000 AXNT20 KNHC 041759 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU APR 04 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 EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC BY SIERRA LEONE NEAR 7N12W AND CONTINUES ALONG 4N14W TO EQ19W WHERE THE ITCZ BEGINS AND CONTINUES ALONG EQ25W EQ33W 1S40W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 1S TO 6N BETWEEN 8W AND 40W. ...DISCUSSION... GULF OF MEXICO... A LOW PRESSURE SYSTEM CONTINUES OVER THE NE GULF. THE 1013 MB LOW ASSOCIATED TO THIS SYSTEM IS LOCATED IN THE FLORIDA PANHANDLE NEAR 30N84W. A COLD FRONT EXTENDS SW FROM THE LOW ALONG 28N86W 26N89W 23N92W 20N94W. RADAR IMAGERY SHOW NUMEROUS RAINSHOWERS AND THUNDERSTORMS FROM TAMPA TO FORT MYERS ALSO EXTENDING WITHIN 200 NM FROM THE WEST FLORIDA COASTLINE FROM 25N- 29N. SCATTERED SHOWERS ARE OCCURRING ALONG THE REMAINING FRONTAL BOUNDARY. IN THE MIDDLE-UPPER LEVELS...THIS SYSTEM IS BEING SUPPORTED BY A CUT-OFF LOW LOCATED OVER THE SOUTHERN PLAINS AND ITS CONVECTION IS BEING ENHANCED BY UPPER LEVEL DIVERGENCE. A PREFRONTAL SURFACE TROUGH IS JUST WEST OF THE YUCATAN PENINSULA EXTENDING FROM 24N89W 21N90W 18N91W. SCATTERED SHOWERS ARE POSSIBLE ALONG THIS TROUGH AS WELL AS 10 NM EITHER SIDE OF THE AXIS. N-NW WIND RANGING FROM 15-25 KT SPREAD OVER THE WESTERN GULF WEST OF THE COLD FRONT WHILE S-SW WIND OF 15-20 KT DOMINATE THE EASTERN GULF E OF 90W. BROKEN TO OVERCAST SKIES ARE IN THE NW GULF N OF 25N AS WELL AS ALONG THE THE EASTERN COAST OF MEXICO BUT RAINSHOWERS ACTIVITY IS LIMITED DUE TO THE PRESENCE OF DRY AIR IN THE MIDDLE-UPPER LEVELS W OF 86W. OVER THE COURSE OF 24 HOURS...A STRONG JET OVER THE GULF EXTENDING TO THE WESTERN CARIBBEAN WILL DRIFT THE FRONTAL SYSTEM TO OVER WEST ATLC WITH THE TAIL OF IT EXTENDING TO THE FLORIDA STRAITS AND THE WESTERN CARIBBEAN. N-NW FLOW RANGING FROM 15-20 KT WILL BUILD OVER THE GULF AFTER THE PASSAGE OF THIS FRONT. CARIBBEAN SEA... STRONG PRESSURE GRADIENT CONTINUES OVER THE CARIBBEAN MAINTAINING EASTERLY TRADEWINDS OF 15-20 KT ACROSS MOST OF THE BASIN...HOWEVER STRONGER WINDS UP TO 30 KT MAY BE FOUND OVER THE CENTRAL CARIBBEAN S OF LA HISPANIOLA. THIS PRESSURE GRADIENT IS DUE TO THE LOWER PRESSURE OVER COLOMBIA AND THE SURFACE RIDGE OVER THE W ATLC. IN THE MIDDLE-UPPER LEVEL...A BROAD RIDGE ANCHORED BY A HIGH CENTERED OVER THE COLOMBIA-VENEZUELA BORDER COVERS THE ENTIRE CARIBBEAN. THE WESTERN PERIPHERY OF THIS RIDGE IS ADVECTING MOISTURE FROM THE E PACIFIC WHICH IS SUPPORTING LOW LEVEL CLOUDINESS AND HAZE OVER THE WESTERN CARIBBEAN W OF 80W... ISOLATED SHOWERS ARE POSSIBLE WITHIN THIS REGION. RAINSHOWERS ACTIVITY CAN ALSO BE FOUND IN THE SOUTHERN CARIBBEAN S OF 13N IN ASSOCIATION TO THE E PACIFIC MONSOON TROUGH. A SCREAMING EAGLE IS OVER THE LESSER ANTILLES PRODUCING RAINSHOWERS FROM ST KITTS TO ST LUCIA. CLEAR SKIES ARE OVER THE REMAINDER OF THE CARIBBEAN BEING ASSISTED BY DRY AIR SUBSIDENCE FROM THE MIDDLE-UPPER LEVELS. OVER THE COURSE OF 24 HOURS...THE COLD FRONT CURRENTLY OVER THE CENTRAL-EASTERN GULF WILL DRIFT EASTWARD TO THE W ATLC AND ITS TAIL WILL BE REACHING THE W CARIBBEAN FROM WESTERN CUBA TO HONDURAS. EASTERLY TRADEWINDS ARE EXPECTED TO CONTINUE E OF THE APPROACHING FRONT. ATLANTIC OCEAN... SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE OVER THE W ATLC N OF 26N AND WITHIN 130 NM OF THE E FLORIDA COAST RELATED WITH THE FRONTAL SYSTEM IN THE GULF OF MEXICO WITH ASSOCIATED LOW OVER THE FLORIDA PANHANDLE. THIS CONVECTION IS BEING SUPPORTED BY MIDDLE-UPPER LEVEL DIVERGENCE. A COLD FRONT EXTENDS ALONG 30N51W 27N55W TO 25N58W WHERE IT TRANSITIONS TO A STATIONARY FRONT ALONG 24N61W 23N64W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 70 NM EITHER SIDE OF THIS FRONTAL BOUNDARY. THE FRONT IS BEING SUPPORTED IN THE MIDDLE-UPPER LEVELS BY A BROAD TROUGH COVERING THE W ATLC AND A PORTION OF THE CENTRAL ATLC. SURFACE RIDGING DOMINATES THE REMAINDER OF THE ATLC N OF 18N E OF THE FRONT. WITHIN THE COURSE OF 24 HOURS...THE FRONT IN THE GULF OF MEXICO WILL DRIFT TO THE W ATLC OVER THE BAHAMAS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR