From FB, translation by Google, with a few measurement notes added
COMSTBARTH informs you:
Vigilance Monitoring Bulletin n ° 5 for the Northern Islands (Saint-Martin and Saint-Barthélemy)
Start of event: in progress.
Estimated end of event: Thursday July 30, 2020 at 12 noon local.
Current situation
Tropical system n ° 9 (ex-tropical wave n ° 21), the pseudo-center of which crossed the Antillean Arc this morning, continues its course towards the west-north-west, at about 37 km / h. Its northern part which has approached St-Martin and St-Barthélémy is very active. It generates numerous showers sometimes accompanied by thunderstorms. [37km/h = 23 mph]
Forecasts
Rain: Generally brief but frequent precipitation is expected this afternoon and into the evening. They can be accompanied by thunderstorms and give rise to temporary flooding. The rain declines during the next night.
Wind: the wind blows strong from east-southeast of 50 to 60 km / h on average with gusts of 90 to 110 km / h. It gradually eases over the next night. [50 - 60 km/h = 31 - 37 mph, 90 - 100 km/h = 56-62 mph]
Sea: the sea is very rough and choppy, the north-easterly swell crossing the sea from the east-south-easterly wind. Average hollows reach 4 to 5m. Very strong waves are expected on the exposed shores, causing in places submersions of the lower parts of the coast. The moorings of boats are likely to skid. Start of depreciation during the next night.
Observed data
Average wind measured between 50 and 60 km / h. [50 - 60 km/h = 31 - 37 mph]
Gusts measured at 105 km / h at Gustavia, 86 km / h at Grand-Case. [105 km/h = 65 mph, 86 km/h = 53 mph]
Rainfall: up to 28 mm in 3 hours in Gustavia, 4 mm in Grand-Case. [28mm = 1.1", 4mm = .16"]