000 AXNT20 KNHC 231737 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST FRI NOV 23 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. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL ATLC NEAR 9N13W TO 7N16W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 6N21W 6N46W TO 7N53W. A SURFACE TROUGH IS DISRUPTING THE ITCZ ALONG 55W/56W FROM 6N-11N. CLUSTERS OF SCATTERED MODERATE/ ISOLATED STRONG CONVECTION ARE S OF 9N TO INLAND OVER SOUTH AMERICA BETWEEN 54W-59W. CLUSTERS OF SCATTERED MODERATE TO SCATTERED STRONG CONVECTION ARE FROM 3N-6N BETWEEN 10W-14W... FROM 3N TO THE MONSOON TROUGH/ITCZ BETWEEN 14W-30W...AND FROM THE ITCZ TO 10N BETWEEN 17W-37W. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE WITHIN 120 NM S OF THE ITCZ BETWEEN 36W-52W AND WITHIN 150 NM N OF THE ITCZ BETWEEN 37W-52W. ...DISCUSSION... GULF OF MEXICO... NEAR ZONAL WESTERLY FLOW ALOFT DOMINATES THE GULF OF MEXICO THIS AFTERNOON WITH A SURFACE RIDGE ANCHORED BY A 1024 MB HIGH NEAR 26N90W AND A SECOND 1024 MB HIGH OVER CENTRAL ALABAMA/ MISSISSIPPI BORDER. SURFACE COLD AIR OVER THE RELATIVELY WARMER GULF WATERS ARE GENERATING BROKEN TO OVERCAST COLD AIR STRATOCUMULUS CLOUDS THAT COVER MOST OF THE GULF BUT WITH LINGERING DRY AIR ALOFT...NO SHOWERS ARE OBSERVED. A COLD FRONT WILL REACH NW GULF THIS EVENING AND FROM THE FLORIDA BIG BEND AREA TO NW GULF ON SAT. BROAD HIGH PRESSURE WILL THEN RE-BUILD INTO THE GULF SAT THROUGH MON. CARIBBEAN SEA... A BROAD UPPER RIDGE DOMINATES THE CARIBBEAN ANCHORED OVER THE WINDWARD ISLANDS EXTENDING A RIDGE AXIS NE INTO THE CENTRAL ATLC. A STATIONARY BOUNDARY ENTERS THE CARIBBEAN ACROSS HAITI NEAR 20N72W TO 17N77W WITH SCATTERED SHOWERS WITHIN 150 NM E OF THE FRONT. A SURFACE TROUGH REMAINS IN THE CENTRAL CARIBBEAN EXTENDING FROM 18N70W TO 12N73W. MOIST SW FLOW ALOFT COVERS THE SW CARIBBEAN AND COUPLED WITH THE NORTHERLY SURFACE FLOW ARE GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 14N BETWEEN 71W-79W AND S OF 11N W OF 79W TO INLAND OVER PANAMA AND COSTA RICA. THE MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 10N74W TO 10N77W CROSSING PANAMA INTO THE E PACIFIC REGION NEAR 9N78W FURTHER ENHANCING THE ACTIVITY DESCRIBED ABOVE. NORTHERLY SURFACE FLOW IS W OF 77W AND IS GENERATING BROKEN COLD AIR STRATOCUMULUS CLOUDS OVER THE NW CARIBBEAN. TRADE WINDS IN E/CENTRAL CARIBBEAN WILL INCREASE MON AND TUE AS STRONG HIGH PRESSURE BUILDS OVER THE W ATLC. THE SURFACE TROUGH WILL DISSIPATE MON. ATLANTIC OCEAN... AN UPPER TROUGH EXTENDS OVER THE W ATLC N OF 25N BETWEEN 56W-70W SUPPORTING COLD FRONT THAT EXTENDS FROM A TRIPLE POINT THROUGH 32N60W ALONG 25N64W TO 21N71W WHERE IT BECOMES STATIONARY INTO THE CARIBBEAN NEAR 20N72W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WELL E OF THE FRONT WITHIN 90/120 NM OF LINE FROM 19N65W 26N57W TO BEYOND 32N53W WITH SCATTERED SHOWERS WITHIN 225 NM DIRECTLY E OF THE FRONT. A RE-ENFORCING SURGE COLD FRONT EXTENDS FROM A 997 MB LOW NEAR 35N64W ENTERING THE DISCUSSION AREA ACROSS BERMUDA ALONG 27N68W 25N73W TO ELEUTHERA ISLAND IN THE BAHAMAS. THE AREA W OF THE LEADING COLD FRONT IS UNDER STRONG SUBSIDENCE AND DRY STABLE AIR...THUS NO SHOWERS ARE ASSOCIATED WITH THIS RE-ENFORCING FRONT. A BROAD UPPER TROUGH IS IN THE E ATLC N OF 20N BETWEEN 13W-30W SUPPORTING A COLD FRONT N OF THE DISCUSSION AREA AND A PRE-FRONTAL SURFACE TROUGH THAT EXTENDS THROUGH 32N23W ALONG 27N31W TO 24N43W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE WITHIN 225 NM E OF THE TROUGH N OF 30N. THIS SURFACE TROUGH IS BISECTING A WEAK SURFACE RIDGE WITH A 1018 MB HIGH NW OF THE TROUGH NEAR 27N42W AND A 1020 MB HIGH SE OF THE TROUGH NEAR 25N24W. LEADING COLD FRONT WILL DISSIPATE LATER TODAY WHILE THE RE-ENFORCING COLD FRONT BECOMES THE PRIMARY FRONT MOVING INTO THE CENTRAL ATLC SAT THROUGH MON. ANOTHER COLD FRONT WILL MOVE INTO THE NW WATERS SAT AND INTO THE CENTRAL ATLC BY MON. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW