000 AXNT20 KNHC 112356 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON APR 11 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH NORTHERN COASTAL LIBERIA NEAR 06N11W TO 04N14W 03N17W. THE ITCZ CONTINUES FROM 03N17W TO 01N25W EQ42W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 85 NM N OF THE ITCZ AXIS BETWEEN 17W AND 20W...SIMILAR CONVECTION IS FROM 02S TO 4S BETWEEN 17W AND 20W. SCATTERED SHOWERS ARE FROM 03S TO 06N BETWEEN 30W AND 48W. ...DISCUSSION... THE GULF OF MEXICO... A COLD FRONT EXTENDS ACROSS THE GULF FROM COASTAL MISSISSIPPI NEAR 30N88W TO 25N90W 19N96W THEN ALONG EASTERN SIERRA MADRE IN MEXICO. THIS FRONT IS BEING SUPPORTED BY A MIDDLE TO UPPER LEVEL TROUGH EXTENDING FROM A LOW THAT IS OVER THE NORTHERN PLAINS. TWO LINES OF STRONG TO SEVERE CONVECTION ARE ACROSS ALABAMA AND OVER PENSACOLA FLORIDA WITH THUNDERSTORMS EXTENDING OVER THE GULF FROM 27N TO 30N BETWEEN 86W AND 90W. RAINSHOWERS ARE ALSO OCCURRING FROM 22N TO 27N WITHIN 130 NM EAST OF THE FRONT AND WITHIN 120 NM W OF THE FRONT S OF 22N. NW TO N WIND IN THE RANGE OF 10 TO 20 KT SPREAD WEST OF THE FRONT WHILE S TO SW WIND OF THE SAME MAGNITUDE COVERS THE REMAINDER OF THE GULF EAST OF THE FRONT. OVER THE COURSE OF 24 HOURS...THE COLD FRONT WILL BE EXTENDING ACROSS NORTHERN FLORIDA...THE EASTERN GULF TO THE YUCATAN PENINSULA. SURFACE RIDGING WILL DEVELOP W OF THE FRONT ANCHORED BY A SURFACE HIGH OVER TEXAS. RAINSHOWERS WILL CONTINUE TO AFFECT THE GULF WATERS. THE CARIBBEAN SEA... A RELATIVELY STRONG PRESSURE GRADIENT BETWEEN A BROAD HIGH ACROSS THE ATLC BASIN AND A LOW PRESSURE OVER NORTHERN COLOMBIA IS PROVIDING EASTERLY TRADEWINDS UP TO 20 KT OVER THE CENTRAL AND EASTERN CARIBBEAN WITH A MAXIMUM OF 25 KT ALONG THE COAST OF COLOMBIA. OVER THE WESTERN CARIBBEAN SE WINDS UP TO 25 KT SPREAD W OF 80W. IN THE MIDDLE-UPPER LEVELS A RIDGE AXIS EXTENDS ALONG THE EASTERN CONUS AND OVER THE WESTERN CARIBBEAN. WATER VAPOR IMAGERY SHOW DRY AIR EMBEDDED WITHIN THE MIDDLE-UPPER LEVEL WIND FLOW WHICH IS PROVIDING WITH FAIR WEATHER TO MOST OF THE REGION. PATCHES OF LOW LEVEL MOISTURE MAY BE CAUSING SCATTERED/ISOLATED SHOWERS OVER THE EASTERN CARIBBEAN FROM 14N TO 17N EAST OF 68W. SIMILAR CONVECTION CAN BE EXPECTED WITHIN 150 NM OF THE COASTS OF COLOMBIA...PANAMA AND COSTA RICA. OVER THE COURSE OF 24 HOURS...NO CHANGES IN THE WIND PATTERN IS EXPECTED. HOWEVER RAINSHOWERS MAY DEVELOP OVER THE WESTERN CARIBBEAN AS THE COLD FRONT OVER THE CENTRAL GULF DRIFTS EASTWARD. THE ATLANTIC OCEAN... BROAD SURFACE RIDGING COVERS THE WEST...CENTRAL AND EASTERN ATLC ANCHORED BY A 1024 MB HIGH CENTERED NEAR 29N56W AND 1023 MB HIGH NEAR 32N31W. A COLD FRONT N OF 30N TRANSITIONS INTO A STATIONARY FRONT NEAR 30N21W AND EXTENDS ALONG 28N31W 25N40W 24N54W. THIS FRONT IS BEING SUPPORTED BY A BROAD TROUGH OVER THE W ATLC IN THE MIDDLE-UPPER LEVELS AS WELL AS ANOTHER UPPER LEVEL TROUGH OVER THE EASTERN ATLC N OF 30N. NO CONVECTIVE PRECIPITATION IS OBSERVED ASSOCIATED TO THIS FRONT...HOWEVER ISOLATED SHOWERS ARE POSSIBLE WITHIN 60 NM EITHER SIDE OF THE FRONTAL BOUNDARY. THE HIGH PRESSURE OVER THE CENTRAL ATLC IS EXPECTED TO REMAIN STATIONARY WHILE THE FRONT WEAKENS. BY LATE NIGHT ON FRIDAY A COLD FRONT WILL ENTER THE W ATLC WATERS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR