Hurricane Tracker Updates Show Heavy Rain and Red Alerts Hit Delhi

Hurricane tracker updates show heavy rain and thunderstorms triggered red alerts in Delhi while record rainfall from an unusually slow-moving storm system caused deadly flooding in Chiba, Japan, and ongoing flood warnings remain in effect in parts of Ohio as severe weather impacts multiple regions globally.

Delhi Issues Red Alert Amid Heavy Rain

Heavy rain lashed parts of Delhi on Friday as the weather office issued a red alert for the next few hours. [1] Several areas, including central Delhi, received light to moderate rain, while the India Meteorological Department forecast moderate to heavy rainfall in many parts of the city. [1] The IMD's district-level nowcast issued a red alert in view of the forecast for moderate to heavy rainfall of up to and exceeding 15 mm per hour in parts of the city. [4] Meteorologists said Delhi could also see light to moderate rain in the evening, with rainfall activity expected to continue over the city for the next two days, till Sunday. [1] The capital remained under a blanket of clouds as preparations continued for the BRICS Summit. [4] Parts of central and north Delhi, including the Parliament Street and Bharat Mandapam areas, received light to moderate rain. [4] The India Meteorological Department, in an update issued at 1 pm, said several areas could receive light to moderate rain of up to 15 mm per hour, while some parts may see heavy rainfall exceeding 15 mm per hour over the next few hours. [4] Experts said the rain was due to the monsoon axis passing over the city. [4]

Japan Analysis Reveals Causes of Deadly Chiba Downpour

A rare thunderstorm system that would normally move rapidly instead remained nearly stationary for hours over Chiba Prefecture last month, contributing to the record rainfall that killed at least 13 people, researchers said Thursday. [5] A preliminary analysis by the Meteorological Research Institute said a squall-line-type precipitation system was responsible for the Aug. 13 downpours. [5] In Chiba, however, the storm remained near the Boso Peninsula, with its northern portion lingering there for more than six hours. [5] The city of Chiba recorded 367 millimeters of rain over 24 hours, the highest level ever observed there. [5] Researchers said the storm’s movement was likely suppressed by opposing air flows. [5] The central and southern portions of the storm moved only about 20 to 30 kilometers between 6 p.m. and 9 p.m., while its northern section stayed almost stationary for over six hours. [5]

Flood Warnings Continue in Southeastern Ohio

Flooding caused by prior excessive rainfall continues in northern Jackson County in southeastern Ohio until 8:30 AM EDT. [2] At 5:00 AM EDT, emergency management reported lingering high water across portions of the warned area from prior heavy rainfall last evening. [2] Flooding of rivers, creeks, streams, and other low-lying and flood-prone locations is imminent or occurring. [2] Flooding caused by prior excessive rainfall continues in north central Gallia County in southeastern Ohio until 8:30 AM EDT. [3] At 4:45 AM EDT, emergency management reported lingering high water across portions of the warned area from prior heavy rainfall last evening. [3] Flooding of rivers, creeks, streams, and other low-lying and flood-prone locations is imminent or occurring. [3]

Forecast for BRICS Summit in Delhi

The capital remained under a blanket of clouds as preparations continued for the BRICS Summit, scheduled for September 12 and 13. [4] India Meteorological Department has forecasted multiple spells of rain on September 12 and 13. [4] For Saturday, the first day of the summit, IMD has forecast one or two spells of very light to light rain, accompanied by thunderstorm and lightning, at many places from early morning to forenoon, followed by another spell of light to moderate rain from evening to night. [4] Due to rain, the city’s maximum temperature, which recorded a high of 36.6°C on Thursday, is expected to dip and remain below 33°C from Saturday. [4] Meanwhile, due to the lack of rain over the past couple of days, the city’s overall air quality index rose, with the Central Pollution Control Board recording 134 on Thursday. [4]

Scientific Insights from the Chiba Event

The system developed in two stages. [5] Daytime rainfall first created a pool of cold air over inland parts of the Kanto region. [5] Near the Boso Peninsula, warm air flowing in from the Pacific met the cold air, forming a localized boundary known as a shear line. [5] From around 5:30 p.m., rainfall from those clouds strengthened the cold-air layer and pushed the boundary outward into a bow shape, creating what meteorologists call a gust front. [5] At the same time, a strong current known as a rear-inflow jet developed on the western side of the system, helping intensify the front and fuel further thunderstorm growth. [5] The clouds repeatedly regenerated above the gust front and reached heights of more than 15 km. [5] Researchers also detected a counterclockwise vortex about 2 to 5 km in diameter inside thunderclouds in the northern part of the system, where some of the heaviest rainfall occurred. [5] The vortex, found at an altitude of roughly 1 to 3 km, may have locally strengthened upward air currents and accelerated the formation of precipitation particles, contributing to the extreme rainfall, the institute said. [5]

What to watch next: The institute said the findings remain preliminary and that researchers plan further analysis to determine more precisely how the opposing air masses allowed the storm to remain in place for so long, which could eventually help improve monitoring and forecasting of similar extreme rainfall events.

Further Reading

• Hurricane Tracker