000 AXNT20 KNHC 181755 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST THU FEB 18 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 1715 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 7N11W 1N25W 1N50W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM EITHER SIDE OF THE AXIS BETWEEN 19W-28W. ...DISCUSSION... GULF OF MEXICO... A SURFACE RIDGE CURRENTLY RESIDES OVER THE ENTIRE GULF OF MEXICO ANCHORED BY A 1025 MB HIGH CENTERED OVER NE LOUISIANA. THE RIDGE EXTENDS OVER THE FLORIDA PENINSULA TO THE SE AND OVER THE WESTERN GULF AND SOUTHERN MEXICO TO THE SSW PROVIDING LIGHT NE TO E WINDS THIS AFTERNOON. ALOFT...MOIST SOUTHWESTERLY UPPER LEVEL FLOW IS ACROSS THE GULF W OF 85W EAST OF AN UPPER LEVEL SHORTWAVE TROUGH BEGINNING TO MOVE ACROSS NW MEXICO AS NOTED ON WATER VAPOR IMAGERY. THIS UPPER LEVEL REGIME IS GENERATING EXTENSIVE MULTILAYERED CLOUDINESS WITH ISOLATED SHOWERS POSSIBLE SW OF A LINE FROM PORT ARTHUR TEXAS TO THE YUCATAN PENINSULA NEAR MERIDA. AS THE SURFACE RIDGE SLIDES EASTWARD AND THE UPPER LEVEL SHORTWAVE TROUGH APPROACHES FROM THE WEST...A SURFACE TROUGH IS FORECAST TO DEVELOP ACROSS THE FAR WESTERN GULF BY EARLY SATURDAY AND PROVIDE FOR INCREASED SOUTHEASTERLY WINDS. CARIBBEAN SEA... A STATIONARY FRONT ENTERS THE WESTERN CARIBBEAN FROM ACROSS HISPANIOLA TO 16N76W WHERE THE BOUNDARY LOSES FRONTAL CHARACTERISTICS AND BECOMES A SHEARLINE TO 12N80W. LOW-LEVEL CONVERGENCE OF N TO NE WINDS OVER THE NW CARIBBEAN AND E TO NE WINDS OVER THE EASTERN CARIBBEAN ARE GENERATING ISOLATED SHOWERS WITHIN 90 NM NW OF THE BOUNDARY. ALOFT...AN UPPER LEVEL RIDGE IS IN PLACE ACROSS THE CARIBBEAN WITH MODERATELY DRY AIR NOTED ON WATER VAPOR IMAGERY S OF 18N E OF 82W. WITH MOIST SOUTHWESTERLY UPPER LEVEL FLOW ACROSS SOUTHERN MEXICO AND THE NW CARIBBEAN... POSSIBLE ISOLATED SHOWERS ARE POSSIBLE OVER THE REMAINDER OF THE WESTERN CARIBBEAN NW OF THE BOUNDARY. E OF THE BOUNDARY...FAIR WEATHER AND CLEAR SKIES PREVAIL. ATLANTIC OCEAN. AN UPPER LEVEL LONGWAVE TROUGH IS ACROSS THE WESTERN NORTH ATLC AND DIPS TROUGHING SOUTH INTO THE DISCUSSION AREA REMAINING MAINLY N OF 29N. THIS TROUGH SUPPORTS A COLD FRONT THAT ENTERS THE CENTRAL ATLC NEAR 32N38W AND EXTENDS TO 29N41W WHERE IT TRANSITIONS STATIONARY ALONG 29N TO 55W. A DEVELOPING FRONTAL WAVE NEAR 29N55W THEN SUPPORTS A COLD FRONT TO HISPANIOLA NEAR 19N70W. LOW-LEVEL CONVERGENCE ALONG THE FRONTAL BOUNDARIES COUPLED WITH UPPER LEVEL DIFFLUENCE N OF 27N BETWEEN 40W-57W IS GENERATING SCATTERED SHOWERS WITHIN 120 NM OF THE COLD FRONT AND N OF 27N BETWEEN 40W-60W. A SECONDARY COLD FRONT REMAINS LARGELY NORTH OF THE DISCUSSION AREA EXTENDING FROM 30N65W TO BEYOND 32N63W. FARTHER SE...A SURFACE RIDGE DOMINATES THE REMAINDER OF THE CENTRAL AND EASTERN TROPICAL ATLC ANCHORED BY A 1020 MB HIGH CENTERED NEAR 22N36W. HOWEVER...A STRONG 985 MB LOW IS CENTERED NORTH OF THE AREA NEAR 34N12W AND EXTENDS A SURFACE TROUGH FROM THE LOW CENTER ACROSS THE CANARY ISLANDS TO 26N18W. ISOLATED SHOWERS ARE POSSIBLE WITH THE PASSAGE OF THE SURFACE TROUGH WITH STRONG NW WINDS N OF 28N E OF 19W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN