WEST LAFAYETTE, Ind. — If it has already rained, it’s going to continue to pour, according to a Purdue University study of how ocean-origin storms behave when they come ashore.

Storm clouds gather as India braces for a storm during monsoon season.

More than 30 years of monsoon data from India showed that ground moisture where the storms make landfall is a major indicator of what the storm will do from there. If the ground is wet, the storm is likely to sustain, while dry conditions should calm the storm.

“Once a storm comes overland, it was unclear whether it would stall, accelerate or fizzle out,” said Dev Niyogi, Indiana state climatologist and associate professor of agronomy and earth and atmospheric sciences. “We found that whether a storm becomes more intense or causes heavy rains could depend on the land conditions – something we’d not considered. Thus far we’ve looked at these storms based mainly on ocean conditions or upper atmosphere.”

Niyogi said tropical storms gain their strength from warm ocean water evaporation.

“The same phenomenon – the evaporation from the ocean that sustains the storms – could be the same phenomenon that sustains that storm over land with moisture in the soil,” he said. “The storm will have more moisture and energy available over wet soil than dry.”

Niyogi’s team’s findings were published in the August edition of the journal Geophysical Research Letters.

Storm data fed into a model showed that higher levels of ground moisture would sustain Indian monsoon depressions. The model’s prediction was proven when compared to ground conditions for 125 Indian monsoons over 33 years, where storms sustained when the ground was wet at landfall.

Knowing the sustainability of a storm could lead to better predictions on flooding and damage inland before a monsoon or a hurricane makes landfall.

“We think the physics is such that we could see similar results more broadly, such as in the United States,” Niyogi said.

The National Science Foundation and NASA funded the research. The Purdue led-team also consisted of researchers from the National Center for Atmospheric Research, NASA-GSFC/ESSIC, the University of Georgia, the Indian Space Research Organization and the Indian Institute of Technology Delhi.

Niyogi said the next step is to use the model and ground moisture data to test these theories for hurricanes in the United States.

WEST LAFAYETTE, Ind. — As spring approaches, Purdue emergency preparedness officials are urging the campus community to review the university’s severe weather procedures and know their shelter-in-place locations.

March 15-21 is Severe Weather Awareness Week, and tests of the all-hazards warning sirens, along with a pair of free tornado awareness training sessions, are scheduled on campus.

The Tippecanoe County Emergency Management Agency will sound the sirens between 10-10:30 a.m. and between 7-7:30 p.m. March 18. The tests’ objectives are to ensure the sirens are operational, to allow the community to hear what they sound like, and to emphasize severe weather awareness and the need to prepare. If there is a threat of severe weather during that day, the tests will be postponed. The tests coincide with statewide siren testing.

Tornado awareness training sessions are scheduled for 10:30-11:30 a.m. March 27 and April 3 in the Terry Memorial Conference Room at the Purdue Police Department.

The tornado awareness training sessions are scheduled for 10:30-11:30 a.m. March 27 and April 3 in the Terry Memorial Conference Room at the Purdue Police Department. The training, offered through the university’s Emergency Preparedness and Planning Office and facilitated by Purdue fire safety specialist Tom Cooper, is free and open to faculty, staff and students. The training is designed to provide tornado awareness information and recommended response actions during and after the incident. Those interested in attending one of the sessions should contact Mary Stair at 765-494-1424.

Cooper also is available to speak in campus offices or departments. For more information, contact him at 765-494-1432 or at tncooper@purdue.edu.

Ron Wright, director of Campus Emergency Preparedness recommends that the campus community review severe weather response actions. Information is available on the Purdue home page weather link at http://news.uns.purdue.edu/weather.html. Links on the Web page provide awareness pointers and recommended emergency kits. Each Purdue building should have a building emergency plan that provides specific evacuation and shelter-in-place procedures, and the awareness week provides an opportunity to review those plans, Wright said. The plan is normally developed and maintained by the building deputy or the Building Safety Committee.