000 AXNT20 KNHC 020535 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0445 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 22W/23W S OF 13N 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 3N-7N BETWEEN 22W-25W. A TROPICAL WAVE IS ALONG 37W S OF 13N MOVING W NEAR 18 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 JUST W OF THE LESSER ANTILLES EXTENDS FROM 17N64W TO 1N67W MOVING W 15-20 KT. THIS WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED ON TOTAL PRECIPITABLE WATER IMAGERY. THIS WAVE IS JUST E OF AN UPPER LEVEL RIDGE OVER THE ERN CARIBBEAN WHICH IS INHIBITING CONVECTION. ISOLATED MODERATE CONVECTION IS FROM EQ-1N BETWEEN 67W-68W AND FROM 6N-7N BETWEEN 65W-67W. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 12N15W 10N21W 7N29W 4N45W AND INTO NE S AMERICA NEAR 5N57W. SCATTERED MODERATE CONVECTION IS FROM 10N-16N BETWEEN 14W-20W. SIMILAR CONVECTION IS FROM 5N-8N BETWEEN 27W-33W. ...DISCUSSION... GULF OF MEXICO... SCATTERED SHOWERS/THUNDERSTORMS REMAIN ACROSS THE ERN GULF OF MEXICO FROM 24N-30N E OF 90W ESPECIALLY CONCENTRATED OVER S FLORIDA AND THE STRAITS OF FLORIDA. UPPER LEVEL DIFFLUENCE BETWEEN AN UPPER LEVEL TROUGH EXTENDING DOWN THE ERN UNITED STATES INTO THE CENTRAL GULF TO NEAR 25N91W AND AN UPPER LEVEL RIDGE OVER THE WRN ATLC ALONG WITH MOIST SWLY FLOW ALOFT ARE SUPPORTING THE SHOWER ACTIVITY. THE REMAINDER OF THE WRN GULF OF MEXICO IS UNDER A WEAK PRESSURE GRADIENT AND REMAINS CALM WITH GENERALLY FAIR WEATHER AND LIGHT WINDS. THIS IS SUPPORTED BY UPPER LEVEL CONFLUENCE OVER THE NW GULF WHICH IS PROVIDING SUBSIDENCE OVER THE WRN GULF. CARIBBEAN SEA... AN UPPER LEVEL LOW IS OVER THE WRN CARIBBEAN NEAR 16N82W. 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 AROUND THE BASE OF THE LOW IS SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS S OF 14N W OF 78W INCLUDING PORTIONS OF NICARAGUA AND COSTA RICA. AN UPPER LEVEL RIDGE IS OVER THE ERN CARIBBEAN CENTERED AROUND AN UPPER LEVEL HIGH NEAR 14N67W. 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... SCATTERED SHOWERS/THUNDERSTORMS OVER THE S CENTRAL CARIBBEAN S OF 12N BETWEEN 72W-78W INCLUDING N COLUMBIA...AND ISOLATED SHOWERS IN THE CENTRAL CARIBBEAN FROM 16N-19N BETWEEN 74W-80W INCLUDING JAMAICA. 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 SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE NW ATLC EXTENDING FROM THE ERN GULF N OF 26N W OF 74W. A SURFACE TROUGH N OF THE DISCUSSION AREA IS SUPPORTING SCATTERED SHOWERS N OF 28N BETWEEN 42W-54W. THE REMAINDER OF THE ATLC IS UNDER A BROAD SURFACE RIDGE ANCHORED BY A PAIR OF SURFACE HIGHS...A 1022 MB HIGH CENTERED NEAR 26N57W AND A 1024 MB HIGH CENTERED NEAR 29N34W. A BROAD AREA OF LOW/MID-LEVEL DRY SAHARAN AIR COVERS THE E ATLC S OF 25N TO THE ITCZ E OF 55W...WHICH IS LIMITING DEEP CONVECTION ALONG THE ITCZ. $$ WALTON