In like a lion, out like . . . a wildcat?

The old weather adage regarding March coming in like a lion and going out like a lamb or vice versa is going out the window this year.

The National Weather Service on Wednesday issued a 10-day outlook predicting precipitation that indicates there is as high as a 90 percent chance that snow and rain through the end of the month will be above average in California.

And for the Northern San Joaquin Valley and Bay Area there is a 100 percent chance precipitation will be higher than normal.

That forecast comes as rain tapers off today and then  returns again on Monday.

Equally unusual are the temperatures.

After being below average with bottom temperatures in the high 40s for the past week, the forecast calls for Manteca to drop down to 38 or 39 degrees overnight though Sunday.

That is substantially lower than normal.

That is good news and bad news for the snowpack that is now approaching 280 percent of normal in the Central Sierra mountains that feed the Stanislaus and Tuolumne rivers. It as much as 300 percent above normal in the Southern Sierra that drains into the San Joaquin River directly and its other tributaries.

It will assure that snowmelt will slow down sending water into reservoirs that are all approaching capacity with the exception of New Melones on the Stanislaus River.

But at the same time by delaying the natural snowbelt longer, it could mean the excessive snow will create an even larger snowmelt when it finally starts to warm up.

Water  that isn’t stored behind reservoirs or diverted to replenish underground aquifers within the 12,250 square miles of the San Joaquin River watershed eventually will need to pass through the tourniquet in South San Joaquin County.

That tourniquet starts at the Airport Way bridge 10 miles south of Manteca. It ends just west of Mossdale crossing in Lathrop where the San Joaquin splits into the old River and new channel as it enters the Delta proper.

The Vernalis gauge just north of the Airport Way bridge was rising Wednesday after dropping slightly the previous two days.

It was at 29.55 feet at 11:45 p.m. Wednesday and as such is still in  flood stage. The highest peak this winter was 29.83 feet on Sunday.

There are currently numerous boils being addressed in River Junction — the 5,000-acre reclamation district 10 miles south of Manteca where the Stanislaus and San Joaquín rivers meet.

There are a number of boils directly behind the Durham Ferry School operated by the San Joaquin County Office of Education off of Airport Way.

Boils can be a precursor to a levee failure if efforts to sandbag and shore the area around them up isn’t successful.

In 1997, boils triggered levee breaks in 11 different areas along the river south of Manteca. That led to 70 square miles between Manteca and Tracy being flooded.

To contact Dennis Wyatt, email dwyatt@mantecabulletin.com