Thursday's live blog: South's hail, West's flood risk & snow

It's a big weather day! So we got a live blog for you to easily follow along with what's happening at the moment. This blog was updated throughout the day Thursday with the latest information about the isolated severe storms from Texas through Alabama, with a risk for large hail. Also, the West faces rounds of heavy mountain snow and heavy rains which will bring flooding to California through the Pacific Northwest.

The atmospheric river can be easily seen on the satellite streaming out of the same latitude as the Hawaiian Islands, more than 2,000 miles away.

Southern California will begin to feel the effects starting in the middle of the night through the early morning commute hours. Many schools across California have already delayed or closed on Friday ahead of the worst of the event. Continue to monitor the WeatherRadar and heed any warnings that come through, including evacuation warnings.

The main feature of this atmospheric river event is the warmer temperatures coming along with it. This has to do with its departure out of the same latitude as the Hawaiian Islands.

Above-freezing temperatures mean that much of the snowpack in California below 6,000 foot elevations could melt, adding to the over-saturated soils. Those in Truckee are seeing the effects this evening with a wet snow falling and mixing in with rain at 6,000 feet.

It's official. A high risk for excessive rainfall has been issued for the Day 1 period - now through 5 a.m., Friday local time in the California central coast, south of San Francisco Bay. The atmospheric river has shown increasing intensity, prompting the added risk from the National Weather Service.

Rainfall rates near one inch per hour are possible as the system surges inland. More serious language from the National Weather Service continues to be release with the following concerning those within the high risk area, "more rapid water rises and immediate flooding concerns could arise early Friday morning."

As a result, many residents in the high risk area are under evacuation orders ahead of the anticipated flooding.

Governor Newsom declared a State of Emergency in California ahead of the significant atmospheric river event. Additionally, since power outages are anticipated, PG&E, has already mobilized crews to stay on top of possible outages.

Our meteorologist, James West, was live with the latest update in our YouTube Page.

As the low pressure moves inland overnight tonight, thunderstorms are also expected. San Francisco, Sacramento, and coastal Oregon residents could all see passing thunderstorms starting this evening. Check the WeatherRadar before you head out and have at least three ways to receive a weather warning.

Meanwhile, severe storms continue to fire in the southern Plains. Hail and gusty winds are the main threats.

The high risk for excessive rainfall on Friday in the West is rare and the first one for the central coast since 2010 - 13 years ago. High risks are the top-most level of risk from the National Weather Service and are only issued around 4 percent of the time.

Flooding is going to happen with this winter storm, both from the heavy rainfall and from the snowmelt through Friday evening. Streams, creeks, and rivers are expected to crest as the atmospheric river feeds this storm with plentiful moisture. See the mechanism driving this moisture below.

Meanwhile in the southern Plains, storms with heavy rain and hail are firing now that the evening commute has begun. The Dallas-Fort Worth Metroplex through Little Rock, Ark., will see these storms through the evening hours. Those hitting the road soon should heed any warnings and provide extra time to get to your destinations.

New maps are in! And Friday's forecast calls for more rain for parts of California. The highest rainfall will be focused along the San Joaquin Valley and across coastal areas just south of San Francisco from Salinas to Santa Barbara.

You can read all the details about the forecast for the West by our meteorologist Mary Mays below.

Rains are ramping up across northern California. From Chico to Redding high rainfall rates as deep moisture moves in from the Pacific. Toward the coast, a batch of heavy rains also affects areas from Salinas to the San Francisco Bay area.

Do you know what a Pineapple Express is? We discussed this term and where it comes from below

Touching base with the stormy setup across the South, there are several thunderstorms from Oklahoma to Arkansas. With the day's heating, there will be more storms developing across Texas where there have been periods of sunshine, which will allow the atmosphere to become more unstable.

Rivers across Arkansas are rising. There are flood warnings in effect for the White River at Georgetown, Des Arc, Augusta, and Clarendon. If you encounter a barricade, please do not attempt to cross it.

As of Wednesday, March 8, Little Rock, Ark., has the 4th wettest year to date on record. A small break from the rain is in the forecast on Friday, but rain will be back for the weekend.

The big worry for California, especially for parts of the coastal and southern mountains is that all the snow from recent storms has not melted. Now, with this new storm, there will be torrential rains, which will put more weight on roofs, trees, etc. There will be more people at risk not only from possible roof collapses but also from power outages.

Across northern California, the rains and snow have arrived this Thursday morning. Expect periods of heavier rains (and mountain snow) to intensify by the afternoon and into Friday.

Remember all that snow that fell across the Southern California mountains last week? Some people are just now digging themselves out of the snow after being trapped for days in their homes, often without electricity.

Unfortunately, 12 people were found dead. Authorities were able to confirm that one of those dead have been due to an accident and was strictly weather-related. And while the other deaths might not seem to be weather-related, they are still investigating.

Over 500 emergency crews and the National Guard are working on rescuing people in the San Bernardino Mountains after some areas are still in over 10 feet of snow. About 40% of the roads are still unplowed. Officials estimate that there could be several days until they reach all residents in the region.

Volunteers have set up several areas to pass out essentials and provide aid to anyone injured or in distress.

The northern tier of the low-pressure system and more specifically a trough is moving through the Midwest and the Great Lakes area where periods of heavy snow are in the forecast. Meteorologist James West has the latest information in the article below.

Now let's talk about the next atmospheric river threatening the West to finish the week with heavy rains and heavy snow. The snow will be confined to elevations above 8,000 feet.

The last California storms mainly affected Southern California, but there were a series of atmospheric rivers that affected northern and central California in December and January. This time around excessive rainfall will affect much of the valleys across Central California, where 2 to 3 inches of rain are in the forecast through Sunday across San Francisco, Stockton, and Sacramento. In the foothills, like in Sonora, and South Lake Tahoe, there could be up to 7 inches of rain.

Although the heavy rains will start on Thursday afternoon, it will take about 12- 24 hours for the water to get to the rivers, many are around flood levels. Nearby residents should be aware that the impacts of the rivers will come a bit after the heaviest rain happens.

Across the Sierra, between 60 and 80 inches of snow, that's 5 to 7 feet of snow are possible with this storm moving in through Sunday. Make sure to avoid traveling as the roads will be very dangerous and many roads could once again be closed.

Gusts could also become a major issue as gusts could be reaching 50 mph which could be causing power outages.

Check out the areas and severity of the storms that will likely affect parts of Texas and the South on Thursday. Although there are some morning storms affecting parts of Arkansas, the rain will persist across much of the state but also new storms will develop to the southwest over Texas. There could be two rounds of hail.

The first round could happen this afternoon, then as the cold front finally gets moving, more severe storms will develop across central and eastern Texas, with the chance of large hail falling. Please make sure to secure your belongings and park your car under a roof to protect them.

Our WeatherRadar shows morning thunderstorms across Arkansas to western Tennessee and northern Mississippi. Storms will continue to affect Arkansas throughout the day and more storms to develop over North Texas, increasing the risk of large hail. Over Arkansas and western Tennessee, the flood risk will continue to be high as the showers will not let go.