000 AXNT20 KNHC 151803 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST WED NOV 15 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 1745 UTC. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 47W SOUTH OF 14N MOVING WEST 10 TO 15 KT. THIS WAVE CONTINUES TO EXHIBIT A BROAD INVERTED V PATTERN. SCATTERED MODERATE CONVECTION IS FROM 10N-15N BETWEEN 41W-47W. THE ASSOCIATED CLOUD TOPS ARE BEING STRETCHED TO THE NE WITH UPPER SW FLOW AROUND A RIDGE JUST E OF THE AREA. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 59W SOUTH OF 15N MOVING WEST NEAR 15 KT. VERY SMALL AREA OF CYCLONIC TURNING NOTED IN THE LOW CLOUD FIELD JUST S OF BARBADOS...THOUGH ANOTHER NOTED FURTHER SE NEAR 11N55W WHICH MADE THE WAVE PLACEMENT DIFFICULT. REGARDLESS...DEEP CONVECTION IS MINIMAL WITHIN 200NM EITHER SIDE OF THE AXIS. A CENTRAL CARIBBEAN SEA TROPICAL WAVE IS ALONG 76W SOUTH OF 16N MOVING WEST 10 TO 15 KT. WAS TEMPTED TO REMOVE THIS WAVE AS THE CYCLONIC TURNING NOTED IN THE CENTRAL CARIBBEAN SEEMS MORE RELATED TO NATURAL VARIATIONS IN THE TRADE FLOW AROUND THE ADJACENT OROGRAPHY. HOWEVER...COULD MAKE OUT SOME SORT OF WESTWARD PROPAGATING PERTURBATION IN THE GOES-E HOVMOLLER DIAGRAM THROUGH S AMERICA SO DECIDED TO KEEP THE FEATURE. SCATTERED MODERATE NOW FROM 9N-13N BETWEEN 75W-78W. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 9N13W 5N25W 11N45W 12N57W. ASIDE FROM THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVE ALONG 47W...SCATTERED MODERATE FROM 5N-9N BETWEEN 31W-36W. ISOLATED SHOWERS/TSTMS NOTED ELSEWHERE WITHIN 100NM EITHER SIDE OF THE AXIS. ...DISCUSSION... THE GULF OF MEXICO... MAIN FEATURE IN THE GULF IS THE STRONG FRONTAL SYSTEM THAT HAS PUSHED INTO THE NW PORTION. AS OF 1500 UTC...THE COLD FRONT EXTENDS FROM MARSH ISLAND OFF THE CENTRAL LOUISIANA COAST TO JUST NORTH OF TAMPICO MEXICO. A SQUALL LINE ASSOCIATED WITH THE FRONT IS PRODUCING HEAVY SHOWERS/TSTMS NEAR THE BOUNDARY. ISOLATED CELLS ALSO NOTED IN THE WARM SECTOR AHEAD OF THE FRONT...STREAMING NNE...N OF 25N BETWEEN THE FRONT AND 83W. THE FRONT AND ASSOCIATED CONVECTION WILL CONTINUE MOVING E/SE OVER THE NEXT 24HRS...WITH THE FRONT EXPECTED TO MOVE INTO THE FAR SE GULF BY TOMORROW AFTERNOON. A GALE WARNING IS IN EFFECT FOR BOTH PREFRONTAL AND POSTFRONTAL WINDS...SEE MIAOFFNT4 AND MIAHSFAT2 FOR DETAILS. FRONTAL SYSTEM IS ASSOCIATED WITH DEEP LAYER TROUGH EXTENDING S THROUGH OKLAHOMA AND TEXAS...AND IS ADVECTING VERY DRY AIR INTO THE FAR NW GULF BEHIND THE FRONT. UPPER RIDGE IS E OF THE TROF EXTENDING THROUGH THE FAR ERN GULF. THE CARIBBEAN SEA... NEARLY ZONAL MID TO UPPER FLOW FOUND ACROSS THE CARIBBEAN N OF 13N...BUT HAS A SLIGHT ANTICYCLONIC CURVATURE WITH A HIGH ORIGIN SOMEWHERE JUST W OF NRN COLOMBIA. THIS IS ENHANCING THE CONVECTION DESCRIBED WITH THE TROPICAL WAVE ALONG 76W. AT THE SFC...TRADES ARE FAIRLY LIGHT WITH A WEAK PRESSURE GRADIENT IN TACT. LIGHT TO MODERATE TRADES TO PERSIST THROUGH THE END OF THE WORKWEEK...WHILE A COLD FRONT MOVES INTO THE NW CARIBBEAN ON THU THEN STALLS FROM CENTRAL CUBA TO THE GULF OF HONDURAS ON FRI. THE ATLANTIC OCEAN... THE STATIONARY FRONT THAT EXTENDED THROUGH THE SW NORTH ATLC THE LAST FEW DAYS HAS DISSIPATED...WITH THE STRONG 1036 MB HIGH JUST SE OF NEWFOUNDLAND HAVEN BUSTED THROUGH. UPPER RIDGING AND PLENTIFUL DRY AIR ALSO NOTED IN THE SW NORTH ATLC N OF 23N AND W OF 65W...WITH HIGH CLOUDS AND UPPER MOISTURE NOTED JUST S AND E OF THIS BOUNDARY. NEXT INTERESTING FEATURE IS THE BROAD...WEAKENING DEEP LAYER LOW NEAR 30N45W THAT HAS A 1011 MB SFC LOW NEAR 29N49W. DEEP CONVECTION REMAINS MINIMAL ANYWHERE NEAR THIS LOW. HOWEVER...AS THIS SYSTEM CONTINUES TO INTERACT WITH THE STRONG BLOCKING HIGH TO ITS NORTH NEAR NEWFOUNDLAND...IT WILL SEND A SMALL TO MODERATE ENE SWELL TO EXPOSED FLORIDA AND BAHAMA BEACHES LATER THIS WEEK. SFC TROUGH ASSOCIATED WITH THIS SYSTEM EXTENDS FROM THE LOW TO 26N47W 22N54W...MARKED BY WEAK LOW LEVEL CONFLUENCE AND A RAGGED LINE OF LOW TO MID CLOUDS WITHIN 150 NM. PRONOUNCED UPPER RIDGING EXTENDS THROUGH THE E ATLC ALONG 31W...THAT HAS ABUNDANT MID TO UPPER MOISTURE STREAMING AROUND IT BETWEEN AFRICA AND 48W...THAT LIKELY HAS ISOLATED EMBEDDED SHOWERS. SFC HIGH PRESSURE ALSO DOMINATING THE E ATLC WITH A 1019MB CENTER NEAR 26N28W...FORECAST TO DISSIPATE IN 24HRS AS A MORE SIGNIFICANT HIGH TAKES OVER FROM THE NNW. $$ WILLIS