000 AXNT20 KNHC 040546 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON MAY 04 2009 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...THE ITCZ... THE ITCZ AXIS IS ALONG 4N7W 1N20W TO THE EQUATOR AT 35W AND INTO NE BRAZIL NEAR 2S45W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS ALONG THE COAST OF LIBERIA AND ADJACENT COASTAL WATERS FROM 1N-7N BETWEEN 6W-9W. SIMILAR CONVECTION IS FROM THE EQUATOR TO 3N BETWEEN 31W-36W. ...DISCUSSION... GULF OF MEXICO... THE COMBINATION OF BROAD SURFACE LOW PRESSURE ACROSS THE MEXICAN PLATEAU AND A SURFACE RIDGE EXTENDING FROM THE W ATLC ACROSS THE FLORIDA PENINSULA INTO THE NRN GULF IS PRODUCING SE WINDS FROM 10 TO 20 KT. NO ORGANIZED AREAS OF DEEP CONVECTION ARE OCCURRING OVER THE GULF...HOWEVER A MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS MOVING ACROSS THE SE CONUS AND IS SUPPORTING A COLD FRONT THAT IS POSITIONED INLAND ALONG THE TEXAS GULF COAST. THIS FRONT IS FORECAST TO GRAZE THE NW GULF WATERS OVER THE NEXT 24 HOURS BEFORE WEAKENING SLIGHTLY AND LIFTING NORTHWARD AS A STATIONARY BOUNDARY. UPPER LEVEL WINDS WILL CONTINUE TO TRANSITION TO MORE OVERALL ZONAL FLOW AS THE SHORTWAVE TROUGH LIFTS TO THE NE. ONLY A BAND OF CIRRUS CLOUDS STRETCH ACROSS THE NE GULF ON DIFFLUENT FLOW LOCATED ACROSS THE ERN GULF AND FLORIDA. CARIBBEAN SEA... FRESH TRADEWINDS REMAIN ACROSS THE CARIBBEAN AS THE ANALYZED PRESSURE FIELD CONTINUES TO EXHIBIT A RELATIVELY RELAXED GRADIENT. A SURFACE TROUGH EXISTS IN THE ERN CARIBBEAN EXTENDING FROM THE ANEGADA PASSAGE SWD ALONG 64W TO THE NE COAST OF VENEZUELA. SCATTERED SHOWERS ARE AFFECTING THE LESSER ANTILLES AND NE CARIBBEAN MAINLY N OF A SAINT LUCIA TO ERN PUERTO RICO LINE...AS OBSERVED FROM THE GUADELOUPE...MARTINIQUE AND PUERTO RICO RADARS. ELSEWHERE...AN UPPER LEVEL HIGH CENTERED OVER NRN COLOMBIA EXTENDS RIDGING TO THE NW ACROSS CENTRAL AMERICA AS FAR N AS BELIZE. UPPER DIFFLUENCE IS GENERATING A FEW ISOLATED SHOWERS AND TSTMS ACROSS CENTRAL AMERICA WITH MORE SCATTERED ACTIVITY INLAND ACROSS NRN SOUTH AMERICA. DEBRIS MOISTURE FROM THE DEEP CONVECTION OVER COLOMBIA AND VENEZUELA...IN THE FORM OF CIRRUS CLOUDS...IS SPREADING NE ACROSS THE CARIBBEAN S OF 18N. ATLANTIC OCEAN... THE ATLANTIC IS DOMINATED BY A SURFACE HIGH PRESSURE CENTERED WELL NORTH OF THE DISCUSSION AREA NEAR 46N23W WITH RIDGING EXTENDING WEST-SOUTHWESTWARD TO 32N58W AND TO THE FLORIDA PENINSULA. TWO SMALLER SCALE FEATURES ARE OF INTEREST WHICH ARE EMBEDDED WEAKNESSES WITHIN THE SURFACE RIDGE. THE FIRST IS A SURFACE TROUGH N OF PUERTO RICO ALONG 67W FROM ROUGHLY 19N TO 27N. THIS TROUGH HAS BEEN PROGRESSING W-NW WITH A MIDDLE TO UPPER LEVEL LOW OBSERVED ON WATER VAPOR IMAGERY W OF THE SURFACE TROUGH CENTERED NEAR 27N70W. SCATTERED SHOWERS ARE PRESENT WITHIN 90 NM OF A LINE FROM 21N62W TO 28N68W. THE SURFACE WINDS ARE ENHANCED E OF THE TROUGH AXIS WITH E TO SE WINDS OF UP TO 20 KT. THE SECOND FEATURE IS A SURFACE TROUGH EXTENDING FROM 26N38W TO BEYOND 32N42W. SCATTERED SHOWERS ARE OCCURRING WITHIN 300 NM E OF THE TROUGH AXIS N OF 27N. A BOARD UPPER LOW CENTERED NEAR 32N38W ASSOCIATED WITH THE SURFACE TROUGH DOMINATES THE UPPER LEVEL WINDS OVER MOST OF THE CENTRAL ATLC WITH CYCLONICALLY TURNING WINDS OBSERVED AS FAR S AS 10N. FINALLY...THERE IS AN ENHANCEMENT OF NELY SURFACE WINDS OF 20-25 KT NORTHEAST OF THE CAPE VERDE ISLANDS TO THE WEST COAST OF MAURITANIA AND SENEGAL. OVER THE NEXT FEW DAYS...THE SURFACE TROUGH N OF PUERTO RICO IS FORECAST TO CONTINUE MOVING NORTHWESTWARD...WHILE THE TROUGH IN THE CENTRAL ATLANTIC SHOULD GRADUALLY FILL. $$ HUFFMAN