-28° to 72° in 6 days: a wild ride in Oklahoma
The plants and animals of northeast Oklahoma are officially freaking out. Cold air pouring in behind last week's remarkable snowstorm over northeast Oklahoma brought unprecedented cold to the state on February 10, with a bone-chilling -31°F recorded at Nowata and -28°F at Bartlesville. These were the coldest temperatures ever measured in Oklahoma. But what a difference a week makes! Yesterday afternoon, just six days after experiencing -28°F, Bartlesville hit 72°F--an incredible 100°F temperature swing in just six days. Nearby Ponca City, which hit -25°F six days previously, hit 75°F yesterday, also achieving a 100°F temperature swing in just six days.
Figure 1. Record snows of 25" piled up in northeast Oklahoma near Afton on February 9, 2011. The fresh coasting of snow, which is a very excellent emitter of infrared radiation to space, enabled temperatures in Northeast Oklahoma to plunge to record lows on the morning of February 10. Image credit: wunderphotographer Bladerider.
A 100+ degree temperature change in just six days is a phenomenally rare event. I checked the records for over twenty major cities in the Midwest in Oklahoma, Texas, Kansas, Wyoming, Nebraska, South Dakota, North Dakota, and Montana, and could not find any examples of a 100-degree temperature swing in so short a period of time. The closest I came was a 108° swing in temperature in fourteen days at Valentine, Nebraska, from -27°F on March 11, 1998 to 82°F on March 25, 1998. Valentine also had a 105°F temperature swing in fifteen days from November 29, 1901 (71°F) to December 14, 1901 (-34°F.) Our weather historian, Christopher C. Burt, lists the world record for fastest 24-hour change in temperature as the 103°F warm-up from -54° to 49° that occurred on January 14 - 15, 1972, during a chinook wind in Lowe, Montana. This week's remarkable roller coaster ride of temperatures in Oklahoma is truly a remarkable event that has few parallels in recorded history.
Darwin sets its all-time 24-hour rainfall record
Darwin, Australia suffered its greatest 24-hour rainfall in its history on Wednesday, when a deluge of 13.4 inches (339.4 mm) hit the city when Tropical Cyclone Carlos formed virtually on top of city and remained nearly stationary. Over the past three days, Carlos has dumped a remarkable 25.37" (644.6 mm) of rain on the Darwin (population 125,000), capital of Australia's Northern Territory. Carlos has moved slowly inland today, and continues to dump rain on Darwin, but these rains will gradually subside over the next few days as the storm weakens and moves farther inland. Not surprisingly, the rains have triggered major flooding in the Darwin area. The heavy rains in Darwin are due to the very slow motion of the storm, which has been able to keep a significant portion of its circulation over the warm 30°C (86°F) waters off the coast. These water temperatures are near normal for this time of year. Australia's west coast is also watching Tropical Cyclone Dianne, which is expected to remain offshore as it moves southwards, parallel to the coast.
Figure 2. Radar image of Tropical Cyclone Carlos taken at 14:35 UTC on February 17, 2011. Spiral bands from Tropical Storm Carlos were rotating clockwise onto shore near Darwin, adding to that city's record rainfall totals. Image credit: Australia Bureau of Meteorology.
Carlos' deluge add to the misery of flood-weary Australia, which has suffered from some of its greatest natural disasters in history in 2011. Earlier this month, Category 4 Tropical Cyclone Yasi smashed into Queensland with 155 mph winds, making it the strongest hurricane to hit Queensland since at least 1918. Yasi was the second most expensive tropical cyclone ever to hit Australia, with damages currently estimated near $3 billion. Australia is still reeling from torrential deluges that affected the states of Queensland and Victoria November - January, triggering flooding that caused the most expensive natural disaster in Australian history. Damage estimates of the flood are speculative, but range from $10 - $30 billion. The floods were spawned by the rainiest September - November (spring) and December in Queensland's history, driven in part by La Niña-enhanced sea surface temperatures along the coast that were the warmest on record. However, all rivers in the flooded eastern half of Queensland have now fallen below flood level. Rainfall amounts in the coming week are expected to be in the 1 - 4 inch range, which should not cause any significant new flooding problems.
Tropical Cyclone Bingiza makes a 2nd landfall in Madagascar
On Monday, Tropical Cyclone Bingiza roared ashore over Northern Madagascar as a dangerous Category 3 hurricane with 115 mph winds. The storm is being blamed for six deaths, has left 15,000 homeless, and has destroyed 8,500 buildings. After re-emerging over the waters of the Mozambique Channel between Africa and Madagascar on Tuesday, Bingiza re-intensified, and made a second landfall along the southwest coast of Madagascar early today as a tropical storm. Bingiza is expected to dissipate over Madagascar tomorrow, but not before dumping very heavy rains capable of causing additional flooding problems on Madagascar's deforested mountain slopes.
Figure 3. Visible satellite image of Tropical Cyclone Bingiza making its second landfall over Madagascar at 14 UTC on February 17, 2011. Image credit: Navy Research Lab, Monterey.
Bingiza is just the second tropical cyclone in the Southwest Indian Ocean (west of 90E) during the 2010 - 2011 season; this is an unusually low amount of activity for the basin. According to an email I received from Sebastien Langlade of the tropical cyclone forecasting office on La Reunion Island, January 2011 was the first January since accurate records began in 1998 that the Southwest Indian Ocean failed to record a single tropical storm. The only other storm in the basin so far this season has been Tropical Cyclone Abele (29 Nov - 4 Dec 2010), a Category 1 storm that stayed out to sea. Bingiza was the 4th major (Category 3 or stronger) tropical cyclone world-wide this year.