000 AXNT20 KNHC 290510 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON JUN 29 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0445 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 45W S OF 17N MOVING W 10-15 KT AND IS AFFECTING PORTIONS OF THE TROPICAL ATLC. THIS WAVE COINCIDES WITH A MAXIMUM IN DEEP LAYER MOISTURE BASED ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. SATELLITE IMAGERY INDICATES THAT THE WAVE COINCIDES WITH AN INVERTED-V PATTERN IN THE COVERAGE OF LOW LEVEL CLOUDS. SATELLITE-DERIVED WINDS ALSO INDICATE CYCLONIC CURVATURE IN THE LOW LEVEL FLOW NEAR THIS WAVE. STABLE ATMOSPHERIC CONDITIONS BENEATH AN UPPER LEVEL RIDGE AND DEEP LAYER DRY AIR ARE INHIBITING DEEP CONVECTION NEAR THIS WAVE. HOWEVER...SCATTERED SHOWERS ARE OCCURRING FROM 9N-12N BETWEEN 40W-43W. A TROPICAL WAVE IS ALONG 81W S OF 20N MOVING W NEAR 15 KT AND IS AFFECTING PORTIONS OF THE W CARIBBEAN. THIS WAVE IS NOT PARTICULARLY WELL-DEFINED. HOWEVER...THE CIMSS WAVETRAK PRODUCT INDICATES THAT THE WAVE COINCIDES WITH WEAK LOW LEVEL CYCLONIC CIRCULATION. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 10N-14N BETWEEN 79W-83W. SCATTERED MODERATE CONVECTION IS FROM 15N-17N BETWEEN 82W-85W. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 9N13W 5N27W 5N38W 6N48W 5N55W. SCATTERED MODERATE CONVECTION IS FROM 5N-12N BETWEEN 17W-25W. SCATTERED MODERATE CONVECTION IS ALSO FROM 5N-7N BETWEEN 30W-34W. ...DISCUSSION... GULF OF MEXICO... A SURFACE TROUGH OVER THE SE GULF EXTENDS FROM 26N86W TO THE COAST OF THE YUCATAN PENINSULA NEAR 21N90W TO 17N91W. LOW LEVEL CONVERGENCE IS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS WITHIN 90 NM EITHER SIDE OF THIS SURFACE TROUGH S OF 22N INCLUDING PORTIONS OF THE YUCATAN PENINSULA AND GUATEMALA. THIS ACTIVITY IS ALSO BEING SUPPORTED BY UPPER LEVEL DIVERGENCE ASSOCIATED WITH AN UPPER LEVEL RIDGE OVER THE YUCATAN PENINSULA AND W CARIBBEAN SEA. ADDITIONALLY...ATMOSPHERIC INSTABILITY ASSOCIATED WITH AN UPPER LEVEL LOW CENTERED OVER N MEXICO NEAR 25N100W IS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS FROM 19N-24N W OF 96W INCLUDING ADJACENT AREAS OF E MEXICO. ELSEWHERE ACROSS THE N GULF...SUBSIDENCE IN CONFLUENT SOUTHEASTERLY FLOW ALOFT IS OCCURRING BETWEEN THE AFOREMENTIONED UPPER LEVEL LOW OVER N MEXICO AND AN UPPER LEVEL HIGH OVER E TEXAS. THE SUBSIDENCE IS SUPPORTING A 1012 MB SURFACE HIGH NEAR 27N93W. HOWEVER... ATMOSPHERIC INSTABILITY IS INTERACTING WITH UPPER LEVEL MOISTURE STREAMING SOUTHWARD OVER THE E GULF TO SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS N OF 27N E OF 86W. CARIBBEAN SEA... A TROPICAL WAVE IS ASSOCIATED WITH CONVECTION ACROSS THE W CARIBBEAN AND IS DISCUSSED IN THE TROPICAL WAVES SECTION ABOVE. THIS CONVECTION IS BEING SUPPORTED BY UPPER LEVEL DIFFLUENCE BETWEEN AN UPPER LEVEL RIDGE OVER THE YUCATAN PENINSULA AND W CARIBBEAN SEA AND AN UPPER LEVEL TROUGH OVER THE CENTRAL CARIBBEAN...AS WELL AS THE PRESENCE OF DEEP LAYER MOISTURE. ALSO...UPPER LEVEL DIFFLUENCE IS SUPPORTING SCATTERED SHOWERS N OF 18N BETWEEN 74W-78W. ACROSS THE E CARIBBEAN...SUBSIDENCE IN CONFLUENT WESTERLY FLOW ALOFT AND DEEP LAYER DRY AIR...INCLUDING LOW/MID-LEVEL DRY SAHARAN AIR...ARE RESULTING IN GENERALLY FAIR WEATHER. ADDITIONALLY...E TO SE WINDS OF 20 TO 25 KT ARE OCCURRING ACROSS PORTIONS OF THE CENTRAL AND E CARIBBEAN. ATLANTIC OCEAN... ATMOSPHERIC INSTABILITY ASSOCIATED WITH AN UPPER LEVEL TROUGH OVER THE SW NORTH ATLC IS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS N OF 28N BETWEEN 60W-68W. ALSO...DIFFLUENCE IN NORTHWESTERLY FLOW ALOFT IS INTERACTING WITH DEEP LAYER MOISTURE W OF THE UPPER LEVEL TROUGH TO SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS N OF 28N BETWEEN 74W-79W. FARTHER TO THE E... GENERALLY FAIR WEATHER IS PRESENT ACROSS MUCH OF THE CENTRAL AND E ATLC...WHERE SUBSIDENCE IS OCCURRING NEAR A BROAD SURFACE RIDGE. THIS SURFACE RIDGE IS ASSOCIATED WITH A 1020 MB SURFACE HIGH NEAR 29N43W. HOWEVER...AN UPPER LEVEL TROUGH N OF 17N E OF 24W IS SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 24N33W TO 26N24W TO 31N16W AND A STATIONARY FRONT THAT EXTENDS FROM 31N16W TO 32N13W TO NE OF THE DISCUSSION AREA. LOW LEVEL CONVERGENCE IS SUPPORTING SCATTERED SHOWERS WITHIN 60 NM EITHER SIDE OF THE SURFACE TROUGH AND STATIONARY FRONT. ALSO...ATMOSPHERIC INSTABILITY ASSOCIATED WITH AN UPPER LEVEL LOW NEAR 27N50W IS SUPPORTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FROM 26N-31N BETWEEN 46W-52W. ACROSS THE TROPICAL ATLC...MOIST EASTERLY FLOW ALOFT IS PRESENT...WITH UPPER LEVEL DIFFLUENCE SUPPORTING CONVECTION ASSOCIATED WITH THE ITCZ AND THE TROPICAL WAVE ALONG 45W S OF 17N. $$ COHEN