Tropical and Monsoonal Rain Brings Life-Threatening Flooding to India, Pakistan

By Eric Leister, Meteorologist

July 30,2015; 10:18PM,EDT

 

 

After lessening for much of July, monsoonal rain has increased across India and southeastern Pakistan over the past few days resulting in record rainfall and flooding.
This uptick in rainfall is being partially generated primarily by now weakened Tropical Cyclone 02B that will continue to impact northeastern India and Bangladesh, but also by a monsoon low impacting northwestern India and eastern Pakistan.
"The wet pattern may even spill into the first full week of August," stated AccuWeather Senior Meteorologist Jason Nicholls.

The monsoonal low in northwestern India and southeastern Pakistan will continue to bring rounds of heavy rainfall to those regions. The Indian states of Rajasthan and Gujarat will receive daily rain and thunderstorms. While the heaviest rain has already fallen for many areas, additional heavy rain and flooding are expected in northern Gujarat and western Rajasthan into Thursday.
Bhuj received more than 432 mm (17 inches) of rain from Monday into Tuesday, more than their average yearly total of 373.7 mm (14.72 inches).
The low in northwestern India will also continue to bring downpours to southeastern Pakistan, supplying Karachi and Hyderabad with more rainfall and the threat for flooding.
Karachi had a huge surplus rain from July 23 to 25, totaling around 75 mm (3.0 inches). Although not an amount many locations would consider catastrophic, this recent rainfall total is more than all of the rain Karachi received in 2013 and 2014 combined. The periods of heavy rain brought both power outages and major travel problems with flooding roads, according to The Siasat Daily.
Hyderabad got into the rain Monday with more than 50 mm (2 inches) falling in parts of the city. Significant rainfall and flooding remain a threat through the middle of the week before the monsoonal low moves into northern Pakistan.
This low will drift northward and weaken late this week, however downpours can still result in flash flooding across parts of northern and central Pakistan where daily rainfall can exceed 75 mm (3 inches).
Meanwhile, Tropical Cyclone 02B has weakened to a low as it moved inland, following the flooding it brought to Bangladesh and Myanmar. Rainfall on Thursday in Teknaf, Bangladesh reached 138 mm (5.46 inches) as the tropical cyclone stat off to the south.
Despite no further warnings, this system will still bring excessive rain and will slowly move westward as torrential rains fall from Myanmar to northeastern India this week. This low will continue to bring a significant flooding threat to the region, including Kolkata.

"Monsoonal moisture plays a big role in crop farming across the country and the economy highly depends on it," stated AccuWeather Meteorologist Jordan Root. "While the rain is welcome, too much can cause crop damage and create flooding. On the other end, too little will induce drought which can devastate crops and drinking supplies."
"The potential exists for some areas to pick up 250 mm (10 inches) of rain in a single day," added AccuWeather Meteorologist Rob Richards in regards to the heaviest downpours the tropical cyclone may unleash.
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"New Delhi will receive some rain through the start of August, but the heaviest rain will remain to the south," continued Nicholls.
Toward the end of the first full week in August, Nicholls expects the monsoon to quiet down across India and stay quiet, leading to August being drier than normal. The pulse of instability that is helping to reactivate the monsoon will depart, resulting in less rain and fewer thunderstorms.
"All monsoons have these breaks and active periods," stated Nicholls. "However, during most El Nino years [as what this year is], the drier breaks tend to be longer and lead to drier-than-normal conditions."
As the monsoonal rain and thunderstorms lessen, heat can build and put the region further at risk for drought.
Senior Meteorologist Kristina Pydynowski and Meteorologist Courtney Spamer contributed to this story.