Post by James on Dec 2, 2007 11:54:58 GMT -5
Dense Fog Advisory
A dense fog advisory is issued when widespread fog is expected to reduce
visibilities to 1/4 mile or less over a large area for an extended period of
time (more than 3 hours).
High Wind Watch
A high wind watch is issued when the following conditions are possible:
1) sustained winds of 40 mph or higher for one hour or more
OR
2) wind gusts of 58 mph or higher for one hour or more.
High Wind Warning
A high wind warning is issued when the following conditions are occuring or imminent:
1) sustained winds of 40 mph or higher for one hour or more
OR
2) wind gusts of 58 mph or higher for one hour or more.
Hurricane Watch
A hurricane watch is issued when the following conditions are possible.
1) storm surge, coastal flooding, river flooding
AND
2) winds of 74 mph or higher
The watch is issued for areas that border the Potomac River from Washington
DC southward and for areas that border the Chesapeake Bay.
The watch does not mean that hurricane conditions will occur. It only means
that these conditions are possible.
Hurricane Warning
A hurricane warning is issued when the following conditions are occurring
or imminent.
1) storm surge, coastal flooding, river flooding
AND
2) winds of 74 mph or higher
The warning is issued for areas that border the Potomac River from
Washington DC southward and for areas that border the Chesapeake Bay.
Inland Hurricane Wind Watch
This watch is issued when there is a possibility that hurricane force winds
(74 mph or higher) will move inland from the coast beyond areas that are
covered by the hurricane watch.
The watch does not mean that the hurricane force winds will occur. It just
means that they are possible.
Inland Hurricane Wind Warning
This watch is issued when hurricane force winds (74 mph or higher) are expected
to move inland from the coast beyond areas that are covered by the hurricane warning.
Coastal Flood Watch
A coastal flood watch is issued when moderate to severe coastal flooding is possible.
Coastal flood watches are issued for areas along the Tidal Potomac River and
areas along the Chesapeake Bay.
Coastal Flood Warning
A coastal flood warning is issued when moderate to severe coastal flooding is
occurring or imminent.
Coastal flood warnings are issued for areas along the Tidal Potomac River
and areas along the Chesapeake Bay.
Excessive Heat Outlook
This is issued when the heat index value is expected to reach or exceed 110 degrees within the next 2 1/2 to 5 days.
Excessive Heat Watch
The excessive heat watch shall be issued when the heat index value is expected to reach or exceed 110 degrees within the next 24 to 48 hours.
Excessive Heat Warning
The excessive heat warning shall be issued when the heat index value is expected to reach or exceed 110 degrees within the next 12 to 24 hours.
Heat Advisory
The heat advisory shall be issued when the heat index value is expected to reach 105 to 109 degrees within the next 12 to 24 hours.
A dense fog advisory is issued when widespread fog is expected to reduce
visibilities to 1/4 mile or less over a large area for an extended period of
time (more than 3 hours).
High Wind Watch
A high wind watch is issued when the following conditions are possible:
1) sustained winds of 40 mph or higher for one hour or more
OR
2) wind gusts of 58 mph or higher for one hour or more.
High Wind Warning
A high wind warning is issued when the following conditions are occuring or imminent:
1) sustained winds of 40 mph or higher for one hour or more
OR
2) wind gusts of 58 mph or higher for one hour or more.
Hurricane Watch
A hurricane watch is issued when the following conditions are possible.
1) storm surge, coastal flooding, river flooding
AND
2) winds of 74 mph or higher
The watch is issued for areas that border the Potomac River from Washington
DC southward and for areas that border the Chesapeake Bay.
The watch does not mean that hurricane conditions will occur. It only means
that these conditions are possible.
Hurricane Warning
A hurricane warning is issued when the following conditions are occurring
or imminent.
1) storm surge, coastal flooding, river flooding
AND
2) winds of 74 mph or higher
The warning is issued for areas that border the Potomac River from
Washington DC southward and for areas that border the Chesapeake Bay.
Inland Hurricane Wind Watch
This watch is issued when there is a possibility that hurricane force winds
(74 mph or higher) will move inland from the coast beyond areas that are
covered by the hurricane watch.
The watch does not mean that the hurricane force winds will occur. It just
means that they are possible.
Inland Hurricane Wind Warning
This watch is issued when hurricane force winds (74 mph or higher) are expected
to move inland from the coast beyond areas that are covered by the hurricane warning.
Coastal Flood Watch
A coastal flood watch is issued when moderate to severe coastal flooding is possible.
Coastal flood watches are issued for areas along the Tidal Potomac River and
areas along the Chesapeake Bay.
Coastal Flood Warning
A coastal flood warning is issued when moderate to severe coastal flooding is
occurring or imminent.
Coastal flood warnings are issued for areas along the Tidal Potomac River
and areas along the Chesapeake Bay.
Excessive Heat Outlook
This is issued when the heat index value is expected to reach or exceed 110 degrees within the next 2 1/2 to 5 days.
Excessive Heat Watch
The excessive heat watch shall be issued when the heat index value is expected to reach or exceed 110 degrees within the next 24 to 48 hours.
Excessive Heat Warning
The excessive heat warning shall be issued when the heat index value is expected to reach or exceed 110 degrees within the next 12 to 24 hours.
Heat Advisory
The heat advisory shall be issued when the heat index value is expected to reach 105 to 109 degrees within the next 12 to 24 hours.