000 AXNT20 KNHC 282346 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST MON JAN 28 2013 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 PRIME MERIDIAN AT 03N TO 03N16W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 03N16W TO 02N30W TO 04N44W TO 02N50W. SCATTERED MODERATE CONVECTION IS FROM THE EQUATOR TO 06N BETWEEN THE PRIME MERIDIAN AND 04W. ...DISCUSSION... GULF OF MEXICO... VERY WEAK AND BROAD UPPER LEVEL TROUGHING IS ACROSS THE GULF... HOWEVER OVERRIDING THIS SUBTLE FEATURE IS A MID-LEVEL RIDGE THAT REMAINS ANCHORED OVER THE CARIBBEAN SEA. WATER VAPOR IMAGERY INDICATES A FAIRLY DRY AND STABLE AIRMASS IS OVER MUCH OF THE GULF THIS EVENING. AT THE SURFACE...THE WESTERN PERIPHERY OF A SURFACE RIDGE...ANCHORED BY A 1032 MB HIGH CENTERED IN THE SW NORTH ATLC NEAR 33N72W...IS PROVIDING SE WINDS IN THE RANGE OF 10 TO 20 KT AND MOSTLY CLEAR SKIES WITH FAIR CONDITIONS. A WEAK SURFACE TROUGH EMBEDDED WITHIN THE RIDGING IS ANALYZED FROM 25N88W TO 28N86W AND IS GENERATING ISOLATED SHOWERS AND TSTMS FROM 26N-28N BETWEEN 85W-88W. THIS ACTIVITY IS EXPECTED TO CONTINUE MOVING NE THROUGH THE EVENING HOURS. THE SURFACE RIDGE IS EXPECTED TO GRADUALLY SLIDE EASTWARD THROUGH EARLY WEDNESDAY AS SOUTHERLY FLOW INCREASES ACROSS THE GULF. BY EARLY WEDNESDAY...THE NEXT COLD FRONT IS FORECAST TO EMERGE OFF THE TEXAS AND LOUISIANA COAST SHIFTING WINDS NORTHERLY BEHIND THE FRONT. CARIBBEAN SEA... SOUTH-SOUTHWESTERLY FLOW ALOFT DOMINATES OVER THE CARIBBEAN SEA THIS EVENING AS WATER VAPOR IMAGERY INDICATES A VERY DRY AND SUBSIDENT ATMOSPHERE IS IN PLACE DUE TO A MID-LEVEL RIDGING ANCHORED OVER THE BASIN NEAR 17N73W. WHILE THE MIDDLE TO UPPER LEVELS ARE PROVIDING FAIRLY BENIGN WEATHER...AT THE SURFACE THE TRADE WINDS REMAIN IN THE RANGE OF 15 TO 25 KT...WITH HIGHER WINDS POSSIBLE IN CLOSE PROXIMITY TO THE COAST OF COLOMBIA...DUE TO A STRONG PRESSURE GRADIENT BETWEEN STRONG SURFACE RIDGING OVER THE SW NORTH ATLC REGION AND LOWER PRESSURE LOCATED OVER THE NORTHERN SOUTH AMERICAN CONTINENT. ISOLATED SHOWERS ARE NOTED ON SATELLITE IMAGERY ACROSS THE BASIN THIS EVENING...WITH THE MOST CONCENTRATED AREAS E OF 70W...AND ACROSS PORTIONS OF THE NW CARIBBEAN AND WESTERN CUBA. OVERALL LITTLE CHANGE IS EXPECTED SYNOPICALLY OVER THE NEXT 24 TO 36 HOURS. ATLANTIC OCEAN... SURFACE HIGH PRESSURE IS CONTROLLING THE SW NORTH ATLC ANCHORED BY A 1032 MB HIGH CENTERED NEAR 33N72W. THE HIGH IS SUPPORTED BY A MIDDLE TO UPPER LEVEL RIDGE COVERING THE EASTERN CONUS. EAST OF THE RIDGING...BROAD UPPER LEVEL TROUGHING IS NOTED ON WATER VAPOR IMAGERY N OF 27N BETWEEN 30W-60W THAT SUPPORTS A PAIR OF FRONTAL BOUNDARIES ENTERING THE DISCUSSION AREA IN THE CENTRAL ATLC. THE EASTERN-MOST FRONT IS A DISSIPATING COLD FRONT ANALYZED FROM 32N39W TO 25N50W TO 21N62W...AND THE WESTERN-MOST COLD FRONT IS ANALYZED FROM 32N41W TO 25N54W TO 24N66W...THEN CONTINUES AS A DIFFUSE CLOUD LINE NW TO 27N78W NEAR THE NW BAHAMAS. WIDELY SCATTERED SHOWERS ARE OCCURRING WITHIN 150 NM EITHER SIDE OF THE FRONTS E OF 64W. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1031 MB HIGH CENTERED OVER THE IBERIAN PENINSULA NEAR 39N06W. THE RIDGE AXIS EXTENDS FROM THE HIGH SW TO 20N40W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN