AXNT20 KNHC 251740

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
140 PM EDT Thu May 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 1715 UTC.


A tropical wave extends from 12N40W to 03N41W, moving westward at around 20 kt. The TPW data indicate a decent surge of moisture in association with this wave. Isolated moderate convection is within about 210 nm E of wave axis from 07N to 10N.

A tropical wave extends from 13N50W to 03N51W, moving westward at 15-20 kt. This wave shows up pretty well on the TPW animation and satellite derived winds. Isolated showers is near the wave axis.

A tropical wave is over the south-central Caribbean and extends from 15N76W to Colombia near 06N77W, moving westward at 10-15 kt. The wave is well depicted in the moisture product with the TPW showing a bulge a moisture near the wave axis. A custer of moderate to strong convection is near the southern end of the wave axis over Colombia.

A tropical wave is over northern central America and extends from 19N78W through El Salvador into the EPAC region, moving westward at 10-15 kt. The TPW data indicate a decent surge of moisture in association with this wave.


The Monsoon Trough enters the tropical Atlantic near 12N16W and continues to 06N16W to 05N21W. The ITCZ begins near 05N21W and extends to 08N39W, then resumes west of a tropical wave near 40W to 07N49W. Aside from the convection associated with the tropical wave, scattered moderate isolated strong convection can be found from 01N-05N between 15W-25W. Scattered moderate convection is from 08N-10N between 43W and 45W.



As of 1500 UTC, a cold front extends from near Ft. Myers to the SW Gulf near 20N93W. A band of showers with embedded thunderstorms is related to the front and is affecting mainly south-central Florida. Moderate to fresh winds are noted on either side of the front E of 87W. A weak 1015 mb high pressure follows the front and it is located near 26N91W. Mainly gentle to moderate winds are north of the front west of 87W due to the presence of the weak high. The cold front is forecast to stall and dissipate over the SE Gulf on Friday. The high pressure will move eastward toward the NE Gulf by Thursday night. At that time, southerly return flow will set-up over the western Gulf.


A tropical wave is over the south-central Caribbean and a second one is leaving the basin. Please refer to the Tropical Waves section for more details. The combination of the eastern Pacific monsoon trough and the tropical wave over the south-central Caribbean supports some convective activity over parts of Panama and Costa Rica. Shallow moisture embededed in the trade wind flow will move across the remainder of the region producing isolated to scattered passing showrs. High pressure located over the central Atlantic extends a ridge toward the SW across much the Caribbean Sea and the Greater Antilles supporting fresh to strong easterly winds across the east and central Caribbean and moderate to fresh southeast winds over the western part of the basin. Although the cold front, currently moving across the Gulf of Mexico, is not expected to reach the northwest Caribbean, showers and thunderstorms well ahead of the front may enter the northwest Caribbean later today and linger through Thursday. Fresh to strong winds will persist over the central Caribbean through Friday, then diminish on Saturday. Pulsing fresh easterly winds are expected across the Gulf of Hunduras at night through Monday night. Visible satellite imagery and Saharan Air layer from UW- CIMSS reveal the presense of saharan dust across much of the Caribbean producing dry and hazy conditions.


Mostly dry and hazy conditions will prevail across the island under the influence of a ridge. Model guidance continue to show limted moisture across the region.


A cold front enters the forecast area near 31N77W and extends SW to central Florida. A band of showers and thunderstorms is ahead of the front, forecast to reach from 31N70W to south Florida by early Friday morning. Mosaic Doppler Radar from the SE U.S. depicts an active line of thunderstorms over the central areas of South Florida, which will be moving through the Atlantic metro areas through the early afternoon hours. Gusty winds and frequent lightning are expected in association with the thunderstorms. Fresh to strong winds are on either side of the front, but mainly north of 27N. A 1026 mb high pressure centered near 32N44W currently dominates the remainder of the western Atlantic and central Atlantic. Another cold front extends from 31N23W to 27N31W where it becomes nearly stationary to 22N44W. This front will remain nearly stationary over the next 24-36 hours while weakening. Two tropical waves are between 40W and thw Windward Islands, Please refer to the tropical waves section for more details. African dust is noted across much of the Atlantic Ocean ahead of the first cold front and from 10N-30N.

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

$$ GR