Timeline: New Year's rainstorm to drench Southern California

Rainstorm moves into SoCal

Get ready to ring in the new year with some wet weather across Southern California.

LOS ANGELES - Santa Ana winds are expected to continue gusting across much of Southern California on Tuesday, setting off a week of unsettled weather that is forecasted to include more rain in the saturated region, including the likelihood of heavy rains falling on the normally sunny Rose Parade in Pasadena.

Rain chances, timing

Timeline:

Wind advisories for the Los Angeles area have been extended through 3 p.m. Tuesday as Santa Ana winds continue to gust across the region. 

Following the wind, a wet weather system fueled by moisture from the coast of Mexico is expected to arrive as early as Wednesday morning. 

Rain begins Wednesday morning, starting off mostly light to moderate. A heavier wave of rain is forecast for late Wednesday night (New Year's Eve) into Thursday morning (New Year's Day).

On-and-off rain showers continue through Thursday, with more scattered rain in the forecast for Friday. 

The wet weather continues into the weekend, with a more widespread wave of rain expected on Saturday.

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Forecasters anticipate between 1 and 3 inches of rain in coastal and valley areas and 2 to 5 inches in the mountains by the end of the week.

‘Extremely high’ chance for wet Rose Parade

What they're saying:

The NWS is warning those planning to attend holiday festivities to prepare for inclement weather.

Forecasters specifically addressed the high probability of a wet holiday: "... The chances of a wet New Year's parade, and including the night before when people came out before the parade, are extremely high, 80-90% at this point," forecasters said in a statement Monday afternoon.

Weather Forecast for Tuesday, Dec. 30

The latest forecast and air quality conditions for the greater Los Angeles area, including beaches, valleys and desert regions.

What we don't know:

The exact timing of the rain on New Year's Day is unclear.

First rainy parade since 2006

The backstory:

The Rose Parade in Pasadena is famous for its historically clear weather, having avoided rain less than a dozen times in its 136-year history. 

If the current forecast holds, New Year’s Day will mark the first time rain has fallen on the floral procession since 2006. 

While the upcoming storm is significant, the NWS notes that it will likely be "at least 50% lighter than the last event."

Rose Parade floats near perfection

It's getting down to the wire to finish decorating those floats for the Rose Parade on New Year's Day.

Plan accordingly

Why you should care:

The primary concern for residents is the condition of the terrain following last week’s heavy storms. 

Because the ground is already saturated, authorities have issued warnings regarding possible mud and debris flows. 

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Additionally, spectators and participants in the Rose Parade should expect "periods of light to moderate rain" and should plan accordingly to stay dry.