000 AXNT20 KNHC 202345 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST FRI JAN 20 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 08N13W TO 04N19W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 04N19W TO 02N38W TO THE EQUATOR NEAR 50W. WIDELY SCATTERED MODERATE CONVECTION IS FROM THE EQUATOR TO 06N BETWEEN 25W-39W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES THAT WESTERLY UPPER LEVEL FLOW IS DOMINANT ALOFT ACROSS THE GULF THIS EVENING ON THE NORTHERN PERIPHERY OF A BROAD UPPER LEVEL RIDGE STRETCHING FROM WESTERN MEXICO TO THE FLORIDA PENINSULA. THIS UPPER LEVEL FEATURE IS SUPPORTIVE OF A SURFACE RIDGE EXTENDING ACROSS THE GULF FROM THE SW NORTH ATLC AND FLORIDA PENINSULA SW TO SOUTHERN MEXICO NEAR 21N97W. SOUTHERLY RETURN FLOW IS EXPECTED TO PERSIST THROUGH THIS EVENING INTO THE OVERNIGHT HOURS WITH A WEAK FRONT EXPECTED TO ENTER THE NW GULF BRIEFLY SATURDAY MORNING THEN LIFT NORTHWARD BY LATE SATURDAY. ANOTHER AREA OF SURFACE LOW PRESSURE IS FORECAST TO DEVELOP OVER THE CENTRAL PLAINS AND INTRODUCE A STRONGER COLD FRONT INTO THE NW GULF LATE SUNDAY INTO EARLY MORNING WHICH WILL PROVIDE NORTHERLY WINDS TO PORTIONS OF THE WESTERN GULF ON MONDAY. CARIBBEAN SEA... NORTHWEST TO WESTERLY UPPER LEVEL FLOW IS OVER THE CARIBBEAN BASIN THIS EVENING WHICH IS PROVIDING AN OVERALL DRY AND STABLE ATMOSPHERE ALOFT LIMITING ANY SIGNIFICANT AREAS OF DEEP CONVECTION. FRESH TO STRONG EASTERLY TRADES ARE FORECAST TO PERSIST THROUGH THE UPCOMING WEEKEND WITH NO MAJOR CHANGES EXPECTED TO MODIFY THE CURRENT WEATHER PATTERN. ATLANTIC OCEAN... MOST OF THE SW NORTH ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1024 MB HIGH CENTERED NEAR 31N73W WITH AXIS EXTENDING SW ACROSS THE FLORIDA PENINSULA INTO THE GULF OF MEXICO. MOSTLY CLEAR SKIES AND FAIR WEATHER ARE OCCURRING ACROSS THE BAHAMAS AND THE FLORIDA PENINSULA THIS EVENING. AN UPPER LEVEL TROUGH IS OVER THE WESTERN NORTH ATLC WATERS WITH AXIS ALONG 60W THAT SUPPORTS A WEAKENING COLD FRONT ANALYZED FROM 32N58W TO 24N68W. LOW-LEVEL MOISTURE IN THE VICINITY OF THE FRONT S OF 30N REMAINS LIMITED...HOWEVER SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING N OF 27N BETWEEN 53W-58W EAST OF THE FRONT WHERE LOW-LEVEL MOISTURE CONVERGENCE AND UPPER LEVEL DIFFLUENCE ARE MAXIMIZED. AS THIS COLD FRONT IS FORECAST TO CONTINUE MOVING OFF TO THE NE...A MIDDLE TO UPPER LEVEL LOW CENTERED NEAR 28N44W SUPPORTS A 1014 MB SURFACE LOW CENTERED NEAR 27N44W THAT IS EXPECTED TO DRIFT NORTHWARD AND BECOMING ABSORBED INTO THE FRONTAL BOUNDARY BY EARLY SUNDAY. CURRENTLY A WARM FRONT EXTENDS FROM THE LOW CENTER TO 30N45W TO 32N44W. A STATIONARY FRONT ALSO EXTENDS FROM THE LOW CENTER ALONG 25N42W TO 20N43W TO 15N50W. THE SYSTEM EXHIBITS A CLASSIC COMMA CLOUD SATELLITE PRESENTATION WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED TSTMS OCCURRING WITHIN THE NORTHEAST SEMICIRCLE AT A RANGE OF 360 NM FROM THE LOW CENTER. ADDITIONAL ISOLATED SHOWERS ARE OCCURRING WITHIN 90 NM EAST OF THE STATIONARY FRONT FROM 21N-24N. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1038 MB HIGH CENTERED WEST OF THE IBERIAN PENINSULA NEAR 42N16W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN