Storm-Force Wind Gusts and Hazardous Seas Are Returning to the Area

7 03 2017

Storm-force wind gusts and hazardous seas are returning to the area. The weather will be generally good but the increased winds will cause the lower atmosphere to become somewhat unsettled, giving rise to occasional showers.

The Met Office has already issued a small craft warning and this is expected to continue in place through, at least, Friday. Given the expected conditions, small craft operators should not venture far from port, especially on the windward side of the islands. Beachgoers should avoid the waters of the north and east facing beaches.

The expected strong gusts will also make some outdoor activities very uncomfortable if not dangerous. At least, light objects should be secured, as minimal storm conditions are possible. Please be guided accordingly.

The wind speed will steadily rise to 28 to 44 km/h (17 to 28 mph) by late Tuesday and continue in that range until Thursday; thereafter, subsiding. Wind gusts as high as 67 km/h (41 mph) are possible in showers. The prevailing winds will be east-northeast.

The major concern about the winds is the impact on the seas. They will cause the seas to become very hazardous, with heights reaching 4 metres (13 ft), occasionally reaching 5 metres (17 ft) late Tuesday and staying at those heights until Friday, when they will start to subside.

These conditions, especially the seas, will not be dissimilar to what would obtain during the passage of a tropical storm through the area. However, no such system will be around.

The brunt of this windy weather will be felt mainly over open waters on the windward side of the islands, windward coastlines and elevated places.

The gale-force or storm-force wind gusts and associated strong winds will be as a result of a very steep pressure gradient across the area. Recall that winds blow due to pressure differences or pressure gradients, and the greater the gradients the stronger the winds and vice versa.

The last episode of similarly strong winds and rough seas was a recent as last week.

Follow us for all you need to know about this windy weather and all things weather and climate. We can be followed on twitterfacebookinstagramtumblrflickrgoogle+, and youtube.





Storm-Force Winds and Hurricane-Like Seas to Impact Antigua and Barbuda This Weekend

17 12 2016

Dale C. S. Destin |

Significant tightening of the pressure gradient across the area is expected to cause strong winds with frequent gusts to storm force strength or gale force. The seas will respond to the strong winds and become very rough.

Surface chart

Surface Chart for Sunday 8 am, Showing a Tight Pressure Gradient As Evident by the Closeness of the Isobars (pressure lines)

The winds – they will generally be in excess of 18 mph (16 kt) from late Saturday night to Monday afternoon. The winds will peak as high as 30 mph (26 kt) with frequent gusts between 38 and 46 mph (33 and 38 kt) Sunday morning to Monday morning.

High Sustained Winds

Sustained Winds

Wind Gusts

Wind Gusts

The seas –  they will respond to the winds and become very rough, rising to as high as 3.9 metres (13 ft) on Sunday night. Waves will rise above six feet by Saturday morning and remain above this height through midweek. Waves of 2.7 to 3.9 metres (9 to 13 ft) will prevail from Saturday night to Wednesday. Waves are expected to fall off rapidly after Wednesday.

Seas

Seas

The cause – as indicated above, it is the substantial tightening or steepening of the pressure gradient.  This is in response to a very strong surface high pressure system moving from west to east across the Atlantic from the United States.  This will NOT be due to any tropical cyclone (tropical depression, tropical storms or hurricane).

Fundamentally, wind blow as a result of pressure differential (pressure gradient). The greater the pressure between point A and point B (pressure gradient) the stronger the winds.

Where – the strong winds will mostly take place over open waters, exposed eastern coastal areas and elevated areas of Antigua and Barbuda. The seas will be roughest in the Atlantic coastal waters east of the islands, as the winds will be generally easterly. Similar conditions are expected across most of the rest of the Eastern Caribbean. However, Antigua and Barbuda could get the worst of it.

Precautions – The Antigua and Barbuda Meteorological Services have issued warnings for sea-bather and small craft operators. The former should avoid the beaches, especially those on the Atlantic or eastern side of the islands, and the latter should not venture far from port, at least, until Thursday.

A small craft warning generally means that wind speeds in excess of 16 knots is causing or expected to cause hazardous sea conditions to small craft within 24 hours. Inexperience mariners, especially those operating smaller vessels should avoid navigating these conditions.

According to the Beaufort Scale, gale-force winds run from 39 to 54 mph (34 to 47 kt). Operating a vessel in gale conditions requires special expertise and specially equipped vessels. It is highly recommended that mariners without the proper experience seek safe harbour prior to the onset of gale conditions.

The strong winds, especially if frequently gusting to gale force, could also make some outdoor activities very uncomfortable if not hazardous, please be guided accordingly.

We will be keeping a close eye on this developing situation and keep you informed via our social media platform: twitterfacebookinstagramtumblrflickrgoogle+, and youtube.








%d bloggers like this: