000 AXNT20 KNHC 301757 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT SEP 30 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 1715 UTC. ...SPECIAL FEATURES... THE CENTER OF HURRICANE ISAAC AT 30/1500 UTC IS NEAR 30.9N 58.7W MOVING NORTHWEST AT 6 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 992 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 65 KT WITH GUSTS TO 80 KT. PLEASE READ THE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC AND THE PUBLIC ADVISORY UNDER MIATCPAT4/WTNT34 KNHC FOR MORE DETAILS. ISAAC HAS A RAGGED EYE WITH A DIAMETER OF 25 NM. CONVECTION IS MOSTLY N OF THE CENTER. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 30N-33N BETWEEN 57W-60W. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 33W SOUTH OF 20N MOVING WEST 10 KT. A CYCLONIC TURNING IS SEEN AT LOW LEVELS. SCATTERED MODERATE CONVECTION IS OVER THE NORTHERN END OF THE WAVE AXIS FROM 21N-23N BETWEEN 31W-33W. TROPICAL WAVE IS OVER THE E CARIBBEAN ALONG 61W SOUTH OF 16N MOVING WEST 10 KT. WIDELY SCATTERED MODERATE CONVECTION IS MAINLY OVER THE WINDWARD ISLANDS FROM 11N-13N BETWEEN 60W-65W. A TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN ALONG 70W MOVING WEST AT 10-15 KT. THIS WAVE ALSO EXTENDS NE INTO THE W ATLANTIC TO 24N65W. AN AREA OF SCATTERED MODERATE CONVECTION IS S OF HISPANIOLA FROM 15N-17N BETWEEN 69W-71W. A TROPICAL WAVE IS INLAND OVER S MEXICO AND THE E PACIFIC ALONG 93W/94W MOVING WEST 15 KT. CONVECTION IS CONFINED TO THE PACIFIC COAST OVER THE GULF OF TEHUANTEPEC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 11N15W 10N20W 11N30W 10N40W 12N60W. OUTSIDE THE CONVECTION MENTIONED IN THE TROPICAL WAVE SECTION... ISOLATED MODERATE CONVECTION IS FROM 2N-9N BETWEEN 16W-30W. ...DISCUSSION... THE GULF OF MEXICO... THE TAIL END OF A COLD FRONT IS OVER S FLORIDA MOVING E. SCATTERED SHOWERS REMAIN OVER THE STRAITS OF FLORIDA FROM 23N-25N BETWEEN 80W-83W. HIGH PRESSURE RIDGING IS OVER THE REMAINDER OF THE GULF OF MEXICO WITH FAIR WEATHER. IN THE UPPER LEVELS... THE BASE OF A LONGWAVE TROUGH IS OVER THE GULF OF MEXICO MOVING E. EXPECT CONTINUED SURFACE RIDGING AND FAIR WEATHER FOR THE NEXT 24 HOURS. THE CARIBBEAN SEA... TWO TROPICAL WAVE ARE OVER THE CARIBBEAN...SEE ABOVE. MODERATE TRADEWINDS ARE TRAVERSING THE CARIBBEAN SEA. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS ALONG THE COASTS OF PANAMA AND COSTA RICA FROM 8N-12N BETWEEN 75W-84W. ISOLATED MODERATE CONVECTION IS ALONG THE COAST OF W CUBA FROM 20N-22N BETWEEN 80W-83W. IN THE UPPER LEVELS... NW FLOW IS OVER THE W CARIBBEAN SEA DUE TO UPPER LEVEL RIDGING W OF 77W. A LOW IS CENTERED S OF HISPANIOLA NEAR 16N69W. CYCLONIC FLOW IS FROM 10N-25N BETWEEN 60W-77W. EXPECT THE TROPICAL WAVES TO MOVE W WITH CONVECTION. THE ATLANTIC OCEAN... A COLD FRONT IS OVER THE W ATLANTIC AND EXTENDS SW TO S FLORIDA ALONG 32N69W 29N73W 26N80W. A PREFRONTAL TROUGH IS OVER THE BAHAMAS AND CUBA FROM 26N74W 20N80W. PATCHES OF SCATTERED MODERATE CONVECTION EXTENDS FROM 22N-29N BETWEEN 72W-80W. A 1020 MB HIGH IS OVER THE E ATLANTIC NEAR 31N25W. IN THE UPPER LEVELS... AN UPPER LEVEL LOW IS W OF HURRICANE ISAAC NEAR 30N64W. A RIDGE IS ALONG 55W. A LARGE UPPER LEVEL LOW IS OVER THE E ATLANTIC NEAR 20N45W. CYCLONIC FLOW IS FROM 10N-25N BETWEEN 35W-55W. ANOTHER UPPER LEVEL LOW IS CENTERED NEAR 25N30W. A LARGE UPPER LEVEL HIGH IS CENTERED ALONG THE COAST OF W AFRICA NEAR 14N20W. ANTICYCLONIC FLOW IS FROM 5N-25N BETWEEN 5W-28W. $$ FORMOSA