000 AXNT20 KNHC 161136 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT APR 15 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1000 UTC. ...ITCZ... ITCZ AXIS IS ALONG 8N10W 1N25W INTO S AMERICA NEAR 4N52W. WIDELY SCATTERED SHOWERS AND ISOLATED MODERATE CONVECTION WITHIN 90 NM EITHER SIDE OF AXIS BETWEEN 17W-40W AND W OF 47W. ...DISCUSSION... GULF OF MEXICO... RATHER BENIGN WEATHER PATTERN CONTINUES OVER THE GULF WITH HIGH PRESSURE DOMINATING. MID/UPPER RIDGING IS GENERATING STRONG SUBSIDENCE AND VERY DRY/STABLE CONDITIONS RESULTING IN NEAR CLOUD FREE CONDITIONS. AT THE SURFACE...1017 MB HIGH PRESSURE CURRENTLY OVER THE FLORIDA STRAITS WILL SHIFT E INTO THE W ATLC EARLY TODAY BUT SUBTROPICAL RIDGE WILL CONTINUE TO STRETCH WESTWARD OVER THE AREA. DRY CONDITIONS SHOULD PREVAIL THROUGH EARLY WEEK UNTIL A WEAK BACKDOOR COLD FRONT OVER THE W ATLC DROPS SWD AFFECTING FLORIDA TUE AND WED. A FEW SHOWERS MAY ACCOMPANY THE FRONT BUT IT IS NOT EXPECTED TO BE A BIG WEATHER MAKER AT THIS POINT. CARIBBEAN SEA... BROAD MID/UPPER LEVEL TROUGH ACROSS THE W ATLC CONTINUES TO AMPLIFY AND PUSH EASTWARD WITH S EXTENT AFFECTING THE NW CARIBBEAN FROM HISPANIOLA TO BELIZE. THE LOW LEVEL REMNANTS OF A FRONTAL BOUNDARY OVER THE CENTRAL ATLC TRAILS SWD OVER PUERTO RICO TO JUST S OF JAMAICA NEAR 17N78W. WIDELY SCATTERED SHOWERS ARE NOTED ALONG THE BOUNDARY INCLUDING PUERTO RICO...HISPANIOLA...AND WINDWARD PASSAGE. CONFLUENT FLOW ALOFT INTO THE BASE OF THE UPPER TROUGH IS PRODUCING MODERATE TO STRONG SUBSIDENCE ELSEWHERE ACROSS THE W HALF OF THE CARIBBEAN. OVER THE E CARIBBEAN...AN E/W ORIENTED MIDDLE TO UPPER LEVEL RIDGE NOSES INTO THE AREA OVER THE WINDWARD ISLANDS TO THE ABC ISLANDS. HIGH LEVEL MOISTURE MOVING NWD AROUND THE W PERIPHERY OF THE RIDGE FROM S AMERICA IS PRODUCING SOME HIGH CLOUDINESS. SHOWERS OVER THE LESSER ANTILLES SAT EVENING HAVE SHIFTED MOSTLY E OF THE AREA OVERNIGHT. OWING TO A WEAKER THAN USUAL ATLANTIC SUBTROPICAL RIDGE...ELY TRADES ARE RATHER WEAK IN THE CARIBBEAN AND SHOULD REMAIN SO AS A NEW FRONT MOVES INTO THE W ATLC EARLY IN WORK WEEK. ATLC... A FAIRLY BROAD TROUGH-RIDGE PATTERN PREVAILS IN THE UPPER LEVELS OVER THE SUBTROPICAL ATLC WITH A TROUGH W OF 50W AND RIDGE E OF 50W. SIGNIFICANT WEATHER CONTINUES TO BE FOCUSED OVER THE CENTRAL ATLC WHERE GOOD UPPER LEVEL DYNAMICS ARE PRODUCING NUMEROUS SHOWERS/TSTMS ALONG AND AHEAD OF A 1007 MB LOW NEAR 29N49W WITH COLD FRONT SWD TO 22N57W. THE STRONGEST AND MOST NUMEROUS OF THE THIS ACTIVITY IS CURRENTLY NOTED N OF 28N BETWEEN 35W-45W. ADDITIONALLY...SCATTERED SHOWERS ARE NOTED FURTHER S WITHIN SEVERAL HUNDRED NM EITHER SIDE OF THE WEAKENING PORTION OF THE FRONT WHICH TRAILS SWD TO PUERTO RICO. SHOWERS/TSTMS WILL CONTINUE ALONG THE FRONT DURING THE NEXT 24 HRS AS IT PUSHES SEWD INTO THE E ATLC. ELSEWHERE...CONFLUENT FLOW AND SUBSIDENCE ALOFT IS PRODUCING DRY/TRANQUIL CONDITIONS OVER THE W ATLC. OVER THE E ATLC...SURFACE HIGH PRESSURE FROM THE AZORES TO 20N45W IS FORECAST TO STRENGTHEN WHICH SHOULD INCREASE THE TRADES ESPECIALLY E OF 40W. OVER THE TROPICAL ATLC...A LARGE AND WELL-DEFINED MID/UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 12N50W WITH ASSOCIATED RIDGE EXTENDING E/W FROM THE LESSER ANTILLES TO W AFRICA NEAR DAKAR. STRONG MID/UPPER SUBSIDENCE ALONG THE RIDGE AXIS IS KEEPING THE ITCZ AND ASSOCIATED CONVECTION SUPPRESSED TO RIGHT ALONG THE EQUATOR. $$ RHOME