000 AXNT20 KNHC 281805 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI JUN 27 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE IN THE E TROPICAL ATLC IS ANALYZED FROM 13N24W TO 6N24W DRIFTING W OVER THE PAST 24 HOURS. THIS WAVE HAS BECOME ILL-DEFINED SINCE EMERGING INTO THE ATLC WATERS. WAVE REMAINS EMBEDDED WITHIN A LOW AMPLITUDE AREA OF DEEP MOISTURE AS DEPICTED BY THE TOTAL PRECIPITABLE WATER IMAGERY. NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE IN THE W TROPICAL ATLC EXTENDS FROM 16N54W TO THE COAST OF SOUTH AMERICA NEAR 6N57W MOVING W NEAR 20 KT. WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE AS DEPICTED BY THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 12N TO THE COAST OF SOUTH AMERICA BETWEEN 54W-61W WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS DOTTING THE AREA FROM 12N-17N BETWEEN 50W-59W. TROPICAL WAVE IN THE CENTRAL CARIBBEAN EXTENDS FROM 23N78W ACROSS CUBA TO THE COAST OF PANAMA NEAR 9N79W MOVING W NEAR 15 KT. WAVE IS EMBEDDED WITHIN MODERATE TO DEEP MOISTURE THAT COVERS THE CARIBBEAN W OF 70W. CLUSTERS OF SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE FROM 19N-23N BETWEEN 73W-80W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 10N14W AND CONTINUES TO 7N24W. THE ITCZ BEGINS WEST OF THE TROPICAL WAVE NEAR 7N27W AND CONTINUES ALONG 5N32W THEN S OF THE EQUATOR NEAR 37W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 8N-12N E OF 19W TO INLAND OVER W AFRICA AND FROM 8N-10N BETWEEN 19W-23W. ...DISCUSSION... GULF OF MEXICO... A CUT-OFF UPPER LOW IS OVER THE SW GULF CENTERED NEAR 23N95W WHILE A SHORTWAVE UPPER TROUGH EXTENDS FROM THE W ATLC ACROSS FLORIDA NEAR LAKE OKEECHOBEE TO 26N86W. THIS IS ALLOWING THE UPPER RIDGE ANCHORED OVER THE SW CONUS TO EXTEND ACROSS TO THE SE CONUS COVERING THE N GULF OF MEXICO. THIS UPPER RIDGE IS PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 29N TO OVER THE FLORIDA PANHANDLE E OF 88W 90W TO OVER THE FLORIDA PENINSULA. ISOLATED SHOWERS/ THUNDERSTORMS ARE POSSIBLE OVER THE REMAINDER OF THE E GULF N OF 24N E OF 90W. A WEAK SURFACE RIDGE EXTENDS FROM THE W ATLC OVER THE GULF WITH A 1016 MB HIGH LOCATED NEAR 25N92W GIVING THE REMAINDER OF THE GULF MOSTLY CLEAR SKIES THIS AFTERNOON. SURFACE RIDGE WILL SHIFT S BY LATE SAT AS A WEAK COLD FRONT MOVES INTO THE NW GULF SUN AND MON THEN DISSIPATES TUE. THE RIDGE WILL N BY TUE. CARIBBEAN SEA... A BROAD UPPER RIDGE COVERS THE CARIBBEAN ANCHORED OVER SOUTH AMERICA AND IS ADVECTING MOISTURE ALOFT OVER THE CARIBBEAN. THE MONSOON TROUGH EXTENDS ACROSS THE SW CARIBBEAN FROM COLOMBIA NEAR 10N74W ALONG 1N79W ACROSS COSTA RICA NEAR 10N85W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF TROUGH TO ACROSS CENTRAL AMERICA. SOME ISOLATED SHOWERS/THUNDERSTORMS ARE POSSIBLE WITHIN 60 NM ALONG THE COAST OF THE YUCATAN PENINSULA N OF 19N AND SW CUBA W OF 80W. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN UNDER MOSTLY SKIES THIS AFTERNOON. TROPICAL WAVE WILL WEAKEN AS IT CONTINUES W ENTERING THE W CARIBBEAN SAT THEN SLOWING DOWN AS IT MOVES THROUGH CENTRAL AMERICA SUN. W TROPICAL ATLC TROPICAL WAVE WILL APPROACH THE WINDWARD ISLANDS TODAY MOVING ACROSS THE E CARIBBEAN THIS WEEKEND INTO THE CENTRAL CARIBBEAN LATE SUN AND MON AND INTO THE W CARIBBEAN BY TUE. HISPANIOLA... CURRENTLY SOME SHOWER ACTIVITY IS NOTED OVER THE ISLAND OF HISPANIOLA BUT NO THUNDERSTORMS. DEEP LAYER MOISTURE IS LIMITED OVER HISPANIOLA THIS AFTERNOON AS INDICATED BY THE TOTAL PRECIPITABLE WATER IMAGERY THUS LIMITING HEAVY SHOWERS AND THUNDERSTORM ACTIVITY. THIS WILL BE THE CASE THROUGH SAT. A TROPICAL WAVE IS EXPECTED TO MOVE ACROSS THE ISLAND ON SUN THROUGH AFTERNOON MONDAY INCREASING THE CHANCES OF SHOWERS/ THUNDERSTORMS ESPECIALLY IN THE AFTERNOON HOURS. ATLANTIC OCEAN... A SHORTWAVE UPPER TROUGH EXTENDS FROM 30N75W ACROSS CENTRAL FLORIDA NEAR LAKE OKEECHOBEE INTO THE GULF OF MEXICO GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 60/75 NM OF LINE FROM 29N77W TO OVER S FLORIDA NEAR MIAMI INCLUDING THE UPPER FLORIDA KEYS. THE UPPER RIDGE OVER THE CARIBBEAN EXTENDS A RIDGE AXIS OVER THE W ATLC ACROSS CENTRAL CUBA TO NEAR 26N72W ENHANCING THE ACTIVITY ASSOCIATED WITH THE W CARIBBEAN TROPICAL WAVE. AN UPPER LOW IS CENTERED TO THE E NEAR 22N66W SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 25N63W TO N OF THE VIRGIN ISLANDS NEAR 19N63W AND IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 150 NM E OF THE SURFACE TROUGH. THE REMAINDER OF THE ATLC IS DOMINATED BY A BROAD SURFACE RIDGE ANCHORED BY A 1022 MB HIGH IN THE CENTRAL ATLC NEAR 32N60W AND A 1038 MB HIGH NE OF THE AZORES. SAHARAN DUST CONTINUES TO COVER THE E ATLC FROM 10N-26N BETWEEN 25W-45W AND N OF 15N E OF 25W. SURFACE RIDGE WILL MOVE S OVER THE W ATLC TO THE STRAITS OF FLORIDA BY SAT AS TROUGHING INCREASES NW OF THE AREA OVER THE SE CONUS THROUGH THE WEEKEND. THE TROUGHING WILL WEAKEN MON AND TUE AND THE RIDGE WILL SHIFT N BACK TO CENTRAL FLORIDA BY LATE TUE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW