The report by the Portuguese Institute of the Sea and Atmosphere (IPMA) on the Pedrógão Grande fire shows that there is only a 5% probability that the ignition was caused by thunderstorms, as indicated by the PJ.
The IPMA held a press conference on 4th July to release the already-known report, pointing out once again that there is a low probability of lightning strikes near the site and at the start of the Pedrógão Grande fire .
“The cloud-to-ground discharges that were detected near the site of the fire occurred at 17:37 hrs, 18:53 hrs and 20:54 hrs, whereas the reference time for the start of the fire was 14.43 hrs,” explained the coordinator of the study, Nuno Moreira.
Thus, the report suggests that there is a low, but non-zero probability of a cloud-soil discharge in the vicinity of the start of the fire, “added the IPMA technician.
Meteorologist Sandra Correia added that there is “a margin of error” and that “the network may not have caught a discharge”, but confirmed everything indicates “that, closer to the place, these discharges only occurred from mid-afternoon until at night”.
“We did not detect any discharge at the time of the fire,” she said.
Meteorologist Paulo Silva pointed out that “given the convective activity [atmospheric instability] near the area of Escalos Fundeiros [village of Pedrógão Grande], it is possible to conclude, according to the radar, that the cloud at that precise moment had no maturity to produce cloud-soil discharge, but would have been later.”
In relation to a downburst (a high intensity wind and near the ground that, from a certain point, blows in a straight line in all directions), Nuno Moreira said that “it was possible to observe this phenomenon by radar in several regions of the upper Alentejo, but none were detected near the site of the fire.
The downburst, according to the IPMA, helps explain the aggressiveness of the fire that destroyed 26,000 hectares and several hundred homes as fire could increase it.
“It was identified a fire plume activation and this activation, the data suggests, may be due to ‘downburst’, which was not directly observed,” explained Nuno Moreira, noting that these phenomena of downward currents are rare.
On June 17, the meteorological stations also detected wind gusts of 80 kph in Proenca-a-nova.
The technicians of the IPMA also mentioned that, at around 19:25, was detected a first activation of the fire plume and that suddenly went for 20 kms.
In the document, sent to the Prime Minister, it is explained that the fire of Pedrógão “broke out and developed in a meteorological frame characterized by a situation of extreme heat and dryness, atmospheric instability with occurrence of thunderstorms, without precipitation in the region and intense bursts of wind”.
This fire, along with another that broke out the same day in Góis, which spread to Arganil and Pampilhosa, will have affected approximately 500 dwellings, 169 of first habitation, 205 of second and 117 empty properties.
Almost 50 companies were also affected, as were the jobs of 372 people. Source Diario de Noticais