000 AXNT20 KNHC 221800 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON AUG 22 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURE... HURRICANE IRENE IS NEAR 19.3N 68.1W AT 1800 UTC AUG 22 OR ABOUT 150 MI...240 KM WNW OF SAN JUAN PUERTO RICO...OR ABOUT 50 MI... 80 KM NNE OF PUNTA CANA DOMINICAN REPUBLIC MOVING WNW AT 11 KT. MINIMUM CENTRAL PRESSURE IS 989 MB. MAXIMUM SUSTAINED WIND SPEED IS 70 KT WITH GUSTS 85 KT. PLEASE SEE THE LATEST INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADER MIATCPAT4/ WTNT34 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADER MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. CLUSTERS OF SCATTERED MODERATE TO STRONG CONVECTION ARE MOSTLY N OF PUERTO RICO FROM 18N-23N BETWEEN 62W-70W. HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 30 MILES...45 KM...FROM THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 185 MILES...295 KM TO THE NORTHEAST OF THE CENTER. HURRICANE WARNINGS ARE IN EFFECT FOR THE NORTH COAST OF THE DOMINICAN REPUBLIC...THE SOUTHEASTERN BAHAMAS... AND THE TURKS AND CAICOS ISLANDS. ...TROPICAL WAVES... A 1008 MB LOW IS CENTERED OVER W AFRICA NEAR 16N15W. A TROPICAL WAVE WITH A MID LEVEL CIRCULATION IS FURTHER SW NEAR 13N17W. THIS SYSTEM WILL BE CLOSELY MONITORED FOR FUTURE DEVELOPMENT AS IT MOVES OFFSHORE TODAY. ...THE ITCZ/THE MONSOON TROUGH... A 1010 MB LOW IS OVER THE E ATLANTIC NEAR 21N32W. THIS LOW IS MOVING NW OVER COOLER WATERS. GUSTY WINDS TO 30 KT ARE FORECAST FOR THE FORECAST PERIOD NEAR THIS LOW. THIS SYSTEM HAS CAUSED THE MONSOON TROUGH OVER THE ATLC WATERS TO WEAKEN AND BECOME DIFFUSE. FURTHER W...HURRICANE IRENE CONTINUES TO MOVE WNW. THE CONVERGENCE OF NE AND SE TRADE WINDS HAVE SLOWLY RETURNED OVER THE CENTRAL TROPICAL ATLANTIC BETWEEN THE TWO SYSTEMS...THUS THE ITCZ IS DEPICTED FROM 12N37W TO 12N56W. THE MONSOON TROUGH IS ANALYZED INLAND OVER WEST AFRICA NE OF 14N17W. WIDELY SCATTERED MODERATE CONVECTION IS OFF THE COAST OF WEST AFRICA FROM 8N-13N BETWEEN 19W-24W. SCATTERED MODERATE CONVECTION IS NE OF THE 1010 MB LOW FROM 21N-24N BETWEEN 29W-32W. ISOLATED MODERATE CONVECTION IS S OF THE ITCZ FROM 5N-11N BETWEEN 40W-52W. ...DISCUSSION... GULF OF MEXICO... WEAK SURFACE RIDGING IS OVER THE GULF OF MEXICO. FURTHER N... A WEAK COLD FRONT IS OVER THE NORTH GULF STATES FROM CENTRAL GEORGIA TO NE TEXAS. RADAR IMAGERY SHOWS SCATTERED SHOWERS OVER THE N GULF OF MEXICO N OF 28N E OF 93W. ELSEWHERE...WIDELY SCATTERED MODERATE CONVECTION IS OVER THE W GULF NEAR TAMPICO MEXICO FROM 20N-24N BETWEEN 93W-98W. IN THE UPPER LEVELS...AN UPPER LEVEL HIGH IS OVER CENTRAL TEXAS PRODUCING NE UPPER LEVEL WINDS OVER THE GULF. EXPECT IN 24 HOURS FOR A SURFACE TROUGH TO BE OVER N FLORIDA WITH SHOWERS. ALSO EXPECT MORE CONVECTION TO ADVECT OVER THE SOUTHERN GULF S OF 24N...AND ADDITIONAL TROPICAL MOISTURE AND CONVECTION TO ADVECT OVER THE STRAITS OF FLORIDA AND S FLORIDA. CARIBBEAN SEA... HURRICANE IRENE IS CENTERED N OF PUERTO RICO PRODUCING CONVECTION FROM THE LEEWARD ISLAND TO HISPANIOLA. SEE ABOVE. ELSEWHERE...WIDELY SCATTERED MODERATE CONVECTION IS OVER THE SW CARIBBEAN FROM 9N-12N BETWEEN 76W-83W DUE TO THE MONSOON TROUGH EXTENDING FROM NORTHERN COLOMBIA TO COSTA RICA. MOSTLY FAIR WEATHER IS OVER THE REMAINDER OF THE AREA. ATLANTIC OCEAN... HURRICANE IRENE IS FORECAST TO MOVE WNW AND BE IN THE VICINITY OF THE TURKS AND CAICOS ISLANDS IN 24 HOURS. SEE ABOVE. A 1027 MB HIGH IS OVER THE CENTRAL ATLANTIC NEAR 37N32W. A SURFACE RIDGE AXIS EXTENDS SW FROM THE HIGH TO 32N60W TO 29N80W PRODUCING MOSTLY FAIR WEATHER. AN AREA OF AFRICAN DUST AND DRY AIR ARE OVER THE E ATLANTIC FROM 15N-30N E OF 35W HAMPERING THE 1010 MB SURFACE LOW NEAR 21N32W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORMOSA