Area in the Bahamas 1st tropical wave?

[boca]

In the NWS discussion they mention an inverted trough.I wonder if that is a tropical wave. Maybe they don't want to call it a tropical wave because its March.What do you think?

A WEAK INVERTED TROUGH WILL APPROACH SOUTH FLORIDA TONIGHT INTO
THURSDAY. THIS WILL ALLOW FOR AN INCREASE IN LOW LEVEL MOISTURE
ACROSS THE REGION WHICH WILL BRING AN INCREASE SHOWER CHANCE LATER
TONIGHT AND INTO THURSDAY. THE BEST CHANCE OF SHOWERS WILL BE
ACROSS THE SOUTHEAST PORTION OF THE SOUTH FLORIDA PENINSULA AS
WELL AS THE ATLANTIC COASTAL WATERS. THERE WILL ALSO BE ENOUGH LOW
LEVEL MOISTURE IN PLACE TO SUPPORT PATCHY FOG TONIGHT ACROSS
INTERIOR AND WESTERN SECTION. THE INVERTED TROUGH WILL BE MOVING AWAY
FROM THE REGION ON FRIDAY AND HIGH PRESSURE WILL BEGIN TO BUILD
BACK INTO THE AREA. THERE IS A SLIGHT CHANCE OF A SHOWER ON FRIDAY
WITH THE EASTERLY WIND FLOW.

[cycloneye]

The 8 PM EDT NHC discussion only mentions this:

WIDELY
SCATTERED MODERATE CONVECTION IS NOTED OVER THE BAHAMAS FROM
24N-27N BETWEEN 73W-78W.

I can tell you that the first Tropical Wave that was analized last year became introduced on May 15th on the 12z package. Will 2012 have the first wave before or after May 15th?