Areal Flood Watch
Areal flood watches will be issued when one or more of the following conditions are met:
a. The possibility exists for meteorological, soil, and/or hydrologic conditions to lead to flooding within a 48-hour period; or
b. The possibility exists for meteorological, soil, and/or hydrologic conditions to lead to flooding more than 48 hours into the future and the forecaster determines that the flood watch is the best way to convey this possibility; or
c. A dam or levee may fail and threaten lives or property, but the threat is not deemed to be imminent, or
d. The effective time of a previously issued flood watch changes; and/or
e. The geographic area covered by a previously issued flood watch increases; and/or
f. An update to a previously issued flood watch is required; and/or
g. A cancellation of all or part of a previously issued flood watch is required; and/or
h. The expiration of a previously issued flood watch is to be announced (optional).
Flash Food Warning
Issue a FLASH FLOOD WARNING if
a) flash flooding is reported;
b) precipitation capable of causing flash flooding is indicated by radar, gage reports, and/or satellite;
c) local tools indicate flash flooding is likely;
d) an existing flash flood warning is expiring and needs to be extended;
e) the area covered by an existing flash flood warning increases; or
f) a dam failure, or failure of a naturally caused stream obstruction (debris slide, ice jam) is imminent or occurring.
Issue a FLOOD WARNING for counties or portions of counties when
a) flood monitoring and prediction tools and/or RFC guidance indicate flooding is likely, or
b) when flooding is reported, or
c) when an existing Flood Warning is expiring and needs to be extended, or
d) when the area covered by an existing Flood Warning increases, or
e) the magnitude of flooding changes category (e.g. minor to moderate, etc.).
Flash Flood Statement
Flash Flood Statements should include the following:
a. Appropriate headline (...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SULLIVAN COUNTY IN CENTRAL NEW HAMPSHIRE UNTIL 630 PM HAS BEEN CANCELLED...)
b. Area affected
c. Cancellation notice or updated warning information
d. Call-to-action statement (if appropriate)
e. Updated impact information
f. Additional information including reports, observed data, etc.
Issue a HYDROLOGIC STATEMENT
a) to provide information on significant rises on rivers and streams when no flooding is expected; or
b) to provide other hydrologic information of interest to customers and partners when no flooding is expected.