Tropical Storm Neoguri Hits Japan; NOAA Holds Summer El Niño Odds at 70%

Tropical Storm Neoguri made landfall near the city of Akune in southwest Japan's Kagoshima Prefecture on the island of Kyushu just before 7 a.m. Japanese time Thursday (6 p.m. Wednesday Eastern time in the U.S.). Once a mighty super typhoon with 155 mph winds, the Japan Meteorological Agency estimated that Neoguri weakened to maximum 10-minute sustained winds of 60 mph at landfall (equivalent to maximum winds of about 65 to 70 mph using the U.S. 1-minute sustained wind standard.) Neoguri will track along the east coast of Japan on Thursday, and Japan Meteorological Agency radar showed very heavy rains in excess of one inch (25.4 mm) per hour were affecting portions of the country this morning. On Kyushu, Ebino reported 13.20 inches (335.5 mm) of rain in the 24 hours ending at 8 a.m. Japanese time Thursday, and a 72-hour rainfall total of 398 mm (15.67 inches) was recorded at Ushibuka. Public broadcaster NHK said parts of central Japan, including Nagoya, could see up to 16 inches (400 mm) of rain by Friday morning. Neoguri killed two people and injured 32 in Japan's Ryukyu Islands, which include Okinawa. The islands may have another typhoon to worry about next week--recent runs of the GFS model have been predicting that tropical disturbance 92W will develop into a tropical cyclone and potentially affect the Ryukyu Islands by the middle of next week.


Figure 1. A wooden house collapsed during strong winds in Naha on Japan's southern island of Okinawa on July 8, 2014. (Jiji Press/AFP/Getty Images)

NOAA Holds El Niño Odds at 70% for this Summer
NOAA's monthly El Niño discussion, issued on Thursday July 10, maintains an El Niño watch, and continues to project a 70% chance of El Niño forming this summer, and an 80% chance by fall. The forecasters anticipate El Niño will peak at weak-to-moderate strength during the late fall and early winter, with 3-month values of the Niño-3.4 index between 0.5°C and 1.4°C. The Niño-3.4 index is a measure of the departure from average of sea surface temperatures (SSTs) along the Equator in the Pacific between 120°W - 170°W, 5°N - 5°S. SSTs in this region have been hovering near the threshold for El Niño, +0.5°C from average, from late April through mid-July. However, the atmosphere has not been behaving like it should during an El Niño event. The Southern Oscillation Index (SOI)--the difference in surface pressure between Darwin, Australia and the island of Tahiti--tends to drop to negative values during the presence of an El Niño atmosphere. The SOI has been trending downwards the past 50 days, but was still positive in June. Heavy thunderstorm activity over Indonesia and near the International Date Line is typically enhanced during an El Niño event, and has been picking up over the past month, but must increase more before we can say the atmosphere is responding in an El Niño-like fashion.


Figure 2. Forecasts of the departure of SST from average along the Equator in the Pacific between 120°W - 170°W, 5°N - 5°S as made by computer models that forecast ENSO (the El Niño/Southern Oscillation.) Forecasts above the thick red line indicate an El Niño event; forecasts below the thick blue line are for a La Niña event; forecasts between the red and blue line are for neutral conditions. None of the models are predicting La Niña, and about 2/3 are predicting El Niño. Image credit: IRI/NOAA.

Quiet in the Atlantic
None of the reliable models for predicting genesis of Atlantic tropical cyclones is predicting development over the next five days, and there are no threat areas to discuss. The tropical Atlantic is dominated by dry air and high wind shear, and SSTs are 0.3°C below average in the Hurricane Main Development region between the coast of Africa and Central America, between 10°N - 20°N. If we get another tropical storm this month, the most likely area for formation would be off the Southeast U.S. coast or in the Gulf of Mexico.

Jeff Masters