000 AXNT20 KNHC 160003 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU SEP 15 2011 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND 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... TROPICAL STORM MARIA WAS UPGRADED TO HURRICANE STATUS AT 15/2100 UTC. MARIA IS CENTERED NEAR 36.8N 65.0W AT 16/0000 UTC OR ABOUT 915 MI...1475 KM SW OF CAPE RACE NEWFOUNDLAND MOVING N-NE AT 35 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 987 MB. MAXIMUM SUSTAINED WIND SPEED IS 65 KT WITH GUSTS TO 80 KT. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 34N-40N BETWEEN 61W-68W. THE HURRICANE IS EXPECTED TO TURN TO THE NORTHEAST AND MOVE 45 KT OR FASTER ON FRIDAY AS IT GET CAUGHT IN VERY STRONG SOUTHWESTERLY FLOW AHEAD OF A LARGE TROUGH OVER THE NORTHEASTERN UNITED STATES. THE GLOBAL MODEL GUIDANCE CONTINUES TO SHIFT TO THE NORTHWEST CLOSE TO NEWFOUNDLAND IN 24 HOURS.SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT4/ WTNT34 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST OF MAURITANIA NEAR 16N17W ALONG 12N21W TO A WEAK 1011 MB LOW NEAR 11N28W TO ANOTHER 1011 MB LOW NEAR 9N35W TO NEAR 7N45W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 7N45W TO 8N56W. WHILE THE ITCZ REMAINS INACTIVE...THE LARGE AND STRETCHED OUT MONSOON GYRE IS PRODUCING WIDELY SCATTERED MODERATE TO ISOLATED STRONG CONVECTION FROM 3N-12N E OF 40W. ...DISCUSSION... GULF OF MEXICO... SATELLITE VISIBLE IMAGERY SHOWS MOSTLY CLEAR SKIES WITH A FEW ISOLATED WEAK SHOWERS...MOVING WITH THE LIGHT ANTICYCLONIC FLOW PRESENT ACROSS THE BASIN. WATER VAPOR IMAGERY SHOWS A LARGE RIDGE OF HIGH PRESSURE CENTERED OVER EAST-CENTRAL MEXICO REGION ...PROVIDING MUCH OF THE GULF WITH MIDDLE TO UPPER LEVEL DRY AIR AND SUBSIDENCE. AN COLD FRONT CURRENTLY ANALYZED INLAND ACROSS THE GULF COASTAL PLAINS WILL INTRODUCE LIMITED CONVECTION AND A MILDER AIRMASS TO THE NORTH-CENTRAL AND NE GULF WATERS THROUGH EARLY SATURDAY. CARIBBEAN SEA... BROAD SURFACE CYCLONIC FLOW BETWEEN 72W-84W IS GENERATING ISOLATED SHOWERS AND THUNDERSTORMS ACROSS THIS AREA. WITHIN THIS AREA OF WEAK SCATTERED CONVECTION...MOST OF THE ACTIVITY IS FOCUSED S OF 15N WHERE THE MONSOON TROUGH IS ANALYZED OVER THE FAR SW BASIN EXTENDING INLAND ACROSS COSTA RICO...PANAMA...AND NORTHERN COLOMBIA. WATER VAPOR IMAGERY SHOWS A BROAD UPPER LEVEL CYCLONIC CIRCULATION NE OF THE LESSER ANTILLES. THIS FEATURE IS ENHANCING AN AREA OF SCATTERED MODERATE TO STRONG CONVECTION ENTERING THE SE CARIBBEAN S OF 15N E OF 64W. AS THE SYSTEM CONTINUES TO MOVE WESTWARD...A SURFACE TROUGH MAY DEVELOP OVER THE SE AND S CENTRAL CARIBBEAN WATERS DURING THE NEXT 12-24 HOURS. THE REMAINDER OF THE BASIN REMAINS UNDER FAIR WEATHER CONDITIONS. COMPUTER MODELS SUGGEST THE MONSOON TROUGH OVER THE SW BASIN WILL LIFT N OVER THE NEXT 24-36...HOURS WITH INCREASING CONVECTION OVER THIS REGION AND INLAND PORTIONS OF CENTRAL AMERICA. ATLANTIC OCEAN... HURRICANE MARIA IS TRACKING QUICKLY N-NE ACROSS THE HIGH SEAS WATERS OF THE WESTERN ATLC THIS EVENING...INFLUENCED BY AN UPPER LEVEL TROUGH TO ITS WEST. WATER VAPOR AND TOTAL PRECIPITABLE WATER IMAGERY INDICATE A DEEP LAYER OF DRY AIR AND SUBSIDENCE W OF 74W...MAINTAINING FAIR WEATHER CONDITIONS W OF MAINTAINING MOSTLY FAIR SKIES W OF THIS LONGITUDE INCLUDING THE WATERS NEAR THE BAHAMAS AND THE FLORIDA PENINSULA. AN OUTER BAND ASSOCIATED TO MARIA EXTENDS WELL S INTO THE DISCUSSION AREA. THIS BAND IS ANALYZED AS A LOW-LEVEL CONVERGENCE BOUNDARY/SURFACE TROUGH ALONG 31N70W TO 25N73W GENERATING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 70 NM ON EITHER SIDE OF THE AXIS. FARTHER SE...A BROAD UPPER LEVEL CYCLONIC CIRCULATION IS CENTERED NEAR 20N57W. THIS FEATURE IS PROVIDING DIVERGENCE FLOW ALOFT TO THE SE ENHANCING AN AREA OF SCATTERED MODERATE TO STRONG CONVECTION FROM 10N-15N BETWEEN 50W-64W. THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A BROAD SURFACE RIDGE N OF THE AREA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA