New Delhi:

Heavy rainfall across large parts of India has compensated for the June deficit, bringing the overall monsoon precipitation into the surplus category.

According to the India Meteorological Department (IMD), more spells of heavy to very heavy rain are likely over northwest India and the western parts of the peninsular India during the next two-three days and over the northeast during the next five days.

India, the world’s top producer of critical crops such as rice, wheat and sugarcane, logged a rainfall deficit of 11 percent in June, with northwest India recording a shortfall of 33 per cent.

Heavy rain in the first week of July compensated for the shortfall but caused flooding in many northeastern states.

Since the four-month monsoon season began on June 1, the country has received 214.9 mm of rainfall against a normal of 213.3 mm, according to IMD data.

Northwest India and the southern peninsula have recorded 3 per cent and 13 per cent above-normal rainfall, respectively.

The heavy rain in the east and northeast region has reduced the deficit from 13 per cent on June 30 to zero on July 6.

The rainfall deficit in central India has decreased from 14 per cent to 6 per cent during this period.

The IMD data showed that 23 per cent of the sub-divisional area of the country experienced excess to large excess rainfall, 67 percent received normal rainfall, and only 10 per cent experienced deficient rainfall.

After making an early onset over Kerala and the northeastern region on May 30, and progressing normally up to Maharashtra, the monsoon lost momentum.

This delayed the rains in West Bengal, Jharkhand, Bihar, Uttar Pradesh, Chhattisgarh, and Madhya Pradesh and exacerbated the impact of a scorching heatwave in northwest India.

Monsoonal winds stalled from June 10 to June 18 and made slow progress until June 26-27. The annual rain-bearing system covered a major part of northwest India after June 25, according to IMD data.

The weather department on Saturday said heavy rainfall will continue in northeast India over the next five days.

The northeastern states are already grappling with severe floods.

Assam’s flood situation remains critical, with over 2.45 million people affected and 52 lives lost in the second wave of flooding this year.

Heavy rainfall in Manipur, Mizoram, and Arunachal Pradesh has caused rivers to reach warning levels and triggered landslides.

The IMD earlier this week said India could experience above-normal rainfall in July, and heavy rain may lead to floods in the hilly states and river basins in the central parts of the country.

Experts from the International Centre for Integrated Mountain Development (ICIMOD), a Nepal-based intergovernmental organisation, have also warned about a difficult monsoon season for the countries in the Hindukush Himalayan region, including Bangladesh, Bhutan, India, Nepal, and Pakistan.

IMD data shows that in 20 out of the 25 years when June rainfall was below normal (less than 92 percent of the long-period average), July rainfall was normal (94-106 percent of LPA) or above normal.

In 17 of the 25 years when June rainfall was below normal, the seasonal rainfall was normal or above normal, the IMD said.

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

Telangana’s cumulative rainfall for October has been a mere 6.5 mm against the normal rainfall of 89.2 mm with a deviation of -93%, which is the lowest monthly rainfall recorded in 58 years. The earlier lowest rainfall of 0.9 mm was recorded way back in October 1965 and 7.2 mm in October 1967, respectively.

Meteorologists at the Telangana State Development Planning Society (TSDPS) have informed that while the global ‘El Nino’ (Pacific Ocean warming that affects the Indian monsoon) is the most likely phenomenon because no other activity has been witnessed, the suppressed Easterly winds from the Bay of Bengal could have led to the weak rainfall during the month.

“There were a couple of low-pressure cyclones that formed in the Bay of Bengal but one prominent one went off towards Bangladesh, hence there was no rainfall. There won’t be much rainfall in November and December also,” said TSDPS weather forecast consultant Y.V. Rama Rao on Wednesday.

During the current period from October to December, the northeast monsoon season is supposed to be receiving about 11.3 cm rain or about 12% of the total annual rainfall of 91.9 cm, a majority of which is to be received during the Southwest monsoon from June to September.

The rainfall deficit takes overall rainfall received since June to October to 86.8 cm as against the normal of 82.8 cm with a deviation of 5%. Within the GHMC limits, the overall rainfall has been 77.6 cm as against the normal of 72.4 cm or a deviation of 7 %.

The climatology for November is about 2 cm rainfall, with the highest rainfall ever recorded being 24.2 cm at Burgampadu (Bhadradri-Kothagudem) on November 3, 2012. The average minimum temperature is 19.2 degrees C and the lowest minimum temperature is 7 degree C recorded at Sirpur in Kumurum-Bheem district on November 27, 2017.

The weather consultant also stated that the current cloudy sky with warm day temperatures is also because of the Easterly winds strengthening, but by the middle of this month the temperatures could see a downward trend by a couple of degrees. “We can notice the signs of winter in a couple of weeks, where we can expect the night temperature to fall, though the season will officially set in December,” he added.

An aerial view shows the destruction, in the aftermath of the floods in Derna, Libya September 16, 2023. REUTERS/Ayman Al-sahili TPX IMAGES OF THE DAY
| Photo Credit: AYMAN AL-SAHILI

Storm Daniel makes landfall

On September 10, a Mediterranean storm made landfall near the Benghazi city in northeast Libya. It brought record-breaking rainfall to the country. Between September 9 and 11, more than 100 mm rainfall was recorded. The Al Bayda station near the coast saw 414 mm of rainfall, the highest ever recorded in 24 hours. Usually, the region receives just around 1.5 mm of rain for the whole of September.

Nine areas were affected by the storm, and seven were severely affected. Derna city was among the areas severely affected. However, rainfall alone did not cause the destruction in the city.

Dams near Derna collapse

As the storm brought record-breaking rainfall, Al-Wadia dam to the south of the city collapsed. Following this, water rushed down the Wadia valley for around 12 kilometres before reaching the second dam closer to Derna city.

The second dam, too, collapsed under the force of the fast-moving water. With this, the water surged into Derna. The floodwaters destroyed entire blocks. and five bridges along its path.

Estimated deaths have crossed 11,000. More than 38,000 people have been displaced. Around 2,176 structures have been damaged in Derna alone.

Also read |Libya’s deadly floods: what we know

The problem of altitude

Derna’s low-lying terrain made it more vulnerable to flooding. The elevation near the first dam is around 200 m, gradually dropping to around 45 m near the second dam. At Derna’s coastline, elevation is around just 10 m. Combined with this, the Wadi valley acted as an effective conduit in channelling the floodwaters straight into the city.