According to the GBP/USD Linear Regression Channel 1H chart :

Yesterday the lower limit of the wider blue channel at 1.5800 served as a strong support for the GBP/USD pair initiating a new bullish move as it was forecasted. 

The bullish move has managed to break the resistance level at 1.5880 allowing the pair to reach the daily high at 1.5972 which corresponds to the upper limit of the yellow channel.

Now the pair is expected to retrace to the downside to test its support levels located at 1.5900 & 1.5840 which correspond to the intermediate and lower limit of the Yellow channel respectively.

A breakdown of these support levels will result in a strong bearish movement near the level 1.5740. However, a bullish reaction towards them allows the pair to resume its bullish movement towards yesterday's high.

A breakdown of the upper limit of the Yellow channel at 1.5972 will initiate a bullish movement towards 1.6030 & 1.6065.