000 AXNT20 KNHC 111802 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST SAT NOV 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 1745 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 56W S OF 15N MOVING W NEAR 15 KT. THE WAVE WAS ADJUSTED E OVERNIGHT...WHICH WAS A GOOD MOVE...AS VISIBLE IMAGERY SHOWS CLEAR BUT LOW AMPLITUDE CYCLONIC TURNING OF THE LOWER CLOUD FIELD ABOUT THE WAVE AXIS. THIS WAVE HAS SIGNIFICANTLY WEAKENED OVER THE LAST COUPLE OF DAYS AS MODERATE TO STRONG SW-WLY WINDS ALOFT IN COMBINATION WITH STRONG SUBSIDENCE HAVE TAKEN THEIR TOLL ON THIS ONCE ACTIVE TROPICAL WAVE. A COUPLE OF SMALL CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION NOTED FROM 10N-13N WITHIN 100NM OF THE AXIS. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N13W 7N25W 8N50W 10N59W 8N63W. SMALL CLUSTER OF MODERATE CONVECTION NOTED NEAR 9N20W. ISOLATED SHOWERS/TSTMS FROM 7N-11N BETWEEN 38W-48W. MINIMAL ACTIVITY NOTED ELSEWHERE WITHIN 200 NM EITHER SIDE OF THE AXIS. ...DISCUSSION... GULF OF MEXICO... UPPER SW/W FLOW DOMINATES THE GULF AROUND UPPER RIDGING FROM THE NW CARIBBEAN AND OFF THE EAST COAST...ALONG WITH THE APPROACHING TROUGH MOVING THROUGH THE NATIONS MID SECTION AND INTO THE NW GULF. THIS BROAD W/SW FLOW IS ADVECTING DEBRIS MOISTURE THROUGH MUCH OF THE GULF...DOWNSTREAM FROM THE VERY ACTIVE EAST PACIFIC. SCATTERED MODERATE CONVECTION NOTED IN THE WRN GULF FROM 19N-25N BETWEEN 94W-98W IN ASSOCIATION WITH THE SFC COLD FRONT THAT HAS MOVED INTO THE GULF. AS OF 1500 UTC THE COLD FRONT IS ANALYZED FROM NEAR BILOXI MISSISSIPPI TO 24N95W 23N98W. 20-25KT N/NE WINDS HAVE DEVELOPED BEHIND THE FRONT WITH A 1030 MB SFC HIGH BUILDING FROM N TEXAS. MUCH LIGHTER...MORE VARIABLE FLOW IS AHEAD OF THE FRONT WITH A WEAK GRADIENT AROUND A NEWLY FORMED 1020 MB HIGH NEAR 25N87W. HIGH PRESSURE WILL CONTINUE TAKING OVER THE GULF PATTERN FROM THE N WHILE WEAKENING THROUGH MONDAY...AS THE COLD FRONT PUSHES E/SE AND OUT OF THE AREA. CARIBBEAN SEA... THE CARIB REMAINS QUIET THIS AFTERNOON WITH PLENTY OF DRY/STABLE SINKING AIR ALOFT IN PLACE. THE MID-UPPER LEVEL PATTERN PRODUCING THIS STABLE ENVIRONMENT CONSISTS OF AN UPPER HIGH CENTERED IN THE NW CARIB NEAR 17N83W AND ANOTHER RIDGE EXTENDING N THROUGH THE ERN CARIBBEAN AND LESSER ANTILLES. A WEAK UPPER TROUGH IN THE MIDDLE EXTENDS S THROUGH THE CNTRL CARIB S OF HISPANIOLA. AT THE SFC...THERE DOES APPEAR TO BE A NARROW ZONE OF LOW LEVEL CONFLUENCE THAT WEAVES ITS WAY THROUGH THE CARIBBEAN WATERS FROM HAITI TO THE YUCATAN...BUT THERE IS NO DEEP CONVECTION ASSOCIATED WITH A PIECE OF WHAT SEEMS TO BE THE OLD ATLC FRONTAL BOUNDARY TO THE NE. ONE CLUSTER OF SCATTERED MODERATE CONVECTION NOTED OFF THE COAST OF PANAMA ASSOCIATED WITH THE ITCZ. TRADE WINDS ARE MODERATE AND WILL LIKELY REMAIN THAT WAY OVER THE NEXT COUPLE DAYS. ATLANTIC OCEAN... UPPER RIDGE EXTENDS N THROUGH THE SW NORTH ATLC ACCOMPANIED BY PLEASANT WEATHER WITH JUST A FEW HIGH CLOUDS/DEBRIS MOISTURE EXTENDING THROUGH THE REGION. A 1020 MB SFC HIGH ALSO NOTED NEAR 32N75W...PRODUCING LIGHT WINDS/LOW SEAS. A NARROW UPPER TROUGH EXTENDING S ALONG 51W HAS AN ASSOCIATED SFC COLD FRONT ALONG 32N53W 23N60W TO NEAR THE N COAST OF THE DOMINICAN REPUBLIC. A PRE-FRONTAL TROUGH LIES ABOUT 150 NM AHEAD OF THE FRONT N OF 25N. ONLY LOW AND MID LEVEL CLOUDS AND ISOLATED SHOWERS ARE ALONG THE FRONT AND TROUGH WITH THE UPPER SUPPORT NOW CUT OFF. SHORTWAVE UPPER RIDGE EXTENDS N THROUGH THE CENTRAL ATLC ALONG 42W N OF AN UPPER HIGH E OF THE LEEWARD ISLANDS. E OF THE RIDGE...THE PATTERN IS DOMINATED BY A LARGE CUT OFF UPPER LOW CENTERED NEAR 32N31W. THIS UPPER FEATURE HAS A RELATED SFC LOW WHICH IS ANALYZED AT 1008 MB JUST E OF THE UPPER-LEVEL CENTER. MOST OF THE WEATHER IS E OF THE SFC LOW...WHERE SCATTERED MODERATE CONVECTION EXISTS N OF 27N BETWEEN 22W-26W...LINED ALONG A SFC TROUGH. IN THE DEEP TROPICS...THE MAIN FEATURE IS A WELL-DEFINED UPPER LEVEL JET STREAM WHICH ORIGINATES NEAR VENEZUELA AND RACES ENE TO THE W COAST OF AFRICA. THE JET IS HEAVILY SHEARING THE CLOUD TOPS OVER THE ITCZ CONVECTION. $$ WILLIS