Texas Snowfall Totals, Image: NOAA

It’s snowing again in Texas! Snow showers have been falling all day in the Lone Star State. Dallas, Texas has very few accumulations (snow on the ground), but hill country areas such as Waco have 3 inches of snow on the ground.

The National Weather Service has issued Winter Storm Warnings for Texas, California, New York and other parts of the Northeast.

US Watches and Warnings, Image: NOAA

Two weather patterns are colliding over the United States this winter to produce storm after storm for the southern Gulf Coast and the Northeast. The El Nino Southern Oscillation is a weather pattern that causes a warming of the Pacific Ocean off the coast of Central America. This winter, El Nino is being credited with the surge of moisture and added rainfall/snow events in California, Arizona, New Mexico, Texas, and the Gulf Coast.  At the same time El Nino is occurring, scientists are also examining the effects of a Negative Arctic Oscillation. The NAO is associated with cold winters across the Northern Hemisphere, as more cold air descends from the Arctic to the nearby continents of North America, Europe and Asia.

Arctic Oscillation, Image: NOAA

The above graphic is data taken from the entire month of December 2009. What this graphic shows is average temperatures across Asia, Europe and North America have been substantially cooler than normal, whereas temperatures in the Arctic, Africa and parts of the Mid-East have been warmer.

Forecasted Lows, Image: NOAA

Take a look at the large dip of cold air across Minnesota, Iowa and the Dakotas. Once again, folks in Minneapolis will be waking up to below freezing temperatures. Look at the forecast lows across Louisiana… below freezing. If you add the extra moisture coming in from the Pacific due to El Nino and the cold air due to the Arctic Oscillation, you have the perfect recipe for snow.

TV forecasters in Shreveport and New Orleans, Louisiana are reporting once again on the unusual snowfall events.  In the Northeast, where snow has caused massive transportation problems, another round this week is expected.

-Dawn Brown

National Satellite Image, Image: NOAA

Click here for the latest national satellite imagery.

In the meantime, yet another El Nino storm is moving through the Deep South. This has provided for a couple of inches of rain across the central Gulf Coast and tornado watches from just north of New Orleans, all the way up into Mississippi, east Texas, and southern Arkansas.  Tornadoes were even spotted Wednesday afternoon over portions of Southeastern Louisiana.  Tornado Watches are in effect for cities like Jackson, MS.

US Watches & Warnings, Image: NOAA

Rainfall Forecast, Image: NOAA

Rain continues to fall across most of California today. Up to 20 inches of rain is possible in isolated locations across Southern California. In higher elevations of the Sierra Nevada Mountain Range, that could translate into more than 10 feet of snow!

Check out the latest TV forecast in San Francisco, Sacramento, Los Angeles, and San Diego.

Skiers and snowboarders are loving this! Go to my Mammoth Mountain and Tahoe webcams under Ski Weather for the latest conditions.

-Dawn Brown

West Coast Radar, Image: NOAA

Click for the latest radar imagery. 

Heavy rain storms continue to pound the West Coast. Mudslides have forced the evacuation of homes in California. A series of storms is lined up in the Pacific Ocean.

Tonight's Forecast, Image: Unisys Weather

This is a computer model forecast for tonight’s rainfall. You can see the entire state of California will be swamped by this Pacific storm. 

The National Weather Service is forecasting more than 7 inches of rainfall for Southern California over the next 3 days.

It will begin to dry out by late Saturday night into Sunday.

We are currently in a moderate El Nino pattern. El Nino is  a term to describe a change in the weather pattern in the western Pacific Ocean. An El Nino winter in California can lead to torrential rainfall.

-Dawn Brown