March 2, 2019
Summary: Numerous thunderstorms have broken out, mainly along the east side of the valley and over the Sierra Nevada foothills. A well developed squall line was moving through Madera and Fresno Counties. On radar, it appears much of Fresno County is currently being nailed. There are also a number of cells over Tulare County, mainly right above the foothills. The movement of these storms is only about 20 MPH, so locally very heavy rain is occurring in localized areas. I noticed Madera has recorded .25 in the past hour.
Another very interesting feature on satellite imagery is standing wave clouds covering the western half of the San Joaquin Valley. These clouds indicate strong winds aloft which are, in part, responsible for the thunderstorms. It’s not that unusual to see wave clouds along the west side, but on satellite imagery it’s particularly dramatic this time around.
Showers and thunderstorms will continue through the evening then, as the main body of low pressure finally moves into Nevada during the late evening hours, the showers will come to an end with the exception of the Sierra Nevada where orographic lift will keep the shower machine going through Sunday.
On the valley floor, Sunday and Monday appear dry. We are still closely studying the potential behavior of the next lower latitude storm which will have strong dynamics. The atmospheric river of air we’ve been discussing still shows up on models coming inland from southern Monterey County on the north to LA County on the south, putting Kern County in the bulls eye.
As far as precipitation amounts go, yes, there will be heavy rain under the AR, but heavy rain is also likely elsewhere due to several smaller but dynamically strong systems which will move through Tuesday through Wednesday. Several more impulses will move from west to east across central California Thursday and Friday for at least a 50/50 chance of rain each day.
It appears the trough building out of the Gulf of Alaska we’ve been discussing for next week may actually begin this coming weekend as the first in a series of colder storms is now scheduled to arrive Saturday with a decent chance of much lighter precipitation. Temperatures will begin to fall back possibly as early as Friday but more so as we move into next week as a trough extends from the Gulf of Alaska to California with a dominant northwesterly flow aloft.
Forecast: Scattered showers with more thunderstorms possible through the evening, tapering off into the late evening hours. Partly to mostly cloudy later tonight and Sunday. Partly cloudy Sunday night and Monday. Increasing cloudiness Monday night with a chance of rain after midnight. Rain likely Tuesday through Wednesday, possibly heavy at times. Showers likely Wednesday night with a continuing chance of showers Thursday through Saturday.
Short Term:
| Madera 53/63/46/62 | Reedley 53/64/46/62 | Dinuba 52/63/46/61 | |
| Porterville 53/64/47/62 | Lindsay 53/64/46/61 | Delano 53/65/47/62 | |
| Bakersfield 53/66/47/61 | Taft 54/65/49/62 | Arvin 52/64/47/62 | |
| Lamont 53/65/47/61 | Pixley 53/63/47/62 | Tulare 51/63/47/61 | |
| Woodlake 52/64/47/62 | Hanford 53/63/47/62 | Orosi 52/63/46/61 | |
Winds: Winds through the evening hours will be mainly out of the southwest at 10 to 15 MPH but with local gusts to 30 MPH in the vicinity of thunderstorms. Winds late tonight through Monday will be generally at or less than 12 MPH. later Monday night and Tuesday, winds will be out of the southeast at 10 to 20 MPH with gusts to 30 MPH possible from Fresno north and along the west side.
Rain: Quite a colorful Doppler radar this afternoon as numerous thunderstorms have formed over the eastern side of the valley from Kern County northward, many of which have already swept into the foothills. A squall line of showers and thunderstorms is currently moving through Fresno County. I can count roughly 10 separate cells east of Visalia and southward to the Kern County line. This is quite unusual, to say the least. Scattered showers with possible thunderstorms can be expected through the evening then will taper off in the late evening, ending after midnight with the exception of the foothill and mountain areas where showers will continue through Sunday. On the valley floor, Sunday and Monday will be dry. The chance for rain will begin to increase later Monday night, mainly after midnight, possibly becoming heavy at times towards morning. The long awaited atmospheric river of air continues to show up on paper. Most of the models indicate the bulk of the moisture feed from the tropics will move from southwest to northeast across southern Kings and Tulare counties on the north with Kern County being in the bulls eye. There will be several dynamic impulses moving through Tuesday through Wednesday night. from my chair, it appears even areas outside of the AR will pick up potentially heavy rain. From late Monday night through Wednesday night, one to two inches is possible on the valley floor, especially along the east side and, believe it or not, in Kern County. We have at least a 50/50 proposition for rain Thursday through Friday as more, weaker impulses move in from the west. Models for the coming weekend now look quite different. The first in a series of low pressure systems with origins in the Gulf of Alaska will move into California Saturday for yet another chance of lighter showers. The following week also appears to be active as a broad trough of low pressure extends from the Gulf of Alaska to southern California.
Frost Discussion: All locations will be above freezing for the foreseeable future.
Next report: Sunday morning/March 3