000 AXNT20 KNHC 140000 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU APR 13 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE 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. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 5N10W 2N20W 2N30W 1S45W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN AROUND 100 NM NORTH OF THE AXIS BETWEEN 22W-36W. SIMILAR CONVECTION IS OVER LIBERIA IN AFRICA AND OVER NE BRAZIL. ...DISCUSSION... THE GULF OF MEXICO... A MIDDLE/UPPER LEVEL RIDGE EXTENDS FROM AN UPPER HIGH IN THE EPAC AND COVERS MUCH OF MEXICO AND THE GULF. UPPER LEVEL MOISTURE IS BEING ADVECTED FROM THE EPAC ACROSS THE NORTHERN PORTION OF MEXICO AND THE GULF SOUTH OF 26N. DRIER AIR IS FOUND ACROSS THE AREA NORTH OF 26N. EAST OF THE RIDGE AN UPPER LEVEL TROUGH EXTENDS ALONG THE EASTERN U.S. AND CUBA TO THE WESTERN CARIBBEAN. AT THE SURFACE...HIGH PRESSURE RIDGE DOMINATES THE AREA. NO FRONTS ARE EXPECTED TO ENTER THE GULF TROUGH THE UPCOMING WEEKEND. HIGH PRES RIDGE WILL MOVE S OVER THE N GULF TONIGHT AND FRIDAY. AS THE RIDGE MOVES E SAT THROUGH TUE...SLY FLOW WILL RETURN TO THE WESTERN GULF. THE CARIBBEAN SEA AND THE ATLANTIC OCEAN WEST OF 60W... A MIDDLE/UPPER TROUGH LIES ACROSS THE EASTERN U.S. AND CUBA TO THE WESTERN CARIBBEAN...WITH AN UPPER LOW OVER THE CENTRAL BAHAMAS AT MID LEVELS. SLY FLOW ON THE EAST SIDE OF THE TROUGH IS ENHANCING THE DEVELOPMENT OF SHOWERS AND TSTMS OVER COLOMBIA AND PARTS OF VENEZUELA AS WELL AS OVER HISPANIOLA...PUERTO RICO AND THE VIRGIN ISLANDS. THIS UPPER LOW IS FORECAST TO WEAKEN BUT A BROAD TROUGH WILL PERSIST ACROSS THE EASTERN BAHAMAS/CUBA AND THE NW CARIBBEAN DURING THE NEXT 24 HOURS OR SO. HUMID AND UNSTABLE WEATHER CONDITIONS WILL PERSIST ACROSS THE GREATER ANTILLES...THANKS TO THE PRESENCE OF THIS UPPER TROUGH. AT THE SURFACE...A 1011 MB LOW PRESSURE CENTER IS NEAR 21N70W. A COLD FRONT ENTERS THE CENTRAL ATLC NEAR 31N-54W THEN CONTINUES SW TO THE 1011 MB LOW CENTER. A LARGE AREA OF MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS AND ISOLATED TSTMS IS ASSOCIATED WITH THE LOW AND THE FRONTAL BOUNDARY FROM 20-30N BETWEEN 55W-70W. HIGH CLOUDS ARE STREAMING NWD FROM VENEZUELA Y COLOMBIA INTO THE EASTERN CARIBBEAN SEA TOWARD PUERTO RICO AND THE LEEWARD ISLANDS. MODERATE TO STRONG NELY FLOW IS STILL BLOWING JUST NORTH OF THE COLD FRONT. THESE WINDS ARE AFFECTING SOUTH FLORIDA AND THE WESTERN BAHAMAS. MODERATE NLY WINDS ARE OVER THE NW CARIBBEAN. TRADE WINDS WILL REMAIN LIGHT TO MODERATE ACROSS THE REMAINDER OF THE CARIBBEAN SEA. COMPUTER MODELS INDICATE THAT THE SURFACE LOW WILL MOVE NEWD WHILE SLIGHTLY DEEPENS. THE REST OF THE ATLANTIC OCEAN... A RIDGE/TROUGH/RIDGE PATTERN CONTROLS THE REST OF THE ATLANTIC OCEAN. A MIDDLE TO UPPER RIDGE DOMINATES THE CENTRAL ATLANTIC WHILE A DEEP LAYER TROUGH IS OVER THE E ATLC ALONG 27-28W. A 80-100 KT SWLY JET RUNS SE OF THE TROUGH AND EXTENDS NEWD FROM 23N-27W TO 31N-18W AND BEYOND...PRODUCING SCATTERED SHOWERS OVER THE CANARY ISLANDS AND THE ADJACENT WATERS. A MIDDLE/UPPER RIDGE COVERS W AFRICA...WITH AN UPPER HIGH NEAR 19N AND THE PRIME MERIDIAN AT MID LEVELS. AT THE SURFACE...A 1010 MB LOW PRESSURE CENTER IS NEAR 29.5N25.5W. WIDELY SCATTERED MODERATE SHOWERS ARE ASSOCIATED WITH THIS LOW...MAINLY EAST OF THE CENTER. $$ GR