000 AXNT20 KNHC 291158 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT MON OCT 29 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 1045 UTC. ...SPECIAL FEATURES... THE CENTER OF HURRICANE SANDY AT 29/1200 UTC IS NEAR 36.8N 71.1W. SANDY IS ABOUT 230 NM TO THE SOUTHEAST OF ATLANTIC CITY NEW JERSEY...AND ABOUT 270 NM TO THE SOUTH-SOUTHEAST OF NEW YORK CITY. SANDY IS MOVING NORTH-NORTHWEST 11 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 946 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 75 KNOTS WITH GUSTS TO 90 KNOTS. PLEASE READ THE FORECAST/ADVISORY UNDER THE AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC...AND THE PUBLIC ADVISORY UNDER MIATCPAT3/WTNT33 KNHC FOR MORE DETAILS. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO STRONG FROM 35N TO 40N BETWEEN 67W AND 76W. THE SURFACE PRESSURE PATTERN OF LOW PRESSURE COVERS THE ATLANTIC OCEAN FROM 26N TO 42N BETWEEN 57W AND 81W IN SOUTH CAROLINA...IN A CLOSED 1004 MB ISOBAR. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH THE COASTAL GUINEA-BISSAU NEAR 12N16W 8N19W 8N24W. THE ITCZ CONTINUES FROM 8N24W TO 8N33W 7N40W TO 7N56W. CONVECTIVE PRECIPITATION...SCATTERED STRONG WITHIN A 30 NM RADIUS OF 9N38.5W AND FROM 7N TO 9N BETWEEN 41W AND 44W. ISOLATED MODERATE TO LOCALLY STRONG ELSEWHERE TO THE SOUTH OF 10N TO THE EAST OF 56W. A SURFACE TROUGH IS ALONG 41W/42W TO THE SOUTH OF 13N...BREAKING UP THE ITCZ. ISOLATED MODERATE CONVECTIVE PRECIPITATION IS FROM 10N TO 15N BETWEEN 40W AND 50W. ...DISCUSSION... THE GULF OF MEXICO... BROAD MIDDLE LEVEL TO UPPER LEVEL NORTHWESTERLY-TO-WESTERLY WIND FLOW COVERS THE AREA. THIS PATTERN IS TO THE WEST OF THE DEEP LAYER TROUGH THAT SURROUNDS HURRICANE SANDY...IN THE WESTERN ATLANTIC OCEAN. UPPER LEVEL MOISTURE HAS BEEN MOVING FROM MEXICO INTO THE GULF OF MEXICO...MIXING WITH THE EARLIER COMPARATIVELY DRIER AIR IN SUBSIDENCE THAT HAS BEEN SPANNING THE AREA FOR AT LEAST THE LAST 48 HOURS OR SO. THE DEEP LAYER TROUGH THAT ENGULFS HURRICANE SANDY AT THE MOMENT SUPPORTS A SLOWLY-MOVING DISSIPATING COLD FRONT THAT PASSES THROUGH THE ATLANTIC OCEAN NEAR 32N76W...ACROSS ABACO ISLAND AND ANDROS ISLAND IN THE BAHAMAS...ACROSS CUBA NEAR 22N80W...TO THE SOUTHEASTERN YUCATAN PENINSULA...TO THE ISTHMUS OF TEHUANTEPEC OF MEXICO NEAR 17N92W. A DEFINITE BREAK EXISTS IN THE FRONTAL BOUNDARY IN THE ISTHMUS OF TEHUANTEPEC. THE STATIONARY FRONT STARTS NEAR 18N98W AND IT CURVES NORTHWESTWARD TO 24N100W. WIDELY SCATTERED TO SCATTERED MODERATE CONVECTIVE PRECIPITATION IS TO THE SOUTH OF 22N TO THE WEST OF 91W IN THE SOUTHWESTERN CORNER OF THE AREA. A SURFACE RIDGE PASSES THROUGH THE DEEP SOUTH OF TEXAS TO 20N96W IN COASTAL MEXICO...THROUGH NORTHERN GUATEMALA... TO 16N81W IN THE WESTERN CARIBBEAN SEA. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT4...FOR DETAILS ABOUT THE 20 TO 30 KNOT WINDS AND 8 TO 10 FOOT SEA HEIGHTS TO THE NORTH OF 23N TO THE EAST OF 90W. THE CARIBBEAN SEA... THE MIDDLE LEVEL TO UPPER LEVEL TROUGH THAT ENGULFS HURRICANE SANDY PASSES THROUGH 32N72W IN THE ATLANTIC OCEAN...TO THE CENTRAL BAHAMAS...ACROSS JAMAICA...TO 15N79W IN THE CARIBBEAN SEA. COMPARATIVELY DRIER AIR IN SUBSIDENCE IS TO THE WEST OF THE LINE THAT PASSES THROUGH 20N70W TO 16N76W TO 10N80W AT THE PANAMA COAST. BROAD MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE REST OF THE CARIBBEAN SEA...TO THE EAST OF THE LINE OF COMPARATIVELY DRIER AIR...20N70W 10N80W. SCATTERED MODERATE TO STRONG CONVECTIVE PRECIPITATION IS WITHIN 60 TO 120 NM ON EITHER SIDE OF 14N70W 9N76W 4N81W. THE PRECIPITATION IS OCCURRING IN THE AREA OF A MIDDLE LEVEL TO UPPER LEVEL INVERTED TROUGH...THAT IS ALONG 13N73W 7N77W 3N79W. THE TROUGH SPANS THE AREA FROM THE COASTAL WATERS OF COLOMBIA...INTO COLOMBIA...TO THE EASTERN PACIFIC OCEAN TO THE WEST OF COLOMBIA. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR DETAILS ABOUT 20 TO 25 KNOT WINDS AND 8 TO 9 FOOT SEA HEIGHTS TO THE NORTH OF 20N TO THE WEST OF 84W...INCLUDING YUCATAN CHANNEL...FOR THE NEXT 24 HOURS OR SO. THE ATLANTIC OCEAN... A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM A 35N39W CYCLONIC CIRCULATION CENTER TO 26N40W. NORTHWESTERLY-TO-WESTERLY WIND FLOW COVERS THE ATLANTIC OCEAN TO THE NORTH OF 25N BETWEEN AND 50W. THE TROUGH SUPPORTS A COLD FRONT THAT PASSES THROUGH 32N34W TO 25N39W. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO STRONG TO THE NORTH OF 22N BETWEEN 25W AND 34W. BROKEN TO OVERCAST MULTILAYERED CLOUDS ISOLATED MODERATE TO LOCALLY STRONG CONVECTIVE PRECIPITATION ARE ELSEWHERE TO THE NORTH OF 17N BETWEEN 20W AND 50W. ISOLATED MODERATE TO LOCALLY STRONG CONVECTIVE PRECIPITATION COVERS THE AREA FROM 19N TO 24N BETWEEN 53W AND 65W. THIS PRECIPITATION IS OCCURRING ON THE EASTERN SIDE OF THE DEEP LAYER TROUGH THAT SURROUNDS HURRICANE SANDY...AND UNDER THE AREA OF A MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC CIRCULATION CENTER THAT IS NEAR 20N54W. A 1016 MB HIGH PRESSURE CENTER IS NEAR 22N24W. SURFACE ANTICYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN FROM 11N TO 28N BETWEEN AFRICA AND 31W. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...FOR DETAILS ABOUT HURRICANE SANDY. A SECOND AREA OF INTEREST HAS TO DO WITH A 986 MB LOW PRESSURE CENTER THAT IS NEAR 35N40W AT THE START OF THE FORECAST...MOVING TO 990 MB NEAR 35N35W AT 24 HOURS...AND MOVING TO 993 MB NEAR 35N32W AT 48 HOURS. EXPECT 20 TO 30 KNOT WINDS AND SEA HEIGHTS REACHING 15 FEET IN AREAS AROUND THE LOW PRESSURE CENTER. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT