Category 1 Rusty drenching Australia; major winter storm hits Midwest U.S.

Tropical Cyclone Rusty is intensifying as it remains nearly stationary off the coast of northwest Australia, and poses a dangerous heavy rainfall threat to the coast. Rusty peaked at Category 1 strength with 85 mph winds on Monday at 18 UTC, then weakened to 75 mph by 06 UTC on Tuesday, due to a combination of dry wrapping into the center, interaction with land, and the storm's slow movement allowing it to upwell cooler waters from down deep. However, recent satellite loops show that Rusty's eyewall clouds now have colder tops, and the eye has shrunk, indicating that the storm is strengthening. A 7 am EST satellite intensity estimate from NOAA put Rusty at Category 2 strength with 105 mph winds. The storm may intensify even more, thanks to low wind shear of 5 - 10 knots and near-record warm ocean temperatures of 31 - 32°C (88 - 90°F). It's not often that a tropical cyclone gets 31 - 32°C waters to feed off of; these temperature are about 1.5°C (2.7°F) warmer than average for this time of year. Rusty is very close to the coast, though, and doesn't have much time to intensify further. The storm is predicted to make landfall near Port Hedland (population 15,000), on Wednesday between 06 UTC and 12 UTC (1 am - 7 am EST in the U.S.) Port Hedland is Australia's top iron ore export port, which is ironic, considering that a storm named "Rusty" has now shut down the port. With its slow movement, large circulation, and near-record warm waters to feed off, Rusty is going to dump some prodigious rains on the coast of northwestern Australia over the next few days. Radar out of Port Hedland shows very heavy rains have been affecting the coast all day, and sustained winds as high as 55 mph, gusting to 74 mph, have been observed at the Port Hedland airport. Rusty is also capable of causing considerable wind and storm surge damage, and evacuations have been ordered in low-lying areas of Port Hedland. Rusty is the strongest tropical cyclone to affect Australia in the 2012 - 2013 tropical cyclone season.


Figure 1. Tropical Cyclone Rusty at 0545 UTC on February 26, 2013 as seen by NASA's Aqua satellite. At the time, Rusty was a Category 1 storm with sustained 75 mph winds. Image credit: NASA.


Figure 2. Radar image of Rusty showing the large cloud-free eye and an intense band of precipitation to its southwest moving ashore over the coast of Australia near Port Hedland. image credit: Bureau of Meteorology.

Major blizzard pummels Midwest U.S.
Meanwhile, back in the U.S., the second major winter storm in a week is blasting the Midwest with heavy snow and high winds. The snowstorm, dubbed "Rocky", ended this morning in Wichita, Kansas, which got 6.8" of snow. When combined with heavy snows that fell in last week's storm, the 21.0" inches of snow in February 2013 now ranks as Wichita's snowiest month in its history, breaking the old record of 20.5" set exactly 100 years ago in February 1913. The 19" of snow that fell on Amarillo, Texas over a 24 hours period ending yesterday (February 25) was that city's second greatest 1-day snowfall on record, says wunderground's weather historian Christopher C. Burt in his latest blog post. A band of very heavy snow of up to 3" per hour set up over the airport for several hours, accompanied by lightning and thunder. Thundersnow was also reported in Versailles, Illinois this morning, bringing 3" of snow in just 30 minutes. Wunderblogger Lee Grenci has a detailed post on thundersnow, and analyzes the thundersnow episode that occurred during last week's snowstorm ("Q") over the Midwest. The 19" of snow that fell on Amarillo yesterday was equivalent to 1.48" of rain, making Monday the wettest day in the city in over two years (November 11, 2010 was the last time the city got so much precipitation.) While the precipitation from the two major winter storms during the past week will not come anywhere close to busting the Midwest drought, the value of this moisture runs into the billions of dollars for the parched fields and aquifers of the Midwest.


Figure 3. Snowfall amounts from Winter Storm Rocky.

Jeff Masters