Dangerous weather conditions present special problems for metropolitan Washington's biggest single employer, Uncle Sam, who has 350,000 workers scattered in thousands of offices from downtown to the borders of Pennsylvania and West Virginia and the Chesapeake Bay.

During a severe weather situation -- and here that can mean two inches of snow -- radio and television are used to get the word to the troops, especially after an overnight snowfall or ice storm.

Because of snow predictions, area snow-watchers went to preassigned stations yesterday afternoon to plan what happens, or doesn't happen, today.

The government has a set of secret prearranged code words and phrases officials use when contacting the news media about late arrivals or shutdowns. Area school administrators also have media passwords to, as an official said yesterday, "make sure that some 7-year-old doesn't call radio stations pretending he is the superintendent of schools."

Because of past snafus (either releasing employees too early or too late), the government has modified and remodified its snow plans.

Generally speaking, the policy is: Go to work unless otherwise notified. But there is always the chance that some or all agencies will close early, or not open, if conditions are bad enough.

In the case of early release, the government has divided the area into four zones, with employees being released according to where they live, not work.

Zone One covers Stafford, Prince William, Fauquier and Loudown counties in Virginia, as well as Frederick, Carroll, Howard, Anne Arundel, Calvert and Saint Mary's counties in Maryland. Normally residents of those counties would be sent home first.

Zone Two includes areas outside the Capital Beltway in Fairfax County, Montgomery and Prince George's counties.

Zone Three is the area inside the Beltway, which includes most of Alexandria, Falls Church, Arlington and parts of Montgomery and Prince George's.

Zone Four people, District residents, would be the last to go in a snow emergency.

No employees will be released, the government plan says, until at least one hour after Metro and traffic officials have been notified to prepare for an early rush hour.

When a snow emergency develops, this is what you will hear on radio or TV, and what it means: If you hear nothing (unless your radio or TV is dead), then come in, and on time.

If the message is that "federal agencies are open; reasonable tardiness will be excused," that means your boss, on a case-by-case basis, can excuse you for being late if you can convince her or him that you live in a remote area or encountered horrendous commuting problems.

If the word is "agencies are open; employees may take leave without prior approval," it means reasonable tardiness may be excused, and any but essential workers "who are prevented from reporting to work because of emergency conditions, or who could expect to have difficulty returning home . . . may take annual leave or leave-without-pay without prior approval." Employees are still expected to call in if they can't make it.

Good luck this morning!