SAN DIEGO — Sunny skies are expected Tuesday throughout San Diego County before a major storm system arrives Wednesday and drops moderate to heavy amounts of rain and snow through Friday, according to the National Weather Service.

The agency has issued a Flash Flood Warning that will be in effect from Wednesday morning through Thursday evening in coastal areas and the inland valleys.

Rainfall totals through Friday could reach 3 to 5 inches in the San Diego County mountains, 1.5 to 3 inches in the inland valleys, and 1 to 2 inches in coastal areas. 

Rain is expected to start falling Wednesday evening, but the brunt of the system will hit with heavy rain in the afternoon on Thursday. 

A winter storm warning will be in effect from 4 a.m. Wednesday to 10 p.m. Friday in the mountains above 3,000 feet.

"If you must travel, keep an extra flashlight, food and water in your vehicle in case of emergency," NWS officials warned.

The wet week is expected to be a busy one for law enforcement officers. 

"Anytime you're driving fast in the rain, it's a recipe for disaster," said California Highway Patrol Officer Jake Sanchez. "We don't get it very often, so people don't know what to do in the rain."

The holiday also means there will be more cars on the road. 

“We schedule heavy for holidays, so fortunately this rain period we’re going to have extra patrols out there,” Sanchez said.   

He says on an average day CHP responds to around 75 crashes in San Diego County, but on a rainy or bad weather day that number jumps to 300 or 400.  

“Everybody knows it's going to rain, so give yourself that extra time and you won't be late for events,” said Sanchez.  

But it's not just the roads expected to be busy. San Diego International Airport was already slammed with travelers Tuesday - many of which have already experienced delays due to weather reporting sitting on the runway for 20 – 30 minutes.  

Wednesday is expected to be the busiest travel day but if you wanted to avoid the storm your best bet was getting out Tuesday.  

A Winter Storm Warning has been issued for the San Diego County mountains from 4 AM Wednesday until 10 PM Friday. Areas above 3000' will see heavy snowfall. The heaviest will be above 5,500' with 1' to 3' of snow expected.

Mount Laguna, Palomar Mountain and Cuyamaca Mountain could get up to 12 inches of snow at their highest peaks before the storm system makes its exit by Saturday, Miller said.

Thunderstorms will also be possible Wednesday night through late Thursday night throughout the county, forecasters said.

Directions to turn on Severe Weather Alerts in the News 8 app 

Open the News 8 app (which you can find here) 

Tap on the gear icon in the upper right-hand corner 

Tap on “Notification Settings” under “Notifications”  

Tap on “Severe Weather Alerts” under “Weather”  

Toggle the slider next to Severe Weather Alerts and additional options will open 

You can tap to choose:  

“Statements/Advisories, Watches and Warnings” - this will provide the most amount of alerts pushed to your phone. 

“Watches and Warnings”  

Or simply “Warnings” - this will provide the least amount of alerts pushed to your phone.  

You can also toggle on and off “Red Badge Notifications” that will appear from Severe Weather Alerts at the top of the app’s homepage when you return to it.  

If you would like to change your default location – perhaps while traveling – you can do so at the top of this page following these steps:  

Tap “Change Default Location”  

Tap Add Location (you can have up to 5)  

Search for a location and tap the correct 

Tap Add Location 

Back on the Change Location page tap the pencil icon next to the new location and tap “Set as Default” on the box that pops up