000 AXNT20 KNHC 171149 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT AUG 17 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 1015 UTC. ...SPECIAL FEATURES... TROPICAL STORM ERIN IS CENTERED NEAR 18.9N 35.6W AT 17/0900 UTC OR ABOUT 690 NM W-NW OF THE CAPE VERDE ISLANDS MOVING W-NW AT 13 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUST TO 45 KT. PLEASE SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT5/WTNT35 AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. THE CONVECTION IS N OF THE EXPESED LOW LEVEL CENTER THIS MORNING. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 19N-23N BETWEEN 33W- 36W. THE SURFACE TROUGH IN THE GULF OF MEXICO EXTENDS FROM 26N90W THROUGH A WEAK 1010 MB LOW NEAR 21N93W TO S MEXICO NEAR 17N94W. A MID/UPPER LOW IS TO THE NE NEAR 22N90W. AN UPPER RIDGE IS ANCHORED IN THE YUCATAN CHANNEL EXTENDING AN AXIS E OF THE LOWS THROUGH THE GULF TO ACROSS S/CENTRAL FLORIDA DRAWING THE MOISTURE AND SHOWER/THUNDERSTORM ACTIVITY NE OF THE LOW LEVEL SYSTEM. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 120 NM OF LINE FROM OVER S MEXICO NEAR 18N93W ALONG 26N87W TO OVER NE FLORIDA NEAR 30N83W. ENVIRONMENTAL CONDITIONS COULD BECOME SOMEWHAT MORE FAVORABLE FOR DEVELOPMENT WHILE THE LOW GENERALLY MOVES TOWARD THE WEST-NORTHWEST OR NORTHWEST OVER THE NEXT COUPLE OF DAYS. INTERESTS IN THE CENTRAL AND WESTERN GULF OF MEXICO SHOULD MONITOR THE PROGRESS OF THE SYSTEM THROUGH EARLY NEXT WEEK. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS...AND A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS. ...TROPICAL WAVES... TROPICAL WAVE IN THE E TROPICAL WAVE EXTENDS FROM 22N56W TO 10N56W MOVING W 15-20 KT. WAVE REMAINS EMBEDDED WITHIN AN AREA OF MODERATE MOISTURE AS DEPICTED IN TOTAL PRECIPITABLE WATER IMAGERY. NO ASSOCIATED SHOWERS OR DEEP CONVECTION. TROPICAL WAVE IS MOVING ACROSS THE CARIBBEAN EXTENDS FROM 22N70W TO 13N71W MOVING W NEAR 20 KT. PORTION OF THE WAVE N OF 16N IS EMBEDDED WITHIN AN AREA OF DEEP MOISTURE COVERING THE AREA FROM PUERTO RICO TO THE DOMINICAN REPUBLIC AS DEPICTED IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS DOT THE AREA FROM 15N-21N BETWEEN 64W-75W INCLUDING THE VIRGIN ISLANDS...PUERTO RICO...AND HISPANIOLA. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 12N15W CONTINUING ALONG 9N20W TO 10N27W THEN RESUMES SW OF T.S. ERIN NEAR 13N41W TO A WEAK 1012 MB LOW NEAR 12N46W. THE ITCZ BEGINS W OF THE LOW NEAR 12N48W AND CONTINUES ALONG 11N55W TO SOUTH AMERICA NEAR 8N59W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-10N BETWEEN 14W-22W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 6N-13N BETWEEN 40W-52W. ...DISCUSSION... GULF OF MEXICO... MOST OF THE ACTIVITY OVER E GULF IS ASSOCIATED WITH THE SURFACE TROUGH/LOW IN THE SW GULF. SEE SPECIAL FEATURES ABOVE. AN UPPER TROUGH COVERS THE E CONUS EXTENDING FROM AN UPPER LOW OVER THE MIDDLE MISSISSIPPI VALLEY TO S TEXAS AND SUPPORTING A STATIONARY BOUNDARY THAT MEANDERS ALONG THE GULF COAST FROM SW GEORGIA INTO THE GULF NEAR PENSACOLA TO A WEAK 1014 MB LOW JUST W OF NEW ORLEANS THEN RE-EMERGING INTO THE GULF OVER ATCHAFALAYA BAY LOUISIANA TO NEAR GALVESTON TEXAS. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 60 NM S OF THE FRONT E OF 93W. AN UPPER RIDGE IS ANCHORED IN THE YUCATAN CHANNEL EXTENDING AN AXIS OVER THE E GULF ALONG 26N85W TO ACROSS S/CENTRAL FLORIDA INTO THE W ATLC DRAWING MOISTURE AND SUBSEQUENT SHOWERS/THUNDERSTORMS OVER THE E GULF...ASSOCIATED WITH THE SYSTEM IN THE SPECIAL FEATURES ABOVE. WEAK SURFACE RIDGE EXTENDS FROM THE W ATLC ACROSS CENTRAL FLORIDA TO OVER THE E GULF. LOW PRESSURE SYSTEM IN SPECIAL FEATURES IS FORECAST TO CONTINUE TO MOVE IN A W-NW DIRECTION REACHING THE W/CENTRAL GULF LATE SUN THEN MOVING INLAND OVER EXTREME SE TEXAS COAST LATE MON...WITH THE POSSIBILITY OF TROPICAL CYCLONE FORMATION THROUGH MON. SURFACE RIDGE WILL DOMINATE THE REMAINDER OF THE GULF THROUGH WED. CARIBBEAN SEA... THE UPPER RIDGE OVER THE E GULF OF MEXICO IS ANCHORED IN THE YUCATAN CHANNEL AND COVERS THE FAR NW CARIBBEAN W OF 83W WHILE A SECOND UPPER RIDGE COVERS THE E CARIBBEAN ANCHORED JUST E OF THE LEEWARD ISLANDS. THIS IS INDUCING AN INVERTED UPPER TROUGH OVER THE CENTRAL CARIBBEAN EXTENDING FROM COSTA RICA/PANAMA BORDER ACROSS JAMAICA AND E CUBA. CLUSTERS OF SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE FROM 17N-22N BETWEEN 75W-83W. THE MONSOON TROUGH EXTENDS ALONG 10N FROM COLOMBIA TO COSTA RICA GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 12N W OF 77W TO INLAND OVER PANAMA TO NICARAGUA. THE SHOWER ACTIVITY IN THE N/CENTRAL CARIBBEAN IS ASSOCIATED WITH THE TROPICAL WAVE. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE APPROACHING THE LEEWARD AND VIRGIN ISLANDS WITHIN 60 NM OF LINE FROM 18N61W TO 20N64W. THE REMAINDER OF THE CARIBBEAN IS UNDER FAIR CONDITIONS AGAIN THIS MORNING. CARIBBEAN TROPICAL WAVE WILL CONTINUE W THROUGH THE CENTRAL CARIBBEAN TODAY BECOMING DIFFUSE OVER THE W CARIBBEAN ON SUN. A SECOND TROPICAL WAVE WILL MOVE ACROSS THE E CARIBBEAN ON SUN AND MON AND THROUGH THE CENTRAL CARIBBEAN TUE AND WED. HISPANIOLA... SCATTERED SHOWERS ARE POSSIBLE ISOLATED THUNDERSTORMS CONTINUE ACROSS THE ISLAND THIS MORNING. THE TROPICAL WAVE THAT IS GENERATING THESE SHOWERS WILL CONTINUE TO MOVE ACROSS THE DOMINICAN REPUBLIC TO OVER HAITI TODAY BRINGING THESE SHOWERS AND POSSIBLE MORE ISOLATED THUNDERSTORMS THROUGHOUT THE DAY. ANOTHER WAVE WILL MOVE ACROSS THE ISLAND LATE SUN THROUGH TUE INCREASING THE POSSIBILITY OF HEAVIER OR MORE FREQUENT SHOWERS/THUNDERSTORMS. ATLANTIC OCEAN... THE UPPER RIDGE OVER THE W CARIBBEAN EXTENDS ACROSS THE GULF OF MEXICO INTO THE W ATLC NEAR MELBOURNE FLORIDA TO BEYOND 32N70W. THE UPPER TROUGH OVER THE E CONUS AND THE ASSOCIATED STATIONARY FRONT IS N OF THE DISCUSSION AREA WITH SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS N OF 29N W OF 76W. A BROAD SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC INTO THE GULF OF MEXICO ANCHORED BY A SERIES OF HIGHS N OF THE DISCUSSION AREA. A WEAK UPPER LOW IS IN THE CENTRAL ATLC NEAR 26N48W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 27N-32N BETWEEN 47W-54W. SURFACE RIDGE EXTENDING INTO THE GULF OF MEXICO WILL LIFT IN N TO NEAR 31N TODAY AND SUN AND SHIFT N OF THE AREA NEXT WEEK. THE N PORTION OF CARIBBEAN TROPICAL WAVE WILL MOVE ACROSS THE FAR SW ATLC THROUGH SUN NIGHT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW