000 AXNT20 KNHC 162328 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE JUN 16 2009 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2245 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 84W S OF 18N MOVING W AROUND 15 KT. THIS WAVE COINCIDES WITH A MAXIMUM IN DEEP LAYER MOISTURE BASED ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. VISIBLE SATELLITE IMAGERY DEPICTS CYCLONIC CIRCULATION IN THE MOTION OF LOW LEVEL CLOUDS NEAR THIS WAVE. THIS WAVE IS SUPPORTING SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 10N-18N BETWEEN 82W-86W INCLUDING PORTIONS OF HONDURAS...NICARAGUA...AND COSTA RICA. THIS CONVECTION IS ALSO BEING SUPPORTED BY UPPER LEVEL DIVERGENCE ASSOCIATED WITH AN UPPER LEVEL HIGH CENTERED OVER THE W CARIBBEAN NEAR 18N87W. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 10N13W 7N23W 6N33W 2N43W TO THE EQUATOR ALONG 52W. SCATTERED MODERATE CONVECTION IS FROM 5N-7N BETWEEN 9W-11W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-8N BETWEEN 14W-22W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS ALSO FROM 3N-8N BETWEEN 25W-35W. SCATTERED MODERATE CONVECTION IS S OF 6N BETWEEN 37W-52W. ...DISCUSSION... GULF OF MEXICO... A SURFACE TROUGH EXTENDS FROM THE S FLORIDA PENINSULA NEAR 25N81W TO 24N84W. LOW LEVEL CONVERGENCE IS SUPPORTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 60 NM EITHER SIDE OF THIS TROUGH INCLUDING PORTIONS OF THE S FLORIDA PENINSULA AND THE FLORIDA KEYS. A SECOND SURFACE TROUGH IS AFFECTING PORTIONS OF THE S GULF. THIS SECOND SURFACE TROUGH EXTENDS FROM N OF THE YUCATAN PENINSULA NEAR 22N90W TO S GUATEMALA NEAR 15N90W. LOW LEVEL CONVERGENCE NEAR THIS TROUGH IS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS FROM 16N-22N BETWEEN 87W-92W INCLUDING PORTIONS OF THE YUCATAN PENINSULA...BELIZE...AND GUATEMALA. THIS ACTIVITY IS BEING ENHANCED BY UPPER LEVEL DIVERGENCE AROUND AN UPPER LEVEL HIGH CENTERED OVER THE W CARIBBEAN NEAR 18N87W. THE SECOND SURFACE TROUGH IS FORECAST TO MOVE WESTWARD ACROSS THE BAY OF CAMPECHE TONIGHT THROUGH THURSDAY. ACROSS THE N AND CENTRAL GULF...DEEP LAYER DRY AIR IS PRESENT...WITH A 1017 MB SURFACE HIGH OVER THE N GULF NEAR 28N87W. ANTICYCLONIC FLOW AROUND THE SURFACE HIGH IS AFFECTING MUCH OF THE GULF...WITH SE TO S WINDS OF 15 TO 20 KT OCCURRING ACROSS PORTIONS OF THE NW GULF IN RESPONSE TO A BROAD SURFACE TROUGH OVER MEXICO AND THE SOUTHERN PLAINS OF THE UNITED STATES. CARIBBEAN SEA... A SURFACE TROUGH EXTENDS FROM N OF THE YUCATAN PENINSULA NEAR 22N90W TO S GUATEMALA NEAR 15N90W. DEEP LAYER MOISTURE ACROSS THE W CARIBBEAN AND LOW LEVEL CONVERGENCE NEAR THE TROUGH ARE SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE NW CARIBBEAN FROM 16N-22N W OF 87W INCLUDING PORTIONS OF THE YUCATAN PENINSULA... BELIZE...AND GUATEMALA. THESE SHOWERS AND THUNDERSTORMS ARE BEING ENHANCED BY UPPER LEVEL DIVERGENCE IN THE VICINITY OF AN UPPER LEVEL HIGH CENTERED OVER THE W CARIBBEAN NEAR 18N87W. THIS UPPER LEVEL DIVERGENCE IS ALSO COMBINING WITH ATMOSPHERIC INSTABILITY TO RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS ACROSS CUBA AND THE NEARBY COASTAL WATERS. FARTHER TO THE E...GENERALLY FAIR WEATHER IS OCCURRING ACROSS MUCH OF THE E CARIBBEAN...WHERE DEEP LAYER MOISTURE IS SOMEWHAT MORE LIMITED. HOWEVER...ATMOSPHERIC INSTABILITY NEAR AN UPPER LEVEL TROUGH OVER THE NE CARIBBEAN IS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS ACROSS HISPANIOLA...PUERTO RICO...AND THE NEARBY COASTAL WATERS. ATLANTIC OCEAN... ACROSS THE SW NORTH ATLC...A SURFACE TROUGH EXTENDS FROM 31N81W TO THE E FLORIDA PENINSULA NEAR 28N80W. LOW LEVEL CONVERGENCE NEAR THIS TROUGH IS INTERACTING WITH MOISTURE IN NORTHWESTERLY FLOW ALOFT TO RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS N OF 23N W OF 77W INCLUDING PORTIONS OF THE NW BAHAMAS AND THE E FLORIDA PENINSULA. ALSO...UPPER LEVEL DIFFLUENCE IS SUPPORTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS N OF 27N BETWEEN 67W-76W. ACROSS MUCH OF THE CENTRAL AND E ATLC...GENERALLY FAIR WEATHER IS PRESENT WHERE SUBSIDENCE IS OCCURRING NEAR A BROAD SURFACE RIDGE. HOWEVER...AN UPPER LEVEL TROUGH IS OVER THE CENTRAL ATLC N OF 26N BETWEEN 40W-52W. ATMOSPHERIC INSTABILITY ASSOCIATED WITH THIS TROUGH IS SUPPORTING SCATTERED SHOWERS N OF 28N BETWEEN 42W-50W. ALSO...A DEEP LAYER LOW OVER THE E ATLC IS ASSOCIATED WITH A 1012 MB SURFACE LOW N OF THE CANARY ISLANDS NEAR 32N16W. THIS SURFACE LOW IS ASSOCIATED WITH GALE FORCE WINDS. LOW LEVEL CONVERGENCE NEAR THE SURFACE LOW IS SUPPORTING SCATTERED SHOWERS N OF 30N BETWEEN 14W-19W. THE SURFACE LOW IS FORECAST TO MOVE SOUTHWESTWARD DURING THE NEXT DAY AND BE LOCATED NEAR 29N17W AS A 1011 MB SURFACE LOW AT 17/1800 UTC. ACROSS THE TROPICAL ATLC...A BROAD UPPER LEVEL RIDGE IS PRESENT WITH AN AXIS EXTENDING FROM 12N16W TO AN UPPER LEVEL HIGH NEAR 10N38W TO 7N59W. UPPER LEVEL DIVERGENCE ASSOCIATED WITH THESE FEATURES IS SUPPORTING THE CONVECTION ASSOCIATED WITH THE ITCZ. $$ COHEN