March 16, 2018
Summary: Showers are widespread over Madera and Fresno Counties with showers trying to move over the Coast Range and into the south valley. Isolated thunderstorms are already breaking out in Fresno and Madera Counties. No doubt, with progressively colder air moving in overhead, more cells will develop as the afternoon wears on.
In the broader picture, low pressure is located right off the northern California coast and will move slowly inland tonight and early Saturday. Bands of showers will continue to move in from the west with even a chance of a convective thunderstorm or two even during the nighttime hours. On Saturday, a secondary disturbance will be dragged across central California from the exiting trough for a chance of showers Saturday afternoon and a small chance of isolated thunderstorms. Cold air aloft will be replaced Saturday night through Monday for possibly local frost which is discussed below.
Upper level high pressure will begin to nose in from the west Sunday then move overhead Sunday night and Monday. In the meantime, a large scale lower latitude storm is developing well out over the Pacific. This system will begin to approach the coast Tuesday with precipitation possibly reaching down into Fresno and Madera Counties by late Tuesday night. This system will be interesting to watch as two dynamics will be in play. The first is a second cold low from the Gulf of Alaska merging with the storm moving into the west coast. Also, a southwest tap of subtropical moisture will be feeding in from the southwest. If all this comes together correctly, heavy amounts of precipitation will occur over the mountains and even locally heavy amounts are possible on the valley floor. Snow levels will be high, however, but will eventually lower by late Thursday night or early Friday as a cold north to northwest flow wraps around the backside of this storm.
On Thursday of next week, rain will be falling all the way from northern British Columbia to southern California. That gives you an idea of the potential scope of this weather maker. Models continue to point towards a dry pattern beginning next weekend and, if models hold, all of the following week with temperatures eventually rising above average.
Forecast: Periods of showers this afternoon through Saturday morning. Scattered to isolated thunderstorms are likely this afternoon and evening with a slight chance Saturday afternoon and evening. Otherwise, there will be a chance of showers Saturday. Partly to mostly cloudy later Saturday night and Sunday morning. Becoming mostly clear to occasionally partly cloudy Sunday afternoon through Monday afternoon. Increasing cloudiness Tuesday with a chance of rain from Fresno northward by late afternoon. Rain likely Wednesday through Thursday night, possibly locally heavy at times. A chance of showers for a time Friday morning, clearing in the afternoon.
Short Term:
| Madera 37/59/34/61 | Reedley 38/58/34/62 | Dinuba 36/58/33/63 | |
| Porterville 39/60/34/63 | Lindsay 37/59/33/63 | Delano 41/60/37/63 | |
| Bakersfield 41/61/38/63 | Arvin 41/61/39/63 | Taft 43/60/41/63 | |
| Lamont 41/60/36/62 | Pixley 39/60/36/62 | Tulare 37/59/33/62 | |
| Woodlake 39/59/34/63 | Hanford 38/60/34/63 | Orosi 39/59/33/62 | |
Winds: Winds later tonight will be out of the northwest at 10 to 15 MPH with gusts locally to 25 MPH, continuing at times through Saturday. Winds Saturday night will be out of the northwest at 5 to 10 MPH with generally light winds after midnight. Winds Sunday through Monday will be generally less than 12 MPH. we are still looking at configurations on models for late Tuesday night through Thursday morning. We may see gusty southerly winds develop ahead of a massive low pressure system eventually settling off the northwest coast. For now, it’s a 50/50 proposition and the configuration this afternoon maintains a less likely scenario for strong winds, but small deviations from this could change things in a hurry.
Rain: Showers are fairly widespread over Madera County and portions of Fresno County at this hour. Isolated small thunderstorms have been popping up over those regions. More cells will pop up as the afternoon wears on with isolated heavy rain and small hail. Showers are trying to move over the Coast Range in the south valley and hold together. However, there has been a rain shadow in that area this afternoon. Even so, I believe showers will overspread the area tonight through Saturday morning. The backside of this trough will be moving through Saturday with a continuing risk of showers, possibly even an isolated thunderstorm or two Saturday afternoon. From Saturday night through Monday night, dry conditions will prevail. Some models actually show the chance of rain increasing over Fresno and Madera Counties as early as late Tuesday and Tuesday night. At any rate, precipitation will spread over the entire region Wednesday and continue on and off through Thursday night. This system will be fed by a north/northwest flow out of the Gulf of Alaska and a subtropical flow moving in from the southwest. These are key ingredients for a full blown winter storm, however for much of this event, snow levels will be above 8,000 feet, lowering quickly later Thursday night as the cold sector moves in. dry weather will return by Friday afternoon and last through the weekend. Models continue to trend towards dry weather for not only the weekend, but the following week.
Frost: Even tonight, a few locations may dip into the mid to upper 30s if partial clearing occurs during the early morning hours. However, I’m not anticipating below freezing conditions tonight. Low to mid 30s are certainly possible Sunday and possibly Monday mornings with a slight chance of upper 20s in isolated cold spots. Models show a bit of moderation for Monday morning, but readings will still drop into the low to mid 30s, assuming skies are relatively clear. Rapid moderation of the atmosphere will begin Monday night and Tuesday as a southwest flow develops ahead of a massive Pacific storm which will spread precipitation over the area Wednesday through Friday morning. One model is suggesting next Saturday morning could see readings in the mid to upper 30s, however we’ll worry about that later. The bottom line for now is, nothing serious is at hand.
Lows Tonight:
All locations will be above 32 tonight.
Next report: Saturday, March 17