edu.ucar.opensky::articles:16877 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T03:02:40.707777 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7wq051z https://doi.org/10.5065/D60R9MF6 https Related Dataset #1 NOAA CPC Morphing Technique (CMORPH) Global Precipitation Analyses Version 0.x Influence of a predecessor rain event on the track of Tropical Cyclone Isaac (2012) 2015-09-01T00:00:00Z publication https://n2t.org/ark:/85065/d7wq051z https://doi.org/10.1175/MWR-D-15-0053.1 Galarneau, Thomas author UCAR/NCAR - Library publisher Analysis of a predecessor rain event (PRE) over the Straits of Florida ahead of Tropical Cyclone (TC) Isaac on 25 August 2012 is presented. This PRE is unique compared to previously documented PREs in midlatitudes because it occurred over the oceanic subtropics and impacted the track of an approaching TC. The Isaac PRE developed in conjunction with a tropical moisture plume with precipitable water values over 60 mm that intersected a region of mid- and upper-level frontogenesis and warm air advection on the southeast flank of an upper-level trough. The PRE occurred in an environment with more abundant tropical moisture and weaker synoptic-scale forcing for ascent compared to the environments in which midlatitude PREs developed. The Isaac PRE contributed to the fracture of the upper-level trough through negative potential vorticity advection by convectively driven divergent outflow. Fracture of the upper-level trough and midlevel cyclonic vorticity amplification associated with the PRE acted to steer Isaac south of Florida into the Gulf of Mexico. Forecasts from the National Centers for Environmental Prediction–Global Forecast System (NCEP-GFS) initialized at 0000 UTC 21-24 August 2012 failed to predict the PRE and as a result recurved TC Isaac over Florida and the eastern Gulf of Mexico rather than continued Isaac on a northwest course toward southeast Louisiana. Vorticity inversion and detailed diagnosis of the NCEP-GFS TC track forecast initialized at 0000 UTC 22 August is also presented to assess the relationship between the PRE and TC Isaac's track. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2015 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be "fair use" under Section 107 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Law (17 USC, as revised by P.L. 94-553) does not require the Society's permission. Republication, systematic reproduction, posting in electronic form on servers, or other uses of this material, except as exempted by the above statements, requires written permission or license from the AMS. Additional details are provided in the AMS Copyright Policies, available from the AMS at 617-227-2425 or amspubs@ametsoc.org. Permission to place a copy of this work on this server has been provided by the AMS. The AMS does not guarantee that the copy provided here is an accurate copy of the published work. None eng geoscientificInformation