20040424: Sev Thunderstorm & Flash Flood Warnings

NOUS41 KWBC 231753
PNSWSH

SERVICE CHANGE NOTICE 04-27
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
155 PM EDT FRI APR 23 2004

TO:       FAMILY OF SERVICES /FOS/ SUBSCRIBERS...NOAA WEATHER
         WIRE SERVICE /NWWS/ SUBSCRIBERS... EMERGENCY MANAGERS
         WEATHER INFORMATION NETWORK /EMWIN/ SUBSCRIBERS...
         NOAAPORT SUBSCRIBERS... OTHER NATIONAL WEATHER SERVICE
         /NWS/ CUSTOMERS... PARTNERS...AND USERS OF THE FIRE
         WEATHER FORECAST...NWS EMPLOYEES

FROM:     JAMES E. LEE
         CHIEF...FIRE AND PUBLIC WEATHER SERVICES BRANCH

SUBJECT:  COMBINED SEVERE THUNDERSTORM AND FLASH FLOOD WARNINGS
         TO BE ISSUED IN SOUTHWESTERN UNITED STATES THIS MONSOON
         SEASON: EFFECTIVE JULY 1 2004

EFFECTIVE THURSDAY JULY 1 2004 AT 1200 COORDINATED UNIVERSAL TIME
/UTC/...NATIONAL WEATHER SERVICE /NWS/ WEATHER FORECAST OFFICES
/WFO/ IN THE SOUTHWESTERN U.S. WILL BEGIN ISSUING COMBINED SEVERE
THUNDERSTORM AND FLASH FLOOD WARNINGS WHEN CONDITIONS MEETING
CRITERIA FOR BOTH TYPES OF WARNINGS OCCUR FROM THE SAME
THUNDERSTORM. NWS WEATHER FORECAST OFFICES PARTICIPATING IN THE
COMBINED WARNING PROGRAM AND THE AFFECTED PRODUCTS ARE SHOWN IN
TABLE 1.

THE COMBINED WARNINGS AND FOLLOW-UP STATEMENTS WILL BE ISSUED
USING THE FLASH FLOOD WARNING /FFW/ AND FLOOD STATEMENT /FLS/
IDENTIFIERS.

THE COMBINED WARNINGS WILL BE IMPLEMENTED AS PART OF THE FIELD
TESTING OF THE VALID TIME AND EVENT CODE /VTEC/ BY THE NWS THIS
SUMMER. TRADITIONAL FLASH FLOOD WARNINGS WILL CONTAIN A SINGLE
PRIMARY VTEC LINE...WHILE COMBINED WARNINGS WILL CONTAIN TWO
PRIMARY VTEC LINES: ONE FOR THE FLASH FLOOD WARNING AND ONE FOR
THE SEVERE THUNDERSTORM WARNING.  FURTHER DETAILS ON THE USE OF
VTEC CODE CAN BE FOUND AT THE FOLLOWING WEB SITE /USE LOWER CASE
LETTERS/:

   http://www.nws.noaa.gov/om/vtec/

EXAMPLES OF THE COMBINED WARNINGS PRODUCT CAN BE SEEN AT THE
FOLLOWING WEB SITE /USE LOWER CASE LETTERS/:

http://weather.gov/os/severeweather/combined_warning04example.pdf

CUSTOMERS WHO ALREADY RECEIVE NWS FLASH FLOOD WARNINGS DO NOT
HAVE TO MAKE ANY CHANGES IN ORDER TO RECEIVE THE COMBINED
WARNINGS. TABLE 1. SOUTHWESTERN U.S. COMBINED WARNING PRODUCT
HEADERS...EFFECTIVE JULY 1 2004

                           WMO HEADING AND AWIPS ID
OFFICE              WARNING              FOLLOW-UP STATEMENT

TUCSON AZ /TWC/     WGUS55 KTWC FFWTWC  WGUS85 KTWC FLSTWC
PHOENIX AZ /PSR/    WGUS55 KPSR FFWPSR  WGUS85 KPSR FLSPSR
FLAGSTAFF AZ /FGZ/  WGUS55 KFGZ FFWFGZ  WGUS85 KFGZ FLSFGZ
LAS VEGAS NV /VEF/  WGUS55 KVEF FFWVEF  WGUS85 KVEF FLSVEF
SAN DIEGO CA /SGX/  WGUS56 KSGX FFWSGX  WGUS86 KSGX FLSSGX

IF YOU HAVE ANY QUESTIONS REGARDING THESE NEW PRODUCTS...
PLEASE CONTACT:

         CRAIG SCHMIDT
         DISSEMINATION MANAGER
         NATIONAL WEATHER SERVICE
         WESTERN REGION HEADQUARTERS
         125 SOUTH STATE STREET ROOM 1311
         SALT LAKE CITY UT  84138
         PHONE:  801-524-4000 X266
         E-MAIL: CRAIG.SCHMIDT@xxxxxxxx