000 AXNT20 KNHC 192352 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST TUE JAN 19 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 4N05W 4N20W 2N37W CROSSING THE EQUATOR NEAR 43W THEN TO THE NE BRAZIL COAST NEAR 1S46W. ISOLATED MODERATE CONVECTION IS FROM 2N-4N BETWEEN 3W-7W AND FROM 1N-4N BETWEEN 24W-30W. ...DISCUSSION... GULF OF MEXICO... A SURFACE RIDGE EXTENDS ACROSS THE ENTIRE GULF OF MEXICO ANCHORED BY A 1021 MB HIGH CENTERED IN THE NE GULF NEAR 27N86W THAT CONTINUES TO PROVIDE GENERALLY FAIR WEATHER THIS EVENING. LIGHT ANTICYCLONIC SURFACE FLOW IS NOTED WITH THE RIDGE AS SE WINDS REACH 15 KT ACROSS PORTIONS OF THE WESTERN GULF. ALOFT... ZONAL WESTERLY UPPER LEVEL FLOW EXISTS ACROSS THE GULF WITH WATER VAPOR IMAGERY INDICATING DRY AIR AND RELATIVELY STRONG SUBSIDENCE IN THE MIDDLE TO UPPER LEVELS OF THE ATMOSPHERE. AS THE SURFACE RIDGE SHIFTS EAST INTO THE W ATLC BY LATE WEDNESDAY...SOUTHERLY RETURN FLOW IS FORECAST TO INCREASE ACROSS THE WESTERN AND CENTRAL GULF AHEAD OF THE NEXT COLD FRONT EXPECTED TO ENTER THE NW GULF WATERS EARLY THURSDAY. CARIBBEAN SEA... THE TAIL END OF A SURFACE TROUGH EXTENDS ACROSS HISPANIOLA FROM THE W ATLC AND CONTINUES TO PROVIDE A LOW-LEVEL FOCUS FOR ISOLATED SHOWERS ACROSS THE ISLAND OF HISPANIOLA AND THE ADJACENT COASTAL WATERS. ANOTHER PAIR OF WEAK SURFACE TROUGHS ARE LOCATED EAST OF THE LESSER ANTILLES...ONE ANALYZED FROM 17N57W TO 12N60W. POSSIBLE ISOLATED SHOWERS ARE WITHIN 120 NM W OF THE SURFACE TROUGH...INCLUDING MANY OF THE WINDWARD ISLANDS AND SOUTHERN LEEWARD ISLANDS THIS EVENING. FARTHER NORTH...THE SECOND SURFACE TROUGH IS ANALYZED FROM 20N58W TO 18N61W WITH MUCH OF THE ASSOCIATED SHOWER ACTIVITY REMAINING OVER THE TROPICAL NORTH ATLC WATERS WITHIN 120 NM W OF THE SURFACE TROUGH. THE REMAINDER OF THE CARIBBEAN IS EXPERIENCING GENERALLY FAIR WEATHER UNDER THE INFLUENCE OF DRY AIR AND SUBSIDENCE AROUND AN UPPER LEVEL RIDGE COVERING THE BASIN WITH AXIS ALONG 66W. FRESH TO STRONG TRADEWINDS ARE OVER MUCH OF THE BASIN WITH THE STRONGEST WINDS OFF THE COAST OF COLOMBIA...REACHING GALE FORCE FROM 11N-15N BETWEEN 72W-77W. ATLANTIC OCEAN... A COLD FRONT EXTENDS ACROSS THE W ATLC FROM A 986 MB LOW NEAR 41N49W ENTERING THE DISCUSSION AREA NEAR 32N51W CONTINUING SW ALONG 27N60W TO WESTERN HISPANIOLA NEAR 20N72W. ISOLATED SHOWERS ARE WITHIN 90 NM EITHER SIDE OF THE FRONT N OF 26N. A PRE- FRONTAL SURFACE TROUGH IS E OF THE COLD FRONT ANALYZED FROM 26N61W TO EASTERN PORTIONS OF HISPANIOLA NEAR 18N70W. ISOLATED SHOWERS ARE WITHIN 75 NM OF THE TROUGH AXIS. A SECONDARY COLD FRONT IS ANALYZED FROM 31N59W TO 28N69W. ISOLATED SHOWERS ARE POSSIBLE ALONG THIS FRONT N OF 28N BETWEEN 59W-70W. MOST OF THE UPPER LEVEL SUPPORT FOR THIS COLD FRONT REMAINS N OF THE DISCUSSION AREA AS AN UPPER LEVEL RIDGE AXIS STEMMING FROM THE NE CARIBBEAN NEAR PUERTO RICO AMPLIFIES OVER THE CENTRAL ATLC BETWEEN 50W-70W. ACROSS THE EASTERN ATLC...A SURFACE RIDGE IS IN PLACE ANCHORED BY A 1027 MB HIGH CENTERED NEAR 33N21W. THE SURFACE RIDGE AXIS EXTENDS FROM THE HIGH CENTER TO THE SW ALONG 26N40W TO 22N54W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE. $$ HUFFMAN