The National Weather Service in Birmingham has issued a Flash Flood Watch for most of Alabama until Monday morning.  Heavy rainfall is expected as showers make their way across the state today and Sunday. Tuscaloosa could see close to three inches of rain; even heavier amounts are possible further south.

NWS Birmingham

The video below from the National Weather Service explains the flooding threat in further detail.

The full text of the advisory is as follows:

...FLASH FLOOD WATCH IN EFFECT FROM NOON CST TODAY THROUGH LATE

SUNDAY NIGHT...

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

* FLASH FLOOD WATCH FOR PORTIONS OF CENTRAL ALABAMA...NORTHWEST

ALABAMA AND WEST CENTRAL ALABAMA...INCLUDING THE FOLLOWING

AREAS...IN CENTRAL ALABAMA...AUTAUGA...BIBB...BLOUNT...

CHILTON...COOSA...DALLAS...ELMORE...JEFFERSON...PERRY...

SHELBY...ST. CLAIR...TALLADEGA AND WALKER. IN NORTHWEST

ALABAMA...MARION AND WINSTON. IN WEST CENTRAL ALABAMA...

FAYETTE...GREENE...HALE...LAMAR...MARENGO...PICKENS...SUMTER

AND TUSCALOOSA.

* FROM NOON CST TODAY THROUGH EARLY MONDAY MORNING

* AVERAGE BASIN AVERAGE RAINFALL AMOUNTS OF 2 TO 3 INCHES ARE

EXPECTED TODAY THROUGH EARLY MONDAY MORNING. LOCALIZED HIGHER

AMOUNTS OF OVER 4 INCHES CANNOT BE RULED OUT FROM SHOWERS AND

ISOLATED THUNDERSTORMS MOVING REPEATEDLY OVER THE SAME

AREAS...AND MAY CAUSE FLASH FLOODING. URBAN AREAS WILL BE

ESPECIALLY PRONE TO PONDING OF WATER AND FLOODING ISSUES. DUE TO

HEAVY RAINFALL THAT FELL ON DECEMBER 23RD...ALREADY SATURATED

GROUND CONDITIONS WILL CONTRIBUTE TO A HIGHER THREAT OF FLASH

FLOODING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD

TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION

SHOULD FLASH FLOOD WARNINGS BE ISSUED.