Wind shear has been affecting Tropical Cyclone Iris as it lingers off the coast of eastern Queensland. The Global Precipitation Measurement (GPM) mission core satellite observed how northerly wind shear was pushing Iris’ rainfall to the south of the center.
The GPM core observatory satellite passed over the center of Tropical Cyclone Iris on April 6, 2018 at 0027 UTC (10:27 a.m. AEST local time/April 5 at 8:27 p.m. EDT). Data collected by GPM’s Microwave Imager (GMI) revealed that heavy convective rainfall was sheared to the southeast of Iris’ surface center of circulation. Those GMI data showed that precipitation in that area of strong convection was falling at a rate greater than 59 mm (2.3 inches) per hour while data received by GPM’s Dual Frequency Precipitation Radar (DPR) revealed that very little rain was falling near Iris’ low level center of circulation. The location viewed by GPM’s radar is shown in lighter shades.
GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency, JAXA.
On April 6 at 11 a.m. EDT (1500 UTC) the Joint Typhoon Warning Center (JTWC) noted that Iris had maximum sustained winds near 35 knots (40 mph/62 kph). Iris was centered near 18.9 degrees south latitude and 153.5 degrees east longitude. That’s approximately 464 nautical miles east-southeast of Cairns, Australia. Iris has tracked north-northwestward at 4 knots (4.6 mph/7.4 kph).
JTWC predicts that tropical cyclone Iris “tracks northward it will continue to move into a more favorable vertical wind shear environment which will help to maintain an intensity of 35 knots through 36 hours (early on April 8). Most of the model guidance is indicating that Iris will dissipate by April 8 or sooner.”
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