000 AXNT20 KNHC 091109 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT MON JUL 09 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1030 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS E OF THE CAPE VERDE ISLANDS EXTENDING FROM 21N26N TO 12N28W MOVING W NEAR 15 KT. WAVE IS ALONG THE LEADING EDGE OF A SURGE OF DEEP LAYER MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. AN AREA OF SAHARAN DUST IS W OF THE WAVE LIMITING CONVECTION. TROPICAL WAVE EXTENDS FROM 25N62W THROUGH THE LEEWARD/VIRGIN ISLANDS TO NEAR 17N64W MOVING W 15-20 KT. WAVE IS EMBEDDED WITHIN AN AREA OF MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. WAVE ALSO COINCIDES WITH AN UPPER RIDGE AND WITH AN AREA OF SAHARAN DUST TO THE E OF THE WAVE LIMITING ANY DEEP CONVECTION WITH ISOLATED SHOWERS FROM 18N-14N BETWEEN 61W-65W. TROPICAL WAVE EXTENDS FROM 23N93W TO INLAND OVER S MEXICO NEAR 18N94W MOVING W NEAR 10 KT. WAVE IS EMBEDDED WITHIN A LARGE AREA OF DEEP LAYERED MOISTURE COVERING THE ENTIRE GULF OF MEXICO AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE OVER THE W BAY OF CAMPECHE S OF 21N AND W OF THE WAVE AXIS TO INLAND OVER MEXICO. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL ATLC NEAR 13N17W S OF THE TROPICAL WAVE ALONG 10N27W TO 7N34W WHERE THE ITCZ AXIS CONTINUES THROUGH A 1012 MB LOW NEAR 6N42W TO INLAND OVER SOUTH AMERICA NEAR 2N51W. SCATTERED MODERATE/ ISOLATED STRONG CONVECTION IS OFF THE COAST OF AFRICA FROM 7N-11N E OF 17W BETWEEN 15W-20W. CLUSTERS OF SCATTERED MODERATE/ ISOLATED STRONG CONVECTION ARE WITHIN 150 NM EITHER SIDE OF THE MONSOON TROF/ITCZ BETWEEN 24W AND THE LOW...FROM 6N-10N BETWEEN 40W-48W AND WITHIN 120 NM ALONG THE COAST OF SOUTH AMERICA BETWEEN 47W-57W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE COVERS THE S GULF AND ANCHORED IS IN THE E PACIFIC REGION. AN UPPER RIDGE COVERS THE W GULF AND IS ANCHORED OVER THE CENTRAL PLAIN STATES. AN UPPER TROUGH EXTENDS FROM THE CENTRAL ATLC THROUGH A SERIES OF UPPER LOWS TO AN UPPER LOW IN THE SE GULF NEAR 27N84W COVERING THE E GULF. ISOLATED SHOWERS/ THUNDERSTORMS ARE S OF 28N E OF 85W TO OVER CUBA...THE FLORIDA KEYS AND THROUGH THE STRAITS OF FLORIDA. AT THE SURFACE A WEAK SURFACE RIDGE EXTENDS FROM THE ATLC ACROSS CENTRAL FLORIDA TO A 1018 MB HIGH NEAR 27N87W. THIS IS GIVING MOST OF THE N GULF SOUTHERLY RETURN FLOW AND COUPLED WITH THE OPPOSING FLOW ALOFT IS GENERATING SCATTERED SHOWERS N OF 28N W OF PENSACOLA FLORIDA WITH SCATTERED THUNDERSTORMS N OF 29N BETWEEN PENSACOLA FLORIDA TO LAKE CHARLES LOUISIANA. THE ACTIVITY IN THE BAY OF CAMPECHE IS ASSOCIATED WITH THE TROPICAL WAVE. THIS IS LEAVING THE REMAINDER OF THE GULF WITH FAIR WEATHER THIS MORNING. THE SURFACE RIDGE WILL REMAIN THROUGH THU THEN RETRACT EASTWARD ALLOWING A WEAK COLD FRONT TO MOVE INTO THE NW WATERS AND IMMEDIATELY STALL. THE TROPICAL WAVE WILL SHIFT W ACROSS THE BAY OF CAMPECHE TODAY AND TONIGHT. A SECOND TROPICAL WAVE WILL MOVE THROUGH THE STRAITS OF FLORIDA THU THEN WEAKEN OVER THE S CENTRAL WATERS ON FRI. CARIBBEAN SEA... THE UPPER RIDGE THAT COVERS THE S GULF OF MEXICO EXTENDS OVER THE W CARIBBEAN TO 73W. AN UPPER RIDGE IN THE TROPICAL ATLC EXTENDS TO OVER THE E CARIBBEAN. THE UPPER TROUGH OVER THE E GULF OF MEXICO COVERS THE GREATER ANTILLES GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 18N TO INLAND OVER CUBA BETWEEN 74W-84W. THE MONSOON TROUGH EXTENDS ACROSS THE SW CARIBBEAN S OF 10N FROM COLOMBIA INTO THE E PACIFIC REGION OVER THE PANAMA/COSTA RICA BORDER GENERATING SCATTERED SHOWERS/ THUNDERSTORMS WITHIN 60/75 NM ALONG THE COAST OF PANAMA AND COSTA RICA FROM THE BORDER OF NICARAGUA W OF 81W. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN WITH FAIR WEATHER THIS MORNING. THE TROPICAL WAVE N OF THE LEEWARD ISLANDS WILL PASS THROUGH THE ISLANDS AND THROUGH N/CENTRAL WATERS TUE THEN ACROSS THE NW THU AND INTO THE YUCATAN PENINSULA BY FRI. ATLANTIC OCEAN... AN UPPER RIDGE COVERS MOST OF THE W ATLC ANCHORED OFF THE COAST OF NORTH CAROLINA. AN UPPER TROUGH EXTENDS FROM THE CENTRAL ATLC THROUGH A SERIES OF UPPER LOWS NEAR 31N46W...27N56W...26N66W... TO THE UPPER LOW IN THE SE GULF OF MEXICO GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 28N TO THE COAST OF CUBA W OF 77W TO FLORIDA INCLUDING THE N BAHAMA ISLANDS. SIMILAR ACTIVITY IS ASSOCIATED WITH THE UPPER LOW NEAR 27N567W COVERING THE AREA FROM 22N-29N BETWEEN 52W-57W. A LARGE SURFACE RIDGE DOMINATES THE ENTIRE ATLC ANCHORED BY A 1029 MB HIGH NW OF THE AZORES AND A SURFACE RIDGE EXTENDING THROUGH 32N50W 28N66W ACROSS CENTRAL FLORIA INTO THE GULF OF MEXICO GIVING THE REMAINDER OF THE ATLC BASIN FAIR WEATHER THIS MORNING. SATELLITE IMAGERY INDICATES A LARGE AREA OF SAHARAN DUST COVERING THE ATLC E OF 55W TO AS FAR N AS 30N. SURFACE RIDGE WILL SHIFT N TO ALONG 31N ON WED THEN SHIFT N OF THE AREA THU AND FRI. A TROPICAL WAVE WILL MOVE W ACROSS THE ATLC WATERS REACHING THE SE BAHAMAS TUE AND THE CENTRAL BAHAMAS WED THEN THROUGH THE STRAITS OF FLORIDA BY FRI. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW