000 AXNT20 KNHC 241153 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI AUG 24 2012 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... THE CENTER OF TROPICAL STORM ISAAC AT 24/1200 UTC IS NEAR 16.0N 70.3W. THIS POSITION IS ABOUT 175 MI...280 KM SSW OF SANTO DOMINGO DOMINICAN REPUBLIC ABOUT 220 MI...355 KM SE OF PORT AU PRINCE HAITI. ISAAC IS MOVING WESTWARD 13 KNOTS.THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 45 KT WITH GUSTS TO 55 KT. PLEASE READ THE FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC AND THE PUBLIC ADVISORY...MIATCPAT4/WTNT34 KNHC FOR MORE DETAILS. CONVECTIVE PRECIPITATION...NUMEROUS STRONG IS WITHIN 240 NM OF THE CENTER IN THE SOUTHWESTERN QUADRANT AND WITHIN 240 TO 360 NM OF THE CENTER IN THE SOUTHEASTERN QUADRANT. BANDS OF RAINSHOWERS HAVE BEEN MOVING ACROSS PUERTO RICO AND HISPANIOLA DURING THE LATE NIGHT AND EARLY MORNING HOURS...EVEN SPREADING ACROSS NEARLY ALL THE BAHAMAS EXCEPT FOR POSSIBLY THE NORTHERNMOST ISLANDS BETWEEN 70W AND 80W. SCATTERED MODERATE TO STRONG CONVECTIVE PRECIPITATION EVEN COVERS EXTREME NORTHWESTERN VENEZUELA NEAR LAKE MARACAIBO AND POSSIBLY ACROSS THE BORDER INTO COLOMBIA. THE CENTER OF TROPICAL DEPRESSION JOYCE AT 24/0900 UTC IS NEAR 16.9N 45.0W...NORTHWESTWARD 12 KNOTS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 30 KT WITH GUSTS TO 40 KT. PLEASE READ THE FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC AND THE PUBLIC ADVISORY...MIATCPAT5/WTNT35 KNHC FOR MORE DETAILS. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG FROM 18.5N TO 22N BETWEEN 45W AND 48W. OTHER BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE RAINSHOWERS ARE FROM 16N TO 30N BETWEEN 43W AND 53W. A TROPICAL WAVE IS ALONG 19N19W 16N20W...TO A 1007 MB LOW PRESSURE CENTER THAT IS NEAR 14N21W IN THE MONSOON TROUGH. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG FROM 12N TO 16N BETWEEN 20W AND 26W. SOME DEVELOPMENT OF THIS WAVE IS POSSIBLE DURING THE NEXT COUPLE OF DAYS AS IT MOVES TO THE WEST OR WEST-NORTHWEST 13 KNOTS. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... THE ONLY TROPICAL WAVE IS LISTED NOW IN THE SPECIAL FEATURES SECTION. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH STARTS WITH THE 1007 MB LOW PRESSURE CENTER THAT IS NEAR 14N21W...AND IT CONTINUES TO 11N25W AND 11N29W. THE REST OF THE MONSOON TROUGH IS BROKEN UP BY T.D. JOYCE. THE ITCZ IS ALONG 6N TO 7N BETWEEN 46W AND 55W. CONVECTIVE PRECIPITATION...SCATTERED STRONG FROM 8N TO 11N BETWEEN 25W AND 31W...SCATTERED MODERATE TO ISOLATED STRONG FROM 10N TO 11N BETWEEN AFRICA AND 20W AND FROM 8N TO 10N BETWEEN 53W AND 58W... ISOLATED MODERATE ELSEWHERE TO THE SOUTH OF 10N TO THE EAST OF 60W. ...DISCUSSION... THE GULF OF MEXICO... A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH GEORGIA TO FLORIDA INTO THE FLORIDA KEYS. COMPARATIVELY DRY AIR IN SUBSIDENCE SURROUNDS THE TROUGH. NO SIGNIFICANT DEEP CONVECTIVE PRECIPITATION ACCOMPANIES THE TROUGH AT THIS MOMENT. ONE CELL OF SCATTERED TO NUMEROUS STRONG CONVECTIVE PRECIPITATION IS WITHIN A 30 NM RADIUS OF 13N93W IN THE SOUTHWESTERN CORNER OF THE AREA. SURFACE ANTICYCLONIC WIND FLOW COVERS THE AREA. A RIDGE EXTENDS FROM A 1019 MB HIGH PRESSURE CENTER THAT IS NEAR 29N86W...INTO THE SOUTHWESTERN CORNER OF THE AREA NEAR 21N97W ALONG THE MEXICO COAST. FROM THE WEST CENTRAL ATLANTIC OCEAN...INTO THE WESTERN HALF OF THE CARIBBEAN SEA... A MIDDLE LEVEL TO UPPER LEVEL INVERTED TROUGH IS ALONG 32N72W 29N75W...OVER ANDROS ISLAND IN THE BAHAMAS...ACROSS SOUTHEASTERN CUBA INTO THE WATERS THAT ARE BETWEEN HAITI...CUBA...AND JAMAICA. ISOLATED MODERATE CONVECTIVE PRECIPITATION IS IN THE CARIBBEAN SEA FROM 18N TO 21N BETWEEN 80W AND THE YUCATAN CHANNEL. AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 34N64W. SCATTERED MODERATE CONVECTIVE PRECIPITATION IS FROM 28N TO 33N BETWEEN 65W AND 70W. THE REST OF THE CARIBBEAN SEA... THE MONSOON TROUGH IS ALONG 11N75W IN COASTAL COLOMBIA... TO 12N80W IN THE SOUTHWESTERN CORNER OF THE AREA...BEYOND 12N87W IN NICARAGUA. NUMEROUS STRONG CONVECTIVE PRECIPITATION IS ALONG THE EASTERN PACIFIC OCEAN COAST OF CENTRAL AMERICA FROM NORTHWESTERN COSTA RICA TO EL SALVADOR...AND ALSO A SEPARATE AREA IS IN THE GULF OF TEHUANTEPEC OF MEXICO. THE PRECIPITATION IS OCCURRING IN AN AREA OF BROAD SURFACE LOW PRESSURE AND UPPER LEVEL DIFFLUENT WIND FLOW. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR MORE DETAILS ABOUT TROPICAL STORM ISAAC. A SECOND AREA OF 20 TO 25 KNOT WINDS AND 8 TO 9 FOOT SEA HEIGHTS IS FROM 13N TO 18N BETWEEN 64W AND 71W. THE REST OF THE ATLANTIC OCEAN... A MIDDLE LEVEL TO UPPER LEVEL INVERTED TROUGH IS ALONG 32N55W TO 27N56W...TO A 22N52W CYCLONIC CIRCULATION CENTER. WIDELY SCATTERED TO SCATTERED MODERATE CONVECTIVE PRECIPITATION COVERS THE ATLANTIC OCEAN FROM 20N TO 36N BETWEEN 50W AND 62W. AN UPPER LEVEL TROUGH EXTENDS FROM A 31N22W CYCLONIC CIRCULATION CENTER TO 24N23W AND 17N28W. NO SIGNIFICANT DEEP CONVECTIVE PRECIPITATION. A SURFACE RIDGE EXTENDS FROM A 1018 MB HIGH CENTER THAT IS NEAR 35N18W TO A 1022 MB HIGH PRESSURE CENTER THAT IS NEAR 33N36W... TO A SECOND 1022 MB HIGH PRESSURE CENTER THAT IS NEAR 34N45W. A SURFACE TROUGH PASSES THROUGH 34N55W TO 31N59W. A SURFACE RIDGE ALSO PASSES OVER BERMUDA TO 30N76W...ACROSS FLORIDA NEAR 29N82W...INTO THE CENTRAL GULF OF MEXICO. PLEASE READ THE HIGH SEAS FORECASTS...MIAHSFAT2...FOR DETAILS ABOUT TROPICAL DEPRESSION JOYCE...AND A 1009 MB LOW PRESSURE CENTER...POSSIBLE TROPICAL CYCLONE NEAR 18N33W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT