000 AXNT20 KNHC 280557 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT FRI JUL 28 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR... AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0530 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 30W SOUTH OF 17N MOVING WEST 15-20 KT. THIS WAVE HAS A FAIR AMOUNT OF BROAD LOW-MID LEVEL CURVATURE ASSOCIATED WITH IT. CONVERGENCE IS THE STRONGEST AHEAD OF THE WAVE AXIS EMBEDDED IN THE ITCZ WHERE THERE IS SCATTERED MODERATE CONVECTION FROM 6N-11N BETWEEN 32W-38W. A TROPICAL WAVE IS ALONG 52W SOUTH OF 22N MOVING WEST NEAR 20 KT. THIS WAVE IS NOT AS HIGH AMPLITUDE OR WELL STRUCTURED TODAY THAN IT WAS OVER THE PAST FEW DAYS. HOWEVER...IT IS STILL RATHER EASY TO LOCATE WITH BROAD LOW LEVEL TURING EVIDENT ON SATELLITE IMAGERY. NO SIGNIFICANT DEEP CONVECTION IS ASSOCIATED WITH THIS WAVE. ISOLATED SHOWERS AND TSTMS ARE WITHIN 300 NM EITHER SIDE OF THE AXIS. A TROPICAL WAVE IS IN THE CENTRAL CARIBBEAN ALONG 70W/71W SOUTH OF 23N MOVING WEST NEAR 15 KT. THIS WAVE INTERACTING WITH AN UPPER TROUGH ACROSS THE BAHAMAS IS PRODUCING PATCHES OF SCATTERED MODERATE CONVECTION WITHIN 240 NM EITHER SIDE OF THE ANALYZED WAVE AXIS. BASED UPON THE LATEST APPEARANCE ON SATELLITE IMAGERY...THE AXIS MAY BE ADJUSTED SLIGHTLY AHEAD ON THE 06Z SURFACE ANALYSIS. WESTERLY UPPER LEVEL WINDS ARE SHEARING THE TSTMS TO THE EAST OF THE WAVE AXIS. THESE UPPER WINDS ARE UNFAVORABLE FOR FURTHER DEVELOPMENT. A WESTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 87W/88W SOUTH OF 19N MOVING WEST 15 KT. THIS WAVE AXIS IS ALONG THE LEADING EDGE OF A SURGE OF LOW-MID LEVEL CLOUDS WITH EMBEDDED ISOLATED/SCATTERED SHOWERS AND TSTMS. THIS WAVE REMAINS WEAK AND IS ENTERING THE EAST PACIFIC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 17N16W 11N28W 10N40W TO INLAND OVER SOUTH AMERICA NEAR 9N61W TO COSTA RICA NEAR 10N83W. BESIDES FOR THE CONVECTIVE ACTIVITY ASSOCIATED WITH THE TROPICAL WAVES...A CLUSTER OF MODERATE CONVECTION IS MOVING OFF THE COAST OF AFRICA E OF 18W FROM 14N-19N. SCATTERED MODERATE CONVECTION IS ACROSS SOUTH AMERICA ENHANCED BY THE CENTRAL CARIBBEAN WAVE FROM 1N-8N BETWEEN 57W-76W. ...DISCUSSION... GULF OF MEXICO... RELATIVELY QUIET WEATHER EXISTS ACROSS THE GULF OF MEXICO THIS EARLY MORNING. AN UPPER HIGH IS CENTERED TO THE NORTH OF THE AREA OVER THE SE U.S. A NARROW UPPER TROUGH OFF THE E COAST OF THE U.S. DIGS TO CENTRAL FLORIDA WHERE AN UPPER LOW APPEARS TO BE FORMING. UNLIKE THE PAST FEW NIGHTS...UPPER DIFFLUENCE IS RATHER WEAK ACROSS MUCH OF THE AREA ONLY PRODUCING SCATTERED SHOWERS IN THE E GULF AND FLORIDA AND ISOLATED SHOWERS IN THE CENTRAL AND WESTERN GULF. AT THE SURFACE...RIDGING IS LOCKED IN EXTENDING FROM THE BERMUDA-AZORES HIGH. SFC FLOW IS GENERALLY E-SELY AT 10-15 KT. TROPICAL MOISTURE ASSOCIATED WITH THE CENTRAL CARIBBEAN WAVE WILL BE ENTERING THE AREA THIS WEEKEND POSSIBLY INCREASING THE CHANCE OF PRECIP IN THE SOUTHERN GULF. HOWEVER...MODELS SUGGEST THAT THE WAVE WILL BEGIN TO LOSE SOME OF ITS MOISTURE AS IT HEADS WWD. OTHERWISE...LITTLE CHANGE IS EXPECTED THIS WEEKEND AS SFC RIDGING REMAINS ESTABLISHED. CARIBBEAN SEA... THE MAIN FEATURE IN THE REGION IS A TROPICAL WAVE IN THE CENTRAL CARIBBEAN. THIS WAVE IS INTERACTING WITH AN UPPER TROUGH ACROSS THE BAHAMAS TO GENERATE A WIDE AREA OF SCATTERED MODERATE CONVECTION ACROSS SOUTH AMERICA AND THE CENTRAL CARIBBEAN FROM 9N-18N BETWEEN 67W-75W. THE STRONGEST CONVECTION IS 150 NM SOUTH OF HISPANIOLA FROM 14N-16N BETWEEN 70W-74W. IN THE UPPER LEVELS...A SMALL UPPER LOW CONTINUES TO DIVE SWWD NOW OVER THE YUCATAN PENINSULA. AN UPPER RIDGE COVERS MUCH OF THE REMAINDER OF THE AREA. BESIDES FOR THE CONVECTIVE ACTIVITY ASSOCIATED WITH THE TROPICAL WAVE...ONLY SCATTERED SHOWERS DOT THE CARIBBEAN. TRADE WINDS ARE 10 TO 20 KT ACROSS THE CARIBBEAN...THESE WINDS WILL REMAIN IN THAT RANGE...POSSIBLY SLACKENING A BIT...THRU THE WEEKEND. MOISTURE WILL BE ON THE INCREASE ACROSS THE LESSER ANTILLES TODAY AND SAT AS ANOTHER TROPICAL WAVE APPROACHES THE AREA...HOWEVER THIS WAVE DOES NOT APPEAR THAT IT WILL BE AS CONVECTIVELY ACTIVE AS THE WAVE CURRENTLY IN THE CARIBBEAN. ATLANTIC OCEAN... THE DOMINANT FEATURE IN THE ATLC IS THE BERMUDA-AZORES RIDGE WITH THE SFC RIDGE AXIS EXTENDING FROM A 1027 MB HIGH OVER THE AZORES TO A 1029 MB HIGH NEAR 33N52W ACROSS THE N CENTRAL GULF. SCATTERED PATCHES OF MOISTURE DRIVEN BY MODERATE E WINDS IS THE THEME ACROSS THE ATLC N OF THE TROPICAL WAVES. IN THE UPPER LEVELS...A MID-UPPER LEVEL NARROW TROUGH LIES OFF THE E COAST OF THE U.S. PRODUCING A NARROW PLUME OF HIGH LEVEL MOISTURE W OF 75W. AN UPPER LOW IS N OF THE BAHAMAS NEAR 27N71W INCREASING SHOWER ACTIVITY IN THE CARIBBEAN AS IT INTERACTS WITH THE TROPICAL WAVE. SEE THE CARIBBEAN SECTION FOR MORE DETAILS. THE REMAINDER OF ATLC IS DOMINATED BY A LARGE UPPER RIDGE EXTENDING FROM AFRICA TO 65W. UPPER DIFFLUENCE BETWEEN THIS RIDGE AND TROUGH N OF THE BAHAMAS IS PRODUCING AN AREA OF UPPER LEVEL MOISTURE BETWEEN 61W-73W. MODERATE TO STRONG SUBSIDENCE LIES EAST OF 63W N OF 20N...THIS DRY STABLE AIR IS SUPPRESSING ANY CONVECTION FROM FORMING IN THIS REGION. $$ CANGIALOSI