000 AXNT20 KNHC 301048 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU JUL 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 33W S OF 25N MOVING W NEAR 15 KT. SATELLITE IMAGERY AND SATELLITE DERIVED WINDS INDICATE A BROAD LOW TO MID-LEVEL CYCLONIC FLOW IN THE VICINITY OF THE WAVE AXIS. THIS WAVE ALSO EXHIBITS A HIGH AMPLITUDE DEEP LAYER MOISTURE MAXIMUM OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY...WHILE BEING SURROUNDED BY SAHARAN DUST. SCATTERED MODERATE CONVECTION REMAINS EMBEDDED WITHIN THE ITCZ AXIS AND IS FROM 8N-13N BETWEEN 30W-40W. A TROPICAL WAVE IS ALONG 63W S OF 19N MOVING W NEAR 18 KT. THIS WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION HAS INCREASED IN COVERAGE ACROSS THE WINDWARD ISLANDS AND SE CARIBBEAN OVER THE PAST 6 HOURS AND IS LOCATED FROM 11N-16N BETWEEN 59W-69W. A TROPICAL WAVE IS ALONG 92W S OF 21N MOVING W NEAR 20 KT. THIS WAVE LIES IN A BROAD AREA OF DEEP LAYER MOISTURE OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY ACROSS CENTRAL AMERICA AND SRN MEXICO BECOMING MORE BROAD IN COVERAGE ACROSS THE E PACIFIC REGION. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 11N-17N BETWEEN 90W-94W. THIS CONVECTION IS FURTHER ENHANCED BY UPPER LEVEL RIDGING AND THUS UPPER LEVEL DIFFLUENCE ACROSS NRN PORTIONS OF CENTRAL AMERICA AND SRN MEXICO. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 13N16W 11N32W 10N35W 9N42W 11N61W. SCATTERED MODERATE CONVECTION IS FROM 8N-13N BETWEEN 17W-21W. ELSEWHERE SCATTERED SHOWERS ARE FROM 7N-13N BETWEEN 21W-42W. ...DISCUSSION... GULF OF MEXICO... FAIRLY TRANQUIL WEATHER DOMINATES ACROSS MUCH OF THE GULF OF MEXICO AS AN UPPER LEVEL ANTICYCLONE IS CENTERED IN THE CENTRAL GULF NEAR 25N87W. THIS UPPER LEVEL FEATURE ALONG WITH A SURFACE RIDGE OF HIGH PRESSURE EXTENDING FROM THE W ATLC WATERS ALONG 29N IS PROVIDING MOSTLY CLEAR SKIES AND S-SELY WIND OF 15 TO 20 KT ACROSS THE GULF W OF 88W. HOWEVER...UPPER LEVEL DIFFLUENCE ON THE ERN PERIPHERY OF THE UPPER LEVEL RIDGE IS GENERATING A FEW ISOLATED SHOWERS E OF 83W. MOSTLY CONVECTIVE DEBRIS CLOUDINESS FROM EARLIER ACTIVITY IS ACROSS THE NRN GULF WATERS AND FLORIDA PENINSULA THIS MORNING. THE OTHER AREA TO NOTE ACROSS THE GULF IS THE TROPICAL WAVE ALONG 92W THAT IS BRINGING ISOLATED SHOWERS TO THE S/CENTRAL GULF S OF 22N AND AREAS W TO 93W INCLUDING THE YUCATAN PENINSULA AND ERN BAY OF CAMPECHE. CARIBBEAN SEA... NORTHERLY UPPER LEVEL WINDS PREVAIL ACROSS MUCH OF THE CARIBBEAN BASIN AS AN UPPER LEVEL RIDGE EXTENDS FROM AN UPPER LEVEL ANTICYCLONE CENTERED OVER THE ERN GULF OF MEXICO. THE NLY WINDS ALOFT ARE KEEPING THE MIDDLE AND UPPER LEVELS OF THE ATMOSPHERE DRY AND FAIRLY STABLE. HOWEVER...A TROPICAL WAVE ALONG 63W IS IMPACTING THE FAR ERN CARIBBEAN AND LESSER ANTILLES WITH SCATTERED SHOWERS AND ISOLATED TSTMS FROM 11N-16N BETWEEN 59W-69W. ACROSS THE WRN CARIBBEAN...THE TROPICAL WAVE ALONG 92W AND AN UPPER LEVEL DIFFLUENT PATTERN IS GENERATING WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ACROSS PORTIONS OF THE GULF OF HONDURAS AND AREAS OF INTERIOR HONDURAS AND NICARAGUA. S OF 13N...SCATTERED SHOWERS AND TSTMS ARE OCCURRING BETWEEN 75W-84W DUE TO UPPER LEVEL DIFFLUENCE AND THE PROXIMITY OF THE ITCZ AXIS ALONG 8N CROSSING OVER PANAMA AND NRN COLOMBIA. FRESH TO STRONG TRADE WINDS ARE NOTED ACROSS MUCH OF THE CARIBBEAN WITH THE STRONGEST WINDS NEAR THE COAST OF COLOMBIA. ATLANTIC OCEAN... A SHORTWAVE UPPER LEVEL TROUGH LOCATED OFFSHORE ALONG THE MID- ATLC U.S. SEABOARD IS ENHANCING SCATTERED SHOWERS AND TSTMS OVER THE SW NORTH ATLC WATERS COVERING THE AREA WITHIN 90 NM EITHER SIDE OF A LINE FROM 25N79W TO BEYOND 32N75W. ENHANCEMENT OF THIS CONVECTION IS DUE IN LARGE PART TO UPPER LEVEL DIFFLUENCE LOCATED ON THE ERN PERIPHERY OF THE UPPER LEVEL ANTICYCLONE CENTERED OVER THE ERN GULF OF MEXICO. THE REMAINDER OF THE ATLC IS DOMINATED BY DRY STABLE AIR AND A BROAD SURFACE RIDGE ANCHORED BY A 1026 MB HIGH NEAR 33N56W BRINGING GENERALLY FAIR WEATHER ACROSS THE BASIN. ONE EXCEPTION IS AN AREA OF CLOUDINESS AND POSSIBLE ISOLATED SHOWERS N OF THE TROPICAL WAVE ALONG 33W FROM 24N-31N BETWEEN 25W-35W. OTHER LOW-LEVEL ISOLATED SHOWERS ARE POSSIBLE ACROSS THE CENTRAL ATLC BETWEEN 45W-65W ON THE SRN PERIPHERY OF THE SURFACE RIDGE. $$ HUFFMAN