ACR CAPT MISREADS RADAR SUMMARY.

Narrative

WE WERE COMING FROM WEST COAST TO TEXAS ALL DAY WE HAD SEEN RADAR SUMMARIES SHOWING WX IN CENTRAL TEXAS AND W TEXAS AREAS. WE WERE ON OUR LAST LEG WHEN I GOT A RADAR SUMMARY SUDDENLY SHOWING NO WX AT ALL IN W TEXAS. ALL THE PREVIOUS WX HAD APPARENTLY DISSIPATED AS THE SUN WAS SETTING OR SO WE THOUGHT. I COMMENTED THAT I COULD NOT BELIEVE THE LATEST RADAR SUMMARY. DISPATCH HAD OUR FUEL SLASHED TO A MIN. SO 'NOT BELIEVING' THE RADAR SUMMARY I TOOK EXTRA FUEL FOR OUR LAST LEG FROM ELP TO SAT; CLBING OUT OF ELP WE COULD SEE THE TSTMS STILL QUITE ALIVE AND BLOCKING OUR RTE. WE HAD TO DEV QUITE FAR FROM OUR PLANNED COURSE ENRTE TO SAT AND I WAS GLAD I HAD TAKEN EXTRA FUEL. ON DSCNT I THOUGHT AGAIN ABOUT THE RADAR SUMMARY THAT SHOWED 'NO ECHOS' IN W TEXAS I COULD NOT UNDERSTAND HOW THE TRW'S WE DEVIATED AROUND COULD NOT SHOW UP ON THE SUMMARY! THEN I NOTICED THAT ON MY COPY OF THE RADAR SUMMARY IT DID NOT SAY 'NE' (NO ECHOES) BUT RATHER NA (NOT AVAILABLE) FOR THE W TEXAS AREA! THE 'NA' HAD FOOLED BOTH MYSELF AND DISPATCH! I STRONGLY SUGGEST THAT THE RADAR SUMMARIES BE CHANGED SO THAT ANY AREA WITH RADAR 'NOT AVAILABLE' BE NOTED BY A QUESTION MARK (?) OR SOME OTHER SYMBOL THAT DOES NOT SO CLOSELY RESEMBLE THE NE OF 'NO ECHOES!'