000 AXNT20 KNHC 271805 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED MAR 27 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL LIBERIA NEAR 5N10W TO 4N16W 2N23W. A CLUSTER OF MODERATE CONVECTION EXTENDS S OF THE MONSOON TROUGH TO THE EQUATOR BETWEEN 7W AND 14W. CLUSTERS OF SIMILAR CONVECTION ARE FURTHER WEST IN THE VICINITY OF THE MONSOON TROUGH FROM THE EQUATOR TO 5N BETWEEN 18W AND 23W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 270 NM FROM EITHER SIDE OF THE ITCZ AXIS. ...DISCUSSION... THE GULF OF MEXICO... SURFACE RIDGING CONTINUE OVER THE GULF ANCHORED BY A 1031 MB HIGH PRESSURE LOCATED OVER MISSISSIPPI NEAR 33N88W. THE HIGH PRESSURE IS PROVIDING NORTHEASTERLY WINDS OF 10-15 KT TO THE EASTERN GULF E OF 91W AND THE SOUTHERN GULF S OF 22N WHILE IN THE WESTERN GULF N OF 22N EASTERLY-SOUTHEASTERLY WINDS OF THE SAME MAGNITUDE DOMINATE. THIS SURFACE WIND FLOW OVER THE WESTERN GULF IS BANKING LOW LEVEL CLOUDS FROM THE SOUTHERN TIP OF TEXAS ALL THE WAY DOWN ALONG THE E COAST OF MEXICO TO CAMPECHE CITY IN THE WESTERN YUCATAN PENINSULA. METAR OBSERVATIONS ALONG THE E COAST OF MEXICO HAVE REPORTED HAZE AND FOG. NO CONVECTIVE PRECIPITATION IS OBSERVED AT THIS TIME...HOWEVER THE SATELLITE COMPOSITE TOTAL PRECIPITABLE WATER IMAGERY SUGGEST THE POSSIBILITY OF ISOLATED SHOWERS S OF 23N W OF 90W. CLEAR SKIES AND FAIR WEATHER DOMINATE THE REMAINDER OF THE BASIN ASSISTED BY DRY AIR ALOFT EMBEDDED IN MIDDLE TO UPPER LEVEL WESTERLY FLOW. OVER THE COURSE OF 24 HOURS...ANTICYCLONIC WIND FLOW WILL CONTINUE ACROSS THE BASIN AS THE HIGH OVER MISSISSIPPI REMAINS NEARLY STATIONARY. WIND MAGNITUDE IS EXPECTED TO MAINTAINED WITHIN 10-15 KT. THE CARIBBEAN SEA... AS OF 1500 UTC...THE PORTION OF THE COLD FRONT OVER THE W ATLC EXTENDING TO THE WESTERN CARIBBEAN HAS TRANSITIONED TO A SHEARLINE ALONG 19N73W 17N78W AND THE NORTHERN COAST OF HONDURAS NEAR 15N83W. WEST OF THE SHEARLINE...NORTHEASTERLY FLOW UP TO 25 KT IS BANKING LOW LEVEL CLOUDS ALONG THE COAST OF HONDURAS WHERE CONTINUOUS RAIN AND HAZE HAVE BEEN REPORTED. SHOWERS ARE ALSO OCCURRING FROM THE WINDWARD PASSAGE ALL THE WAY THROUGH JAMAICA AND ALONG THE REMAINDER OF THE SHEARLINE. NORTHEASTERLY FLOW IN THE RANGE OF 15-25 KT SPREAD E OF THE SHEARLINE TO 73W. IN THE SOUTHERN CARIBBEAN...SHOWERS AND POSSIBLE THUNDERSTORMS ARE WITHIN 100 NM OF THE NORTHERN COAST OF COLOMBIA WHERE NORTHEASTERLY WIND OF 25 KT FLOWS TOWARD AN INLAND AREA OF LOW PRESSURE. OVER THE REMAINDER OF THE CARIBBEAN EASTERLY TRADEWINDS OF 10-15 KT ABOUNDS AS WELL AS FAIR WEATHER CONDITIONS BEING SUPPORTED BY DRY AIR ALOFT EMBEDDED IN MIDDLE TO UPPER LEVEL SOUTHWESTERLY FLOW. THE SHEARLINE WILL DISPLACE SLOWLY EASTWARD TOWARD DOMINICAN REPUBLIC WITH AXIS CROSSING THE WESTERN CARIBBEAN ALL THE WAY TO COASTAL WATERS OF COSTA RICA. LITTLE CHANGES ARE EXPECTED ELSEWHERE. THE ATLANTIC OCEAN... A COLD FRONT CONTINUES TO MOVE TOWARD THE CENTRAL ATLC EXTENDING ALONG 30N51W 25N61W 20N71W TO WEST OF HAITI NEAR 19N73W THEN TRANSITIONING INTO A SHEARLINE OVER THE WESTERN CARIBBEAN. ISOLATED SHOWERS ARE POSSIBLE ALONG THE FRONTAL BOUNDARY AS WELL AS WITHIN 70 NM EAST OF IT N OF 22N AND WITHIN 120 NM W OF THE FRONT S OF 22N. A BROAD SURFACE RIDGE COVERS THE CENTRAL AND EASTERN ATLC N OF 11N ANCHORED BY A 1021 MB HIGH PRESSURE NEAR 25N34W. A DISSIPATING COLD FRONT IS OVER THE E ATLC EXTENDING FROM 30N18W TO 27N24W. NO PRECIPITATION IS ASSOCIATED TO THIS FRONT. THE COLD FRONT WILL CONTINUE TO MOVE OVER THE CENTRAL ATLC WATERS WHILE THE BROAD HIGH PRESSURE IN THE REGION DRIFT SLIGHTLY NORTHEASTWARD. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR