The primary modes of Pacific Sea Surface Temperature (SST) variability for 1950-1993 are extracted with Rotated Principal Component Analysis (RPCA), yielding, as the first three modes, the El Nino-Southern Oscillation (ENSO) mode, a mode with ENSO-like spatial structure but considerable interdecadal variability, and a mode with a North Pacific center of action and, also, considerable interdecadal variability. All three SST modes are shown to have a robust relationship to United States warm season hydroclimatology, in terms of station precipitation, the Palmer Drought Severity Index (PDSI), and river flow. In particular, considering the drought relationships of the three SST modes together appears to yield some insight into two major droughts of the century, reproducing the main elements of the large scale patterns during the warm season for the 1952-1957 and the 1961-1966 droughts, albeit with smaller magnitude than observed. Monthly analysis is shown to be necessary to resolve the precipitation relationships. The river flow relationships are examined for different drainage basins in the U.S., with an emphasis on the lagged nature of the relationship with precipitation