IHOP: International H2O Project (IHOP)


IHOP, an NCAR-led experiment, took place in May and June of 2002 over the Southern Great Plains. In one of the largest-ever field experiments in North America, scientists from the U.S. and several foreign countries teamed to improve characterization of the four-dimensional distribution of water vapor and its application to improving the understanding and prediction of thunderstorms. Airflow, temperature, and humidity data were collected with a large armada of aircraft and ground-based mobile sensors and fixed-base remote and in-situ sensors.

Drylines and fronts were a key focus of the experiment. Scientists from Canada, France, Germany and the U.S. hoped to enhance their understanding of the process of convection initiation and boundary evolution, and learn what types of data are needed to make forecasts of thunderstorms and rainfall amounts more specific.


To provide current GOES Sounder products in support of the IHOP field campaign over the south central US during the spring of 2002, CIMSS provided provided near real-time displays tailored to the IHOP domain. Presentations of the Derived Product Images (DPI) of profile parameters in clear air, such as, total precipitable water (PW in [mm]), lifted index stability (LI in [C]), and surface skin temperature (SKT in [C]), show hourly imagery over the last six hours. "Pseudo DPI" were also available, for Convective Available Potential Energy (CAPE) and Convective Inhibition (CIN), where an image was created from retrieval profiles, "after the fact". In addition, cloud top pressure (CTP in [hPa]) DPI was also provided.

Cooperative Institute for Meteorological Satellite Studies (CIMSS), University of Wisconsin-Madison


Related Websites


  • Champollion, C.; Flamant, C.; Bock, O.; Masson, F.; Turner, D. D., and Weckwerth, T. Mesoscale GPS tomography applied to the 12 June 2002 convective initiation event of IHOP 2002. Quarterly Journal of the Royal Meteorological Society v.135, no.640, 2009, pp645-662. Reprint #6076.

  • Demoz, Belay; Flamant, Cyrille; Weckwerth, Tammy; Whiteman, David; Evans, Keith; Fabry, Frederic; Di Girolamo, Paolo; Miller, David; Geerts, Bart; Brown, William; Schwemmer, Geary; Gentry, Bruce; Feltz, Wayne, and Wang, Zhien. The dryline on 22 May 2002 during IHOP_2002: Convective-scale measurements at the profiling site. Monthly Weather Review v.134, no.1, 2006, pp294-310. Reprint #4998.

  • Knuteson, Robert, Antonelli, Paolo, Best, Fred, Dutcher, Steve, Feltz, Wayne, and Revercomb, Henry. The University of Wisconsin-Madison participation in the International Water-Vapor Project (IHOP). Final report on NASA Grant NAG-1-02057. Madison, WI, University of Wisconsin-Madison, Space Science and Engineering Center, 2003. Unpaged. UW SSEC Publication No.03.00.K1.

  • Li, Jun; Li, Jinlong; Otkin, Jason; Schmit, Timothy J., and Liu, Chian-Yi. Warning information in a preconvection environment from the geostationary advanced infrared sounding system – a simulation study using the IHOP case. Journal of Applied Meteorology and Climatology v.50, no.3, 2011, pp776-783. Reprint #6426.

  • Rasmussen, Erik N.; Buban, Michael S.; Richardson, Yvette P.; Miller, L. Jay, and Rabin, Robert M. The “triple point” on 24 May 2002 during IHOP, part II: Ground-radar and in situ boundary layer analysis of cumulus development and convection initiation. Monthly Weather Review v.135, no.7, 2007, pp2443-2472.

  • Tanamachi, Robin L.; Feltz, Wayne F., and Xue, Ming. Observations and numerical simulation of upper boundary layer rapid drying and moistening events during the International H2O Project (IHOP_2002). Monthly Weather Review v.136, no.8, 2008, pp3106-3120. Reprint #5800.

  • Weckwerth, Tammy M.; Parsons, David B.; Koch, Steven E.; Moore, James A.; LeMone, Margaret A.; Demoz, Belay B.; Flamant, Cyrille; Geerts, Bart; Wang, Jungong, and Feltz, Wayne F. An overview of the International H2O Project (IHOP_2002) and some preliminary highlights. Bulletin of the American Meteorological Society v.85, no.2, 2004, pp253-277. Reprint #3696.