AXNT20 KNHC 251651

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1251 PM EDT Tue Apr 25 2017

Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis.

Based on 1200 UTC surface analysis and satellite imagery through 1700 UTC.


The Monsoon Trough extends SW from the coast of Sierra Leone in western Africa at 07N12W to 04N18W. The Intertropical Convergence Zone continues from 04N18W to 00N35W to 01N42W to the coast of Brazil near 00N48W. Scattered moderate convection is observed from 00N to 02N between 17W and 21W and from 01S to 03N between 47W and 51W.



A weakening frontal boundary crosses the southern Gulf of Mexico from NW Yucatan near 21N90W to 25N94W. This boundary is devoid of significant cloudiness or convection. Weak high pressure ridges northward from the Straits of Yucatan to the Florida Panhandle. Satellite-derived wind data depict moderate to fresh northwest winds over the Eastern Gulf and moderate to fresh south to southeast winds over the Western Gulf. The frontal boundary will dissipate this afternoon as high pressure over the Yucatan Channel merges with a ridge extending into the SE Gulf from the Western Atlantic. The high pressure ridge will continue to shift eastward over the Gulf as a cold front approaches the NW Gulf from Texas on Wednesday morning. Return flow over the Gulf will increase over the Gulf as the cold front approaches. South winds over the Western Gulf will become fresh to strong by Wednesday morning. The front will enter the NW Gulf on Wednesday night.


A 1008 mb low is centered just off the coast of Northern Colombia near 11.5N73.5W. A surface trough extends northward from the low to Cabo Beata in the Dominican Republic. Broad upper-level ridging over the Caribbean is producing subsidence which is limiting cloudiness and showers in the vicinity of the trough. Moderate to fresh E to SE winds are observed E of the trough. Light to moderate NE winds are generally observed W of the trough. An upper-level trough extending northward from Hispaniola is supporting scattered showers and isolated thunderstorms, mainly over the Dominican Republic. The trough is expected to lift NNE during the next 24 hours. As the trough lifts NE, shower and thunderstorm coverage will decrease. Winds will remain light to moderate.


Divergent upper-level flow prevails, especially over the eastern portion of the island. These dynamics are supporting scattered showers and isolated thunderstorms over the Dominican Republic. This activity will continue until tonight, then the trough will swing to the NNE and allow the atmosphere to stabilize on Wednesday.


A cold front enters the discussion area near 32N75W, then curves SSW to 27N75W to the coast of Central Cuba at 22N79W. A surface trough extends SE from 30N73W to 23N68W. Only a narrow band of cloudiness and scattered showers accompanies the front to the N of 26N. Scattered moderate and isolated strong convection associated with the trough is occurring from 22N to 26N between 64W and 68W. Scattered moderate convection is present farther to the N from 26N to 32N between 64W and 68W. Ridging over the Atlantic between intense low pressure over the Carolinas and a much broader area of low pressure centered just S of the Canary Islands near 36N28W is producing moderate trade winds between 30W and the Lesser Antilles from 02N to 17N. The low over the Carolinas is expected to head NE during the next 24 hours, but the ridge over the Atlantic and low near the Canary Islands will remain in place through Wednesday. This will maintain the same weather conditions in these areas. As the cold front moves slowly east, it will continue to weaken and eventually dissipate by Wednesday evening.

For additional information please visit http://www.hurricanes.gov/marine

$$ McElroy