November 21, 2019
Summary: It is nice to observe a visible satellite image with a mantle of snow over the southern
Sierra Nevada and even the Kern County mountains. The low responsible for the snow is now in northwest Arizona and it continues to pull off to the east. In the meantime, a new cut off low will develop Friday and Friday night several hundred miles off the central coast then will drift southward, allowing a rather flat ridge of high pressure to build eastward into northern California and Oregon, creating a weak off shore flow this coming weekend. Temperatures will warm into the mid 60s Friday through Monday as the area of high pressure off shore is rather weak.
The high will begin to move off shore Monday as a weak low dives southeastward from the Pacific Northwest into Utah, Wyoming, and Colorado. That will open the gate for a developing low in the Gulf of Alaska to slide south/southeast, positioning over northern California late Tuesday night and Wednesday. one element of this system is the amount of isobars wrapping around the low.
Isobars are lines of equal surface pressure and the tighter they are, the greater the potential for strong winds. That’s what’s showing up over northern and central California, especially for early Wednesday morning. This would create strong, gusty, southeast winds up the valley with a chance of strong, gusty downslope winds off the Kern County mountains and onto the valley floor. We are still six days out on this, so this is very much in the chance category, but if the configuration turns out to be the way some models are suggesting, strong winds could become a problem, especially in Kern County. The other element of this system is rain, a possibility that seems to increase each day. Other models are falling in line with this, so we can almost say there’s a likelihood of precipitation from late Tuesday night at times through Thursday. This will also be a cold system with relatively low snow levels.
As this storm moves into the Rockies Friday into early Saturday, most models are still showing a northwest flow. This is a cold flow, but it could be colder. More in the frost discussion below.
Forecast: Mostly clear skies with areas of night and morning fog and low clouds through Monday night. increasing cloudiness Tuesday. An increasing chance of rain Tuesday after midnight with periods of rain and strong, gusty winds Wednesday and Wednesday night. periods of rain continuing Thanksgiving.
Short Term:
| Madera 34/65/34/65 | Reedley 36/66/36/65 | Dinuba 33/63/33/64 | |
| Porterville 35/65/35/66 | Lindsay 34/64/34/65 | Delano 37/65/37/65 | |
| Bakersfield 42/64/44/65 | Taft 46/64/46/65 | Arvin 39/64/38/65 | |
| Lamont 39/65/38/65 | Pixley 36/64/36/65 | Tulare 33/65/34/64 | |
| Woodlake 34/64/34/65 | Hanford 37/65/37/66 | Orosi 34/65/34/66 | |
Winds: Winds will be generally at or less than 6 MPH with periods of near calm conditions through Sunday. Models are suggesting a strong winter storm will center possibly over northern California late Tuesday night and Wednesday. the surface model indicates there are lots of isobars, or lines of equal pressure. The more of these lines there are, the greater the risk of strong winds, especially in Kern County. There is a chance, and for now it’s just a chance, of a strong wind event over the valley portion of Kern County. There will no doubt be tweaks to this forecast between now and then, but it looks quite interesting on paper.
Rain: Dry weather will prevail through Tuesday. More models are falling in line this afternoon on the possibility of rain for the period between midnight Tuesday and Thanksgiving. For now, it doesn’t look like a pineapple connection will be involved, but it still looks pretty robust at this juncture. We could see some substantial precipitation over the mountains. Strong winds may also be associated with this system, which always reduces rainfall amounts, especially on the west side and in Kern County. This is still evolving, so we’ll keep you posted as new developments occur.
Frost Discussion: From Friday morning through Monday morning, the very coldest locations may drop to around the freezing mark with most locations between 33 and 40, depending upon topography. Dew points will remain in the 40s, so look for pockets of fog to form each morning, especially in Kern County where the ground is soaking wet. Above freezing conditions will prevail Tuesday morning through Thursday morning due to heavy cloud cover associated with a possibly strong weather system.
Most models show a north/northwest flow at the mid and upper levels of the atmosphere Friday and Saturday, spreading colder air over central California for some possible upper 20s and lower 30s. the first week in December also looks cold. For now, there is little evidence of a true freeze configuration occurring, but even the two week model from the 29th through the 5th is pointing to below average temperatures.
Next report: Friday morning/November 22