Boston, Massachusetts

The Flood Warning continues for
the Charles River at Dover.
* At 4:00 am Friday the stage was 7.6 feet.
* Flood stage is 5.0 feet.
* Moderate flooding is occurring and moderate flooding is forecast.
* Forecast... the river will continue to fall to a stage of 6.7 feet
by tomorrow morning.
* Impact... at 8.0 feet... flooding will impact portions of Dover...
Medfield... Millis... Medway... South Natick... Needham and Wellesley
with Road closures and local evacuations possible.

... Public information statement...

The National Weather Service has declared March 15 to 19 flood
safety awareness week. The National Weather Service in Taunton MA is
featuring a different educational topic each day during the
awareness week. Today's topic... tropical cyclone inland flooding.

When it comes to tropical cyclones, a generic term for a hurricane...
typhoon... or tropical storm... wind speeds do not tell the whole story.
Intense rainfall... not directly related to the wind speed of a tropical
cyclone... often causes more damage. Since the 1970s... inland flooding
has been responsible for more than half of the deaths associated with
tropical cyclones in the United States. Typically... greater rainfall
amounts and flooding are associated with tropical cyclones that have
a slow forward speed or stall over an area.

What do I need to know about inland flooding from tropical cyclones?
Inland freshwater floods accounted for more than half of U.S. Tropical
cyclone deaths over the past 30 years.

Rainfall is typically heavier with slower moving storms as slower
moving tropical cyclones allow heavy rain to persist over a location.

What types of inland flooding are caused by tropical cyclones?
Flash flooding occurs in creeks... streams... and urban areas within a few
minutes or hours of excessive rainfall. Streets can become swift moving
rivers and underpasses can become flooded to dangerous depths.

River flooding occurs from heavy rains associated with decaying
hurricanes or tropical storms, and in extreme cases... river floods can
last a week or more.

How do I know how severe a flood will be?
Within Flood Warning products... the NWS conveys the magnitude of observed
or forecast flooding using flood severity categories. These flood severity
categories include minor flooding... moderate flooding... and major flooding.
Each category has a definition based on property damage and public threat.

Minor flooding... minimal or no property damage... but possibly some public
threat or inconvenience.

Moderate flooding... some inundation of structures and roads near streams.
Some evacuations of people and... or Transfer of property to higher
elevations are necessary.

Major flooding... extensive inundation of structures and roads. Significant
evacuations of people and... or Transfer of property to higher elevations.

The impacts of a floods vary locally. For each NWS river forecast
location... flood stage and the stage associated with each of the NWS flood
severity categories are established in cooperation with local public
officials. Increasing river levels above flood stage constitute minor...
moderate... and major flooding. Impacts vary from one river location to
another because a certain river stage /height/ in one location may have
an entirely different impact than the same level above flood stage at
another location.