A FIERCE WINTER STORM IS BARRELING ACROSS THE COUNTRY, WITH MORE THAN 70 MILLION AMERICANS ON THEIR WINTER WEATHER ALERTS TONIGHT.

4 MILLION FACE BLIZZARD CONDITIONS.

HEAVY SNOW BLANKETED PARTS OF THAN THERE ARE THESE.

THIS WILL REACH THE MID ATLANTIC AREA LATER TONIGHT.

IT IS EXPECTED TO BRING FRIGID TEMPERATURES AS FAR SOUTH AS FLORIDA.

A SENIOR METEOROLOGIST JOINS US.

THANK YOU SO MUCH FOR BEING HERE.

WHEN YOU LOOK AT WHAT IS COMING DOWN NOW AND WHAT IS FORECAST TO COME, WHAT IS MOST CONCERNING FOR YOU?

>> THE FACT THAT WE ARE NOT TO SEEING SNOW.

IT IS THE MIX.

IT IS REALLY COMPLICATING THINGS.

THAT MAKES IT HARD FOR CLUES TO GET AHEAD OF THE GAME IN SITUATIONS LIKE THIS.

COLD ARCTIC AIR IS INFILTRATING THE PLANES.

>> WHY IS IT THAT WE ARE SEEING THIS?

WIRE WE ALSO SEEING RAIN IN THE MIX SO THAT?

>> ONE OF THE ISSUES WITH THIS SYSTEM IS TWOFOLD.

IT IS BRINGING A RIVER OF WARMTH AND MOISTURE AT THE MID-LEVELS.

THIS IS WHY THIS IS A WATER LOADED SYSTEM.

WE ARE SEEING IF ALL IS LIQUID AND FREEZE ON THE GROUND.

THAT IS ENOUGH TO PULL DOWN POWER LINES.

AN KNOCKED DOWN TREE BRANCHES.

>> HELP US PUT THIS INTO CONTEXT.

IT IS JANUARY.

PEOPLE EXPECT SNOW AND COLD.

BUT THIS SEEMS TO BE A LITTLE BIT OUT OF THE ORDINARY.

>> WE HAVE WINTER STORM WARNINGS.

THIS COULD BE THE BIGGEST SNOWFALL IN YEARS.

IT IS SETTING RECORDS ACROSS THE COUNTRY.

ON THE BACKSIDE OF THIS SYSTEM, IT IS SET TO PRODUCE BLIZZARD CONDITIONS LATER ON TONIGHT.

EVERY TYPE OF HAZARD IS ON THE TABLE WITH THE SYSTEM.

I THINK A LOT OF PEOPLE WILL SEE SIGNIFICANT DISRUPTIONS FOR QUITE SOME TIME.

>> I IMAGINE THAT TRAVEL WILL BE NEAR IMPOSSIBLE.

>> IT GOES BACK TO WHAT WE WERE SAYING.

SNOW HAS BEEN A HEADACHE.

AVIATION IS A BIG PROBLEM RIGHT NOW.

IT IS CASCADING FLIGHT DELAYS RIGHT NOW.

INTERSTATES WILL BE VERY ROUGH.

WE HOPE FOLKS CAN STAY HOME.

WAIT FOR THINGS TO GET BETTER.

MOST FOLKS SHOULD BE IN A MUCH BETTER STATE BY TUESDAY OR WEDNESDAY.

>> WHAT ELSE CAN PEOPLE DO TUESDAY SMART?

>> NOT GOING OUT ON THE ROADS.

WAITING THIS ONE OUT.

SO MANY TIMES WE ARE TEMPTED TO GO OUT AND SEE A GET A FIRST-HAND PERSPECTIVE.

IN THIS SITUATION, WE SHOULD NOT BE DOING THAT.

THIS IS A LIGHTNING LOADED SYSTEM.

WE HAVE SEEN THUNDER SNOW ACROSS KANSAS.

THERE IS ENOUGH TO GET SPARKS OF LIGHTNING.

PEOPLE MIGHT BE TRYING TO SHOVEL AND A FLASH OF LIGHTNING COMES DOWN.

YOU SHOULD NOT BE OUTSIDE SHOVELING IF YOU HEAR THUNDER.

PEOPLE FORGET THAT THIS TIME OF YEAR.

THE LIGHTNING CAN BE DANGEROUS.

>> HOW MANY DAYS SHOULD PEOPLE EXPECT THIS AND THEN DO THINGS CLEAR UP?

DOES IT LOOK LIKE RELIEF WILL BE INSIGHT?

>> THINGS WILL WIND DOWN WEST TO EAST OVERNIGHT TONIGHT.

IN WASHINGTON, THINGS WILL WIND DOWN BY TUESDAY MORNING.

BUT THE ACTIVE WEATHER WILL NOT BE OVER.

A NEW SYSTEM TO FORM IN TEXAS LATER THIS WEEK.

THERE IS A SYSTEM IT COULD GO UP THE EASTERN SEABOARD.

>> THANK YOU SO MUCH.