000 AXNT20 KNHC 240603 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... THE CENTER OF TROPICAL STORM ISAAC AT 24/0600 UTC IS NEAR 16.7N 68.7W...MOVING WEST-NORTHWESTWARD 16 KNOTS. THIS POSITION IS ABOUT 225 NM/360 KM ESE OF SAN JUAN PUERTO RICO... OR ABOUT 315 MI...505 KM ESE OF ISLA SAONA DOMINICAN REPUBLIC. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1001 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 40 KT WITH GUSTS TO 50 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 WITHIN 280 NM OF THE CENTER IN THE SOUTHWESTERN QUADRANT AND WITHIN 150 TO 300 NM OF THE CENTER IN THE EASTERN QUADRANT. BANDS OF RAINSHOWERS ARE MOVING ACROSS PUERTO RICO REACHING THE ATLANTIC OCEAN NEAR 21N BETWEEN 64W AND 70W. SIMILAR PRECIPITATION ALSO IS REACHING THE DOMINICAN REPUBLIC FROM EAST TO WEST. UPPER LEVEL NORTHEASTERLY TO EASTERLY WIND FLOW THAT IS AWAY FROM THE ISAAC CIRCULATION IS MOVING ACROSS COLOMBIA...SHEARING SOME OF THE CLOUD TOPS IN PRECIPITATION THAT IS RELATED TO THE MONSOON TROUGH. STRONG CONVECTIVE PRECIPITATION THAT WAS IN NORTHERN VENEZUELA FROM 9N TO 11N BETWEEN 67W AND 70W AT 24/0000 UTC...HAS WEAKENED AS CLOUD TOP TEMPERATURES HAVE BEEN WARMING WITH TIME. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE RAINSHOWERS ARE WITHIN 150 NM ON EITHER SIDE OF 20N68W 24N73W 28N72W...TO THE EAST OF THE INVERTED TROUGH AND IN THE AREA OF UPPER LEVEL ANTICYCLONIC WIND FLOW THAT IS MOVING AWAY FROM THE TROPICAL STORM. THE CENTER OF TROPICAL DEPRESSION JOYCE AT 24/0300 UTC IS NEAR 16.3N 43.7W...MOVING WEST-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...BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE RAINSHOWERS COVER THE ATLANTIC OCEAN FROM 17N TO 26N BETWEEN 41W AND 51W. A TROPICAL WAVE IS ALONG 19N18W 16N20W...TO A 1009 MB LOW PRESSURE CENTER THAT IS NEAR 14N21W IN THE MONSOON TROUGH. ISOLATED MODERATE TO LOCALLY STRONG CONVECTIVE PRECIPITATION IS FROM 10N TO 17N BETWEEN 20W AND 25W. 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 1009 MB LOW PRESSURE CENTER THAT IS NEAR 14N21W...AND IT CONTINUES TO 11N26W AND 14N34W. THE REST OF THE MONSOON TROUGH IS BROKEN UP BY T.D. JOYCE. THE ITCZ IS ALONG 11N49W 10N53W 10N56W. CONVECTIVE PRECIPITATION...SCATTERED STRONG ALONG THE AFRICA COAST FROM 10N TO 11N BETWEEN LAND AND 17W...SCATTERED MODERATE TO STRONG FROM 8N TO 11N BETWEEN 24W AND 27W...ISOLATED MODERATE ELSEWHERE TO THE SOUTH OF 11N TO THE EAST OF 32W AND TO THE SOUTH OF 11N TO THE WEST OF 45W. ...DISCUSSION... THE GULF OF MEXICO... A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH GEORGIA INTO THE EASTERN AND SOUTHEASTERN GULF OF MEXICO NEAR 24N83W. NO SIGNIFICANT DEEP CONVECTIVE PRECIPITATION ACCOMPANIES THE TROUGH AT THIS MOMENT. SCATTERED TO NUMEROUS STRONG CONVECTIVE PRECIPITATION WAS IN THE NORTHWESTERN CORNER OF THE AREA FROM 24N TO 28N BETWEEN 90W AND 96W AT 23/2115 UTC. THE CLOUD TOP TEMPERATURES IN THIS AREA HAVE WARMED AND THE PRECIPITATION HAS WEAKENED/BEEN WEAKENING WITH TIME. RAINSHOWERS ARE POSSIBLE WITHIN 120 TO 240 NM TO THE WEST OF THE LINE THAT PASSES THROUGH 32N76W IN THE ATLANTIC OCEAN...TO 29N78W 26N80W AND 24N84W IN THE SOUTHEASTERN 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 79W AND 85W IN THE WATERS THAT ARE TO THE SOUTH OF CUBA. AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 34N64W. SCATTERED MODERATE CONVECTIVE PRECIPITATION IS FROM 29N TO 34N BETWEEN 62W AND 70W. THE REST OF THE CARIBBEAN SEA... SCATTERED STRONG CONVECTIVE PRECIPITATION IN INDIVIDUAL CELLS IS ALONG THE EASTERN PACIFIC OCEAN COAST OF CENTRAL AMERICA FROM SOUTHWESTERN NICARAGUA TO THE GULF OF TEHUANTEPEC OF MEXICO. THE PRECIPITATION IS OCCURRING IN AN AREA OF BROAD SURFACE LOW PRESSURE AND UPPER LEVEL DIFFLUENT WIND FLOW. THE MONSOON TROUGH IS ALONG 11N74W IN COLOMBIA...TO 11N80W IN THE SOUTHWESTERN CORNER OF THE AREA...BEYOND 12N86W IN NICARAGUA. NO SIGNIFICANT DEEP CONVECTIVE PRECIPITATION. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR MORE DETAILS ABOUT TROPICAL STORM ISAAC. A SECOND AREA OF 20 KNOT WINDS AND 8 FOOT SEA HEIGHTS IS AT 48 HOURS TO THE SOUTH OF 14N BETWEEN 67W AND 70W. THE REST OF THE ATLANTIC OCEAN... A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N19W TO 28N20W...BECOMING A SHEAR AXIS FROM 28N20W TO 25N28W AND 30N46W. A TROUGH CONTINUES FROM 30N46W TO A 20N49W CYCLONIC CIRCULATION CENTER. CONVECTIVE PRECIPITATION SCATTERED MODERATE TO ISOLATED STRONG FROM 29N TO 32N BETWEEN 53W AND 55W...ISOLATED MODERATE ELSEWHERE TO THE NORTH OF 20N BETWEEN 48W AND 60W. A SEPARATE MIDDLE LEVEL TO UPPER LEVEL TROUGH IS ALONG 20N45W 16N43W TO 10N44W...STILL JUST TO THE WEST OF T.D. TEN. A SURFACE RIDGE EXTENDS FROM A 1023 MB HIGH PRESSURE CENTER THAT IS NEAR 37N20W...TO A SECOND 1023 MB HIGH PRESSURE CENTER THAT IS NEAR 36N40W...TO A 1022 MB HIGH PRESSURE CENTER THAT IS NEAR 35N57W...THROUGH 30N72W...ACROSS FLORIDA NEAR 28N...INTO THE GULF OF MEXICO NEAR 25N90W. PLEASE READ THE HIGH SEAS FORECASTS...MIAHSFAT2... FOR DETAILS ABOUT TROPICAL DEPRESSION JOYCE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT