GBP/USD has moved below the support implied by the February intraday bullish reversal (1.5573). Further weakness is favoured. Supports can be found at 1.5491 (02/08/2012 low) and 1.5394 (12/07/2012 low). An hourly resistance is at 1.5689 (13/02/2013 high).
The medium-term double-top (from 1.5829 to 1.6302) implies a downside risk at 1.5356.
In the longer-term, GBP/USD is moving in a horizontal range defined by the strong support at 1.5235 (13/01/2012 low) and the strong resistance at 1.6302 (30/04/2012 high).