000 AXNT20 KNHC 222353 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU AUG 22 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 IN THE TROPICAL ATLC EXTENDS FROM 16N48W TO 7N49W MOVING W 20 KT. WAVE IS ALONG THE LEADING EDGE OF A SURGE OF DEEP MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. NO ASSOCIATED SHOWERS/CONVECTION. TROPICAL WAVE IN THE CARIBBEAN EXTENDS FROM 21N82W TO 11N81W MOVING W 5-10 KT. WAVE IS EMBEDDED WITHIN A BROAD AREA OF DEEP MOISTURE THAT COVERS MOST OF THE CARIBBEAN AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. WAVE IS MOVING BENEATH THE UPPER LOW OVER THE NW CARIBBEAN ENHANCING SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS N OF 12N TO OVER CUBA BETWEEN 75W-84W INCLUDING JAMAICA. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 14N16W AND CONTINUES ALONG 13N19W 14N29W TO 12N45W. THE ITCZ BEGINS W OF THE TROPICAL WAVE NEAR 11N50W AND CONTINUES INTO SOUTH AMERICA NEAR 9N61W. A MID LEVEL LOW IS CENTERED NEAR 17N35W WITH A SURFACE TROUGH EXTENDING FROM 19N35W TO 15N34W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 75 NM W OF THE TROUGH FROM 16N-18N. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 11N-14N E OF 18W TO INLAND OVER W AFRICA. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION DOT THE AREA FROM 9N-14N BETWEEN 19W-42W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE IS ANCHORED ALONG THE SW MEXICO COAST EXTENDING A RIDGE AXIS NE ACROSS S MEXICO TO OVER THE W GULF FROM TUXPAN MEXICO TO OFF THE COAST OF TEXAS NEAR 17N95W. A SECOND UPPER RIDGE IS OVER THE NE GULF ANCHORED NEAR 28N84W. A SURFACE TROUGH IS BENEATH THE UPPER RIDGE EXTENDING ALONG 86W BETWEEN 26N-30N WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 24N-29N E OF 86W TO OVER THE FLORIDA PENINSULA. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE WITHIN 90/120 NM W OF THE SURFACE TROUGH. AN UPPER LOW IS CENTERED NEAR THE W TIP OF CUBA AND COVERS THE SE GULF S OF 25N E OF 90W THROUGH THE STRAITS OF FLORIDA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS THAT HAVE DEVELOPED OVER CUBA ARE MOVING INTO THE SE GULF AND THE YUCATAN CHANNEL DUE TO THE EASTERLY UPPER FLOW AROUND THIS UPPER LOW. THESE SHOWERS/THUNDERSTORMS ARE S OF 24N BETWEEN 81W-86W. THE CARIBBEAN TROPICAL WAVE WILL REACH THE YUCATAN PENINSULA FRI MORNING AND MOVE ACROSS THE SW GULF SAT AND SUN. THE SURFACE TROUGH OVER THE NE GULF WILL MOVE W AND EXTEND FROM SE LOUISIANA TO ABOUT 26N92W FRI MORNING. THE TROUGH WILL REACH THE FAR NW GULF SAT MORNING MOVING INLAND LATER ON SAT. CARIBBEAN SEA... THE CARIBBEAN TROPICAL WAVE IS BENEATH AN UPPER LOW THAT IS CENTERED NEAR THE W TIP OF CUBA AND COVERING THE NW CARIBBEAN N OF 17N W OF 80W. AN UPPER RIDGE EXTENDS FROM CENTRAL AMERICA NEAR THE TIP OF HONDURAS/NICARAGUA TO E CUBA NEAR 20N77W ENHANCING THE ACTIVITY ASSOCIATED WITH THE TROPICAL WAVE. THE MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 11N75W ALONG 12N79W TO ACROSS COSTA RICA NEAR 10N85W GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 12N W OF 78W TO INLAND OVER PANAMA TO NICARAGUA. AN UPPER LOW IS CENTERED N OF PUERTO RICO EXTENDING OVER THE REMAINDER OF THE E CARIBBEAN GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND OVER HISPANIOLA AND NE OF THE LEEWARD ISLANDS LEAVING THE SE CARIBBEAN CLEAR THIS EVENING. TROPICAL WAVE WILL MOVE ACROSS THE REMAINDER OF THE W CARIBBEAN TONIGHT THEN ACROSS THE YUCATAN PENINSULA FRI AND FRI NIGHT. TROPICAL ATLC TROPICAL WAVE WILL MOVE INTO THE E CARIBBEAN SUN AND THE CENTRAL CARIBBEAN MON. HISPANIOLA... AFTERNOON HEATING COUPLED WITH THE UPPER LOW N OF PUERTO RICO 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 SUN INTO MON THEN INCREASE AGAIN AS THE NEXT TROPICAL WAVE WILL MOVE 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 65W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE FROM 26N-31N W OF 78W TO INLAND OVER FLORIDA. A BROAD UPPER TROUGH COVERS THE AREA N OF 27N BETWEEN 52W-65W SUPPORTING A SURFACE TROUGH THAT EXTENDS THROUGH 32N52W ALONG 28N56W TO 27N63W GENERATING SCATTERED SHOWERS WITHIN 60 NM EITHER SIDE OF THE SURFACE TROUGH. A SURFACE RIDGE COVERS THE REMAINDER OF THE ATLC ANCHORED BY A 1021 MB HIGH NEAR 32N76W AND A 1023 MB HIGH NEAR 34N31W. AN UPPER LOW IS N OF PUERTO RICO NEAR 20N65W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 17N-19N BETWEEN 60W AND THE LEEWARD ISLANDS. THE SURFACE RIDGE WILL SLIDE SE FRI THROUGH SUN AND WEAKEN AS A WEAK COLD FRONT PUSHES SOUTHWARD TO THE FAR NW ATLC. THE FRONT WILL THEN BECOME STATIONARY AND WEAKEN LATE SUN INTO MON AS HIGH PRESSURE BUILDS S BEHIND IT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW