000 AXNT20 KNHC 130005 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE MON 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. ...SPECIAL FEATURES... THE CENTER OF HURRICANE FLORENCE AT 12/2100 UTC WAS NEAR 39.3N 59.3W. THIS POSITION IS ALSO ABOUT 520 NM/965 KM SOUTHWEST OF CAPE RACE NEWFOUNDLAND. FLORENCE IS MOVING NORTHEAST AT 17 KT. SOME INCREASE IN FORWARD SPEED IS EXPECTED DURING THE NEXT 24 HOURS. THE CENTER OF FLORENCE IS EXPECTED TO PASS JUST SOUTHEAST OF NEWFOUNDLAND DURING THE NEXT DAY OR SO. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 980 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 65 KT WITH GUSTS TO 80 KT. LITTLE CHANGE IN STRENGTH IS FORECAST DURING THE NEXT 24 HOURS AS FLORENCE TRANSITIONS INTO A LARGE AND POWERFUL EXTRATROPICAL CYCLONE. PLEASE READ THE LAST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC OR THE PUBLIC ADVISORY UNDER MIATCPAT1/WTNT31 KNHC FOR MORE DETAILS. RESIDENTS IN EXTREME EASTERN CANADA SHOULD CONSULT BULLETINS ISSUED BY ENVIRONMENT CANADA FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE WATCHES AND WARNINGS. THE ONLY CONVECTION REMAINING NEAR THE CENTER IS A BAND OF SHOWERS AND THUNDERSTORMS LOCATED ABOUT 100 NM NORTHWEST OF THE CENTER. THE CENTER OF TROPICAL STORM GORDON AT 12/2100 UTC WAS NEAR 23.7N 58.4W. THIS POSITION ALSO IS ABOUT 440 NM/815 KM NORTH-NORTHEAST OF THE LEEWARD ISLANDS. GORDON IS MOVING NORTH AT 6 KT AND THIS MOTION IS EXPECTED TO CONTINUE FOR THE NEXT 24 HOURS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 994 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 55 KT WITH GUSTS TO 65 KT. ADDITIONAL STRENGTHENING IS FORECAST AND GORDON COULD BECOME A HURRICANE TONIGHT OR ON WEDNESDAY. PLEASE READ THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC AND THE PUBLIC ADVISORY MIATCPAT2/WTNT32 KNHC FOR MORE DETAILS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION EXISTS FROM 22N-26N BETWEEN 56W-60W. ANOTHER REGION OF NUMEROUS SHOWERS/TSTMS IS NOTED FURTHER E OF THE CENTER FROM 20N-26N BETWEEN 51W-56W...SPREADING E WITH UPPER LEVEL WESTERLY FLOW. THE CENTER OF TROPICAL DEPRESSION EIGHT AT 12/2100 UTC WAS NEAR 12.0N 23.9W. THIS POSITION ALSO IS ABOUT 170 NM/295 KM SOUTH SOUTHERNMOST CAPE VERDE ISLANDS. T.D. EIGHT IS MOVING WEST AT 13 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1007 MB. THE MAXIMUM SUSTAINED WINDS ARE 30 KT WITH GUSTS TO 40 KT. STRENGTHENING IS FORECAST DURING THE NEXT 24 HOURS...AND THE DEPRESSION COULD BECOME A TROPICAL STORM TONIGHT OR EARLY WEDNESDAY.PLEASE READ THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC AND THE PUBLIC ADVISORY MIATCPAT3/WTNT33 KNHC FOR MORE DETAILS. SATELLITE IMAGES SHOW THAT THE DEPRESSION IS GRADUALLY BECOMING MORE ORGANIZED WITH FAIRLY PROMINENT BANDING FEATURES OVER THE WESTERN AND SOUTHERN PORTIONS OF THE CIRCULATION. HOWEVER THE CENTER IS STILL RATHER BROAD AND ELONGATED...AND THE AREA OF CONVECTION TO THE WEST OF THE CENTER IS MOVING WESTWARD AND BECOMING MORE SEPARATED FROM THE CENTER OF THE CYCLONE. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 37W/38W SOUTH OF 17N MOVING WEST NEAR 10 KT. THIS WAVE HAS BEEN FAIRLY STRAIGHTFORWARD TO TRACK THE LAST FEW DAYS WITH A CLEAR SIGNAL ON A METEOSAT8 HOVMOLLER DIAGRAM...BUT IS NOT THE CASE ANYMORE. ONE CAN DETECT A BIT OF LOW/MID CLOUD TURNING CURRENTLY APPROACHING 40W FROM 5N-10N THAT IS PROPAGATING WWARD. ASSOCIATED SCATTERED MODERATE CONVECTION LIES FROM 5N-8N BETWEEN 39W-43W. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 48W SOUTH OF 16N MOVING WEST 10 TO 15 KT. THIS WAVE IS LOW AMPLITUDE WITH MINIMAL DEEP CONVECTION. ISOLATED MODERATE CONVECTION FROM 4N-7N BETWEEN 46W-50W. A NEW TROPICAL WAVE OR REPOSITION OF THE WAVE NEAR 48W WILL LIKELY BE ADDED TO THE 13/0000 UTC MAP JUST E OF THE WINDWARD ISLANDS ALONG 57W. A CLASSIC WAVE PATTERN IS SEEN IN THIS REGION S OF 19N. ISOLATED SHOWERS/TSTMS DOT THE AREA FROM 11N-16N BETWEEN 54W-60W. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 65W SOUTH OF 16N MOVING WEST NEAR 15 KT. THERE IS A HINT OF LOW/MID CYCLONIC TURNING NEAR THE WAVE AXIS ALONG WITH NUMEROUS SHOWERS/TSTMS OVER S AMERICA MOVING W...THOUGH OVERALL THE SIGNAL IS VAGUE. ...THE ITCZ... ITCZ IS CENTERED ALONG 9N25W 8N35W 7N39W 7N46W 8N50W 10N62W. ASIDE FROM THE CONVECTION NEAR THE TROPICAL WAVES AND T.D. EIGHT...A CLUSTER OF SCATTERED MODERATE CONVECTION IS SEEN FROM 7N-11N BETWEEN 55W-58W. SEVERAL SIMILAR CLUSTERS OVER NRN S AMERICA ALSO LIKELY ENHANCED BY THE ITCZ. ...DISCUSSION... THE GULF OF MEXICO... A MID TO UPPER LEVEL ANTICYCLONE IS SPINNING NEAR COASTAL NE MEXICO...THAT HAS RIDGING EXTENDING E TO NEAR 86W MORE OR LESS ALONG 27N. ANOTHER SMALLER MID/UPPER HIGH IS OVER THE FAR SE GULF. UPPER DIFFLUENT AIR BETWEEN THIS FEATURES AND THE WRLY FLOW OVER THE SRN UNITED STATES IS HELPING TO SUPPORT THE SCATTERED MODERATE CONVECTION IN THE NW GULF FROM 25N-30N BETWEEN 93W-98W...AS WELL AS IN THE NE GULF FROM 25N-30N BETWEEN 83W-88W. A MID TO UPPER LOW IS MOVING SLOWLY W THROUGH THE BAY OF CAMPECHE CENTERED NEAR 20N94W...THAT HAS ISOLATED SHOWERS/TSTMS MOVING AROUND ITS PERIPHERY. A CLUSTER OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION OVER THE YUCATAN SEEMS MORE ASSOCIATED WITH AFTERNOON HEATING...AND IS MOVING INTO THE EXTREME ERN BAY OF CAMPECHE. AT THE SURFACE...FAIRLY LIGHT SE FLOW DOMINATES MUCH OF THE GULF ON THE S/SW PORTION OF THE HIGH BUILDING OVER NEW ENGLAND. THE EXCEPTION IS LIGHT W/SW FLOW IN THE NW GULF AHEAD OF A STATIONARY FRONTAL BOUNDARY. THE CARIBBEAN SEA... OVERALL THE CARIBBEAN REMAINS FAIRLY QUIET THIS EVENING WITH ABUNDANT DRY AIR. AFTERNOON AND EVENING SHOWERS/TSTMS OVER CUBA...JAMAICA...AND HISPANIOLA ARE DRIFTING SOUTH INTO THE FAR NRN PORTION OF THE CARIBBEAN...WITH MID/UPPER LEVEL NRLY FLOW BETWEEN UPPER ANTICYCLONES OVER THE FAR NW CARIBBEAN AND SE GULF...AND UPPER TROUGHING EXTENDING THROUGH THE CTRL AND ERN CARIBBEAN BETWEEN 61W-75W. 10-20 KT TRADES PERSIST THIS EVENING AND WILL CONTINUE THROUGH TOMORROW...EXCEPT LIGHTER FAR NW CARIB. THE ATLANTIC OCEAN... ABUNDANT DRY MID TO UPPER LEVEL AIR OVER THE SW NORTH ATLC IS SEEN IN WV IMAGERY THIS EVENING...AND IS BEING ADVECTED SW/S BETWEEN AN UPPER ANTICYCLONE EXTENDING E FROM THE SE GULF...AND THE UPPER TROUGH EXTENDING NE THROUGH THE LEEWARD ISLANDS TO NEAR 25N BETWEEN 61W-72W. A LARGE FETCH OF N/NE WINDS PERSISTS OFF THE MID ATLC AND NE US COAST BETWEEN FLORENCE AND THE 1026MB HIGH BUILDING INTO NEW ENGLAND. ASSOCIATED MODERATE TO STRONG NE SWELL WILL CONTINUE TO PRODUCE DANGEROUS SURF CONDITIONS AT BEACHES EXPOSED TO NE SWELL OVER THE NEXT COUPLE OF DAYS...BEFORE SUBSIDING THROUGH THE WEEKEND. SEE STATEMENTS FROM LOCAL WEATHER SERVICE OFFICES FOR MORE DETAILS. GORDON CONTINUES TO STRENGTHEN AS DESCRIBED ABOVE. SE OF GORDON LIES AN UPPER ANTICYCLONE CENTERED NEAR 18N54W....AND NE OF GORDON IS AN UPPER LOW NEAR 30N44W. ISOLATED SHOWERS/TSTMS ARE SPINNING CYCLONICALLY AROUND THIS UPPER LOW WITHIN 150NM OF ANY SIDE OF THE CENTER. A MID TO UPPER HIGH IS OVER THE ERN ATLC OFF THE COAST OF AFRICA NEAR 25N28W. THIS REGION IS ALSO DOMINATED BY THE SRN PORTION OF A 1025MB SFC HIGH CENTERED ESE OF THE AZORES NEAR 36N37W. $$ WILLIS