000 AXNT20 KNHC 281213 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT MAY 28 2011 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 1035 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS OFF THE COAST OF SURINAME FROM 11N54W TO 6N55W MOVING W AT 10-15 KT. CYCLONIC FLOW IS NOTED ALONG THE NORTHER AXIS IN THE LOW-LEVEL CLOUD PATTERN. HOWEVER...DRY NW FLOW IN THE MIDDLE TO UPPER LEVELS ABOVE THE LOW-LEVEL WAVE SIGNATURE IS INHIBITING ANY SIGNIFICANT CONVECTION WITH THE WAVE THIS EVENING. TROPICAL WAVE IS INLAND OVER VENEZUELA FROM 10N63W TO 5N64W MOVING W AT ABOUT 10 KT. THIS WAVE IS EXPECTED TO REMAIN INLAND AND CONTINUE TO MOVE WEST WITH CONVECTION OVER THE NEXT 24 HOURS. ...ITCZ... THE ITCZ AXIS IS ANALYZED FROM THE COAST OF SIERRA LEONE NEAR 8N13W SW ALONG 6N20W 4N30W 3N40W EQ50W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 120 NM ON EITHER SIDE OF THE AXIS E OF 44W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY COMBINED WITH UPPER LEVEL SATELLITE DERIVED WINDS INDICATE NW FLOW ALOFT MOVING A VERY DRY AIRMASS ACROSS THE GULF. AT SURFACE...WEAK SURFACE RIDGING COVERS THE AREA... CENTERED OVER THE NE CORNER OF THE BASIN BY A WEAK 1013 MB HIGH NEAR 28N84W. THE OUTPUT OF THESE CONDITIONS BRINGS FAIR WEATHER ACROSS THE DISCUSSION AREA THIS MORNING...WITH A FEW ISOLATED SHOWERS DEVELOPING OVER THE FAR SE BASIN S OF 26N E OF 83W... INCLUDING THE FLORIDA STRAITS. HAZY SKIES ACROSS THE WESTERN HALF OF THE BASIN ARE POSSIBLE DUE TO THE ADVECTION OF SMOKE FROM THE SOUTHERN MEXICO WILDFIRES. OTHERWISE...NO SIGNIFICANT CHANGES ARE EXPECTED OVER THE NEXT 24 HOURS. CARIBBEAN SEA... DRY WESTERLY ZONAL FLOW ALOFT IS NOTED ACROSS MUCH OF THE CARIBBEAN SEA THIS MORNING. THIS FEATURE IS KEEPING FAIR WEATHER CONDITIONS OVER MUCH OF THE CARIBBEAN...WITH A FEW ISOLATED SHOWERS LINGERING WITHIN 20 NM WEST AND SW OF THE GREATER ANTILLES. ON THE OTHER HAND...BROAD CYCLONIC TURNING IS NOTED ON THE S CENTRAL BASIN ACROSS THE COASTAL WATERS OF COLOMBIA. LOW LEVEL MOISTURE REMAINS QUITE HIGH IN THIS REGION...NOTICED ON TPW PRODUCT. SCATTERED SHOWERS AND TSTMS ARE S OF 14N AND W OF 73W. THIS CONVECTION REMAINS ENHANCED OVER INTERIOR PORTIONS OF PANAMA...COSTA RICA...AND NICARAGUA...DUE TO THE CLOSE PROXIMITY OF THE EASTERN PACIFIC OCEAN ITCZ AXIS. MODEL GUIDANCE SUGGEST THE ACTIVITY IN THE SW BASIN WILL INCREASE OVER THE NEXT 24 HOURS...AS A WEAK LOW/TROUGH SYSTEM DEVELOPS IN THIS REGION. ATLANTIC OCEAN... A SURFACE RIDGE COVERS THE WESTERN ATLC W OF 63W KEEPING CONDITIONS MOSTLY FAIR THIS EVENING. FARTHER EAST...A BROAD ELONGATED UPPER LEVEL LOW/TROUGH CONTINUES TO ROTATE AROUND 31N50W. THIS UPPER LEVEL FEATURE IS SUPPORTING A SERIES OF SURFACE LOWS MOVING ACROSS THE S CENTRAL ATLC...ANALYZED AS A 1014 MB LOW NEAR 31N52W...A 1013 MB LOW NEAR 29N58W...AND A 1013 MB LOW NEAR 23N51W. A SURFACE TROUGH EXTENDS FROM THE SUTHEASTERNMOST LOW TO 18N55W. A SURFACE TROUGH IS ALSO NOTED FROM 28N53W TO 23N56W. DESPITE THE LOCATION OF THESE SURFACE FEATURES...SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS N OF 18N BETWEEN 43W-51W...ASSOCIATED TO DIFFLUENCE FLOW ALOFT NOTED ON UPPER LEVEL SATELLITE DERIVED WINDS. WITHIN THIS AREA OF CONVECTION...A SHEAR LINE AXIS EXTENDS ALONG 32N47W TO 27N45W. THE PRESSURE GRADIENT IN THIS REGION REMAINS QUITE STRONG. AN EARLIER ASCAT PASS DEPICTED A CONTRAST OF 5 KT TO 25 KT FROM THE SW TO THE NE SIDE OF THE SHEAR AXIS. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE KEEPING FAIR WEATHER CONDITIONS E OF 40W. FINALLY...AN ELONGATED UPPER LEVEL LOW IS CENTERED NE OF THE MADEIRA ISLANDS SUPPORTING A SURFACE TROUGH EXTENDING ALONG 33N13W TO 28N17W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA