000 AXNT20 KNHC 111756 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED OCT 11 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 34W S OF 18N MOVING W 10 KT. LOW/MID INVERTED-V SIGNATURE IS NOTED ON SATELLITE IMAGERY...WITH A SWIRL OF LOW CLOUDS NEAR 14N. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 12N-16N BETWEEN 30W-34W. A LARGE TROPICAL WAVE IS ALONG 60W/61W S OF 24N MOVING W NEAR 10 KT. EARLIER QUIKSCAT PASS SHOWS EVIDENCE OF A CLOSED SURFACE CIRCULATION. A 1012 MB LOW IS ANALYZED NEAR 13.N59.5W ON THE 1200 UTC MAP. A CLUSTER OF MODERATE/ISOLATED STRONG CONVECTION IS JUST E OF THE WEAK SURFACE LOW FROM 12N-15N BETWEEN 57W-59W. THE WAVE IS EXPECTED TO MOVE WEST-NORTHWESTWARD ACROSS THE WINDWARD AND LEEWARD ISLANDS INTO THE EASTERN CARIBBEAN SEA DURING THE NEXT DAY OR TWO. ENVIRONMENTAL CONDITIONS DO NOT FAVOR SIGNIFICANT DEVELOPMENT OF THIS SYSTEM WHICH COULD BRING LOCALLY HEAVY RAIN AND GUSTY WINDS TO THESE ISLANDS. BARBADOS REPORTED HEAVY RAIN AND SUSTAINED WINDS OF 20 KT THIS MORNING. TROPICAL WAVE IS ALONG 72W S OF 20N MOVING W 10 KT. BROAD LOW LEVEL INVERTED-V STRUCTURE IS NOTED ON SATELLITE IMAGERY. THIS SYSTEM IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE LAKE MARACAIBO. ELSEWHERE ISOLATED SHOWERS ARE FOUND. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 1ON14W 6N25W 8N32W 8N40W 12N57W WIDELY SCATTERED MODERATE CONVECTION IS MAINLY SOUTH OF THE AXIS FROM 4N-8N EAST OF 20W. CLUSTER OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE INLAND OVER AFRICA FROM 7N-11N BETWEEN 8W-12W. ...DISCUSSION... GULF OF MEXICO... DEEP LAYERED TROUGH IS MOVING RAPIDLY EASTWARD ACROSS THE MISSISSIPPI VALLEY TO OVER THE SE US. THE ASSOCIATED FRONTAL BOUNDARY IS APPROACHING THE N GULF COAST AND WILL EXTEND FROM THE FLORIDA PANHANDLE TO THE CENTRAL PORTION OF THE GULF LATE TONIGHT. AS OF 1500 UTC...A WEAK PRE-FRONTAL TROUGH EXTENDS FROM SE LOUISIANA TO NE MEXICO. A NARROW LINE OF SHOWERS AND ISOLATED TSTMS IS RELATED TO THE TROUGH. AN UPPER ANTICYCLONE CENTERED OVER CENTRAL MEXICO NEAR 20N101W COVERS MOST OF THE GULF AND CENTRAL AMERICA. AT THE SURFACE...A REMNANT FRONTAL SURFACE TROUGH EXTENDS THROUGH THE STRAITS OF FLORIDA NEAR 24N80W WWD TO 24N89W WITH ISOLATED SHOWERS/TSTMS MOVING ALONG THE TROUGH AXIS BETWEEN 81W-84W. THIS SHOWER ACTIVITY MAY REACH SOUTH FLORIDA TONIGHT. A STRONG COLD FRONT WILL MOVE OFF THE TEXAS AND LOUISIANA COAST LATE THU AFTERNOON. THIS FRONT PROMISES TO BRING THE COLDEST AIR OF THE SEASON SO FAR ACROSS THE CENTRAL AND EAST PARTS OF THE U.S.. TEMPERATURES MAY DROP A FEW DEGREES BELOW NORMAL ACROSS SOUTH FLORIDA ON SUNDAY. CARIBBEAN SEA... AN UPPER RIDGE COVERS THE W-CENTRAL CARIBBEAN WHILE AN UPPER TROUGH IN THE W ATLC EXTENDS S INTO THE CARIBBEAN ACROSS HISPANIOLA. THIS UPPER TROUGH WILL APPROACH PUERTO RICO ON THURSDAY AND MAY INTERACT WITH THE TROPICAL WAVE LOCATED CURRENTLY ALONG 60/61W...BRINGING THE POTENTIAL OF HEAVY RAIN TO THE ENCHANTED ISLAND. BROAD RIDGE ANCHORED IN THE TROPICS COVERING THE CENTRAL ATLC INCLUDES THE FAR E CARIBBEAN. UPPER DRY AIR DOMINATES MOST OF THE BASIN WITH THE EXCEPTION OF THE SW CARIBBEAN WHERE THERE ARE ISOLATED SHOWERS/TSTMS. SCATTERED MODERATE CONVECTION IS ALSO SEEN FROM NORTHERN COLOMBIA TO COSTA RICA DUE TO THE PRESENCE OF THE ITCZ AXIS. MODERATE TRADE WINDS OF 10-15 KT WILL CONTINUE TO BLOW ACROSS THE AREA DURING THE NEXT FEW DAYS. ATLANTIC OCEAN... A SHORT WAVE TROUGH ENTERS THE AREA NEAR 31N70W THEN CONTINUES S INTO THE CARIBBEAN SEA ACROSS HISPANIOLA. A CLUSTER OF MODERATE TO ISOLATED STRONG CONVECTION IS JUST AHEAD OF THE TROUGH AXIS FROM 19N-22W BETWEEN 65W-69W. PART OF THIS CONVECTIVE ACTIVITY EXTENDS SW AFFECTING THE EASTERN PART OF DOMINICAN REPUBLIC. THE ASSOCIATED WEAKENING FRONTAL BOUNDARY STRETCHES FROM 32N70W TO 24N80W. A NARROW LINE OF SHOWERS WITH EMBEDDED TSTMS IS ASSOCIATED WITH THIS FEATURE. BROAD UPPER RIDGE DOMINATES THE CENTRAL ATLC ANCHORED IN THE TROPICS NEAR 12N46W COVERING THE AREA FROM 40W-65W. UPPER TROUGH IS OVER THE E ATLC WITH THE AXIS EXTENDING THROUGH 32N16W SW TO NEAR 15N30W WITH THE ASSOCIATED COLD FRONT N OF THE REGION. AT THE SURFACE A BROAD SURFACE RIDGE COVERS THE ATLC E OF 55W WITH A 1023 MB HIGH LOCATED NEAR 29N44W. AN AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS IS FROM 20N-28N BETWEEN 39W-47W ASSOCIATED WITH A SHORT WAVE TROUGH THAT LIES ALONG 48W. $$ GR