The newly formed depression moved very slowly due to weak steering currents aloft. Moving towards the east-northeast over weak steering currents, the computer models used to predict the movement of the depression varied greatly, with one predicting an eventual Mexican landfall. Located in conditions ideal for tropical development, the developing cyclone formed a central dense overcast, a large area of deep convection. The depression steadily intensified to become Tropical Storm Adolph on May 26 about south-southwest of Acapulco. Adolph was in a low wind shear environment with warm sea surface temperatures and as such, the NHC forecasted intensification to hurricane status within two days. Adolph turned northward on May 27, a turn influenced by a mid-level ridge building to the east and southeast, thus causing the tropical storm to approach Mexico. A banding eye feature, a type of eye common in minor hurricanes, became apparent on satellite imagery. Convection around the eye deepened while the eye became more pronounced, and Adolph was upgraded to hurricane strength on May 27. On May 28, the hurricane passed within roughly 165 mi (265 km) of the Mexican coastline the next day, its closest approach to land. Shortly thereafter, Adolph turned westward under the influence of a mid-tropospheric ridge. The high upper-oceanic heat content, good outflow, and lack of vertical shear allowed the hurricane to begin a burst of rapid intensification, dropping 1.46 mbars per hour. While reducing in size, Adolph reached its peak strength of 145 mph (230 km/h) on May 29. Dvorak classifications reported a T-number of 7.0 for Adolph, equivalent to a low-end Category 5 hurricane on the Saffir-Simpson Hurricane Scale. However, because of a lack of data from the storm via Hurricane Hunters, these strength measurements may be disputed.