000 AXNT20 KNHC 021120 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU JUL 02 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1000 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 24W S OF 14N MOVING W 15-20 KT. THIS WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED ON TOTAL PRECIPITABLE WATER IMAGERY. SATELLITE IMAGERY INDICATES LOW-LEVEL CYCLONIC FLOW AROUND THE VICINITY OF THE WAVE AXIS. ISOLATED MODERATE CONVECTION IS FROM 7N-11N BETWEEN 21W-27W. A TROPICAL WAVE IS ALONG 39W S OF 12N MOVING W 15-20 KT. THIS WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED ON TOTAL PRECIPITABLE WATER IMAGERY. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THIS WAVE. A TROPICAL WAVE EXTENDS FROM 17N66W TO 3N69W MOVING W 15-20 KT. POSITION IS BASED ON CONTINUITY. THIS WAVE IS JUST E OF AN UPPER LEVEL RIDGE OVER THE ERN CARIBBEAN WHICH IS INHIBITING CONVECTION BESIDES A CLUSTER OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION OVER VENEZUELA FROM 7N-10N BETWEEN 67W-70W. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 13N17W 9N22W 6N31W 5N47W AND INTO NE S AMERICA NEAR 5N57W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-8N BETWEEN 28W-35W. SCATTERED MODERATE CONVECTION IS FROM 4N-6N BETWEEN 45W-53W. ...DISCUSSION... GULF OF MEXICO... ISOLATED SHOWERS/THUNDERSTORMS REMAIN ACROSS THE ERN GULF OF MEXICO FROM 24N-28N E OF 86W. UPPER LEVEL DIFFLUENCE BETWEEN AN UPPER LEVEL TROUGH EXTENDING DOWN THE ERN UNITED STATES INTO THE CENTRAL GULF TO NEAR 24N91W AND AN UPPER LEVEL RIDGE OVER THE WRN ATLC ALONG WITH MOIST SWLY FLOW ALOFT ARE SUPPORTING THE SHOWER ACTIVITY. A SURFACE TROUGH IS OVER THE BAY OF CAMPECHE FROM 16N92W TO 20N91W. SURFACE CONVERGENCE NEAR THE TROUGH ALONG WITH UPPER LEVEL DIFFLUENCE BETWEEN AN UPPER LEVEL RIDGE OVER MEXICO AND AN UPPER LEVEL TROUGH OVER THE WRN CARIBBEAN ARE SUPPORTING A LARGE CLUSTER OF NUMEROUS SHOWERS/THUNDERSTORMS OVER THE YUCATAN PENINSULA AND THE BAY OF CAMPECHE FROM 16N-21N BETWEEN 91W-94W. THE REMAINDER OF THE NW GULF OF MEXICO IS UNDER A WEAK RIDGE AND REMAINS CALM WITH GENERALLY FAIR WEATHER AND LIGHT WINDS. THIS IS SUPPORTED BY UPPER LEVEL CONFLUENCE WHICH IS PROVIDING SUBSIDENCE OVER THE NW GULF. CARIBBEAN SEA... AN UPPER LEVEL LOW IS OVER THE WRN CARIBBEAN NEAR 17N82W. UPPER LEVEL CONFLUENCE NW OF THE UPPER LEVEL LOW IS PROVIDING SUBSIDENCE OVER THE NW CARIBBEAN ALONG WITH DEEP LAYER DRY AIR BRINGING THE NW GULF GENERALLY FAIR WEATHER. ATMOSPHERIC INSTABILITY NEAR THE UPPER LOW IS SUPPORTING ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS S OF 15N W OF 80W AND FROM 18N-20N BETWEEN 802-92W. AN UPPER LEVEL RIDGE IS OVER THE ERN CARIBBEAN CENTERED AROUND AN UPPER LEVEL HIGH NEAR 12N72W. UPPER LEVEL DIFFLUENCE BETWEEN THE UPPER LEVEL TROUGH OVER THE W CARIBBEAN AND THE UPPER LEVEL RIDGE OVER THE E CARIBBEAN ALONG WITH MOIST SLY FLOW ALOFT ARE SUPPORTING ISOLATED SHOWERS IN THE CENTRAL CARIBBEAN FROM 14N-16N BETWEEN 77W-80W. SURFACE CONVERGENCE NEAR A 1009 MB SURFACE LOW OVER COLUMBIA NEAR 7N76W IS SUPPORTING NUMEROUS SHOWERS/THUNDERSTORMS S OF 11N BETWEEN 76W-81W. THIS ACTIVITY IS BEING ENHANCED BY A START OF THE ITCZ IN THE E PACIFIC. THE REMAINDER OF THE ERN CARIBBEAN IS EXPERIENCING GENERALLY FAIR WEATHER DESPITE THE PRESENCE OF A TROPICAL WAVE DUE TO SUBSIDENCE ALOFT FROM UPPER LEVEL CONFLUENCE E OF THE UPPER LEVEL RIDGE. ELY TRADE WINDS OF 20 KT COVER THE MAJORITY OF THE CARIBBEAN REACHING 30 KT IN SOME AREAS. ATLANTIC OCEAN... UPPER LEVEL DIFFLUENCE BETWEEN AN UPPER LEVEL TROUGH EXTENDING DOWN THE ERN UNITED STATES INTO THE CENTRAL GULF AND AN UPPER LEVEL RIDGE OVER THE WRN ATLC CENTERED AROUND AN UPPER LEVEL HIGH NEAR 28N65W ALONG WITH MOIST SWLY FLOW ALOFT ARE SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS ACROSS THE NW ATLC EXTENDING FROM THE ERN GULF N OF 26N W OF 76W. A SURFACE TROUGH IN THE CENTRAL ATLC EXTENDS FROM 31N48W TO 29N49W. SURFACE CONVERGENCE NEAR THIS TROUGH AS WELL AS A 1017 MB SURFACE LOW N OF THE DISCUSSION AREA NEAR 34N48W ARE SUPPORTING SCATTERED SHOWERS N OF 28N BETWEEN 42W-52W. A BROAD SURFACE RIDGE COVERS THE REMAINDER OF THE ATLC BRINGING GENERALLY FAIR WEATHER. THE RIDGE IS ANCHORED BY A SERIES OF SURFACE HIGHS...A 1023 MB HIGH CENTERED NEAR 27N55W...A 1025 MB HIGH CENTERED NEAR 29N33W...AND A 1025 MB HIGH AT THE EDGE OF THE DISCUSSION AREA NEAR 32N22N. $$ WALTON