SUNDAY 17th SEPTEMBER 2017
HERE'S A LOOK AT TODAY'S WEATHER
A Summary of Watches, Warnings, Advisories & Bulletins for the Lesser Antilles as of 11PM Saturday 16th September 2017.A Hurricane Watch is in effect for:
- Antigua, Barbuda, St. Kitts, Nevis, and Montserrat
- Saba and St. Eustatius
- St. Maarten
A Tropical Storm Watch is in effect for:
- St. Lucia
- St. Vincent and the Grenadines
A Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous.
A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours.
Interests elsewhere in the Lesser Antilles and the British and U. S. Virgin Islands should monitor the progress of this system.
Additional Tropical Storm or Hurricane Watches and Warnings will likely be issued early Sunday.
For storm information specific to your area, please monitor products issued by your national meteorological service.
Trinidad, Tobago, Grenada & Dependencies: Tropical Storm Maria Bulletin #1 is in effect for the area as of 5:45PM Saturday 16th September 2017. Inclement Weather is expected on Sunday into Monday as moderate to heavy showers associated with Tropical Storm Maria as it nears the Lesser Antilles.
Residents of the Lesser Antilles should be aware of information from their local meteorological office as Tropical Storm or even Hurricane Watches may be issued on short notice on Saturday. Specifically, for Trinidad and Tobago, there is NO watch or warning issued for Trinidad, Tobago, Grenada and its dependencies at this time. Tropical Storm/Hurricane Watches will not be needed as the center of circulation is expected to move well north of Trinidad and Tobago, keeping sustained tropical storm to hurricane force winds north of T&T. A tropical storm watch is issued when a tropical cyclone containing winds of 63 to 117 KM/H (39 to 73 mph) or higher poses a possible threat within 48 hours.
Although Trinidad and Tobago may not be placed under a watch or warning over the weekend, citizens should not need a watch or warning to prepare for inclement weather. Moderate to heavy rainfall is expected on Sunday into Monday (possibly through Tuesday) which will cause street/flash flooding across the islands. Gusty winds may occur during heavy showers or thunderstorms which may cause downed trees and downed utility poles. Landslides may occur in elevated areas, particularly along the Lady Young Road, Saddle Road and North Coast Road which have seen numerous landslides since the landfall of Tropical Storm Bret. Marine conditions will also deteriorate Sunday into Monday as this system nears the Lesser Antilles. It is also important to note that the percentage for sustained tropical storm force winds have been on the increase for Trinidad and Tobago. While T&T may not see any significant impacts from Tropical Storm Maria, squally weather with tropical storm force gusts may occur in heavy thunderstorms.
Hazards Affecting Land
WIND: Hurricane conditions are possible within the hurricane watch area by Monday night or Tuesday, with tropical storm conditions possible on Monday. Tropical storm conditions are possible in the tropical storm watch area on Monday.
STORM SURGE: A dangerous storm surge accompanied by large and destructive waves will raise water levels by as much as 3 to 5 feet above normal tide levels within the hurricane watch area.
RAINFALL: Maria is expected to produce total rain accumulations of 6 to 12 inches with isolated maximum amounts of 20 inches across the central and southern Leeward Islands through Tuesday night. Maria is also expected to produce total rain
accumulations of 2 to 4 inches with isolated maximum amounts of 8 inches in the northern Leeward Islands through Tuesday night. This rainfall could cause life-threatening flash floods and mudslides.
SURF: Swells generated by Maria are expected to begin affecting the Lesser Antilles by Sunday night. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office.
Forecast & Discussion
Tropical Storm Maria is located 800 Kilometers northeast of Trinidad and Tobago as of 11PM Saturday afternoon and is moving west at about 26KM/H at 12.5˚N, 53.7˚W. A turn toward the west-northwest and a slower forward speed are expected during next couple of days. On the forecast track, the center of Maria will be near the Leeward Islands Monday or Monday night. Strengthening is expected during the next 48 hours, and Maria is forecast to be a hurricane when it approaches the Leeward Islands.
Maria has become a little better organized this evening, with satellite imagery showing the formation of a small convective area near the center that may reflect the formation of an inner wind core. However, this has not yet resulted in intensification, as various subjective and objective satellite intensity estimates remain about 85 KM/H
The longer-term initial motion is 26 KM/H westward (280˚), while recent satellite imagery suggests the system may be turning a little more to the right. A mid-level ridge to the north of the cyclone is expected to gradually weaken through the forecast period, which would allow Maria to move generally west-northwestward with a decrease in forward speed during the next five days. The track guidance is tightly clustered, and the new forecast track is nudged only slightly to the left of the previous track based on the initial location. The forecast continues to take the core of Maria near the Leeward Islands in Monday through Tuesday, close to the Virgin Islands and Puerto Rico in about Thursday, and near eastern Hispaniola at about Friday.
Maria is expected to remain in an environment of good moisture, light shear, and warm sea surface temperatures for at least the next 4 days. This should result in steady to rapid intensification. The new intensity forecast is similar to the previous forecast in calling for Maria to become a hurricane in 24 hours and a major hurricane in 72 hours, and it lies at the upper edge of the intensity guidance. However, rapid intensification is a distinct possibility, and it would be no surprise if Maria got significantly stronger than currently forecast.
Trinidad and Tobago will see periphery impacts from a possible tropical cyclone resulting from TD15. This means that feeder band activity may occur across the islands. These are the outer bands of a tropical cyclone that usually includes moderate to heavy showers and gusty winds. The key difference between feeder bands and regular moderate to heavy showers associated with a tropical wave is the intensity of the rainfall as well as gustier winds in feeder bands compared to scattered showers in a tropical wave.
Heavy showers and isolated thunderstorms will be possible Sunday through Tuesday as this system nears and moves across the Caribbean Islands. Gusty winds, street/flash flooding will be possible. Gusty winds may down trees and heavy showers may trigger landslides in elevated areas. Marine conditions may deteriorate as this system nears.
Trinidad and Tobago is NOT under any tropical storm or hurricane watch or warning at this time (11PM Saturday 16th September 2017).
Disclaimer: This is not an official forecast from the Trinidad and Tobago Meteorological Service (TTMS) nor is TTWC affiliated with the TTMS. When making decisions, please consult the Trinidad and Tobago Meteorological Service and the National Hurricane Center for all official forecasts, bulletins, watches and warnings.