000 AXNT20 KNHC 311747 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED OCT 31 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS WEST AFRICA TO THE COAST OF GUINEA-BISSAU AT 12N16W CONTINUING ALONG 10N24W 10N33W. THE ITCZ BEGINS FARTHER WEST NEAR 9N44W ALONG 8N53W 10N60W. A SURFACE TROUGH IS ANALYZED NORTH OF THE MONSOON TROUGH NEAR 16N26W TO 12N27W WITH ISOLATED MODERATE CONVECTION WITHIN 90 NM. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS ALSO SOUTH OF THE MONSOON TROUGH FROM 5N-10N BETWEEN 19W-28W. A SECOND WEAK SURFACE TROUGH IS BETWEEN THE MONSOON TROUGH AND ITCZ ALONG 14N38W TO 10N40W...BUT IS NOT CAUSING ANY CONVECTION. SCATTERED STRONG CONVECTION IS WITHIN 100 NM NORTH OF THE ITCZ AXIS BETWEEN 49W-61W. ...DISCUSSION... THE GULF OF MEXICO... A BROAD UPPER TROUGH CONTINUES TO COVER THE GULF OF MEXICO TODAY EXTENDING FROM THE NE CONUS. DRY AIR IS WRAPPING AROUND THE UPPER TROUGH HELPING PROVIDE MOSTLY CLEAR SKIES ACROSS THE AREA. DUE TO THE LARGE LOW PRESSURE SYSTEM THAT WAS ASSOCIATED WITH SANDY THAT CONTINUES TO SPIN...THE SYSTEM HAS PRODUCED SEVERAL FRONTAL BOUNDARIES THAT HAVE MOVED THROUGH THE AREA. A STATIONARY FRONT CURRENTLY EXTENDS FROM CENTRAL FLORIDA NEAR 28N81W TO 28N86W. SURFACE RIDGING COVERS THE REMAINDER OF THE BASIN CENTERED AROUND A 1020 MB HIGH NEAR 25N89W. NW WINDS UP TO 15 KT ARE STILL ACROSS THE NE GULF BEHIND THE FRONT WITH LIGHTER ANTI-CYCLONIC FLOW AROUND THE HIGH CENTER. THE ONLY ACTIVE WEATHER IS A FEW ISOLATED SHOWERS/THUNDERSTORMS JUST OFF THE MEXICAN COAST IN THE SW GULF. SURFACE RIDGING IS EXPECTED TO REMAIN ACROSS THE BASIN FOR THE NEXT 24 HOURS. THE CARIBBEAN SEA... NW SURFACE FLOW IS ACROSS THE NW CARIBBEAN BEHIND A DISSIPATING STATIONARY FRONT THAT EXTENDS FROM THE EASTERN TIP OF CUBA TO NEAR 18N80W. POSSIBLE ISOLATED SHOWERS ARE ACROSS THE NW CARIBBEAN. SOUTHWESTERLY FLOW ALOFT COVERS THE WESTERN AND CENTRAL GULF BETWEEN THE UPPER TROUGH COVERING THE NE CONUS AND AN UPPER LEVEL RIDGE COVERING THE EASTERN CARIBBEAN AND THE CENTRAL ATLC. MOSTLY DRY AIR ACCOMPANIES THE SW FLOW EXCEPT FOR SOME MODERATE MOISTURE ALONG FROM THE YUCATAN PENINSULA TO CUBA....AND IN THE CENTRAL CARIBBEAN NEAR A SURFACE TROUGH ALONG 17N72W TO 10N75W. THE SURFACE TROUGH ALONG WITH THE MONSOON TROUGH WHICH EXTENDS THROUGH PANAMA TO NORTHERN COLOMBIA IS HELPING PRODUCE SCATTERED SHOWERS/THUNDERSTORMS FROM 8N-16N BETWEEN 72W-79W. THE EASTERN CARIBBEAN IS EXPERIENCING MOSTLY FAIR CONDITIONS DUE TO DRY AIR ALOFT MOVING FROM THE ATLC AROUND THE UPPER RIDGE. THE SURFACE TROUGH IS EXPECTED TO DRIFT WESTWARD BRINGING SHOWERS/THUNDERSTORMS WITH IT. THE ATLANTIC OCEAN... CYCLONIC SURFACE FLOW IS STILL PRESENT ACROSS THE WEST ATLC AROUND THE LOW PRESSURE SYSTEM TO THE NORTH. DUE TO THE FACT THAT IT IS STILL SPINNING...SEVERAL SURGES OF COLD AIR ARE MOVING AROUND IT. THE EASTWARD FRONT IS NOW BEGINNING TO DISSIPATE WHERE A DISSIPATING COLD FRONT IS ALONG 32N64W 26N68W 20N75W WHERE IT BECOMES STATIONARY IN THE CARIBBEAN. POSSIBLE ISOLATED SHOWERS ARE WITHIN 120 NM EAST OF THE AXIS. A SECOND COLD FRONT IS TO THE WEST ALONG 32N73W TO 29N79W WHERE IT BECOMES STATIONARY ACROSS FLORIDA. NO SHOWERS ARE ASSOCIATED WITH THE AXIS. THE SYSTEM IS SUPPORTED BY A BROAD UPPER LEVEL RIDGE COVERING THE EASTERN CONUS. AN UPPER LEVEL RIDGE COVERS THE CENTRAL ATLC ALONG 56W SUPPORTING A WEAK SURFACE RIDGE AROUND A 1016 MB HIGH NEAR 24N62W. AN AREA OF SHOWERS/THUNDERSTORMS IS SW OF THE HIGH CENTER FROM 20N-24N BETWEEN 63W-67W DUE TO MOIST SWLY FLOW ALOFT BETWEEN THE UPPER TROUGH AND UPPER RIDGE. FARTHER E...AN UPPER LEVEL LOW COVERS THE EAST ATLC SUPPORTING A 993 MB LOW NEAR 32N34W. THE LOW IS OCCLUDED AND THE COLD FRONT ENTERS THE AREA WELL TO THE EAST ALONG 32N10W TO 24N24W BECOMING STATIONARY TO 19N32W. SCATTERED SHOWERS ARE WITHIN 75 NM EITHER SIDE OF THE AXIS. A SURFACE TROUGH EXTENDS FROM THE LOW CENTER ALONG 27N37W TO 24N45W DEPICTING A WIND SHIFT AROUND THE LOW. PATCHES OF SCATTERED SHOWERS ARE BETWEEN THE TWO BOUNDARIES. UPPER LEVEL RIDGING COVERS THE FAR EASTERN TROPICAL ATLC SUPPORTING A WEAK 1013 MB HIGH OFF THE AFRICAN COAST NEAR 18N18W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON