000 AXNT20 KNHC 110603 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON SEP 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0530 UTC. ...SPECIAL FEATURES... THE CENTER OF HURRICANE FLORENCE WAS LOCATED NEAR 31.2N 66.1W OR ABOUT 110 MILES SOUTHWEST OF BERMUDA AT 11/0600 UTC. FLORENCE IS MOVING TOWARD THE NORTH NEAR 11 KT AND THIS GENERAL MOTION IS EXPECTED TO CONTINUE OVERNIGHT WITH A TURN TOWARD THE NORTH-NORTHEAST ON MONDAY. THE CENTER OF FLORENCE IS EXPECTED TO PASS NEAR OR JUST WEST OF BERMUDA LATER THIS MORNING. TROPICAL STORM FORCE WINDS CONTINUE TO AFFECT BERMUDA. MINIMUM CENTRAL PRESSURE IS 975 MB. MAXIMUM SUSTAINED WINDS REMAIN NEAR 80 KT WITH GUSTS TO 100 KT. FLORENCE IS A LARGE TROPICAL CYCLONE. HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 60 MILES...95 KM...FROM THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 260 MILES...415 KM. SOME STRENGTHENING IS STILL POSSIBLE BEFORE FLORENCE BYPASSES BERMUDA. PLEASE READ THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC OR THE PUBLIC ADVISORY UNDER MIATCPAT1/WTNT31 KNHC FOR MORE DETAILS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION LIES FROM 28N-33N BETWEEN 64W-67W WITH A LARGE SHIELD OF SCATTERED MODERATE CONVECTION STRETCHED OUT TO THE N BY THE UPPER TROUGH. FLORENCE IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS OF 5 TO 8 INCHES OVER BERMUDA...WITH POSSIBLE MAXIMUM AMOUNTS OF 10 INCHES. TROPICAL DEPRESSION SEVEN HAS FORMED EAST-NORTHEAST OF THE LEEWARD ISLANDS. AT 11/0300 UTC THE CENTER OF TROPICAL DEPRESSION SEVEN WAS LOCATED NEAR 20.2N 54.5W OR ABOUT 525 MILES...845 KM...EAST-NORTHEAST OF THE LEEWARD ISLANDS. THE DEPRESSION IS MOVING SLOWLY TO THE WEST NEAR 5 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1012 MB. MAXIMUM SUSTAINED WINDS ARE NEAR 25 KT WITH GUSTS TO 35 KT. FOR MORE DETAILS PLEASE READ THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC OR THE PUBLIC ADVISORY UNDER MIATCPAT2/WTNT32 KNHC. THIS TROPICAL CYCLONE...VERY MUCH UNLIKE FLORENCE...IS COMPACT. OVER THE PAST COUPLE OF DAYS THIS SYSTEM WAS FEELING THE EFFECTS OF NORTHERLY WIND SHEAR EXPOSING THE LOW LEVEL CENTER TO THE NORTH. HOWEVER...IT ESCAPED THE SHEAR ON SUNDAY HELPING THE CONVECTION TO WRAP AROUND THE CENTER. SCATTERED MODERATE CONVECTION EXISTS FROM 18N-21N BETWEEN 53W-57W...STRONGEST TO THE SOUTH OF THE CENTER. SOME STRENGTHENING IS FORECAST DURING THE NEXT 24 HOURS...AND THE DEPRESSION COULD BECOME A TROPICAL STORM ON MONDAY. ...TROPICAL WAVES... A TROPICAL WAVE IS IN THE E ATLC ALONG 29W S OF 18N MOVING W NEAR 10 KT. THE OVERALL STRUCTURE OF THIS WAVE HAS BECOME MORE DISORGANIZED THAN IT WAS OVER THE PAST COUPLE OF DAYS. LOW TO MID CLOUD MOTIONS DO SHOW SOME CYCLONIC TURNING FROM 8N-14N ABOUT THE AXIS. SCATTERED SHOWERS AND TSTMS EXIST WITHIN 300 NM EITHER SIDE OF THE AXIS S OF 10N. SOME INTERACTION WITH A LARGE UPPER LOW TO THE NNW IS TRIGGERING A LINE OF SIMILAR ACTIVITY FROM 18N-23N BETWEEN 28W-30W. A LOW AMPLITUDE TROPICAL WAVE IS ALONG 42W SOUTH OF 15N MOVING WEST 10 TO 15 KT. THIS WAVE IS SLIGHTLY MORE DISCERNIBLE COMPARED TO YESTERDAY BASED ON SATELLITE IMAGES. SHOWER/TSTM ACTIVITY IS DISORGANIZED BUT HAS BECOME SLIGHTLY STRONGER AND EXPANDED IN COVERAGE FROM 10N-12N BETWEEN 41W-48W. A TROPICAL WAVE IS ALONG 55W S OF 17N MOVING W NEAR 10 KT. THIS WAVE AT LEAST IN PART SPAWNED THE DEVELOPMENT OF TROPICAL DEPRESSION SEVEN. THE WAVE APPEARED TO HAVE SPLIT...THE SOUTHERN PORTION IS PROPAGATING W WITH SLIGHT VEERING IN THE LOW LEVEL CLOUDS ABOUT THE AXIS. THIS IS THE LOW AMPLITUDE FEATURE THAT WILL BE TRACKED. SHOWER ACTIVITY IS MAINLY BEHIND THE WAVE AXIS AND ENHANCED BY THE ITCZ AND THE WAVE TO ITS EAST. TROPICAL WAVE ALONG 94W HAS MOVED INTO THE EPAC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 9N13W 8N21W 10N39W 9N61W. BESIDES FOR THE CONVECTION DISCUSSED IN THE TROPICAL WAVES SECTION...SCATTERED MODERATE IS MOVING OFF THE W COAST OF AFRICA E OF 20W FROM 6N-15N ASSOCIATED WITH A WELL DEFINED TROPICAL WAVE AND LOW PRES SYSTEM THAT WILL LIKELY MOVE OFF THE COAST IN THE NEXT DAY OR SO. ...DISCUSSION... THE GULF OF MEXICO... A CONSIDERABLE AMOUNT OF UPPER LEVEL MOISTURE LIES OVER MUCH OF THE GULF N OF 24N. THIS SEEMS MOSTLY ASSOCIATED WITH UPPER DIFFLUENCE BETWEEN AN UPPER HIGH OVER CENTRAL MEXICO NEAR 23N103W WITH RIDGING EXTENDING ACROSS THE GULF ALONG 27N AND BROAD WESTERLY FLOW OVER THE SOUTHERN U.S. HOWEVER...MOST OF THE DEEP MOISTURE OR SHOWER ACTIVITY HAS DISSIPATED OVER THE PAST FEW HOURS LEAVING ONLY ISOLATED SHOWERS EMBEDDED IN THE MOISTURE PLUME. A SFC TROUGH WAS ANALYZED IN REGION EARLIER...HOWEVER SFC OBS AND QUIKSCAT DATA SUGGEST THAT THE TROUGH IS FAIRLY WEAK IF THERE AT ALL. S OF 24N....MOISTURE IS MORE SCATTERED WITH A PATCH OF SHOWERS AND TSTMS IN THE E BAY OF CAMPECHE FROM 18N-21N BETWEEN 90W-93W AND A FEW SHOWERS N OF CUBA MOVING TOWARDS THE KEYS. SFC EAST TO SOUTHEASTERLY WINDS ARE FAIRLY LIGHT DUE TO THE WEAK PRES GRAD. LITTLE PATTERN CHANGE IS EXPECTED OVER THE NEXT DAY OR TWO. GFS SUGGESTS THAT A COLD FRONT MAY ENTER THE NW GULF ON WED. THE CARIBBEAN SEA... THE WEATHER IN THE CENTRAL CARIBBEAN IS VERY QUIET...THANKS TO DRY STABLE AIR ALOFT TO THE SOUTH OF AN UPPER ANTICYCLONE CENTERED JUST N OF HISPANIOLA. MODERATE SUBSIDENCE LIES BETWEEN 68W AND 80W. THERE IS A LITTLE MORE MOISTURE IN THE E CARIBBEAN WITH MAINLY MID-HIGH LEVEL CLOUDINESS AND ISOLATED SHOWERS E OF 68W ACROSS THE LESSER ANTILLES. THIS IS MAINLY ASSOCIATED WITH DEBRIS MOISTURE FROM NEWLY FORMED TROPICAL DEPRESSION SEVEN. SIMILAR WEATHER EXISTS IN THE W CARIBBEAN WHERE A FAIR AMOUNT OF MOISTURE WITH EMBEDDED SCATTERED SHOWERS ARE FOUND W OF 80W. THIS ACTIVITY IS ASSOCIATED WITH AN UPPER LEVEL LOW WHICH IS SEEN SPINNING ON WATER VAPOR IMAGES JUST E OF THE YUCATAN PENINSULA. MUCH MORE ORGANIZED SHOWERS AND TSTMS ARE OVER CENTRAL AMERICA AND S MEXICO WHERE UPPER DIFFLUENCE IS STRONGER AND THERE IS ENHANCEMENT IN THE LOW LEVELS FROM TROPICAL WAVES IN THE EPAC AND THE ITCZ. AT THE SURFACE...TRADES ARE FAIRLY LIGHT 10 TO 15 KT WITH A WEAK PRESSURE GRADIENT LEFT S OF FLORENCE. THE ATLANTIC OCEAN... HURRICANE FLORENCE AND TROPICAL DEPRESSION SEVEN ARE THE HIGHLIGHTS. FLORENCE IS ROUNDING THE SUBTROPICAL RIDGE...WHICH COVERS THE REGION FROM 40W-66W...AND HAS LIKELY BEGAN ITS RECURVATURE. AN UPPER TROUGH LIES TO THE W OF THIS RIDGE OFF THE E COAST OF THE U.S. WHICH HAS CAUSED THE SIGNIFICANT BREAK IN THE RIDGE SUPPORTED THIS STEERING REGIME FOR FLORENCE. SCATTERED MODERATE CONVECTION EXISTS FROM 29N-33N BETWEEN 64W-67W. ANOTHER MORE WIDESPREAD BATCH OF CONVECTION LIES TO THE N STRETCHED OUT BY THE UPPER TROUGH. LONG PERIOD SWELL ASSOCIATED WITH FLORENCE HAS ALREADY BEGUN REGISTERING ON MOST EAST COAST BUOYS...THUS DANGEROUS SURF IS EXPECTED FROM FLORIDA THROUGH NEW ENGLAND AND WILL PERSIST OVER THE NEXT COUPLE OF DAYS. SEE STATEMENTS FROM LOCAL WEATHER SERVICE OFFICES FOR DETAILS ON COASTAL CONDITIONS. ABOUT 900 NM TO THE SE OF FLORENCE LIES NEWLY FORMED T.D. 7. UNLIKE FLORENCE THIS IS A SMALL SYSTEM WITH SCATTERED MODERATE CONVECTION FOUND FROM 17N-21N BETWEEN 53W-57W. FOR MORE DETAILS REFER TO THE SPECIAL FEATURE SECTION. FARTHER EAST...A MID TO UPPER LOW IS CENTERED NEAR 26N34W. ISOLATED TO SCATTERED SHOWERS/TSTMS ARE SPINNING CYCLONICALLY AROUND THE UPPER LOW FROM 20N-30N BETWEEN 30W-37W. A LARGE MID-UPPER RIDGE IS CENTERED JUST S OF THE CANARY ISLANDS WITH THE RIDGE AXIS EXTENDING SWWARD TO NEAR 12N40W. A WELL-DEFINED TROPICAL WAVE AND LOW-MID LEVEL LOW PRES SYSTEM IS MOVING OFF THE COAST OF AFRICA GENERATING SCATTERED SHOWERS AND TSTMS E OF 20W FROM 6N-15N. $$ CANGIALOSI