000 AXNT20 KNHC 071117 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST THU FEB 07 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXITS THE SIERRA LEONE COAST OF AFRICA NEAR 6N11W AND CONTINUES INTO THE E TROPICAL ATLC TO 6N14W. THE ITCZ COMMENCES NEAR 5N15W AND EXTENDS ALONG 4N17W 4N25W 3N31W TO 1N39W. WIDELY MODERATE CONVECTION IS FROM 2N-6N BETWEEN 12W AND 27W. ISOLATED SHOWERS ARE POSSIBLE ELSEWHERE ALONG THE ITCZ AXIS WITHIN 120 NM. ...DISCUSSION... GULF OF MEXICO... A SHORTWAVE UPPER TROUGH IS MOVING OVER LOWER MISSISSIPPI VALLEY. THIS SHORTWAVE UPPER TROUGH EXTENDS TO SOUTHERN LOUISIANA SUPPORTING A 1011 MB LOW PRESSURE SYSTEM LOCATED NEAR 29N90W. A COLD FRONT EXTENDS SW FROM THE LOW TO 27N92W 26N94W TO 25N97W. A WARM FRONT EXTENDS NE FROM THE LOW TO 29N88W 29N86W. THE WATER VAPOR IMAGERY SHOWS UPPER LEVEL MOISTURE SUPPORTING NUMEROUS SHOWERS N OF 27N BETWEEN 84W AND 90W. THE REMAINDER OF THE GULF REMAINS UNDER THE INFLUENCE OF A VERY LARGE UPPER RIDGE WITH AXIS OVER PANAMA WHICH ALSO COVERS THE CARIBBEAN AND PORTIONS OF THE W ATLC. THIS IS PROVIDING THE GULF MAINLY WITH SW FLOW ALOFT. BESIDES FOR THE ABOVE MENTIONED REGION FAIR WEATHER CONDITIONS ARE NOTED OVER THE REST OF THE GULF. RETURN FLOW IN THE RANGE OF 15-20 KT SPREADS MAINLY E OF 92W IN THE GULF. LIGHTER WINDS IN THE RANGE OF 5-15 KT ARE W OF 92W. HOWEVER EAST OF THE LOW AND N OF 28N STRONGER WINDS OF 25-30 KT ARE POSSIBLE. THE LOW IS EXPECTED TO CONTINUE A NORTHEASTWARD TRAJECTORY AND BE POSITIONED OFF THE SOUTH CAROLINA COAST NEAR 33N77W WITHIN 24 HOURS. CARIBBEAN SEA... A VERY BROAD UPPER RIDGE WITH AXIS OVER PANAMA DOMINATES THE CARIBBEAN AND EXTENDS INTO THE GULF OF MEXICO AS WELL AS PORTIONS OF THE W ATLC. WATER VAPOR IMAGERY CONTINUES TO INDICATE MODERATE TO STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT ACROSS THE ENTIRE BASIN. FAIR WEATHER IS ACROSS MOST OF THE CARIBBEAN WITH ONE AREA OF POSSIBLE ISOLATED SHOWERS OVER THE E CARIBBEAN FROM 10N-16N BETWEEN 61W-69W. TRADE WINDS IN THE RANGE OF 15-20 KT ARE OFF THE COLOMBIA COAST WITH GENERALLY 10-15 KT FLOW ELSEWHERE. THESE TRADE WINDS WILL PERSIST THROUGH THE NEXT 24 HOURS. ATLANTIC OCEAN... A SHORTWAVE UPPER TROUGH IS OVER THE NW ATLC N OF 26N BETWEEN 58W-71W SUPPORTING A WEAK COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 30N61W AND CONTINUES TO 28N62W. A SURFACE TROUGH IS SW OF THE COLD FRONT EXTENDING FROM 29N64W 27N65W TO 25N66W. A CLUSTER OF MODERATE CONVECTION IS ASSOCIATED WITH THIS TROUGH FROM 26N-29N BETWEEN 63W AND 66W. A SECOND SURFACE TROUGH IS IN THE CENTRAL ATLC EXTENDING FROM 29N48W TO 25N51W 22N54W. WIDELY SCATTERED SHOWERS CAN BE FOUND BETWEEN THE CENTRAL ATLC TROUGH AND THE W ATLC COLD FRONT FROM 27N-30N BETWEEN 51W AND 62W. AN UPPER LOW REMAINS OVER THE E ATLC CENTERED NEAR 28N22W WITH AN UPPER TROUGH EXTENDING SW TO 6N46W. ISOLATED SHOWERS ASSOCIATED TO THESE UPPER LEVEL FEATURES ARE POSSIBLE FROM 17N-30N BETWEEN 16W AND 25W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR