000 AXNT20 KNHC 262339 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN AUG 26 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 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...METEOROLOGICAL ANALYSIS... WEATHER OBSERVATIONS...AND RADAR. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 32W S OF 16W MOVING W NEAR 10-15 KT. ACCORDING TO THE UW-CIMSS TPW PRODUCT...MUCH OF THE CYCLONIC TURNING AND HIGHEST MOISTURE CONTENT WITH THIS WAVE HAVE HAD A SW MOTION OVER THE LAST DAY OR SO. SCATTERED MODERATE CONVECTION IS SEEN FROM 9N-13N BETWEEN 30W-36W. LOW AMPLITUDE TROPICAL WAVE IS ALONG 54/55W S OF 15N MOVING W 10 KT. A SWIRL OF LOW CLOUDS REMAINS ASSOCIATED WITH THE WAVE NEAR 12N55W. SHOWER AND TSTM ACTIVITY IS MINIMAL. A NEW TROPICAL WAVE IS INTRODUCED ALONG 71W ON THE 1800 UTC SURFACE MAP BASED ON SATELLITE IMAGERY...SFC OBSERVATIONS AND THE CURACAO VERTICAL SOUNDING THAT SHOWED THE PASSAGE OF THE WAVE THIS MORNING. A LARGE AREA OF DISORGANIZED SHOWERS AND THUNDERSTORMS OVER THE CENTRAL CARIBBEAN IS ASSOCIATED WITH THIS FEATURE. THERE ARE NO SIGNS OF A CLOSED SURFACE CIRCULATION AND DEVELOPMENT..IF ANY...IS EXPECTED TO BE SLOW TO OCCUR AS THE SYSTEM MOVES WESTWARD AROUND 15 TO 20 MPH. COMPUTER MODELS HAVE MOISTURE FROM THIS WAVE REACHING THE CARIBBEAN PLAINS OF NICARAGUA LATE MONDAY OR EARLY TUESDAY. TROPICAL WAVE IS IN THE W CARIBBEAN AND OVER CENTRAL AMERICA ALONG 85W S OF 23N MOVING W 10-15 KT. THIS WAVE IS ENHANCING SOME OF THE SHOWER/TSTM ACTIVITY IN THE SE GULF...OVER WESTERN CUBA AND ACROSS NICARAGUA AND NE HONDURAS. AN EARLIER QUIKSCAT PASS SHOWED VERY CLEAR THE WIND SHIFT ASSOCIATED WITH THIS WAVE. SCATTERED SHOWERS ARE OVER THE NW CARIBBEAN. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 11N16W 9N30W 8N40W 10N52W 9N61W. BESIDES FOR THE CONVECTION DISCUSSED IN THE TROPICAL WAVES SECTION...A 70 NM WIDE BAND OF SCATTERED MODERATE CONVECTION IS S OF THE AXIS ALONG 5N-6N BETWEEN 21W-38W. CLUSTERS OF MODERATE TO ISOLATED STRONG CONVECTION ARE OVER SENEGAL IN WESTERN AFRICA. DISCUSSION... GULF OF MEXICO... MAIN FEATURE IN THE AREA THIS EVENING IS A WEAK AREA OF LOW PRESSURE LOCATED JUST EAST OF TAMPICO MEXICO. AS OF 21Z...THE LOW IS LOCATED NEAR 22N97W WITH 1008 MB. THIS SYSTEM HAVE BECOME A LITTLE BETTER ORGANIZED. HOWEVER...THIS FEATURE IS EXPECTED TO MOVE INLAND LATER TONIGHT OR EARLY MONDAY...AND SIGNIFICANT DEVELOPMENT IS UNLIKELY. LOCALLY HEAVY RAINFALL IS POSSIBLE OVER CENTRAL MEXICO DURING THE NEXT DAY OR SO AS THE SYSTEM MOVES SLOWLY WESTWARD. TAMPICO REPORTED NLY WINDS OF 22 KT AND TSRA DURING THE LAST FEW HOURS. THE ASSOCIATED SCATTERED MODERATE CONVECTION IS FROM 20N-26N WEST OF 90W...INCLUDING ALSO THE EASTERN SLOPES OF THE SIERRA MADRE MOUNTAINS. A SFC TROUGH OVER THE EASTERN GULF ALONG 85W CONTINUES TO PRODUCE SCATTERED MODERATE CONVECTION OVER THE GULF MAINLY N OF 24N AND E OF 88W. THIS CONVECTION IS BEING SUPPORTED BY A DIFFLUENT PATTERN ALOFT BETWEEN AN UPPER LOW LOCATED JUST S OF LOUISIANA...RIDGING OVER THE NE CORNER OF THE GULF AND AN INVERTED UPPER TROUGH OVER THE FAR SE PORTION. WEAK RIDGING WILL MEANDER AROUND 30N OVER THE NEXT COUPLE OF DAYS. CARIBBEAN SEA... THE MOST SIGNIFICANT AREA OF CONVECTION IS OFF THE COAST OF COLOMBIA AND VENEZUELA ASSOCIATED WITH A TROPICAL WAVE. SEE ABOVE. CLUSTERS OF MODERATE CONVECTION ARE ALSO OVER NORTHERN VENEZUELA ASSOCIATED WITH A NORTHWARD MODULATION OF THE ITCZ. AFTERNOON HEAT INDUCED SHOWERS ARE OVER PARTS OF THE GREATER ANTILLES. ALL OF THE ACTIVITY IS ALSO BEING SUPPORTED BY DIFFLUENCE ALOFT BETWEEN THE UPPER TROUGHING BETWEEN PANAMA AND JAMAICA...AND ATLC RIDGING EXTENDING INTO THE ERN CARIBBEAN. UPPER NLY WINDS ARE FOUND OVER THE WESTERN CARIBBEAN. ABUNDANT UPPER LEVEL MOISTURE IS ACROSS THE BASIN. THE TRADE WIND FLOW IS ON THE LIGHT TO MODERATE SIDE...AND IS ONLY EXPECTED TO INCREASE SLIGHTLY OVER THE NEXT COUPLE OF DAYS. ATLANTIC OCEAN... THE SFC PATTERN ACROSS THE ATLC DISCUSSION AREA REMAINS FAIRLY WEAK THIS EVENING. THIS WEAK PATTERN IS MAINLY DUE TO AN UNUSUAL FRONTAL BOUNDARY DEEP INTO THE SUBTROPICS ENTERING THE AREA NEAR 32N38W TO 26N55W THEN CONTINUING WSW THEN NW AS A TROUGH THROUGH 23N63W 28N69W. ISOLATED SHOWERS AND TSTMS ARE ASSOCIATED WITH FRONT. A WEAK 1018 MB HIGH IS OVER THE WRN ATLC NEAR 29N72W. A SFC TROUGH IS JUST E OF THE LEEWARD ISLANDS ALONG 21N58W 15N60W GENERATING JUST A FEW SHOWERS WITHIN 60 NM EITHER SIDE OF THE AXIS. A WEAK RIDGE AXIS DOMINATES THE REMAINDER OF THE CENTRAL AND E ATLC. LOOK FOR THE FRONT TO CONTINUE BECOMING DIFFUSE OVER THE NEXT DAY OR SO. ELSEWHERE ALOFT...AN UPPER HIGH IS JUST OFFSHORE N FLORIDA NEAR 30N80W. A TUTT LOW REMAINS NE OF PUERTO RICO NEAR 26N57W. AN UPPER TROUGH EXTENDS SW FROM THIS LOW TO HISPANIOLA. DIFFLUENCE AHEAD OF THIS TROUGH WAS SUPPORTING THE DEVELOPMENT OF SHOWERS AND TSTMS OVER PUERTO RICO AND HISPANIOLA DURING THE AFTERNOON HOURS AND EARLY THIS EVENING. ANOTHER UPPER HIGH IS OVER THE CENTRAL ATLC NEAR 22N42W THAT IS SURROUNDED BY DRY/STABLE AIR. THIS UPPER HIGH IS EMBEDDED IN THE LARGER SCALE RIDGING EXTENDING E FROM WESTERN AFRICA. $$ GR