 to .75 along the east side, mainly from northern Tulare County northward. On the west side, the strong rain shadow will eat up tallies, so .25 is likely there with locally more. In Kern County, up to .25 seems plausible.
Dry weather will return Friday afternoon through the weekend and at least the first few days of next week. Some models suggest another active pattern will set up about December 5.
Frost Discussion: All locations will be above 32 tonight but at or slightly above in river bottom and like locations. Assuming clouds have not arrived by Tuesday morning, temperatures then could be 1 to 3 degrees colder. This is due to gusty, northwesterly winds mainly down the west side which would lower dew points possibly into the mid to upper 20s along the west side and low to mid 30s elsewhere. Currently, it seems likely coldest locations will drop to 28 to 30 degrees with many locations in the low 30s.
Readings Wednesday and Thursday will be above freezing, but even with the storminess, coldest locations will dip into the mid 30s. Upper 20s and lower 30s are possible Friday and Saturday mornings but not likely as I would anticipate there will be plenty of clouds along the back side of this storm. By Sunday and Monday, readings could be in the upper 20s to lower 30s, however there’s a reasonable chance clouds and fog will be fairly widespread over portions of the valley. It’s also possible higher clouds may increase due to a developing low off the northern California coast. The good news is, there’s still no pattern which would threaten a hard freeze at this time. Nevertheless, we are entering into a period of time with below average temperatures.
Next report: Monday morning/November 25