000 AXNT20 KNHC 180533 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON JUN 18 2012 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 45W/46W S OF 19N MOVING W 15-20 KT. WAVE REMAINS ALONG THE LEADING EDGE OF A SURGE IN DEEP LAYER MOISTURE AS INDICATED BY THE TOTAL PRECIPITABLE WATER IMAGERY. NO ASSOCIATED DEEP CONVECTION. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL ATLC NEAR 16N16W CONTINUE ALONG 12N21W TO 9N28W WHERE THE ITCZ CONTINUES ALONG 7N34W TO 9N45W 7N53W TO INLAND OVER SOUTH AMERICA NEAR 7N59W. SCATTERED THUNDERSTORMS ARE WITHIN 90 NM ALONG THE COAST OF SW AFRICA FROM SIERRA LEONE TO ACROSS THE PRIME MERIDIAN. CLUSTERS OF ISOLATED MODERATE CONVECTION ARE WITHIN 75 NM N OF THE ITCZ BETWEEN 34W-43W. ...DISCUSSION... GULF OF MEXICO... THE W GULF IS UNDER NNW FLOW ALOFT WHILE AN UPPER RIDGE IS OVER THE NE GULF AND AN UPPER LOW IS OVER THE SE GULF. A WEAK SURFACE TROUGH IS OVER THE NW GULF EXTENDING FROM SW LOUISIANA NEAR LAKE CHARLES TO 26N94W WITH ISOLATED SHOWERS WITHIN 90/120 NM E OF THE SURFACE TROUGH. DIFFLUENCE ALOFT BETWEEN THE UPPER FLOW OVER THE W GULF AND THE UPPER RIDGE OVER THE NE GULF IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 45 NM OF LINE FROM 25N87W TO OVER LOUISIANA NEAR VERMILION BAY. THE NE SURFACE LOW IS BANKING LOW LEVEL CLOUDS WITH ISOLATED SHOWERS OVER THE BAY OF CAMPECHE WITHIN 90 NM ALONG THE COAST OF MEXICO S OF TUXPAN AND E OF MERIDA. THIS IS LEAVING THE REMAINDER OF THE GULF UNDER MOSTLY CLEAR SKIES TONIGHT. THE SURFACE TROUGH WILL DRIFT W MOVING INTO TEXAS MON. HIGH PRESSURE WILL BUILD OVER THE E GULF LATE MON AS A SECOND AND STRONGER TROUGH WILL MOVE OFF THE YUCATAN INTO THE GULF WED GRADUALLY SHIFTING W-NW THROUGH THE END OF THE WEEK. A WEAK SURFACE LOW MAY FORM ALONG THIS THROUGH OVER THE SW GULF WED THROUGH FRI. ANOTHER TROUGH WILL APPROACH THE E GULF FROM FLORIDA LATE THU AND FRI. CARIBBEAN SEA... BROAD UPPER RIDGE EXTENDS FROM OVER CENTRAL AMERICA NEAR THE TIP OF HONDURAS/NICARAGUA TO ACROSS THE LEEWARD/VIRGIN ISLANDS INTO THE W/CENTRAL ATLC. THIS IS PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED TO HEAVY SHOWERS WITH ISOLATED THUNDERSTORMS ARE N OF 15N BETWEEN 66W-81W. EMBEDDED BENEATH THIS FLOW IS A 1007 MB SURFACE LOW CENTERED NEAR 14N81W WITH A SURFACE TROUGH EXTENDING FROM THE LOW ALONG 18N79W ACROSS CUBA NEAR HOLGUIN INTO THE W/CENTRAL ATLC. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 15N W OF 68W AND FROM 15N-20N W OF 82W. THIS IS LEAVING ONLY THE FAR E CARIBBEAN AND THE LESSER ANTILLES UNDER MOSTLY CLEAR SKIES TONIGHT. LOW/SURFACE TROUGH WILL DRIFT NW THROUGH EARLY WED. TROPICAL WAVE WILL ENTER THE CARIBBEAN MON NIGHT AND DISSIPATING OVER THE CENTRAL ATLC ON THU. A SECOND TROPICAL WAVE WILL ENTER THE CARIBBEAN ON WED. ATLANTIC OCEAN... A BROAD UPPER TROUGH COVERS THE W ATLC N OF 22N W OF 63W TO OVER FLORIDA SUPPORTING 1006 MB LOW N OF THE DISCUSSION AREA AND A SURFACE TROUGH ENTERING THE W/CENTRAL ATLC NEAR 32N54W AND EXTENDING ALONG 26N69W ACROSS CUBA NEAR HOLGUIN INTO THE CARIBBEAN. DENSE CLOUD COVER WITH ISOLATED SHOWERS ARE WITHIN 200 NM E OF THE SURFACE TROUGH WITH CLEAR SKIES W OF THE SURFACE TROUGH. AN UPPER RIDGE EXTENDS FROM THE CARIBBEAN ACROSS THE LEEWARD/VIRGIN ISLANDS ALONG 25N58W TO BEYOND 32N55W PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED TO HEAVY SHOWERS WITH ISOLATED THUNDERSTORMS FROM 18N-22N BETWEEN 62W-68W AND SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 90 NM OF LINE FROM 28N56W TO 24N60W. A LARGE SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC E OF 63W ANCHORED BY A 1027 MB HIGH NEAR 30N37W. TROUGH WILL REMAIN NEARLY STATIONARY THROUGH MON THEN WILL DRIFT W TUE APPROACHING FLORIDA WED AND THU. SURFACE RIDGE WILL BUILD IN FROM THE E BEHIND THE TROUGH WED THROUGH FRI. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW