000 AXNT20 KNHC 280557 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT FRI JUN 28 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 13N21W TO 05N22W MOVING WEST NEAR 5 KT. THE WAVE AXIS IS MOSTLY EMBEDDED IN A MODERATE MOIST ENVIRONMENT WITHIN THE ITCZ AND HAVE NO CONVECTIVE ACTIVITY ASSOCIATED TO IT AT THIS TIME. THE METEOSAT-9 SAL TRACKING PRODUCT INDICATES THE WAVE IS BEING ENGULFED BY SAL DRY AIR WHICH MAY BE LIMITING ANY FORM OF CONVECTION. TROPICAL WAVE IS ALONG 15N48W TO 03N51W MOVING WEST NEAR 10 KT. THE WAVE IS EMBEDDED IN A MOSTLY MODERATE MOIST ENVIRONMENT WITHIN THE ITCZ WITH PATCHES OF HIGH MOISTURE SE-SW OF THE AXIS. SCATTERED MODERATE CONVECTION COINCIDES WITH THE AREAS OF HIGH MOISTURE FROM 0N-04N BETWEEN 42W-50W AND FROM 07N-10N BETWEEN 52W-58W. SCATTERED SHOWERS ARE FROM 06N-09N BETWEEN 42W-46W. TROPICAL WAVE IS MOVING THROUGH THE CENTRAL CARIBBEAN ALONG 21N73W TO 10N74W MOVING WEST NEAR 10 KT. MODERATE LOW LEVEL MOISTURE IS AHEAD OF THE WAVE AXIS ACROSS THE WINDWARD PASSAGE AND OVER HAITI COINCIDING WITH SCATTERED MODERATE CONVECTION FROM 17N-21N BETWEEN 71W-76W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN WEST COAST NEAR 13N16W TO 09N21W. THE ITCZ BEGINS WEST OF A TROPICAL WAVE NEAR 08N24W AND CONTINUES ALONG 05N38W 01N49W. ANY DEEP CONVECTION NEAR THE ITCZ/MONSOON TROUGH IS ASSOCIATED WITH TROPICAL WAVES AND IS DISCUSSED IN THAT SECTION ABOVE. ...DISCUSSION... GULF OF MEXICO... WEAK SURFACE RIDGING IS ACROSS THE GULF OF MEXICO AROUND A 1016 MB HIGH NEAR 27N88W. LIGHT ANTI-CYCLONIC FLOW OF 5-10 KT IS AROUND THE RIDGE. ALOFT...UPPER TROUGHING DOMINATES WITH AN AXIS EXTENDING THROUGH CENTRAL FLORIDA. THE REMAINDER BECOMES A CUT- OFF UPPER LOW IN THE BAY OF CAMPECHE NEAR 23N94W. THE UPPER LOW IS PROVIDING DIFFLUENT FLOW ALOFT OVER THE YUCATAN PENINSULA SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS SOUTH OF 22N BETWEEN 85W-92W. WEAK SURFACE RIDGING WILL REMAIN OVER THE AREA WITHIN THE NEXT 48 HOURS...A COLD FRONT IS EXPECTED TO EXTEND ACROSS THE NORTHERN GULF SATURDAY AFTERNOON. CARIBBEAN SEA... A TROPICAL WAVE WITH AXIS CROSSING THE WINDWARD PASSAGE EXTENDS FROM 21N73W TO 10N74W. MODERATE LOW LEVEL MOISTURE IS ACROSS THE WINDWARD PASSAGE AND OVER HAITI COINCIDING WITH SCATTERED MODERATE CONVECTION AND ISOLATED THUNDERSTORM ACTIVITY FROM 17N- 21N BETWEEN 71W-76W. LARGE CLUSTERS WITH STRONG CONVECTION AND NUMEROUS THUNDERSTORMS ARE OVER NORTHERN COLOMBIA AND PANAMA. THIS CONVECTIVE ACTIVITY EXTENDS SCATTERED MODERATE CONVECTION OVER THE SOUTHERN CARIBBEAN S OF 11N WHERE MODERATE TO HIGH LOW LEVELS MOISTURE LIES. THE CONVECTIVE ACTIVITY OVER THE ABOVE MENTIONED REGION IS MOSTLY ASSOCIATED WITH THE MONSOON TROUGH AXIS WHICH MOVES ACROSS FROM COSTA RICA TO COLOMBIA. ALOFT...BROAD UPPER RIDGING COVERS THE MAJORITY OF THE BASIN CENTERED NEAR 12N74W WHILE BROAD UPPER TROUGHING COVERS THE FAR EASTERN CARIBBEAN. TRADEWINDS OF 10-15 KT ARE ACROSS MOST OF THE BASIN EXCEPT THE CENTRAL CARIBBEAN WHERE WINDS ARE 20-25 KT DUE TO A TIGHTER PRESSURE GRADIENT. THE WAVE WILL CONTINUE TO MOVE WEST AND ITS AXIS IS EXPECTED TO BE OFF WESTERN CUBA FRIDAY AFTERNOON. WINDS IN THE CENTRAL CARIBBEAN ARE EXPECTED TO SUBSIDE TO LESS THAN 25 KT BY SATURDAY AFTERNOON WHILE A NEW WAVE MOVES ACROSS THE LESSER ANTILLES CARRYING LOTS OF MOISTURE. HISPANIOLA... MODERATE LOW LEVEL MOISTURE IS ACROSS THE WINDWARD PASSAGE AND OVER HAITI COINCIDING WITH SCATTERED MODERATE CONVECTION AND ISOLATED THUNDERSTORM ACTIVITY FROM 17N-21N BETWEEN 71W-76W. THIS MOISTURE AND CONVECTIVE ACTIVITY IS ASSOCIATED WITH A TROPICAL WAVE WITH AXIS CROSSING THE WINDWARD PASSAGE. MOISTURE ASSOCIATED WITH THIS WAVE IS EXPECTED TO FADE NEAR MIDNIGHT ON FRIDAY. FAIR WEATHER CAN BE EXPECTED THEN AND THROUGHOUT AT LEAST SUNDAY MORNING. CONDITIONS CAN DETERIORATE AGAIN MONDAY MORNING AS A NEW TROPICAL WAVE WILL BE CROSSING THE EASTERN CARIBBEAN BRINGING LOTS OF MOISTURE AND INCREASING ATMOSPHERE INSTABILITY. ATLANTIC OCEAN... BROAD SURFACE RIDGING COVERS THE WEST ATLC AROUND A 1022 MB HIGH NEAR 31N60W. ALOFT...AN UPPER RIDGE IS ALONG 76W...WHILE AN UPPER LOW SPINS TO THE EAST NEAR 24N63W. THE UPPER LOW IS SUPPORTING A SURFACE TROUGH ALONG 24N63W TO 20N67W. SCATTERED SHOWERS ARE FROM 20N-24N BETWEEN 58W-63W ASSOCIATED WITH THIS FEATURE. AT THE SURFACE...BROAD RIDGING DOMINATES EXTENDING FROM A 1038 MB HIGH NEAR 46N22W. UPPER RIDGING ALSO COVERS THE EXTREME TROPICAL ATLC. THE METEOSAT-9 SAL TRACKING PRODUCT DEPICTS A LARGE AREA OF SAHARAN DRY AIR EXTENDS FROM THE COAST OF AFRICA TO NEAR 55W AROUND THE TROPICAL WAVE THAT WILL ENTER THE EASTERN CARIBBEAN BY SATURDAY AFTERNOON. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS