Predecessor rain event

(abbreviated PRE). A coherent mesoscale region of heavy rainfall, with rainfall rates ≥ 100 mm in 24 hours, that can occur as far away as 1000 km poleward of a recurving tropical cyclone and is sustained by deep tropical moisture that is transported poleward directly from the tropical cyclone.

PREs occur most commonly in August and September, and approximately 36 hours prior to the arrival of the main rain shield associated with the tropical cyclone.  A distinguishing feature of PREs is that they are sustained by deep tropical moisture that is transported poleward directly from the tropical cyclone.  PREs are high-impact weather events that can often result in significant inland flooding, either from the PRE itself or from the subsequent arrival of the main rain shield associated with the tropical cyclone that falls onto soils already saturated by the PRE.

Galarneau, T. J., L. F. Bosart, and R. S. Schumacher, 2010: Predecessor rain events ahead of tropical cyclones. Mon. Wea. Rev., 138, 3272–3297, https://doi.org/10.1175/2010MWR3243.1.

Cote, M. R., 2007: Predecessor rain events in advance of tropical cyclones. M.S. thesis, Dept. of Atmospheric and Environmental Sciences, University at Albany, State University of New York, 200 pp., https://vlab.noaa.gov/documents/2121416/4053968/Cote_Thesis.pdf.