000 AXNT20 KNHC 281054 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 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 1045 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 31W SOUTH OF 17N MOVING WEST 15-20 KT. THIS WAVE HAS BEEN CHALLENGING TO LOCATE THIS MORNING AS IT APPEARS TO HAVE A VERY BROAD ELONGATED LOW-MID LEVEL CYCLONIC CIRCULATION COVERING AN AREA OF OVER 700 NM. THE ANALYZED WAVE AXIS IS PLACED NEAR THE CENTER OF THIS BROAD TURNING. BASED UPON THE FIRST FEW VISIBLE PICTURES THIS MORNING...THIS ANALYZED POSITION APPEARS TO BE IN THE CORRECT LOCATION. HOWEVER...THERE ARE A FEW SFC OBS SUGGESTING THAT THE AXIS MAY BE A FEW DEGREES FURTHER TO THE WEST. CONVERGENCE IS THE STRONGEST AHEAD OF THE ANALYZED WAVE AXIS EMBEDDED IN THE ITCZ WHERE THERE IS SCATTERED MODERATE CONVECTION FROM 6N-11N BETWEEN 35W-41W. THIS WAVE IS SHOWING SOME SIGNS OF ORGANIZATION AND SOME FURTHER DEVELOPMENT IS POSSIBLE OVER THE NEXT FEW DAYS. A TROPICAL WAVE IS ALONG 54W SOUTH OF 20N 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 SLIGHT LOW LEVEL TURING EVIDENT ON SATELLITE IMAGERY. THE WAVE HAS BEEN A RELATIVELY DRY FEATURE AS IT TRACKED ACROSS THE ATLC...HOWEVER SOME SHOWER AND TSTM ACTIVITY IS BEGINNING TO INCREASE AHEAD OF THE WAVE AXIS TO THE EASTERN CARIBBEAN ISLANDS. AN ACTIVE TROPICAL WAVE IN THE CENTRAL CARIBBEAN IS ADJUSTED AHEAD ALONG 72W/73W SOUTH OF 23N MOVING WEST NEAR 15 KT. THIS WAVE AIDED BY UPPER DIFFLUENCE IS GENERATING CLUSTERS OF SCATTERED MODERATE CONVECTION MOSTLY WITHIN 300 NM EAST OF THE ANALYZED WAVE AXIS FROM 12N-19N BETWEEN 69W-75W. WESTERLY UPPER LEVEL WINDS ARE SHEARING THE TSTMS TO THE EAST OF THE WAVE AXIS. THESE UPPER WINDS ARE CURRENTLY UNFAVORABLE AND EXPECTED TO REMAIN THIS WAY FOR FURTHER DEVELOPMENT. A WESTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 89W SOUTH OF 18N MOVING WEST 10-15 KT. THIS WAVE AXIS IS ALONG THE LEADING EDGE OF A SURGE OF LOW-MID LEVEL CLOUDS WITH EMBEDDED ISOLATED/SCATTERED SHOWERS AND TSTMS. A PATCH OF MODERATE CONVECTION HAS DEVELOPED THIS MORNING ALONG THE WAVE FROM 11N-14N BETWEEN 87W-91W AND OVER BELIZE. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 17N14W 11N28W 8N45W 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 WEAKENING MODERATE CONVECTION IS MOVING OFF THE COAST OF AFRICA E OF 19W FROM 13N-18N. SCATTERED MODERATE CONVECTION LIES ACROSS SOUTH AMERICA ENHANCED BY THE CENTRAL CARIBBEAN WAVE FROM THE EQUATOR TO 11N W OF 65W. ...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...AN UPPER RIDGE OVER CENTRAL AND SOUTH AMERICA AND A LARGE RIDGE ACROSS THE ATLC TO GENERATE A WIDE AREA OF SCATTERED MODERATE CONVECTION ACROSS SOUTH AMERICA AND THE CENTRAL CARIBBEAN FROM 12N-22N BETWEEN 68W-76W. THE STRONGEST CONVECTION IS 150 NM SOUTH OF HISPANIOLA FROM 13N-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 1024 MB HIGH OVER THE AZORES TO A 1028 MB HIGH NEAR 33N54W ACROSS THE N CENTRAL GULF. SCATTERED PATCHES OF LOW-MID LEVEL MOISTURE DRIVEN BY MODERATE E WINDS IS THE THEME ACROSS THE ATLC N OF THE TROPICAL WAVES. THE ONLY KINK IN THE RIDGE IS A WEAK DRY SFC TROUGH ALONG 35W FROM 24N-29N. 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. A WEAKENING ELONGATED 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 60W-73W. MODERATE TO STRONG SUBSIDENCE LIES EAST OF 60W N OF 20N...THIS DRY STABLE AIR ALOFT IN COMBINATION WITH DENSE SAHARAN DUST IN THE LOW-MID LEVELS IS SUPPRESSING ANY CONVECTION FROM FORMING IN THIS REGION. $$ CANGIALOSI