000 AXNT20 KNHC 101145 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST MON DEC 10 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. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 10N15W TO 06N19W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N19W TO 05N30W TO 03N51W. ISOLATED MODERATE CONVECTION IS FROM 03N-07N BETWEEN 15W-35W. ...DISCUSSION... GULF OF MEXICO... SOUTHWESTERLY MIDDLE TO UPPER LEVEL FLOW INFLUENCES MUCH OF THE GULF THIS MORNING BETWEEN AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE WESTERN CARIBBEAN SEA AND UPPER LEVEL TROUGHING OVER THE CENTRAL CONUS. WATER VAPOR IMAGERY INDICATES MOST MOISTURE CONTINUES TO IMPACT THE NW GULF REGION AND NORTH-CENTRAL COASTAL REGIONS AS SURFACE RIDGING EXTENDS WESTWARD FROM THE SW NORTH ATLC ACROSS THE BASIN PROVIDING S-SE WINDS IN THE RANGE OF 10 TO 20 KT. ISOLATED SHOWERS ARE POSSIBLE NW OF A LINE FROM 25N98W TO 30N87W AS A COLD FRONT APPROACHES THE TEXAS AND LOUISIANA COAST. CURRENTLY...A LINE OF SCATTERED SHOWERS AND TSTMS ASSOCIATED WITH THE FRONT ARE OCCURRING OFFSHORE OF THE TEXAS COAST MOVING E-NE. ELSEWHERE...A WEAK SURFACE TROUGH EXTENDS ACROSS A PORTION OF THE YUCATAN PENINSULA NEAR 22N88W WITH ISOLATED SHOWERS OCCURRING S OF 26N BETWEEN 84W-90W IN THE SE GULF. CARIBBEAN SEA... A MIDDLE TO UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE WESTERN CARIBBEAN NEAR 19N79W AND CONTINUES TO PROVIDE AN OVERALL STABLE ATMOSPHERE FOR THE BASIN. WATER VAPOR IMAGERY INDICATES STRONG SUBSIDENCE AND DRY AIR WITH THE EXCEPTION OF AN AREA FROM 10N-23N BETWEEN 81W-85W. A FEW ISOLATED SHOWERS AND TSTMS ARE OCCURRING OFFSHORE OF COSTA RICA AND NICARAGUA FROM 10N-13N BETWEEN 81W-85W. FARTHER NORTH...ISOLATED SHOWERS AND TSTMS ARE OCCURRING FROM 18N-23N BETWEEN 81W-85W. OTHERWISE... EASTERLY TRADES REMAIN STRONG DUE TO AN INCREASED PRESSURE GRADIENT BY HIGH PRESSURE ACROSS THE SW NORTH ATLC REGION. THE GRADIENT IS FORECAST TO RELAX BY THURSDAY AS SURFACE TROUGHING IMPACTS THE SW NORTH ATLC N OF 25N. ATLANTIC OCEAN... WEST-NORTHWESTERLY FLOW ALOFT DOMINATES OVER THE SW NORTH ATLC WITH WATER VAPOR IMAGERY INDICATING MOST MIDDLE TO UPPER LEVEL MOISTURE REMAINING N OF 27N BETWEEN 70W-80W. A FEW ISOLATED SHOWERS ARE POSSIBLE OVER THIS AREA AS THE MOISTURE LIFTS TO THE NORTH THROUGHOUT THE DAY. OTHERWISE...A SURFACE RIDGE AXIS EXTENDS ALONG 29N ANCHORED BY A 1026 MB HIGH CENTERED IN THE CENTRAL ATLC NEAR 32N49W. FARTHER EAST...AN UPPER LEVEL TROUGH AXIS IS NOTED ON WATER VAPOR IMAGERY FROM 35N32W TO 13N60W THAT SUPPORTS A DISSIPATING STATIONARY FROM 32N27W TO 26N30W TO 22N32W THAT BECOMES A SHEAR LINE SW TO 11N55W. LOW-LEVEL CONVERGENCE AND MIDDLE TO UPPER LEVEL DIFFLUENCE IN THE VICINITY OF THE FRONT IS GENERATING ISOLATED SHOWERS AND TSTMS WITHIN 120 NM EAST OF THE STATIONARY FRONT. ISOLATED SHOWERS AND TSTMS ARE ALSO FOCUSED ALONG AND WITHIN 180 NM EITHER SIDE OF THE SHEAR LINE AXIS. THIS BOUNDARY WILL CONTINUE TO BECOME MORE DIFFUSE OVER THE NEXT FEW DAYS WITH LINGERING SHOWER ACTIVITY EXPECTED. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN