February 9, 2019
Summary: We still have several more hours of dry weather before modified arctic storm number 2, currently centered just west of Eugene, Oregon, moves south/southeast into southern Oregon and northern California late tonight and Sunday morning. Considering this system’s origins are in northwest Canada, you can well imagine where snow levels are going to wind up. Even ahead of this storm, the freezing level early this morning out of Oakland was only 3,900 feet. The associated cold front will move down the valley Sunday morning, accompanied by rain. The rain will break off into showers later in the morning and in the early afternoon. The modified arctic air mass behind the front is very unstable and will keep showers going and a reasonable risk of isolated to scattered thunderstorms into Sunday afternoon. Any thunderstorms that break out will be accompanied by localized heavy rain and small hail and possibly some wet snowflakes.
Weak upper level high pressure behind the system will trap a layer of very cold air along the valley floor which will result in yet another freeze. Potential temperatures are discussed below.
It is becoming more likely now that rain, possibly heavy at times, will occur late Tuesday night through Thursday morning with increasing confidence of an atmospheric river of air moving from west to east underneath a cold low off the Oregon/northern California coast. This would create rapidly rising snow levels along the Sierra Nevada. Heavy rain on top of a large snowpack could pose flooding problems along the Sierra Nevada from the Kern County line northward.
By Thursday afternoon, the precipitation will begin to taper off with a dry slot Thursday night and Friday. Of course, timing issues are still a problem on models, but it appears another cold low will drop south/southeast from the Gulf of Alaska and spread precipitation over the Pacific Northwest and northern California. Currently, on paper the best way to word the situation for Saturday and Sunday is to call for a chance of showers, mainly north of Kern County, but this is subject to change.
Forecast: Partly cloudy before midnight. Periods of showers beginning during the early morning hours, continuing through Sunday. There will be a risk of isolated to scattered thunderstorms Sunday afternoon which will be accompanied by localized heavy rain, small hail, and a few snowflakes would not be a total shock. Mostly cloudy Tuesday evening with clearing skies after midnight. Mostly clear Monday through Tuesday with cold nights. Increasing cloudiness Tuesday night with a chance of rain after midnight. Rain likely Wednesday through Thursday morning, possibly heavy at times. Showers Thursday afternoon. Partly cloudy Thursday afternoon through Friday. Partly cloudy Friday night. increasing cloudiness Saturday leading to a chance of showers Saturday afternoon and night.
Short Term:
| Madera 42/52/28/53 | Reedley 41/53/28/53 | Dinuba 41/52/27/52 | |
| Porterville 42/53/28/53 | Lindsay 41/52/27/53 | Delano 43/53/29/53 | |
| Bakersfield 44/52/31/54 | Taft 44/52/32/53 | Arvin 43/51/29/53 | |
| Lamont 43/53/29/53 | Pixley 42/52/28/53 | Tulare 41/52/27/53 | |
| Woodlake 41/52/28/52 | Hanford 43/53/29/54 | Orosi 41/52/27/53 | |
Winds: Winds tonight will be out of the southeast at 10 to 15 MPH with gusts to 25 MPH possible from Fresno County north and along the west side north of Kern County. Expect the same wind pattern Sunday morning with winds becoming out of the northwest at 10 to20 MPH with stronger gusts Sunday afternoon and evening. Winds will be generally less than 7 MPH after midnight with periods of near calm conditions. Winds Monday and Tuesday will be generally less than 8 MPH with periods of near calm conditions.
Rain: Dry weather will prevail through this evening until possibly around midnight. After midnight, the chance of showers will increase right into Sunday afternoon, turning showery later in the day. From Sunday afternoon through early Sunday evening, the showers will become more scattered, but there will be a chance of isolated to scattered thunderstorms. If these storms do form, they would be accompanied by localized heavy rain, small hail, and potentially a few light but wet snowflakes. The action will wind down by Sunday evening with dry weather returning Sunday night through Tuesday. From later tonight through Sunday evening, rainfall amounts will vary widely, ranging from a couple of tenths to possible more than half an inch when and where thunderstorms occur.
Models are beginning, finally, to trend towards an atmospheric river of air event late Tuesday night through early Thursday. This would result in much warmer temperatures and rapidly rising snow levels. Three to four inches of rain or more could fall along the west facing slopes of the Sierra Nevada. On the valley floor, .50 to 1.00 totals are possible north of Kern County, and possibly more. Rain shadows on the west side and in Kern County will play their usual role. Timing issues still prevail, but we may see dry weather late Thursday afternoon through Friday with at least a chance of showers next weekend and snow levels lowering again.
Frost Discussion: All locations will be above 32 degrees tonight. The newest storm will begin to affect the area tonight through early Sunday evening. The air associated with this low has its origins in the Yukon Territory of Canada. As it moved southward, it moved partially overwater, which helped modify the system at least some. Still, very low snow levels will occur with this storm which will be followed by cold, modified arctic air which will pool on the valley floor Monday and Tuesday.
We’ll be playing games with cloud cover Monday morning, especially in Kern and southeastern Tulare County where the usual upslope clouds may or may not play a part. Where it clears and winds are calm, early Monday morning could see coldest locations down to 26 to 28 with many flat terrain locations ranging from 29 to 32. It’s possible a river bottom out there somewhere could drop down to 24 to 25 degrees. One blessing we have in all this is the fact the ground is soaking wet. If it were drier, readings would be colder.
Tuesday morning has the potential of being equally as cold but in more locations as winds will be calm and skies will be mostly clear. More locations would be at or near 28 degrees with coldest locations in the mid 20s. fortunately, this will only last for two mornings as westerly winds aloft will break in Tuesday night, bringing significant precipitation to the area Wednesday through much of Thursday. Above freezing conditions can be expected Wednesday through Sunday mornings. Monday and Tuesday of next week are questionable, but if below freezing weather does occur, I don’t feel it would as challenging as the current pattern.
Next report: Sunday morning/February 10