(Updated at 9:45 a.m.) The National Weather Service has issued a Winter Storm Warning for the D.C. region.

The warning, issued last night, revises down the snow forecast for Arlington to 4-8 inches.

… WINTER STORM WARNING REMAINS IN EFFECT FROM 8 PM THIS EVENING TO 3 PM EST THURSDAY…

* PRECIPITATION TYPE… HEAVY SNOW AND SLEET.

* ACCUMULATIONS… 4 TO 8 INCHES.

* TIMING… SNOW WILL OVERSPREAD THE AREA FROM THE SOUTH BETWEEN 8 PM AND 10 PM THIS EVENING. SNOW WILL BE HEAVY AT TIMES TONIGHT INTO THURSDAY MORNING. SNOW IS EXPECTED MIX WITH SLEET AND RAIN LATE THURSDAY MORNING INTO THURSDAY AFTERNOON.

* TEMPERATURES… IN THE MID 20S TONIGHT… SLOWLY RISING INTO THE LOWER TO MIDDLE 30S THURSDAY AFTERNOON.

* WINDS… NORTHEAST 5 TO 15 MPH THIS EVENING… BECOMING NORTH AND INCREASING TO 10 TO 20 MPH WITH GUSTS TO 35 MPH LATE TONIGHT AND THURSDAY.

* IMPACTS… ROADS WILL BECOME SNOW AND SLEET COVERED AND SLIPPERY. TRAVEL WILL BE DANGEROUS TONIGHT AND THURSDAY. HEAVY WET SNOW COUPLED WITH GUSTY WINDS COULD LEAD TO SOME POWER OUTAGES.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

A WINTER STORM WARNING FOR HEAVY SNOW MEANS SEVERE WINTER WEATHER CONDITIONS ARE EXPECTED OR OCCURRING. SIGNIFICANT AMOUNTS OF SNOW ARE FORECAST THAT WILL MAKE TRAVEL DANGEROUS. ONLY TRAVEL IN AN EMERGENCY. IF YOU MUST TRAVEL… KEEP AN EXTRA FLASHLIGHT… FOOD… AND WATER IN YOUR VEHICLE IN CASE OF AN EMERGENCY.