000 AXNT20 KNHC 221207 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...SPECIAL FEATURES... HURRICANE IRENE IS NEAR 18.8N 66.8W AT 1200 UTC AUG 22 OR ABOUT 55 MI...90 KM WNW OF SAN JUAN PUERTO RICO...OR ABOUT 105 MI...165 KM E OF PUNTA CANA DOMINICAN REPUBLIC MOVING WNW AT 13 KT. MINIMUM CENTRAL PRESSURE IS 987 MB. MAXIMUM SUSTAINED WIND SPEED IS 65 KT WITH GUSTS 80 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. SCATTERED STRONG CONVECTION IS OVER PUERTO RICO AND SURROUNDING WATERS FROM 17N-23N BETWEEN 62W-68W. IRENE IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS OF 5 TO 10 INCHES ACROSS PUERTO RICO...THE VIRGIN ISLANDS...THE DOMINICAN REPUBLIC...HAITI...THE SOUTHEASTERN BAHAMAS AND THE TURKS AND CAICOS ISLANDS. ISOLATED MAXIMUM AMOUNTS OF UP TO 20 INCHES ARE POSSIBLE. THESE RAINS COULD CAUSE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES IN AREAS OF STEEP TERRAIN. TROPICAL DEPRESSION HARVEY IS INLAND OVER MEXICO NEAR 18.4N 96.0W AT 0500 UTC AUG 22 OR ABOUT 90 KM SSE OF VERACRUZ MEXICO. HARVEY IS MOVING WNW AT 10 KT. MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT GUSTS 40 KT. PLEASE SEE THE LATEST INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADER MIATCPAT3/WTNT33 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADER MIATCMAT3/ WTNT23 KNHC FOR MORE DETAILS. ALTHOUGH MOST OF THE CONVECTION IS INLAND...SCATTERED MODERATE TO STRONG CONVECTION LINGERS OVER THE BAY OF CAMPECHE S OF 23N W OF 92W. HARVEY IS EXPECTED TO PRODUCE ADDITIONAL RAINFALL ACCUMULATIONS OF 2 TO 4 INCHES OVER PORTIONS OF THE MEXICAN STATES OF VERACRUZ...OAXACA...HIDALGO ...PUEBLA...AND TIAXCALA...WITH ISOLATED MAXIMUM STORM TOTAL AMOUNTS OF 10 INCHES. THESE RAINS COULD PRODUCE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES...ESPECIALLY IN AREAS OF STEEP TERRAIN. THE DEPRESSION IS FORECAST TO DISSIPATE BY MONDAY NIGHT. ...THE ITCZ/THE MONSOON TROUGH... A 1010 MB LOW IS NEAR 20N31W. THIS LOW MOVING NW OVER COOLER WATERS. AS THE SYSTEM TRACKS NW IT WILL BUILD A TIGHT PRESSURE GRADIENT BETWEEN THE BROAD SURFACE RIDGE AND THE SURFACE LOW THAT COULD GENERATE GUSTY WINDS TO NEAR GALE FORCE CRITERIA DURING THE FORECAST PERIOD. THIS SYSTEM HAS ALSO CAUSED THE MONSOON TROUGH OVER THE ATLC WATERS TO WEAKEN AND BECOME DIFFUSE. AS THE BROAD CYCLONIC WIND FIELD ASSOCIATED TO HURRICANE IRENE CONTINUES TO MOVE WNW...THE CONVERGENCE OF NE AND SE TRADE WINDS SLOWLY REBUILDS BEHIND...THUS THE ITCZ CAN BE DEPICTED FROM 11N42W TO 11N50W. THE MONSOON TROUGH IS ANALYZED INLAND OVER WEST AFRICA ENTERING THE ATLC NEAR 18N16W TO THE CAPE VERDE ISLANDS NEAR 16N23W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 120 NM S OF THE ITCZ. SIMILAR CONVECTION IS MOVING OFF THE AFRICAN COAST OF GUINEA...GUINEA-BISSAU...THE GAMBIA...AND SENEGAL FROM 8N-15N E OF 20W ASSOCIATED TO A SURFACE LOW INLAND OVER SENEGAL NEAR 15N14W. THIS LOW WILL BE CLOSELY MONITORED FOR FUTURE DEVELOPMENT AS IT MOVES OFFSHORE OVERNIGHT MON NIGHT. ...DISCUSSION... GULF OF MEXICO... TROPICAL DEPRESSION HARVEY IS INLAND OVER MEXICO. ALTHOUGH MOST OF THE CONVECTION IS INLAND...SCATTERED MODERATE TO STRONG CONVECTION LINGERS OVER THE BAY OF CAMPECHE S OF 23N W OF 92W. FOR MORE INFORMATION SEE SPECIAL FEATURES ABOVE. ELSEWHERE ACROSS THE DISCUSSION AREA...UPPER LEVEL EASTERLY FLOW COVERS THE GULF...ON THE SOUTH SIDE OF THE BROAD UPPER OMEGA RIDGE SETTLED ACROSS THE CONUS. WEAK SURFACE RIDGING DOMINATES THE GULF THIS MORNING...WITH WIDELY SCATTERED WEAK SHOWERS EMBEDDED IN THE EASTERLY FLOW INCLUDING ACROSS THE STRAITS OF FLORIDA. CARIBBEAN SEA... THE PRIMARY CONCERN THIS MORNING IS HURRICANE IRENE MOVING OFF THE NORTHERN COAST OF PUERTO RICO. FOR MORE INFORMATION SEE SPECIAL FEATURES ABOVE. OTHERWISE...WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS REMAIN OVER THE SW BASIN S OF 15N W OF 75W DUE TO THE MONSOON TROUGH EXTENDING INLAND ACROSS COSTA RICA TO NORTHERN COLOMBIA. THE REMAINDER OF THE CARIBBEAN IS UNDER MOSTLY CLEAR SKIES WITH A FEW ISOLATED SHOWERS EMBEDDED IN THE 5-15 KT EASTERLY TRADE WIND FLOW. TROPICAL STORM CONDITIONS ARE EXPECTED TO DIMINISH IN THE CARIBBEAN LATE TODAY AS IRENE TRACKS WNW THROUGH THE NORTHERN PORTION OF HISPANIOLA AND INTO THE SW NORTH ATLANTIC. ATLANTIC OCEAN... THE PRIMARY CONCERN THIS MORNING IS HURRICANE IRENE MOVING OFF THE NORTHERN COAST OF PUERTO RICO. SYMMETRIC CONVECTIVE OUTFLOW FROM IRENE IS NOTICED ON SATELLITE INFRA RED IMAGERY EXTENDING INTO THE ATLANTIC TO NEAR 500 NM NE OF THE CENTER. SEE SPECIAL FEATURES ABOVE FOR MORE INFORMATION ON IRENE. OTHERWISE...THE REMAINDER OF THE ATLC BASIN IS DOMINATED BY A BROAD SURFACE RIDGE ANCHORED BY A 1026 MB HIGH W OF THE AZORES NEAR 37N33W...LEAVING THE REMAINDER OF THE DISCUSSION AREA UNDER FAIR CONDITIONS THIS MORNING. SOUTH OF THE RIDGE LIES A LOW PRES CENTER NEAR 20N31W. THIS LOW IS EMBEDDED IN DRY AIR AND AFRICAN DUST THAT IS INHIBITING DEEP CONVECTION. THIS LOW IS FORECAST TO MOVE NW OVER COOLER WATERS TO THE CENTRAL ATLANTIC OVER THE NEXT SEVERAL DAYS. AS THE SYSTEM TRACKS NW IT WILL BUILD A TIGHT PRESSURE GRADIENT BETWEEN THE BROAD SURFACE RIDGE AND THE SURFACE LOW THAT COULD GENERATE GUSTY WINDS TO NEAR GALE FORCE CRITERIA DURING THE FORECAST PERIOD. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA