[KYHAM] KEN Training March 10: Weather Service Alerting Products

[Ron Dodson]

Severe storms will soon roll over the Commonwealth and 
create the need for us to again serve as the eyes 
of the BWSFO's state-wide.  These next few weeks 
we'll be reviewing some information about the 
National Weather Service and our part in storm
spotter operations.  As communicators, we relay
information from point to point, however...

REMEMBER, AMATEURS DO NOT ISSUE WATCHES or WARNINGS!  

We communicate the existence of any alerts issued by
National Weather Service Field Offices (NWSFO's) to other
amateurs and collect any pertinent information about storm
activity for relay back to NWSFO meteorologists who make
further determinations about needs for watches and
warnings.  Let's look at some of the "products" provided by
NWSFO's in severe weather situations that may confront us. 
These were quoted directly from NWS literature...

           TORNADO WATCH
Conditions are favorable for the development of
tornadoes in and close to the watch area. Watches
are usually in effect for several hours, with 6 hours
being the most common.

           TORNADO WARNING
Tornado is indicated by radar or sighted by storm
spotters. The warning will include where the tornado
is and what towns will be in its path.

           SEVERE THUNDERSTORM WATCH
Conditions are favorable for the development of
severe thunderstorms in and close to the watch area.
Watches are usually in effect for several hours, with 6
hours being the most common.

          SEVERE THUNDERSTORM WARNING
Issued when a thunderstorm produces hail 3/4 of an
inch or larger in diameter and/or winds which equal
or exceed 58 mph. Severe thunderstorms can result
in the loss of life and/or property. Information in this
warning includes: where the storm is, what towns will
be affected, and the primary threat associated with
the storm.

          SEVERE WEATHER STATEMENT
Issued when the forecaster wants to follow up a
warning with important information on the progress
of severe weather elements.

           FLASH FLOOD WATCH
Indicates that flash flooding is possible in and close
to the watch area. Those in the affected area are
urged to be ready to take quick action if a flash flood
warning is issued or flooding is observed.

           FLASH FLOOD WARNING
Signifies a dangerous situation where rapid flooding
of small rivers, streams, creaks, or urban areas are
imminent or already occurring. Very heavy rain that
falls in a short time period can lead to flash flooding,
depending on local terrain, ground cover, degree of
urbanization, degree of man-made changes to river
banks, and initial ground or river conditions.

       URBAN AND SMALL STREAM FLOOD ADVISORY
Alerts the public to flooding which is generally only an
inconvenience and does not pose a threat to life
and/or property. Issued when heavy rain will cause
flooding of streets and low-lying places in urban
areas, or if small rural or urban streams are expected
to reach or exceed bankfull.

           FLASH FLOOD STATEMENT
Used as a follow-up to Flash Flood Warnings and
Watches. The statement will contain the latest
information on the event.

           SPECIAL WEATHER STATEMENT
Issued to convey update information about severe
weather watches.

     WEATHER WATCH REDEFINING STATEMENT
Issued for every tornado and severe thunderstorm
watch that affects a state. It lists the type of watch, its
corresponding number, the ending time of the watch,
all counties included in the watch, and large cities
 and towns in the watch area.

Next week, Spotter Nets and what to do and NOT do, during
them!