000 AXNT20 KNHC 250517 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU JUN 25 2015 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... ...GALE IN THE CARIBBEAN... A GALE WARNING IS IN EFFECT FOR THE SW CARIBBEAN ALONG THE NW COAST OF COLOMBIA UNTIL THIS AFTERNOON THROUGH FRI EVENING. THESE WINDS ARE GENERATED BY A TIGHT PRESSURE GRADIENT BETWEEN THE SURFACE RIDGE OVER THE W ATLC AND THE LOWER PRESSURE OVER SOUTH AMERICA. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE IN TROPICAL ATLC EXTENDS FROM 21N45W TO 7N48W MOVING W-NW 15-20 KT OVER THE PAST 24 HOURS. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS ALONG THE LEADING EDGE A SURGE OF MODERATE MOISTURE. NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE IN THE CENTRAL CARIBBEAN EXTENDS ALONG 71W/72W S OF 18N TO INLAND OVER VENEZUELA MOVING W NEAR 20 KT OVER THE PAST 24 HOURS. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN SURGE OF DEEP MOISTURE THAT COVERS THE CARIBBEAN W OF 70W. NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE IN THE W CARIBBEAN/CENTRAL AMERICA EXTENDS FROM 20N89W ACROSS THE GULF OF FONSECA INTO THE E PACIFIC REGION MOVING W AT 20-25 KT OVER THE PAST 24 HOURS. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED ALONG THE LEADING EDGE OF A BROAD SURGE OF DEEP MOISTURE THAT COVERS THE CARIBBEAN W OF 70W. SCATTERED SHOWERS/THUNDERSTORMS ARE IN THE SW GULF S OF 20N E OF 93W TO INLAND OVER S MEXICO. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 18N16W AND CONTINUES ALONG 11N21W TO 8N26W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 6N35W 9N42W TO 9N46W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 120 NM OF THE ITCZ BETWEEN 28W-42W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE IS ANCHORED OVER THE FLORIDA PANHANDLE NEAR PENSACOLA COVERING THE NE GULF OF MEXICO AND THE FLORIDA PENINSULA. THE REMAINDER OF THE GULF IS UNDER A LARGE UPPER LOW THAT IS CENTERED OVER THE SW GULF NEAR 22N92W. A SURFACE TROUGH EXTENDS FROM FLORIDA COAST NEAR PANAMA CITY ALONG 28N88W TO 27N91W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS THAT ARE DEVELOPING INLAND OVER THE SE CONUS ARE MOVING OFFSHORE N OF 28N BETWEEN 88W AND 90W. THIS IS LEAVING THE REMAINDER OF THE GULF WITH MOSTLY CLEAR SKIES TONIGHT. A WEAK SURFACE RIDGE EXTENDS FROM THE W ATLC ACROSS N FLORIDA COVERING THE GULF WITH A WEAK 1021 MB HIGH NEAR 28N84W. SURFACE RIDGE WILL LINGER OVER THE N GULF THROUGH THU NIGHT THEN SHIFT S INTO THE E/CENTRAL GULF FRI AND THE SE GULF SAT. THE TROPICAL WAVE IN THE W CARIBBEAN/ CENTRAL AMERICA WILL MOVE ACROSS S MEXICO AND THE SW GULF THU AND THU NIGHT. CARIBBEAN SEA... THE LARGE UPPER LOW CENTERED OVER THE GULF OF MEXICO COVERS THE W CARIBBEAN W OF 85W. AN UPPER RIDGE ANCHORED OVER SOUTH AMERICA EXTENDS A RIDGE AXIS FROM COLOMBIA N TO OVER W CUBA NEAR HAVANA WITH NEAR ZONAL WESTERLY FLOW ALOFT COVERING THE E CARIBBEAN E OF 70W. DIFFLUENT FLOW OVER THE W CARIBBEAN IS GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS IN THE GULF OF HONDURAS S OF 18N W OF 84W TO OVER HONDURAS AND BELIZE. AFTERNOON SHOWERS/THUNDERSTORMS THAT DEVELOPED INLAND OVER E CUBA AND SW HAITI HAVE MOVE INTO THE GULF WATERS. A PERSISTENT W ATLC SURFACE RIDGE WILL MAINTAIN STRONG TO GALE FORCE TRADE WINDS ACROSS THE S/CENTRAL CARIBBEAN THROUGH FRI NIGHT THEN STRONG TO NEAR GALE FORCE WINDS SAT AND SUN. THE W CARIBBEAN/ CENTRAL AMERICA TROPICAL WAVE WILL MOVE OUT OF THE AREA TONIGHT. THE CENTRAL CARIBBEAN TROPICAL WAVE WILL MOVE INTO THE W CARIBBEAN THU AND ACROSS CENTRAL AMERICA FRI. A THIRD TROPICAL WAVE WILL MOVE INTO THE E CARIBBEAN THU NIGHT AND THEN THE CENTRAL CARIBBEAN FRI AND W CARIBBEAN SAT. ...HISPANIOLA... SKIES ARE MOSTLY CLEAR ACROSS THE ISLAND TONIGHT WITH SOME LINGERING ISOLATED SHOWERS OVER SW HAITI. THE UPPER LOW N OF THE ISLAND IS BEGINNING TO MOVE NORTHWARD AWAY FROM THE ISLAND. THE TROPICAL WAVE S OF THE ISLAND WILL CONTINUE TO MOVE RAPIDLY WESTWARD. AFTERNOON/EVENING SHOWERS/THUNDERSTORMS ARE POSSIBLE FOR THU AND FRI DUE TO DAYTIME HEATING AND OROGRAPHIC LIFTING. SAT WILL BRING AN INCREASE IN MOISTURE INCREASING THE SHOWERS FROM E TO W. ATLANTIC OCEAN... BROAD BUT WEAK UPPER TROUGH COVERS THE W ATLC WITH AN UPPER LOW N OF HISPANIOLA NEAR 24N69W. A BROAD E/W SURFACE RIDGE DOMINATES THE ATLC BASIN WITH A 1027 MB HIGH NEAR 26N41W AND A 1026 MB HIGH NEAR 28N55W. THIS SURFACE RIDGE EXTENDS W ACROSS N FLORIDA INTO THE GULF OF MEXICO. NOAA/NESDIS AEROSOL PRODUCT AND THE FIRST VISIBLE SATELLITE IMAGERY INDICATES THAT AEROSOLS OR SAHARAN DUST COVERS THE TROPICS S OF 25N TO THE CARIBBEAN. THE SURFACE RIDGE WILL REMAIN ACROSS THE ATLC THROUGH SAT BEFORE SHIFTING SLIGHTLY S. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW