Because its a V like this: < if you look closely.

ANOTHER WELL-DEFINED RATHER LARGE TROPICAL WAVE IS ADJUSTED
AHEAD ALONG 62W/63W SOUTH OF 18N MOVING WEST 15-20 KT. THIS WAVE
IS GENERATING SCATTERED MODERATE TO STRONG SHOWERS AND
THUNDERSTORMS ACROSS THE EASTERN CARIBBEAN. THIS MOISTURE WILL
SPREAD ACROSS PUERTO RICO AND HISPANIOLA LATER TODAY AND
TOMORROW PRODUCING AREAS OF HEAVY RAINFALL. A MODERATE TO STRONG SURGE IN THE TRADE WINDS WILL FOLLOW THIS SYSTEM ACROSS THE CARIBBEAN SEA.

If anyone knows which wave this one is below, please tell me. (the one above is the one we have been talking about).

A TROPICAL WAVE IS ADDED TO THE 12 UTC ANALYSIS ALONG 20W/21W
SOUTH OF 13N MOVING WEST NEAR 15 KT. THIS WAVE IS WELL DEFINED
WITH A LOW-MID LEVEL CIRCULATION NEAR 7N. THIS FEATURE IS
GENERATING A LARGE AREA OF SHOWERS AND TSTMS FROM 2N-12N BETWEEN
14W-27W. COMPUTER MODELS HAVE A GOOD HANDLE ON THE
INITIALIZATION OF THIS WAVE AND TRACK IT TO THE WNW NEAR 15 KT
AS A WELL-DEFINED TROPICAL WAVE OR POSSIBLY A WEAK LOW PRES
SYSTEM.