Capturing the genesis of Tropical Storm Hermine
NOAA Hurricane Hunters are flying back-to-back missions to study the newly developed Tropical Storm Hermine in the Gulf of Mexico, capturing its evolution from a cluster of thunderstorms into a tropical storm. Getting data during such transitions can help improve hurricane models which currently don’t predict transitions well. Our understanding of the physical processes of early storm development remains limited, largely because there are few observations.
“Several of the hurricane models have been predicting this particular system would develop into a tropical storm or hurricane for over a week,” said Robert Rogers, hurricane researcher at NOAA’s Atlantic Oceanographic and Meteorological Laboratory. “We’d like to understand why it did not intensify days earlier as predicted with a goal of improving the models’ ability to better predict these weak systems.”
Multiple flights into storm
This is the planned flight pattern used to study the development of the current Tropical Storm Hermine. (NOAA)
As hurricane researchers fly into these developing storms to better understand the genesis of tropical cylones, they work closely with modelers to improve NOAA’s ability to forecast storm development. A new model to predict storm development in the North Atlantic Ocean is the Tropical Cyclone Genesis Index, providing forecasters a tool to forecast hurricane formation two to five days in advance. Based on early model predictions, NOAA researchers have been flying into and studying Tropical Storm Hermine since it was an area of investigation, called 99L, and transitioned to tropical depression (TD9), and now a tropical storm.
For 2016, researchers decided to execute a multi-plane experiment to target disturbances that forecasters believe have a chance to become a tropical cyclone. This experiment calls for the NOAA P-3 hurricane hunter to sample the system using Doppler radar, GPS dropwindsondes and flight-level instruments to create a full picture of the structure of the potentially developing system.
When possible, the P-3 will fly coordinated missions with the NASA Global Hawk unmanned aircraft, part of NOAA’s Sensing Hazards with Operational Unmanned Technology (SHOUT) experiment, to increase sampling of the system’s surrounding environment. With missions lasting 24 hours, the Global Hawk flies at 60,000 feet and is equipped with a dropwindsonde system capable of deploying up to 88 of these mini weather stations per mission. The high flying aircraft also uses the NASA Jet Propulsion Laboratory High Altitude Monolothic Microwave Integrated Circuit Sounding Radiometer for measuring temperature and moisture below the cloud canopy, and the High Altitude Wind and Rain Airborne Profiler for observing wind at the ocean surface and in the atmosphere below the plane. The data gathered from both the Global Hawk and P3 will help researchers gain a better understanding of both the storm’s inner-core and processes that cause hurricane intensity to change.
For the latest on storm development please visit www.hurricanes.gov.
For the latest on the NOAA UAS Program and SHOUT visit https://uas.noaa.gov/shout/.