A comprehensive data catalog of TCs and their associated PREs occurring between 1998 and 2006 was constructed using radar imagery from NCDC, NHC best-track data, the NPVU online QPE archive, and NWS precipitation data gleaned from online sources. NCEP/NARR gridded datasets provided insight into the key synoptic-scale features responsible for the PREs. Required criteria for inclusion of an event in the PRE dataset were evidence that the TC circulation advected moist tropical air toward the region of PRE formation, and that maximum rainfall directly attributed to the PRE exceeded a rate of 100 mm in 24 h.
Statistical analysis showed that a typical PRE is located ~1000 km ahead of the parent tropical system, occurs 1-2 days prior to the arrival of the TC at the latitude of the PRE, and lasts for ~12 hr, though some significant variability was noted. Detailed examination of environmental flow patterns revealed that a middle- and upper-level jet-entrance-region confluence zone well downstream of an approaching TC was a favored synoptic location for PRE development. The orientations of midlatitude troughs and ridges poleward of the TC modulated whether and where a PRE formed, but there was a strong tendency for the TCs in the dataset to spawn PREs left of their eventual tracks. A climatological and case-study approach will be used to demonstrate these points.