000 AXNT20 KNHC 122350 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST SUN NOV 12 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...TROPICAL WAVES... A LOW AMPLITUDE TROPICAL WAVE IS ALONG 61W S OF 14N MOVING W NEAR 10 KT. THE WAVE APPEARS TO HAVE SLOWED DOWN A BIT AND REMAINS LESS OBVIOUS THAN IT WAS A FEW DAYS AGO...THOUGH SOME CYCLONIC TURNING OF THE LOW TO MID CLOUD FIELD STILL EVIDENT FROM 10N-14N WITHIN 200NM OF THE AXIS. THE CLUSTERS OF SCATTERED MODERATE CONVECTION THAT DEVELOPED BETWEEN BARBADOS AND TRINIDAD EARLIER TODAY HAVE DIMINISHED IN BOTH COVERAGE AND INTENSITY OVER THE LAST SEVERAL HOURS...WITH STRONG WSW SHEAR CONTINUING OVER THE WAVE. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 8N13W 5N30W 7N50W 10N60W. SCATTERED MODERATE CONVECTION IS FROM 4N-11N BETWEEN 20W-36W. SIMILAR CONVECTION IS FROM 10N-14N BETWEEN 45W-50W...THOUGH THIS MAY BE MORE ASSOCIATED WITH UPPER DIFFLUENCE. ...DISCUSSION... GULF OF MEXICO... NEARLY ZONAL FLOW DOMINATES MOST OF THE GULF N OF AN UPPER HIGH CENTERED OVER BELIZE. AN UPPER TROUGH EXTENDS S OFF THE SE U.S. COAST FROM AN UPPER LOW SPINNING OVER DUCK NORTH CAROLINA. AS OF 2100 UTC...THE ASSOCIATED COLD FRONT EXTENDS FROM S CENTRAL FL TO THE CENTRAL GULF NEAR 25N87W...THEN CONTINUES AS A STATIONARY FRONT AS IT DRAPES S TO THE ISTHMUS OF TEHUANTEPEC. HOWEVER...CONFIDENCE ON THE EXACT PLACEMENT OF THIS FRONTAL BOUNDARY IS LOW WITH ABUNDANT UPPER MOISTURE OVER THE AREA OBSCURING THE SFC FEATURES...AND THE FRONT BEGINNING TO WASH OUT. THERE IS A MARKED DEWPOINT GRADIENT THROUGH FLORIDA THOUGH...WITH VALUES IN THE 40S IN NORTH/CENTRAL FLORIDA AND 60S IN SE FL. VERY LITTLE DEEP CONVECTION NOTED WITHIN SEVERAL HUNDRED MILES OF THE FRONT...WITH MUCH OF THE UPPER MOISTURE OVER THE GULF ATTRIBUTED TO DEBRIS DOWNSTREAM OF THE EPAC TROUGH/REMNANTS OF ROSA AND T.D. 20-E. SFC HIGH PRESSURE N OF THE AREA IS TAKING OVER THE GULF AS THE FRONT WASHES OUT. THE HIGH WILL MOVE SLOWLY E INTO EARLY WEEK WITH GRADUALLY DECREASING WINDS AND SEAS EXPECTED. CARIBBEAN... A BROAD UPPER RIDGE COVERS THE WEST-CENTRAL CARIBBEAN AND CENTRAL AMERICA FROM AN UPPER HIGH CENTERED OVER BELIZE. AN UPPER TROUGH OVER THE CENTRAL ATLC DIPS INTO THE E CARIBBEAN...ENTERING THE REGION JUST SE OF PUERTO RICO TO THE ABC ISLANDS. ABUNDANT DRY/STABLE AIR ALOFT...RESULTING IN MODERATE TO STRONG SUBSIDENCE AND FAIR WEATHER...CONTINUES TO DOMINATE MOST OF THE AREA N OF 12N. UPPER LEVEL MOISTURE IS SPREADING ACROSS THE NW CORNER OF THE BASIN WHERE THERE IS A SMALL AREA OF SHOWERS. THIS IS LIKELY ASSOCIATED WITH UPPER DIFFLUENCE ALONG WITH WEAK LOW LEVEL CONFLUENCE. A 1008 MB SURFACE LOW LOCATED NEAR 10N81W...ALONG WITH THE ITCZ...IS GENERATING SCATTERED SHOWERS OVER THE SW CARIBBEAN. 10-20 KT TRADE WINDS ARE BLOWING ACROSS THE REGION AND WILL PERSIST INTO EARLY WEEK. ATLANTIC OCEAN... SFC COLD FRONT ENTERS THE SW NORTH ATLC ALONG 32N75W AND EXTENDS SW TO SOUTH CENTRAL FLORIDA. FRONT IS ASSOCIATED WITH PRONOUNCED UPPER LOW OVER DUCK NORTH CAROLINA...THAT HAS AN UPPER TROUGH EXTENDING S INTO THE REGION. VERY LITTLE DEEP CONVECTION ASSOCIATED WITH THE BOUNDARY THOUGH...WITH JUST ISOLATED SHOWERS EXPECTED WITHIN 150 NM OF THE FRONT. STRONG OFFSHORE FLOW OFF THE SE US COAST VEERS N ALONG THE FL COAST AND DECREASES FURTHER S AS THE GRADIENT WEAKENS...SEE MIAOFFNT3 FOR DETAILS. AN UPPER RIDGE STRETCHES NEWD FROM THE WRN CARIBBEAN ACROSS CUBA AND THE BAHAMAS TOWARDS BERMUDA. A PAIR OF MID/UPPER CUT-OFF LOWS ARE ARE AFFECTING THE CENTRAL/ERN ATLC FROM 26N-40N BETWEEN 20W-60W...COVERING THE CENTRAL AND EASTERN ATLC. THE WRN MOST OF THESE HAS A REFLECTION AT THE SFC AS A 1009MB LOW NEAR 30N51W...WITH A WEAKENING COLD FRONT EXTENDING SW FROM THE LOW TO NEAR THE VIRGIN ISLANDS. THIS BOUNDARY MARKED BY A LINE OF LOW TO MID CLOUDS WITH NO DEEP CONVECTION. THE CLOUD PATTERN OF THIS SYSTEM IS STARTING TO RESEMBLE AN OCCLUSION...THOUGH WITH VERY LITTLE TEMP GRADIENT IN THE AREA A TROF MAY BE THE PREFERRED SOLUTION IN FUTURE MAPS. THE LOW IS EXPECTED TO MOVE LITTLE THROUGH EARLY TO MID WEEK. SUBSTANTIAL ZONAL WLY FLOW ALOFT DOMINATES MUCH OF THE AREA S OF THESE CUT OFF LOWS...FROM 10N-30N BETWEEN 20W-50W. $$ MW/GR