000 AXNT20 KNHC 270539 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 13N44W TO 05N46W MOVING WEST NEAR 15 KT. THE WAVE COINCIDES WITH A SURGE OF DEEP LAYER MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION IS FROM 04N-11N BETWEEN 39W-48W. TROPICAL WAVE IS MOVING THROUGH THE CENTRAL CARIBBEAN ALONG 21N71W TO 12N69W MOVING WEST NEAR 5 KT. A SURGE OF MODERATE MOISTURE IS AT THE LOWER LEVELS EAST OF THE WAVE AND WRAPS AROUND THE NORTHERN PORTION OF THE AXIS. DRIER AIR HAS UNDERCUT THIS MOISTURE TO THE NORTH SO THAT NO DEEP CONVECTION IS AROUND THE SOUTHERN PORTION OF THE WAVE. SCATTERED MODERATE CONVECTION IS OVER LA HISPANIOLA FROM 17N-19N BETWEEN 70W-74W...ISOLATED SHOWERS ARE OVER THE NORTHERN CARIBBEAN ISLANDS. WEAK TROPICAL WAVE IS MOVING INTO THE WESTERN CARIBBEAN ALONG 21N80W TO 10N81W MOVING WEST NEAR 5 KT. THE WAVE HAS A WEAK MOISTURE SIGNAL WITH IT OVER THE NORTHERN PORTION AND A STRONGER SIGNAL TO THE SOUTH WITH RELATIVELY DRY AIR NEAR THE CENTRAL PORTION. CLUSTERS OF MODERATE CONVECTION ARE OVER WESTERN CUBA AND FROM 10N-13N WEST OF THE AXIS IN THE SOUTHERN CARIBBEAN. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COASTAL WEST AFRICA NEAR 14N17W TO 08N22W. THE ITCZ BEGINS NEAR 08N22W AND CONTINUES ALONG 05N31W 07N40W. CLUSTERS OF MODERATE/STRONG CONVECTION ARE FROM 04N-08N BETWEEN 25W-36W AND FROM 04N-11N BETWEEN 39W-48W. ISOLATED SHOWERS ARE FROM 08N-13N EAST OF 22W. ...DISCUSSION... GULF OF MEXICO... THE AZORES HIGH EXTENDS A RIDGE AXIS SW ALL THE WAY THROUGH THE GULF WHICH IS GENERATING RETURN FLOW IN THE RANGE OF 10-15 KT ACROSS THE BASIN. ALOFT...AN UPPER LEVEL TROUGH SPREADS OVER THE GULF WITH AN EMBEDDED CYCLONIC CIRCULATION W OF 88W. THE UPPER TROUGH IS PROVIDING MOIST SOUTHWESTERLY AND DIFFLUENT FLOW ALOFT ACROSS MOST OF THE SE-S GULF. THE UPPER CYCLONIC CIRCULATION IS SUPPORTING A SURFACE TROUGH ENTERING THE BAY OF CAMPECHE FROM 21N89W TO 18N92W WHICH IS GENERATING SCATTERED MODERATE CONVECTION S OF 22N EAST OF 93W. ISOLATED SHOWERS/THUNDERSTORMS SPREAD OVER THE SE GULF S OF 25N. WITHIN A 24 HOUR PERIOD A HIGH PRESSURE WILL BUILD OVER THE CENTRAL GULF. OTHERWISE...LITTLE CHANGE IS EXPECTED. CARIBBEAN SEA... TWO TROPICAL WAVES ARE ACROSS THE CARIBBEAN. THE FIRST IS NEAR 82W WHERE DRY AIR IS LIMITING CONVECTION S OF 20N. IN THE N-NW ENVIRONMENT OF THE WAVE N OF 20N STRONG ISOLATED SHOWERS/THUNDERSTORMS PREVAIL. THE SECOND WAVE IS APPROACHING 71W. MOISTURE WITH THIS WAVE IS MAINLY TO THE NORTH AND EAST OF THE AXIS. SCATTERED MODERATE CONVECTION AND ISOLATED THUNDERSTORMS ARE OVER LA HISPANIOLA FROM 17N-19N BETWEEN 70W- 74W...ISOLATED SHOWERS ARE OVER THE NORTHERN CARIBBEAN ISLANDS. SMALL CLUSTERS OF MODERATE CONVECTION WITH EMBEDDED THUNDERSTORMS ARE WITHIN 100 NM OF THE COASTLINES OF NICARAGUA S OF 13N...COSTA RICA AND PANAMA W OF 80W ASSOCIATED WITH THE MONSOON TROUGH AXIS WHICH EXTENDS TO NORTHERN COLOMBIA. ALOFT...BROAD UPPER RIDGING COVERS THE MAJORITY OF THE BASIN. TRADEWIND FLOW OF 15-20 KT IS THROUGHOUT THE AREA. BOTH WAVES ARE EXPECTED TO CONTINUE MOVING WEST. HISPANIOLA... SCATTERED MODERATE CONVECTION AND ISOLATED THUNDERSTORMS ARE OVER LA HISPANIOLA FROM 17N-19N BETWEEN 70W-74W ASSOCIATED WITH A TROPICAL WAVE WITH AXIS NEAR 71W. THE WAVE AXIS IS EXPECTED TO EXIT HAITI THURSDAY AFTERNOON BUT TRAILING MOISTURE ASSOCIATED WITH THE WAVE IS EXPECTED TO ENHANCE RAINSHOWERS THROUGHOUT THURSDAY EVENING. ATLANTIC OCEAN... BROAD SURFACE RIDGING COVERS THE WEST ATLC AROUND A 1022 MB HIGH NEAR 29N61W. ALOFT...AN UPPER RIDGE IS ALONG 78W...WHILE AN UPPER LOW SPINS TO THE EAST NEAR 25N64W. THE UPPER LOW IS SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS FROM 21N-25N BETWEEN 62W-67W. OTHERWISE...BROAD SURFACE RIDGING DOMINATES THE REMAINDER OF THE BASIN N OF 12N EXTENDING FROM A 1039 MB HIGH NEAR 47N22W. THE METEOSAT-9 SAL TRACKING PRODUCT DEPICTS A TONGUE OF SAL DRY AIR EXTENDING FROM THE COAST OF AFRICA TO NEAR 52W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR