April 11, 2018
Summary: A major weather change is well underway this afternoon. A cold low pressure system is just off the coast of the Pacific Northwest with the associated cold front moving south/southwest off the northern and central California coast. The air behind the system is cold, especially by recent standards, and will result in much cooler temperatures over the next couple days. In fact, Friday morning could see coldest locations brushing with the 32 degree mark. More in the frost discussion below.
Light showers are possible as this system dives rapidly southeastward. Most of the precipitation will be north of Kern County and even as far north as Madera, precipitation amounts will generally be less than a tenth of an inch. I still believe portions of the south valley will remain dry for this event. Large differences in pressure at the surface will develop tonight and Thursday between building high pressure off shore and rapidly falling pressure over the interior west. Add to that, a 150 knot jet stream flanked from northwest to southeast, or pretty much parallel to the San Joaquin Valley, and the recipe is there for the potential for strong gusty winds just about anywhere Thursday with strongest gusts along the west side, especially from western Merced County down into Kings County. The winds will taper off Thursday night with a return to generally light winds Friday.
Upper level high pressure will become reestablished from Thursday afternoon through Sunday evening then will give way to a rapidly moving and relatively cold low pressure system moving into the Pacific Northwest. Its associated frontal system will also dive southeastward through central California Monday and Monday night. Models seem to be more bullish on this system as far as precipitation goes. Another rapid downturn in temperatures will occur behind the front then we’ll swing back the other direction at mid-week. Another front may affect us about Thursday and Thursday night. The seasons are battling each other for dominance at this time and even the latest two week model is indicating the overall pattern will not change much.
Forecast: Increasing cloudiness this afternoon. Light showers spreading down the valley tonight, mainly north of Kern County. Mostly to partly cloudy, breezy, and cooler Thursday morning, becoming partly cloudy in the afternoon. Mostly clear Thursday night and Friday with the possible exception of Kern County and southeastern Tulare County which could remain locally partly to mostly cloudy. Mostly clear Friday afternoon through Sunday night. Increasing cloudiness Monday with light showers becoming likely Monday afternoon and night. Partly cloudy Tuesday. Becoming mostly clear Tuesday night and Wednesday.
Short Term:
| Madera 44/63/38/69 | Reedley 45/65/39/68 | Dinuba 44/64/37/68 | |
| Porterville 45/65/38/70 | Lindsay 44/64/37/69 | Delano 48/65/40/70 | |
| Bakersfield 48/63/43/69 | Arvin 47/63/42/70 | Taft 51/65/44/71 | |
| Lamont 47/64/42/70 | Pixley 46/65/39/70 | Tulare 45/64/37/68 | |
| Woodlake 45/65/39/69 | Hanford 46/64/40/70 | Orosi 44/64/39/69 | |
Winds: Winds will be mainly out of the northwest at 10 to 15 MPH this evening, increasing to 15 to 25 MPH late tonight through early Thursday evening. Gusts to near 40 MPH are possible, especially in western Fresno, Madera, and Kings Counties but locally elsewhere. Winds will die off to around 5 to 15 MPH later Thursday night with winds of generally less than 12 MPH Friday through Sunday. Elevated winds can also be expected Monday afternoon through Tuesday.
Rain: A cold front will move rapidly down the valley tonight. There does seem to be enough jet stream support and cold air to sustain light showers, mainly along the east side and north of Kern County, but locally elsewhere. Amounts of precipitation will not be impressive with most locations recording less than a tenth of an inch with some locations remaining dry, mainly in the south valley. Dry weather will return Thursday with the possible exception of some upslope showers near the base of the Kern County mountains Thursday morning. Dry weather will continue through Sunday night then another rapidly moving cold front will make its way through the valley Monday afternoon and night. Models this afternoon are a bit more hopeful for the chance of showers with this system. The fact that it will be moving quickly will reduce the chance of anything significant. Models also seem to be swaying back to another frontal system moving through the area later next week. For now, it looks like there’s a minimal chance of showers for that time frame.
Frost: A much colder air mass will be driving down the valley tonight and Thursday behind a rapidly moving cold front. Lows Friday morning will generally be in the upper 30s to the mid 40s but where it clears for several hours, and where winds are calm, there will be a slight chance of traditional cold spots briefly teasing with the 32 degree mark. That, by far, would be the exception rather than the rule. Above freezing conditions can be expected Saturday through Monday mornings then a similar situation may develop Tuesday morning behind a similar cold front. The bottom line is, nothing serious is expected. Medium range models are calling for below average temperatures through the middle of the month, but so far it doesn’t appear a pattern will develop that would result in a real spring frost situation.
Next report: Thursday morning, April 12