000 AXNT20 KNHC 121142 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST TUE JAN 12 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 8N13W 2N30W CROSSING THE EQUATOR NEAR 40W THEN TO 1S46W. SCATTERED SHOWERS AND ISOLATED MODERATE CONVECTION ARE FROM THE EQUATOR TO 5N BETWEEN 3W-21W. ISOLATED MODERATE CONVECTION IS FROM 2N-4N BETWEEN 24W-35W. ...DISCUSSION... GULF OF MEXICO... A SURFACE RIDGE ENCOMPASSES THE ENTIRE GULF BASIN ANCHORED BY A 1032 MB HIGH CENTERED OVER THE NW GULF WATERS NEAR 29N94W. THIS SURFACE FEATURE IS PRODUCING PRIMARILY LIGHT NORTHERLY WINDS UP TO 15 KT ACROSS THE EASTERN GULF AND FLORIDA PENINSULA WHILE LIGHT NE TO E WINDS ARE OCCURRING ACROSS THE FAR WESTERN GULF THIS MORNING. ALOFT...A MORE MOIST SOUTHWESTERLY UPPER LEVEL PATTERN IS TAKING SHAPE AHEAD OF THE NEXT UPPER LEVEL SHORTWAVE TROUGH CURRENTLY ACROSS NW MEXICO THAT IS EXPECTED TO IMPACT THE WESTERN GULF BY LATE THURSDAY. THE SURFACE RIDGE IS FORECAST TO REMAIN IN PLACE ACROSS THE NE GULF THROUGH WEDNESDAY MERGING WITH AN EASTERN CONUS SURFACE HIGH WHILE SOUTHEASTERLY RETURN FLOW DEVELOPS OVER THE WESTERN GULF AHEAD OF THE NEXT LOW PRESSURE AREA AND ASSOCIATED COLD FRONT FORECAST TO EMERGE OFF THE EASTERN MEXICO COAST EARLY FRIDAY. CARIBBEAN SEA... A DISSIPATING STATIONARY FRONT ENTERS THE CARIBBEAN SEA FROM ACROSS EASTERN HISPANIOLA AND TRAILS SW AS A SHEAR LINE ALONG 18N73W 15N77W TO THE COAST OF WESTERN PANAMA NEAR 9N81W. THIS BOUNDARY IS SUPPORTED ALOFT BY MOIST SWLY UPPER LEVEL FLOW AND WEAK UPPER LEVEL TROUGHING EXTENDING SOUTHWESTWARD FROM THE W ATLC INTO THE WESTERN CARIBBEAN. ISOLATED SHOWERS ARE WITHIN 90 NM EITHER SIDE OF THE SHEAR LINE WITH MORE ISOLATED SHOWER ACTIVITY OCCURRING NW OF THE BOUNDARY ACROSS THE REMAINDER OF THE NW CARIBBEAN...CUBA...JAMAICA....AND PORTIONS OF CENTRAL AMERICA. SE OF THE FRONT AND ACROSS THE EASTERN CARIBBEAN...NE TO E TRADEWINDS UP TO 25 KT CONTINUE WITH A COUPLE AREAS OF ISOLATED SHOWERS EMBEDDED WITHIN THE TRADE WIND FLOW. ISOLATED SHOWERS ARE S OF 16N BETWEEN 68W-74W AND OVER PORTIONS OF THE LESSER ANTILLES...MAINLY S OF 18N E OF 65W. ALOFT...AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE SE CARIBBEAN NEAR 11N66W CONTINUES TO INFLUENCE THE EASTERN CARIBBEAN E OF 75W WITH RELATIVELY STRONG SUBSIDENCE AND STABLE CONDITIONS PROVIDING FOR GENERALLY CLEAR SKIES...EXCEPT HOWEVER FOR THOSE PREVIOUSLY MENTIONED AREAS OF ISOLATED SHOWERS. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH AXIS IS OVER THE CENTRAL ATLC AND EXTENDS FROM 32N54W TO NEAR 24N66W. THIS UPPER LEVEL FEATURE SUPPORTS A 1004 MB LOW CENTERED NEAR 36N50W AND AN ASSOCIATED COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N52W AND EXTENDS SW TO ALONG 25N58W TO 21N64W WHERE IT CONTINUES AS A STATIONARY BOUNDARY ACROSS EASTERN HISPANIOLA. LOW-LEVEL CONVERGENCE NEAR THE COLD FRONT AND AN AREA OF UPPER LEVEL DIFFLUENCE NEAR THE UPPER LEVEL TROUGH IS GENERATING SCATTERED SHOWERS WITHIN 200 NM EITHER SIDE OF THE FRONT. THE REMAINDER OF THE W ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE EXTENDING FROM A 1032 MB HIGH CENTERED IN THE NORTHERN GULF OF MEXICO. ELSEWHERE THE REMAINDER OF THE CENTRAL AND EASTERN ATLC ARE CONTROLLED BY A SURFACE RIDGE ANCHORED BY A 1028 MB HIGH CENTERED NEAR 28N20W AND CONTINUES TO PROVIDE GENERALLY FAIR WEATHER WITH THE RIDGE AXIS EXTENDING WSW FROM THE HIGH ALONG 25N40W TO NE OF THE LEEWARD ISLANDS NEAR 20N57W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE. $$ HUFFMAN