000 AXNT20 KNHC 210010 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED SEP 20 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 2315 UTC. ...SPECIAL FEATURES... THE CENTER OF HURRICANE HELENE AT 20/2100 UTC IS NEAR 26.6N 57.1W. HELENE IS MOVING NORTHWEST AT 8 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 960 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 90 KT WITH GUSTS TO 110 KT. PLEASE READ THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC OR THE PUBLIC ADVISORY UNDER MIATCPAT3/WTNT33 KNHC FOR MORE DETAILS. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS NEAR THE CENTER FROM 24N-28N BETWEEN 54W-58W. A BAND WITH SCATTERED MODERATE CONVECTION IS W OF THE CENTER FROM 25N-31N BETWEEN 58W-60W. THE CENTER OF TROPICAL STORM GORDON AT 20/2100 UTC IS NEAR 39.2N 16.6W. GORDON IS MOVING EAST-NORTHEAST AT 30 KT. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 45 KT WITH GUSTS TO 55 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. PLEASE READ THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC OR THE PUBLIC ADVISORY UNDER MIATCPAT2/WTNT32 KNHC FOR MORE DETAILS. THE 2100 UTC BULLETINS WERE THE LAST OFFICIAL ADVISORIES ISSUED DUE TO GORDON BECOMING EXTRATROPICAL AND MERGING WITH A COLD FRONT. SCATTERED MODERATE CONVECTION IS FROM 39N-43N BETWEEN 10W-15W. ...TROPICAL WAVES... AN EASTERN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 29W SOUTH OF 18N MOVING WEST 10 TO 15 KT. SCATTERED MODERATE CONVECTION IS FROM 15N-18N BETWEEN 28W-31W. WIDELY SCATTERED MODERATE CONVECTION IS ALONG THE ITCZ FROM 10N-14N BETWEEN 22W-28W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WEST OF THE WAVE AXIS FROM 11N-17N BETWEEN 31W-35W. A CENTRAL ATLANTIC OCEAN TROPICAL WAVE IS ALONG 46W SOUTH OF 19N MOVING WEST 10 TO 15 KT. SCATTERED MODERATE SHOWERS ARE FROM 12N-16N BETWEEN 44W-47W. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 10N12W 12N25W 12N45W 9N50W 9N60W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS INLAND OVER W AFRICA FROM 10N-13N BETWEEN 10W-16W. ISOLATED MODERATE CONVECTION IS FROM 6N-10N BETWEEN 20W-22W...AND FROM 7N-11N BETWEEN 31W-35W. ...DISCUSSION... THE GULF OF MEXICO... A COLD FRONT EXTENDS FROM S FLORIDA TO THE W GULF OF MEXICO ALONG 27N80W 26N90W 26N95W...AND CONTINUES AS A STATIONARY FRONT TO S MEXICO NEAR 20N97W. ISOLATED MODERATE CONVECTION IS OVER S FLORIDA FROM 25N-27N BETWEEN 80W-81W. SIMILAR CONVECTION IS OFF THE COAST OF S TEXAS FROM 24N-27N BETWEEN 94W-97W. IN THE UPPER LEVELS... A TROUGH IS OVER THE E GULF OF MEXICO N OF 25N AND E OF 90W. AN UPPER LEVEL HIGH IS CENTERED OVER THE W GULF OF MEXICO NEAR 26N95W. EXPECT THE FRONT TO MOVE TO THE W ATLANTIC OVER THE NEXT 24 HOURS. A NEW SURFACE LOW IS ALSO FORECAST TO MOVE TO N TEXAS AND PRODUCE SLY SURFACE FLOW OVER THE W GULF OF MEXICO W OF 90W. SCATTERED SHOWERS ARE POSSIBLE OVER THE W GULF DURING THE NEXT 24 HOURS. THE CARIBBEAN SEA... A WEAK 1016 MB HIGH IS CENTERED OVER W CUBA NEAR 22N82W. SCATTERED MODERATE CONVECTION IS OVER INLAND HISPANIOLA FROM 18N-20N BETWEEN 70W-72W. SIMILAR CONVECTION IS ALONG THE COAST OF NICARAGUA FROM 12N-14N BETWEEN 80W-83W...AND OVER PANAMA FROM 6N-9N BETWEEN 80W-83W. PATCHES OF ISOLATED MODERATE CONVECTION IS INLAND OVER CENTRAL AMERICA FROM COSTA RICA TO GUATEMALA. IN THE UPPER LEVELS... AN UPPER LEVEL LOW IS CENTERED OVER THE CAYMAN ISLANDS NEAR 19N81W. AN UPPER LEVEL HIGH IS JUST E OVER THE CENTRAL CARIBBEAN NEAR 16N75W. THE E CARIBBEAN E OF 70W NELY FLOW WITH STRONG SUBSIDENCE. EXPECT MORE CONVECTION OVER THE W CARIBBEAN AND CENTRAL AMERICA OVER THE NEXT 24 HOURS. THE ATLANTIC OCEAN... A COLD FRONT IS OVER THE W ATLANTIC ALONG 32N73W 27N80W. SCATTERED MODERATE CONVECTION IS OVER THE N BAHAMAS FROM 26N-28N BETWEEN 79W-80W. ISOLATED MODERATE CONVECTION IS FROM 29N-31N BETWEEN 69W-74W. HURRICANE HELENE IS WELL SE OF BERMUDA NEAR 26.6N 57.1W. A COLD FRONT IS OVER THE CENTRAL ATLANTIC FROM 32N24W TO 31N30W 32N40W. SCATTERED SHOWERS ARE ALONG THE FRONT. IN THE UPPER LEVELS... IMPRESSIVE OUTFLOW IS OVER HURRICANE HELENE ESPECIALLY N OF THE CENTER. AN UPPER LEVEL LOW IS CENTERED NEAR 22N37W. A LARGE HIGH IS OVER THE E ATLANTIC CENTERED NEAR 20N24W. $$ FORMOSA