000 AXNT20 KNHC 220600 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0545 UTC. ...SPECIAL FEATURES... TROPICAL STORM IRENE NEAR 18.0N 65.7W AT 0500 UTC AUG 22 OR ABOUT 35 MI...55 KM SE OF SAN JUAN PUERTO RICO. IRENE IS MOVING MOVING WNW AT 13 KT. MINIMUM CENTRAL PRESSURE IS 989 MB. MAXIMUM SUSTAINED WIND SPEED IS 60 KT WITH GUSTS 75 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. SOME STRENGTHENING IS STILL POSSIBLE THIS MORNING...AND IRENE COULD BECOME A HURRICANE BEFORE MOVING OVER PUERTO RICO IN THE NEXT COUPLE OF HOURS. 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. SOME WEAKENING IS EXPECTED THIS AFTERNOON AND TONIGHT AS THE CENTER MOVES NEAR OR OVER THE DOMINICAN REPUBLIC. SOME RESTRENGTHENING IS EXPECTED LATE TUESDAY AFTER THE CENTER MOVES BACK OVER WATER. TROPICAL DEPRESSION HARVEY NEAR 19.0N 95.9W AT 0500 UTC AUG 22 OR ABOUT 20 MI...35 KM ESE 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. SCATTERED MODERATE TO STRONG CONVECTION IS OVER SOUTHERN MEXICO AND THE BAY OF CAMPECHE S OF 22N E OF 90W. 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 1011 MB LOW IS EMBEDDED IN THE MONSOON TROUGH NEAR 19N30W. THIS LOW IS FORECAST TO MOVE NW OVER COOLER WATERS TO THE CENTRAL ATLANTIC OVER THE NEXT SEVERAL DAYS. HOWEVER...AS THE SYSTEM TRACKS NW IT WILL BUILD A TIGHT PRESSURE GRADIENT BETWEEN THE BROAD RIDGE AND THE SURFACE LOW THAT COULD GENERATE GUSTY WINDS TO NEAR GALE FORCE CRITERIA DURING THE FORECAST PERIOD. THE FLOW AROUND THE EAST SIDE OF THE LOW HAS BECOME THE DOMINANT FEATURE IN THE AREA. THIS HAS CAUSED THE THE MONSOON TROUGH TO SPLIT BETWEEN THE LOW AND THE AFRICAN COAST. DUE TO THE BROAD CYCLONIC WIND FIELD ASSOCIATED TO T.S. IRENE IN THE SPECIAL FEATURES AND THE MONSOON TROUGH...THERE IS NO CONVERGENCE OF NE AND SE TRADE WINDS...THUS THERE IS NO ITCZ DEPICTED ON THE SURFACE ANALYSIS. THE MONSOON TROUGH IS ANALYZED FROM THE LOW PRESSURE SYSTEM NEAR 19N30W SSW ALONG 12N32W TO 8N40W..THEN W TO NEAR 9N51W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 120 NM ON EITHER SIDE OF THE MONSOON TROUGH AND THE LOW. SIMILAR CONVECTION IS MOVING OFF THE AFRICAN COAST OF GUINEA...GUINEA-BISSAU...THE GAMBIA...AND SENEGAL FROM 9N-15N ASSOCIATED TO A SURFACE LOW ALONG THE MONSOON TROUGH INLAND OVER SENEGAL NEAR 15N13W. THIS LOW WILL BE CLOSELY MONITORED FOR FUTURE DEVELOPMENT AS IT MOVES OFFSHORE OVERNIGHT MON NIGHT. ...DISCUSSION... GULF OF MEXICO... THE MAIN CONCERN OVER THE GULF TONIGHT IS T.D. HARVEY MOVING ACROSS THE WARM WATERS OF THE BAY OF CAMPECHE HEADING TOWARD THE COAST OF VERACRUZ MEXICO. 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. HOWEVER...A WEAK SURFACE TROUGH IS ANALYZED FROM 29N86W TO 25N89W. OTHER THAN A SLIGHT CYCLONIC CURVATURE ALONG THE AXIS...NO CONVECTION IS OBSERVED. THIS TROUGH WILL GRADUALLY DIMINISH THROUGH MONDAY. WIDELY SCATTERED SHOWERS ARE OVER THE SE BASIN INCLUDING THE STRAITS OF FLORIDA S OF 26N E OF 84W. HARVEY IS FORECAST TO BRIEFLY BECOME A MINIMAL TROPICAL STORM BEFORE MAKING LANDFALL MON MORNING AND THEN DIMINISH TO A REMNANT LOW OVER CENTRAL MEXICO BY EARLY TUE. CARIBBEAN SEA... THE PRIMARY CONCERN THIS MORNING IS T.S. IRENE MOVING OVER THE ISLAND OF PUERTO RICO. FOR MORE INFORMATION SEE SPECIAL FEATURES ABOVE. OTHERWISE...WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS REMAIN OVER THE WRN AND NW BASIN W OF 78W. THE ACTIVITY IN THE SW IS 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 MON OR EARLY TUE AS IRENE TRACKS THROUGH THE NORTHERN PORTION OF HISPANIOLA AND INTO THE SW NORTH ATLANTIC. ATLANTIC OCEAN... THE PRIMARY CONCERN THIS EVENING IS T.S. IRENE MOVING OVER THE ISLAND 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 1027 MB HIGH W OF THE AZORES NEAR 37N33W...LEAVING THE REMAINDER OF THE DISCUSSION AREA UNDER FAIR CONDITIONS THIS EVENING. SOUTH OF THE RIDGE LIES A LOW PRES CENTER NEAR 19N30W ASSOCIATED WITH THE MONSOON TROUGH. 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. THE MOST RECENT FORECAST CARRIES IRENE INTO THE EASTERN DOMINICAN REPUBLIC BEFORE PASSING OVER THE NORTH PORTION OF HISPANIOLA ON MONDAY AND BETWEEN EASTERN CUBA AND GREAT INAGUA ISLAND BY TUESDAY EVENING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA