000 AXNT20 KNHC 302343 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE JUN 30 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 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 28W S OF 13N MOVING W NEAR 20 KT. THIS WAVE REMAINS ASSOCIATED WITH A DEEP LAYER MOISTURE MAXIMUM AS OBSERVED ON THE TPW PRODUCT FROM CIMSS AND EXHIBITS A LOW- LATITUDE INVERTED-V CLOUD SIGNATURE IN THE VICINITY OF THE WAVE AXIS S OF 9N. SCATTERED MODERATE CONVECTION IS W OF THE WAVE AXIS FROM 4N-7N BETWEEN 29W-39W AND IS LIKELY ASSOCIATED WITH THE ITCZ. ALSO OF NOTE...THIS WAVE CONTINUES TO TRACK ACROSS THE ERN ATLC UNDER A DRY MIDDLE LEVEL SAHARAN AIR LAYER OF DUST... FURTHER SUPPRESSING ANY DEEP MOIST CONVECTION. TROPICAL WAVE IS ALONG 54W S OF 13N MOVING W NEAR 12 KT. THE WAVE MATCHES UP WELL WITH A MAXIMUM IN DEEP LAYER MOISTURE BASED ON THE TPW PRODUCT FROM CIMSS AND CONTINUES ON THE LEADING EDGE OF DUST AND A MIDDLE LAYER SAHARAN AIR LAYER TO THE W. SCATTERED MODERATE CONVECTION IS FROM 8N-12N BETWEEN 54W-61W. THIS ACTIVITY IS BEING ENHANCED BY AN UPPER LEVEL RIDGE CENTERED OVER TRINIDAD. TROPICAL WAVE IS ALONG 92W/93W S OF 21N MOVING W NEAR 18 KT. THE WAVE REMAINS MORE PROMINENT IN THE E PACIFIC REGION...BUT IS GENERATING SCATTERED MODERATE CONVECTION ACROSS SRN MEXICO AND ALONG THE WRN YUCATAN PENINSULA EXTENDING INTO THE FAR ERN BAY OF CAMPECHE. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 11N15W 9N19W 7N26W 5N30W 3N38W 4N52W. ISOLATED MODERATE CONVECTION IS FROM 3N-6N BETWEEN 11W-24W. SCATTERED MODERATE CONVECTION IS FROM 4N-7N BETWEEN 29W-39W. ...DISCUSSION... GULF OF MEXICO... A STATIONARY FRONT IS POSITIONED ACROSS THE NRN GULF EXTENDING FROM THE W ATLC NEAR JACKSONVILLE FLORIDA TO NEAR NEW ORLEANS LOUISIANA AND THEN ALONG THE LOUISIANA GULF COAST TO NEAR PORT ARTHUR TEXAS. LOCATED ALONG THE SRN EXTENT OF A BROAD UPPER LEVEL TROUGH OVER THE ERN CONUS...THE STATIONARY FRONT IS GENERATING SCATTERED SHOWERS AND TSTMS ACROSS THE ERN GULF FROM 24N-28N E OF 90W TO OVER THE FLORIDA PENINSULA AND INTO THE W ATLC. THIS ACTIVITY IS BEING FURTHER ENHANCED BY A BROAD UPPER RIDGE CENTERED OVER THE NW BAHAMAS EXTENDING TO NEAR 88W. THE WRN GULF REMAINS UNDER A WEAK AND NARROW HIGH PRESSURE RIDGE THAT EXTENDS FROM THE YUCATAN CHANNEL TO NEAR GALVESTON TEXAS... THUS PROVIDING A MAJORITY OF THE GULF WITH LIGHT WINDS TO 15 KT THIS EVENING. CARIBBEAN SEA... A BROAD UPPER LOW DOMINATES THE CENTRAL AND WRN CARIBBEAN CENTERED NEAR 16N77W WHILE AN UPPER RIDGE EXTENDS FROM SOUTH AMERICA OVER THE ERN CARIBBEAN AND LESSER ANTILLES. MOIST SWLY FLOW ALOFT BETWEEN THESE UPPER LEVEL FEATURES IS ENHANCING SCATTERED SHOWERS AND TSTMS ACROSS NRN COLOMBIA AND NW VENEZUELA THAT IS SPREADING UPPER LEVEL CONVECTIVE DEBRIS CLOUDINESS ACROSS THE S/CENTRAL CARIBBEAN. THE UPPER LEVEL RIDGE IS ENHANCING THE SCATTERED SHOWER AND ISOLATED TSTM ACTIVITY ASSOCIATED WITH THE TROPICAL WAVE ALONG 54W IN THE WRN TROPICAL ATLC. LOW LEVEL CONVERGENCE...UPPER LEVEL DIFFLUENCE AND THE PROXIMITY OF THE E PACIFIC ITCZ AXIS IS GENERATING SCATTERED SHOWERS AND TSTMS OVER WRN HONDURAS...NICARAGUA AND COSTA RICA. MODERATE TO STRONG ELY TRADE WINDS COVER MOST OF THE CARIBBEAN USHERING IN ISOLATED SHOWERS MAINLY OVER THE NE CARIBBEAN. ATLANTIC OCEAN... A DISSIPATING COLD FRONT ENTERS THE W ATLC DISCUSSION AREA NEAR 32N77W AND CONTINUES AS A STATIONARY FRONT TO NEAR JACKSONVILLE FLORIDA AND INTO THE NE GULF OF MEXICO. AN UPPER LEVEL RIDGE IS CENTERED OVER THE NW BAHAMAS AND EXTENDS TO NEAR 31N. IT IS PROVIDING A LARGE AREA OF UPPER DIFFLUENCE ACROSS THE W ATLC TO ENHANCE SCATTERED SHOWERS AND TSTMS N OF 25N W OF 68W. THIS ACTIVITY EXTENDS ACROSS THE FLORIDA PENINSULA AND STRAITS OF FLORIDA INTO THE ERN GULF OF MEXICO. THE SAME UPPER RIDGE CONTINUES EWD TO ANOTHER ANTICYCLONIC CENTER NEAR 26N60W THAT IS PROVIDING UPPER DIFFLUENCE TO GENERATE ISOLATED SHOWERS ACROSS THE CENTRAL ATLC N OF 27N BETWEEN 53W-68W. OTHERWISE THE REMAINDER OF THE ATLC IS INFLUENCED BY A SURFACE RIDGE THAT EXTENDS FROM SWRN PORTUGAL TO THE MADEIRA ISLANDS TO NEAR 25N65W THAT IS ANCHORED ON A 1022 MB HIGH CENTERED NEAR 27N34W. A BROAD AREA OF AFRICAN DUST COVERS THE ERN TROPICAL ATLC S OF 26N TO THE ITCZ E OF 50W. $$ HUFFMAN