tailwind, wet runway, night, local terrain to west and south, construction work on the LHS which includes drainage works... and it is a B738, carrying a load and with presumably divert gas. It appears to have gone off the side, not the end, so control/aquaplaning are all on the cards. Runway not grooved/PFC. rainy season comes with risks, this is hardly the first jet off a runway in the wet, wager it won't be the last.

Pax are now reporting via local media that they were held on board for an hour after the incident!
https://www.bangkokpost.com/thailand...-damaged-plane

Airport now closed until 2200 Friday 5th awaiting removal of aircraft

From the Bangkok Post today:Mae Fah Luang Chiang Rai International Airport reopens on Friday after a damaged Nok Air plane was removed from the runway, said Transport Minister Saksayam Chidchob.

He said Airports of Thailand (AoT) and the Department of Airports (DoA) had cleared the runway which Nok Air's Boeing 737-800 skidded off on July 30, causing flight cancellations and an airport shutdown.

The Civil Aviation Authority of Thailand finished examining the runway for safety on Thursday before the airport reopening.

Chiang Rai Airport Director Sqn Ldr Somchanok Tiamtiabrat said the plane's removal was delayed due to difficulties moving it without causing more damage to the aircraft's wings.

Sqn Ldr Somchanok said the airline and airport staff had contacted Thai Airways International (THAI) for a recovery team to send licensed engineers and equipment to remove the stranded plane. The recovery team had to be careful not to cause further damage to both the 60-tonne aircraft and the runway, he said.

Sqn Ldr Somchanok said the operation went according to the International Civil Aviation Organization's regulation on aircraft removal. He also said the plane was now safely parked at a pit stop which is about 600 metres away from the initial position in which it was stranded after it veered off the runway following a brake malfunction.

Nok Air chief executive Wutthiphum Jurangkool said the airline will compensate all passengers on the flight with refunds and free tickets worth one million baht. All passengers are to be given tickets for a round trip valid for a year and they can request refunds, cancellations or destination changes without charges, he said.

Mr Wutthiphum also defended the pilot of the aircraft. "The pilot did his best to land the aircraft and there were no deaths or casualties," he said. "He has worked as a pilot for 15 years and the co-pilot has three years of experience with Nok Air. Every step of the evacuation went according to safety protocols."