Many of the large school districts in the DMV called off classes for Wednesday ahead of a major snow event rolling into the area.

Arlington, Montgomery, Prince George's, and Prince William counties were all among those to cancel school.

FULL LIST OF CLOSINGS AVAILABLE HERE

The US Office of Personnel Management tweeted federal offices in the DC area would be closed.

Emergency and telework-ready employees should follow their agency's policies.

A significant winter storm will impact the DC area Wednesday, arriving by dawn. Snow turns to a wintry mix in the afternoon, followed by a miserable cold rain in the evening. 

A Montgomery County Public Schools spokesperson told WUSA 9 Wednesday's make up day will be June 5. 

Prince George’s County Schools are not yet out of days. Officials told WUSA9 the school system has three built-in days and - before Wednesday's snow day - had only used one. Click the link below to see how other school districts are faring so far this year, snow day-wise.

HOW MANY SNOW DAYS LEFT: Montgomery County is out of snow days. Is your county?

Snow arrives from southwest to northeast between 3 AM and 8 AM, and inside the beltway between 5 AM and 6 AM. The snow will be light at first, but will begin to pick up in intensity as the morning goes on. Snow will become moderate at times 9 AM to Noon, especially northwest of D.C.

WINTER STORM WARNING: Here's what to expect during Wednesday's storm

Snow begins to transition to a wintry mix south and west of town between 11 AM and 1 PM. In D.C., it doesn't transition from snow to sleet and a wintry mix until after 1 PM. Snow continues for the mid-day hours in D.C. and points north of town.

TIMELINE: Here's when to expect snow, sleet, freezing rain and rain on Wednesday

The battle between cold and warm air continues all afternoon leading up to the evening commute. Between 3 PM and 7 PM, the transition from a mix of sleet and freezing rain to just rain will occur from south to north.