Steep Pressure Gradient Producing Strong Winds Across the Region

By: Staff Writer

Strong and gusty winds are moving across most of the Caribbean today. With some parts of the region already experiencing rain, Dale Stein forecasted conditions will last through to Sunday. These winds will make for hazardous conditions onshore and especially offshore.

According Dale Destin, winds will make for hazardous conditions onshore and especially offsgore. Some activities on land will become dangerous and marine conditions will be very hazardous for small craft operators.

The high winds and seas may be reminiscent of the passage of a weak tropical storm, but they won’t be due to any such system. The elevated winds will be the result of a very steep pressure gradient, due to the strength and location of the centre of a high-pressure system. The pressure gradient – the horizontal change of pressure, will be around 25% higher than normal.

Very hazardous seas in excess of 2.5 metres and rising to 3.5 metres (9 to 12 feet) will take place Friday through Sunday across the northeast Caribbean. Winds and seas will start building on Thursday – peaking on Saturday. Seas will occasionally reach 4.5 metres (15 feet).

The winds early Friday morning ranged between 34 and 45 km/h (21 and 32 mph) across the northeast Caribbean and is expected to remain in that range through to Sunday. Destin said, ‘Gusts to gale-force i.e. 64 km/h (40 mph) are expected.’

These kinds of winds very unusual for the region outside of being associated with a tropical cyclone (hurricane, tropical storm or tropical depression). The wind will generally blow from the east.

-Dale Destin

Possible impacts of the strong winds and hazardous seas include:

• injuries or loss of life;
• damage or loss of boats and fishing equipment;
• disruptions to marine recreation and businesses;
• disruptions to air and especially sea transportation;
• disruptions to outdoor sporting activities;
• disruptions of sea search and rescue;
• scarcity of sea food;
• vehicular accidents and
• economic losses.

The worst affected area is likely to be the northern Caribbean – including the Leeward Islands and areas further west. Marine warnings are expected to be issued by most islands. Winds will be strongest over open waters, elevated terrains and windward coastal areas – eastern coastal areas.

Story Credit: Dale Destin

St. Kitts and Nevis Weather Bulletin Issued Earlier today:

Weather Bulletin – Issued at 7 am Friday 28th December, 2018
Present Weather: Cloudy with showers in the vicinity
Winds: Fresh Breeze of 20 mph from the NE
Temperature: 25°C/77°F Humidity: 82%
Sea Level Pressure: 1018.7mb or 30.08″
Sunrise: Tomorrow 6:39 am Sunset: Today 5:46 pm

Weather Forecast Valid until 8am Tomorrow
Winds: Easterly at 17 to 28mph with gusts peaking to near 35mph at times.
Seas: 2.1 to 2.8 metres or 7 to 9 feet. Small craft operators should stay in port as sea conditions have become dangerous to small craft operation and hence a warning is in effect.

Weather Today: Cloudy with an 80 percent or very high chance of showers.
Weather Tonight: Cloudy with an 80 percent or very high chance of showers.

Eastern Caribbean Forecast: A broad area of high pressure accompanied by a steep pressure gradient will produce fresh to strong winds across the entire Eastern Caribbean. Some low level cloud patches being pushed across the region from time to time will also heighten the chance of some quick passing showers across the islands. Deeper moisture and instability moving into the Northern Caribbean from a trough will increase the chance of some moderate to heavy downpours over Puerto Rico east to the Leeward Islands.