000 AXNT20 KNHC 202350 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST WED JAN 20 2010 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 5N09W 4N23W CROSSING THE EQUATOR NEAR 42W AND INTO NE BRAZIL NEAR 1S46W. ISOLATED MODERATE CONVECTION IS FROM THE EQUATOR TO 5N BETWEEN 21W-32W. ...DISCUSSION... GULF OF MEXICO... SOUTHERLY SURFACE FLOW DOMINATES ACROSS THE GULF THIS EVENING BETWEEN A SURFACE RIDGE ACROSS THE W ATLC AND FLORIDA PENINSULA AND A DEVELOPING AREA OF LOW PRESSURE ACROSS THE SOUTHERN U.S. PLAINS. ACCORDING TO THE LATEST SHIP AND BUOY OBSERVATIONS ACROSS THE GULF...S-SE WINDS ARE REACHING UP TO 20 KT ACROSS THE THE GULF W OF 90W. ALOFT...AN WEAK UPPER LEVEL SHORTWAVE DISTURBANCE IS QUICKLY MOVING ACROSS THE SE CONUS GENERATING SCATTERED SHOWERS AND TSTMS N OF 28N. THE NEXT UPPER LEVEL SHORTWAVE TROUGH IS CURRENTLY MOVING ACROSS WESTERN TEXAS AND IS FORECAST TO INTRODUCE A FRONTAL TROUGH TO THE NW GULF WATERS EARLY THURSDAY. AS THE FRONTAL TROUGH DAMPERS OUT AS IT MOVES EASTWARD...SE FLOW WILL INCREASE ONCE AGAIN ACROSS THE WESTERN GULF WITH THE NEXT COLD FRONT TO MOVE OFF THE TEXAS COAST LATE SATURDAY. CARIBBEAN SEA... MOST OF THE CARIBBEAN IS EXPERIENCING GENERALLY FAIR WEATHER UNDER THE INFLUENCE OF DRY AIR AND SUBSIDENCE ALOFT. UPPER LEVEL TROUGHING COVERS THE NW CARIBBEAN WITH AXIS FROM WESTERN CUBA TO HONDURAS AND EL SALVADOR WHILE AN UPPER LEVEL RIDGE IS ACROSS THE REMAINDER OF THE CARIBBEAN WITH AXIS EXTENDING FROM NORTHERN VENEZUELA NE INTO THE CENTRAL ATLC NEAR 25N45W. WHILE THE UPPER LEVELS OF THE ATMOSPHERE ACROSS THE CARIBBEAN ARE RELATIVELY STABLE...A COUPLE OF LOW-LEVEL SHALLOW BOUNDARIES EXIST OVER PORTIONS OF THE BASIN. FIRST...A SURFACE TROUGH EXTENDS FROM THE SW NORTH ATLC ACROSS HISPANIOLA TO JAMAICA. ISOLATED SHOWERS ARE FOCUSED WITHIN 90 NM EITHER SIDE OF THE BOUNDARY. FARTHER EAST...ANOTHER SURFACE TROUGH IS ANALYZED FROM 19N60W ACROSS THE LEEWARD ISLANDS TO 15N64W. ISOLATED SHOWERS ARE OCCURRING MAINLY N OF 16N BETWEEN 59W-63W. FRESH TO STRONG TRADEWINDS CONTINUE ELSEWHERE ACROSS THE CARIBBEAN WITH THE STRONGEST WINDS LOCATED OFF THE COAST OF COLOMBIA REACHING GALE FORCE FROM 11N-15N BETWEEN 72W-77W AND SEAS REACHING 14 FT. ATLANTIC OCEAN... A WEAK SURFACE RIDGE COVERS THE FAR SW NORTH ATLC ANCHORED BY A 1018 MB HIGH CENTERED NEAR 27N77W WHICH IS PROVIDING GENERALLY FAIR WEATHER ACROSS THE BAHAMAS AND AREAS W OF 70W. FARTHER EAST...A WEAKNESS IN THE SUB-TROPICAL RIDGE IS NOTED AS A COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N40W AND CONTINUES SW TO 24N58W AND CONTINUES AS A STATIONARY FRONT TO 21N66W. THE BOUNDARY WEAKENS FURTHER AS A SURFACE TROUGH IS ANALYZED TO HISPANIOLA AND INTO THE WESTERN CARIBBEAN NEAR JAMAICA. SCATTERED SHOWERS ARE WITHIN 90 NM E OF THE FRONTS AND WITHIN 150 NM W OF THE FRONTS ACROSS THE CENTRAL ATLC AND PORTIONS OF THE SW NORTH ATLC. A SECONDARY SURFACE TROUGH FOLLOWS BEHIND THE COLD FRONT ANALYZED FROM 31N47W TO 28N55W. THESE BOUNDARIES ARE ALL SUPPORTED BY BROAD UPPER LEVEL TROUGHING OVER THE CENTRAL NORTH ATLC WITH AN AXIS THAT EXTENDS FROM 40N33W TO 31N48W. OVER THE TROPICAL ATLC...A SHEAR LINE IS ALONG 15N50W 15N55W TO 18N59W. THIS LINE OF CONVERGENT SURFACE WINDS IS GENERATING SCATTERED SHOWERS WITHIN 60 NM EITHER SIDE OF THE SHEAR LINE. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1025 MB HIGH CENTERED OVER THE MADEIRA ISLANDS NEAR 33N16W. THE RIDGE AXIS EXTENDS FROM THE HIGH CENTER THROUGH 25N35W TO NORTH OF THE SHEAR LINE NEAR 21N52W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE. $$ HUFFMAN