Seasonal Trend in Water Vapor Seen from Orbit
"The seasonal trend in the amount of water vapor in Mars' atmosphere,
as observed by thermal emission spectrometer on NASA's Mars Global
Surveyor orbiter, varies by latitude. This plot starts near the
beginning of fall in the southern hemisphere for the year before the
Mars Exploration Rover mission began and ends on August 30, 2004"

When Mars reaches perihelion will be in late southern Spring. This will be in July, 2005. It would be expected that the melting of the southern ice cap and subsequent exposure of water ice would result in a great increase in the amount of water in the atmosphere. However, the data shown in the graph only goes back to the southern Fall so they may not be including the high water content in late Spring and early Summer.
The Hubble images show the clouds over Meridiani in late Spring of 2003. This is when I'm suggesting clouds will again appear over Meridiani in 2005.

Bob Clark