A considerable amount of mid and high level clouds is blocking the sunshine this afternoon, lowering temperatures between roughly 1 and 4 degrees from yesterday at this time. These clouds are not ahead of the upcoming rain event, but rather a benign, dry disturbance running from west to east across central California.
Now we can turn our attention to the first legitimate storm event of the season, the only real change on models this afternoon is the timing of the precipitation. It’s actually running a few hours earlier than previous models. Showers will likely reach Merced County in the early to mid afternoon time frame then Fresno County mid to late afternoon and into Kern County early Tuesday evening. Precipitation totals will not be impressive, but considering it has not rained in central California for several months, it will be a sight to behold.
I still anticipate a rain shadow along the west side of the valley and in Kern County, however the dynamics of this storm appear to be strong enough for precipitation over Kern County and the Kern County mountains. Amounts of rain over the eastern flank of the valley from roughly Highway 99 to the base of the foothills will generally range from .10 to .25. The west side and the valley portion of Kern County will pick up anything from a few hundredths of an inch to as much as .12. Once the cold front moves through Tuesday night, showers will taper off into scattered light showers Wednesday, especially during the morning hours. It now looks like the backside of the trough will clear the Sierra Nevada by late Wednesday night with dry weather beginning Thursday and lasting through at least Friday night.
Newest high resolution models are indicating the storm track will move further south during the second half of the weekend as a low sets up west of British Columbia. Disturbances will rotate underneath the low then quickly move eastward into northern and northcentral California. Some models show the wet/dry line across Merced County, but a few show light showers into Fresno County by Saturday night. In fact, the whole period from Saturday through Tuesday of the following week will likely be active for northern California and possibly parts of central California. I haven’t been this excited since Columbus discovered America.
Forecast: Variable cloudiness through the late evening hours then clearing overnight. Mostly clear skies for a time Tuesday morning. Increasing cloudiness Tuesday afternoon with showers becoming likely as far south as Merced County during the early afternoon, reaching Fresno County by mid to late afternoon then into Kern County in the form of light showers during the early evening. Light showers likely Wednesday morning. A decreasing chance of light showers Wednesday afternoon. Partly cloudy Wednesday night and Thursday morning, but remaining partly cloudy for a time in Kern County and southeast Tulare County. Mostly clear Thursday afternoon through Saturday morning. Increasing cloudiness by Saturday afternoon with a slight chance of showers as far south as Fresno County. There will be on and off chances of light showers from Fresno County north Sunday and Monday.
Temperatures: Lows tonight will cool into the mid to upper 40s north of Kern County and the low to mid 50s in Kern County. Highs Tuesday will generally run in the low 70s. Lows Tuesday night will run in the mid to upper 40s to the low 50s. Highs Wednesday will be in the refreshingly cool upper 50s to the lower 60s.
Temperatures: The air mass behind the Tuesday night/Wednesday storm is relatively cold, so even though frost season doesn’t officially begin until tomorrow, we’ll mention midi to upper 30s Thursday morning and low to mid 30s Friday morning, assuming elements set up just right. There is a small chance of a cold river bottom or two dropping briefly into the upper 20s. More on this as the week progresses.
Next report: October 31 afternoon
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