On October 17 1944 only 39 days had lapsed since the inauguration of the “service of radiosondes” of the National Observatory. Due to its violent and destructive nature, an important character of the tropics was not invited to participate in that event. Perhaps for this reason, this same character decided to present itself to celebrate the first 40 days of the event: Exactly on Wednesday October 18, in hours of the morning, the intense “Hurricane of 1944” crossed very near Havana.

I knew what happened that day in the Observatory of Casablanca in the course of an interview with engineer Luis Larragoiti Alonso, made at his house of El Vedado on October 11 1995, almost 51 years after that event.

According to his memories of that memorable day, during the morning and the afternoon of Tuesday 17 two radiosonde operations were carried out, both successful, at the time the City was getting ready for the imminent danger that approached.

At 22:00 hr (local time) the speed of the wind in gusts had experienced a sensitive increase. In that moment the eye of the hurricane was at about 130 km to the SSW of Havana. Nevertheless, Millás and Larragoiti decided to make any way the launching of another radiosonde.

Indeed, at that same hour a globe was prepared and liberated from the plazoleta of aerologic observations of the Observatory that, as it is known, is located on top of an elevation of almost 50 m of height, adjacent to the bay of Havana. With great effort the device rose, partially protected from the wind by a side of the Meridian Room.

As soon as the globe ascended 5 or 6 meters, it began to lose height quickly and slipped down the hillside of the elevation heading to the bay, dangerously scrapping the roofs of the houses of the town of Casablanca. The balloon with the radiometeorograph in suspension descended at great speed, and in the last moment, when it seemed unavoidable a collision against the water, it oscillated smoothly and began to ascend (Larragoiti, pers com., 1995).

Despite what happened, three hours later (01:00 hr of the day 18), they decided to attempt a new launching; but the wind had already intensified notably and it overcame the 25 m/s level (Millás, 1945b).

As a result, two globes exploded one after other and it was necessary to suspend the operation definitively. In that hurricane, winds above 25 m/s remained blowing over Havana for approximately 17 hours, and one of the two anemometers Negretti & Zambra (of type Dines, of pressure and suction, part of the new equipment of the Observatory) indicated in the morning of Wednesday 18 a maximum gust of 72 m/s (ibídem).

As consequence of the rain produced by the hurricane the reception equipment installed in the Meridian Room got wet and it caused the mandatory suspension of the launchings for space of two weeks.

With this work we put final period to the series of two articles directed to analyze the main facts linked to the beginning of the atmospheric soundings in the National Observatory.

Conclusions