000 AXNT20 KNHC 232349 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI AUG 23 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE OFF AFRICA EXTENDS FROM 15N21W THROUGH A 1010 MB LOW NEAR 11N22W TO 7N23W MOVING W NEAR 10 KT. WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. NO ASSOCIATED SHOWERS/CONVECTION. TROPICAL WAVE IN THE W TROPICAL ATLC EXTENDS FROM 16N53W TO 8N55W MOVING W 10-15 KT. WAVE IS EMBEDDED WITHIN AN AREA OF MODERATE MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 12N- 14N BETWEEN 54W-56W. TROPICAL WAVE OVER S GULF OF MEXICO EXTENDS FROM 22N88W TO INLAND OVER THE YUCATAN PENINSULA ALONG 20N89W TO EL SALVADOR MOVING W NEAR 15 KT. WAVE IS EMBEDDED WITHIN A BROAD AREA OF MODERATE TO DEEP MOISTURE THAT COVERS THE W CARIBBEAN AND GULF OF MEXICO AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. WAVE REMAINS MOVING BENEATH THE UPPER LOW OVER THE E BAY OF CAMPECHE ENHANCING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND AND WITHIN 30/45 NM ALONG COAST OF THE YUCATAN BETWEEN 87W-92W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 15N17W AND CONTINUES THROUGH THE 1010 MB LOW/TROPICAL WAVE NEAR 11N22W THEN 12N30W 10N41W TO 12.50W. A 1014 MB LOW IS CENTERED NEAR 15N38W WITH ISOLATED SHOWERS POSSIBLE WITHIN 175 NM OF THE LOW. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 60 NM OF LINE FROM 11N25W TO 12N28W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 8N-11N BETWEEN 25W- 41W AND FROM 5N-10N BETWEEN 42W-50W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE OVER MEXICO EXTENDS INTO THE SW ATLC S OF 26N E OF 84W. A SECOND UPPER RIDGE IS OVER THE NE GULF ANCHORED NEAR 28N87W. A SURFACE TROUGH IS BENEATH THE UPPER RIDGE EXTENDING FROM TALLAHASSEE FLORIDA ALONG 28N89W TO 24N92W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 26N TO INLAND OVER THE N GULF COAST E OF 89W TO OVER THE FLORIDA PENINSULA. AN UPPER LOW IS CENTERED IN THE E BAY OF CAMPECHE NEAR 20N91W COVERING THE S GULF S OF 24N BETWEEN 81W-94W GENERATING SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS S OF 24N BETWEEN 81W-87W. ISOLATED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS DOT THE REMAINDER OF THE GULF THIS EVENING. TROPICAL WAVE WILL CONTINUE TO MOVE ACROSS THE YUCATAN PENINSULA AND ADJACENT GULF WATERS THROUGH TONIGHT THEN ACROSS THE SW GULF SAT AND SUN. THE SURFACE TROUGH WILL MOVE W REACHING THE TEXAS COAST BY SAT EVENING AND INLAND ACROSS TEXAS AND NE MEXICO ON SUN. CARIBBEAN SEA... AN UPPER RIDGE EXTENDS FROM CENTRAL AMERICA NEAR 16N87W TO CUBA NEAR 21N81W ENHANCING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 18N W OF 77W TO OVER CUBA AND THE YUCATAN. THE MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 9N75W TO ACROSS COSTA RICA NEAR 10N84W. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 75 NM OF LINE FROM PANAMA NEAR 9N78W TO 16N84W. THIS ACTIVITY IS BEING DRAWN NORTHWARD DUE TO THE UPPER RIDGE OVER THE NW CARIBBEAN. AN UPPER LOW IS CENTERED S OF THE MONA PASSAGE COVERING THE AREA FROM 14N-22N BETWEEN 64W-72W INCLUDING THE ISLANDS BETWEEN THE VIRGIN ISLANDS AND HISPANIOLA WITH A SURFACE TROUGH EXTENDING FROM 20N66W TO 25N69W. SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE FROM 17N-20N BETWEEN 65W-70W. THIS IS LEAVING THE SE CARIBBEAN CLEAR THIS EVENING. FRESH TO STRONG WINDS ASSOCIATED WITH THE TROPICAL WAVE OVER THE YUCATAN ARE STILL AFFECTING THE WESTERN CARIBBEAN. ANOTHER TROPICAL WAVE WILL ENTER THE E CARIBBEAN LATE ON SAT AND THE CENTRAL CARIBBEAN LATE ON MON. HISPANIOLA... AFTERNOON HEATING COUPLED WITH THE UPPER LOW S OF THE MONA PASSAGE HAVE GENERATE THUNDERSTORMS ACROSS THE ISLAND THIS EVENING. THIS UPPER LOW/TROUGH WILL TRACK W ACROSS THE ISLAND AND BE W OF THE ISLAND BY EARLY SUN. THE INSTABILITY AND THUS SHOWERS AND THUNDERSTORMS WILL DECREASE LATE SAT THROUGH MON THEN INCREASE AGAIN AS THE NEXT TROPICAL WAVE MOVES ACROSS THE ISLAND LATE MON INTO TUE. ATLANTIC OCEAN... THE UPPER RIDGE OVER THE NE GULF OF MEXICO EXTENDS ACROSS FLORIDA INTO THE FAR W ATLC TO 70W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE FROM 25N-31N W OF 79W TO INLAND OVER FLORIDA. A BROAD UPPER TROUGH N OF THE DISCUSSION AREA EXTENDS A SHORTWAVE UPPER TROUGH INTO THE CENTRAL ATLC NEAR 32N55W TO 26N63W SUPPORTING A SURFACE TROUGH THAT EXTENDS THROUGH 32N57W TO 28N59W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 120 NM E OF THE SURFACE TROUGH. A SURFACE RIDGE COVERS THE REMAINDER OF THE ATLC ANCHORED BY A 1019 MB HIGH NEAR 30N67W AND A 1026 MB HIGH SE OF THE AZORES. SURFACE RIDGE WILL SLIDE SE THROUGH SUN AND WEAKEN AS A WEAK COLD FRONT PUSHES SOUTHWARD TO THE FAR N PORTION OF THE W ATLC. THE FRONT WILL THEN BECOME STATIONARY AND WEAKEN LATE SUN INTO MON AS HIGH PRES BUILDS BEHIND IT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW