000 AXNT20 KNHC 081203 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN SEP 08 2013 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH WWWW UTC. ...SPECIAL FEATURES... TROPICAL WAVE OFF THE COAST OF AFRICA EXTENDS FROM 17N18W THROUGH A 1008 MB LOW NEAR 13N18W TO 11N18W. WAVE HAS BEEN MOVING W 5-10 KT FOR THE PAST 18 HOURS. WAVE IS EMBEDDED WITHIN AN AREA OF DEEP MOISTURE THAT COVERS THE E ATLC E OF 25W AS DEPICTED ON TOTAL PRECIPITABLE WATER IMAGERY. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 10N-17N BETWEEN 18W-22W. ENVIRONMENTAL CONDITIONS APPEAR TO BE CONDUCIVE FOR FURTHER DEVELOPMENT. A TROPICAL DEPRESSION MAY FORM DURING THE NEXT DAY OR SO WHILE THE DISTURBANCE MOVES WEST- NORTHWESTWARD ABOUT 10 KNOTS TOWARD THE CAPE VERDE ISLANDS. THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS...AND A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS. INTERESTS IN THE CAPE VERDE ISLANDS SHOULD MONITOR THE PROGRESS OF THIS SYSTEM. TROPICAL STORM WATCHES OR WARNINGS MAY BE REQUIRED IF A DEPRESSION FORMS. HEAVY RAINFALL AND GUSTY WINDS ARE POSSIBLE IN THE CAPE VERDE ISLANDS BY LATER TODAY...EVEN IF A TROPICAL CYCLONE DOES NOT FORM. ...TROPICAL WAVES... TROPICAL WAVE IN THE CENTRAL ATLC IS ANALYZED FROM 21N38W THROUGH A 1010 MB LOW NEAR 16N36W TO 14N34W. THE WAVE/LOW HAS BEEN NEARLY STATIONARY FOR THE PAST 24 HOURS. LOW/WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE AS DEPICTED ON TOTAL PRECIPITABLE WATER IMAGERY. WAVE REMAINS WELL DEFINED IN THE LOW AND MID LEVEL SATELLITE WINDS. CLUSTERS OF SCATTERED MODERATE/ ISOLATED STRONG CONVECTION ARE WITHIN 60/75 NM OF LINE FROM 16N31W TO 18N38W. TROPICAL WAVE IN THE W CARIBBEAN EXTENDS FROM 19N84W INLAND OVER CENTRAL AMERICA TO 10N84W. WAVE HAS BEEN MOVING W-NW 10-15 KT FOR THE PAST 24 HOURS. WAVE IS EMBEDDED WITHIN AN AREA OF DEEP MOISTURE THAT COVERS THE CARIBBEAN AS DEPICTED ON TOTAL PRECIPITABLE WATER IMAGERY. CLUSTERS OF SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE FROM 15N-19N W OF 82W TO INLAND OVER CENTRAL AMERICA AND THE COAST OF THE YUCATAN PENINSULA. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO HE E TROPICAL ATLC NEAR 14N17W THROUGH LOW/TROPICAL WAVE NEAR 13N18W THEN CONTINUES ALONG 15N26W THROUGH THE LOW/TROPICAL WAVE NEAR 16N35W TO 9N46W WHERE THE ITCZ BEGINS AND CONTINUES INTO SOUTH AMERICA NEAR 6N57W. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE FROM 8N-12N BETWEEN 22W-30W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 5N-10N BETWEEN 40W-51W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE IS ANCHORED ALONG THE W COAST OF MEXICO AND EXTENDS AN AXIS ACROSS THE S GULF ALONG 18N BETWEEN MEXICO AND THE YUCATAN PENINSULA. A SURFACE TROUGH IS IN THE SW GULF EXTENDING FROM 23N97W TO 18N94W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 25N W OF 90W TO INLAND OVER MEXICO. A BROAD UPPER TROUGH COVERS THE REMAINDER OF THE GULF INTO THE W ATLC. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE IN THE NW GULF FROM 26N-28N BETWEEN 90W-95W. WEAK SURFACE RIDGE COVERS THE N GULF WITH A WEAK 1017 MB HIGH OVER SW GEORGIA. SURFACE RIDGE WILL PERSIST ACROSS THE N GULF THROUGH TONIGHT BEFORE SHIFTING JUST N OF THE AREA MON. A TROUGH OF LOW PRESSURE COULD FORM OVER THE SW GULF AND THE BAY OF CAMPECHE IN A FEW DAYS AND SOME DEVELOPMENT OF THIS SYSTEM IS POSSIBLE BY MIDWEEK. CARIBBEAN SEA... AN UPPER RIDGE DOMINATES THE CARIBBEAN ANCHORED S OF HAITI NEAR 17N75W AND EXTENDING A RIDGE AXIS SW TO OVER CENTRAL AMERICA AND NE INTO THE CENTRAL ATLC. SOME OF THE ACTIVITY IN THE W CARIBBEAN IS ASSOCIATED WITH THE TROPICAL WAVE. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 19N TO THE COAST OF CUBA BETWEEN 75W-85W. A SURFACE TROUGH EXTENDS FROM THE REMNANT LOW OF GABRIELLE S TO OVER HISPANIOLA GENERATING SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS N OF 16N BETWEEN 64W-68W INCLUDING THE THE VIRGIN ISLANDS AND PUERTO RICO. THE MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 11N74W ALONG 13N80W TO ACROSS NICARAGUA NEAR 12N84W GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS 11N-16N BETWEEN 71W-82W. FRESH SE WINDS WILL DEVELOP ACROSS MUCH OF THE E CARIBBEAN TODAY. THE CARIBBEAN TROPICAL WAVE WILL MOVE OVER THE YUCATAN PENINSULA LATER THIS EVENING. HISPANIOLA... THE ISLAND REMAINS UNDER CLOUDS WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS. THE NATIONAL OFFICE OF METEOROLOGY IN THE DOMINICAN REPUBLIC MAINTAINS A WEATHER ALERT AGAINST OVERFLOWING RIVERS...STREAMS...CREEKS...AND LANDSLIDES IN SEVERAL PROVINCES OF THE EASTERN DOMINICAN REPUBLIC. THIS ACTIVITY IS ASSOCIATED THE SURFACE TROUGH THAT EXTENDS FROM THE REMNANT LOW OF GABRIELLE IN THE W ATLC TO OVER HISPANIOLA NEAR THE DOMINICAN REPUBLIC/HAITI BORDER AND IS BEING ENHANCED BY THE UPPER RIDGE OVER THE CARIBBEAN. THESE SHOWERS/THUNDERSTORMS COULD CONTINUE THROUGH EARLY TUE WHEN THE TROUGH MOVES NE AWAY FROM THE ISLAND. ATLANTIC OCEAN... BROAD UPPER TROUGH COVERS THE W ATLC N OF 23N W OF 67W SUPPORTING A STATIONARY FRONT THAT REMAINS N OF THE DISCUSSION AREA. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE S OF 28N TO CUBA BETWEEN 75W-80W. A SURFACE TROUGH EXTENDS FROM NEAR BERMUDA ALONG 29N68W TO A 1009 MB LOW...REMNANTS OF GABRIELLE...NEAR 25N69W TO OVER HISPANIOLA NEAR 20N71W. THIS SURFACE TROUGH IS ALONG THE WESTERN EDGE OF AN UPPER RIDGE AXIS THAT EXTENDS FROM THE CARIBBEAN NEAR PUERTO RICO ALONG 25N60W TO BEYOND 32N55W WHICH PROVIDING DIFFLUENCE ALOFT TO GENERATE CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 20N BETWEEN 64W-70W...N OF 20N BETWEEN 60W-69W...AND N OF 25N BETWEEN 52W-60W. A SERIES OF UPPER LOWS ARE IN THE CENTRAL ATLC CENTERED NEAR 34N45W...27N42W...AND 19N51W SUPPORTING A WEAKENING SURFACE TROUGH THAT EXTENDS FROM 32N45W TO 27N46W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE N OF 28N BETWEEN 45W-48W. THE REMAINDER OF THE ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1029 MB HIGH NEAR THE AZORES. THE REMNANT LOW OF GABRIELLE AND SURFACE TROUGH WILL MOVE TO THE NE THROUGH MON NIGHT BEFORE THE LOW DISSIPATES AND THE SURFACE TROUGH WILL THEN CONTINUE NE. A WEAK PRESSURE PATTERN WILL SET UP ACROSS MUCH OF THE AREA LATE MON THROUGH THU. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW