000 AXNT20 KNHC 111748 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED MAR 11 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 5N10W CROSSING THE EQUATOR NEAR 21W CONTINUING ALONG 1S30W 1S40W INTO NE BRAZIL NEAR 3S45W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS S OF 4N BETWEEN 7W-10W...AND S OF 5N BETWEEN 12W-20W. SCATTERED MODERATE CONVECTION IS ALONG THE EQUATOR BETWEEN 20W-24W...AND BETWEEN 36W-40W. SIMILAR CONVECTION IS ALSO FOUND S OF 2N BETWEEN 42W-50W. ...DISCUSSION... GULF OF MEXICO... A WEAK HIGH PRES RIDGE...ANCHORED ON A 1023 MB HIGH OVER THE FAR NE CORNER OF THE GULF...LIES OVER THE GULF WATERS. THIS SYSTEM IS PRODUCING LIGHT WINDS...EXCEPT 15-20 KT E TO SE FLOW OVER THE WRN PORTION OF THE GULF...INCLUDING THE BAY OF CAMPECHE. A QSCAT PASS FROM AROUND 1135 UTC CONFIRMED THESE WIND SPEEDS. ALOFT...A MID-UPPER LEVEL RIDGE DOMINATES MUCH OF THE AREA. THIS FEATURE IS BECOMING INCREASINGLY ELONGATED DUE TO AN APPROACHING UPPER TROUGH FROM THE W. SWLY WINDS BETWEEN THE TROUGH AND THE RIDGE ARE TRANSPORTING A BAND OF MID/UPPER LEVEL MOISTURE FROM THE EPAC ACROSS N-CENTRAL MEXICO INTO THE N GULF STATES. LITTLE OF THIS MOISTURE IS ENTERING THE GULF. IN FACT... WATER VAPOR IMAGERY REVEALS WIDESPREAD DRY AIR ACROSS NEARLY THE ENTIRE REGION...LEADING TO FAIR CONDITIONS. THE NEXT COLD FRONT WILL APPROACH THE N GULF TONIGHT BEFORE BECOMING STATIONARY THROUGH SAT. CARIBBEAN SEA... FRESH TO STRONG TRADE WINDS CONTINUES TO BLOW ACROSS THE SOUTH- CENTRAL CARIBBEAN WHERE A QSCAT PASS FROM AROUND 1130 UTC SHOWED NE WINDS OF 20-30 KW WITH A COUPLE OF WIND BARBS OF 35 KT NEAR THE COAST OF COLOMBIA. TYPICAL SHALLOW MOISTURE EMBEDDED IN THE TRADE WINDS IS NOTED ACROSS MUCH OF THE AREA PRODUCING ISOLATED TO SCATTERED PASSING SHOWERS. IN THE MID AND UPPER LEVELS...A RIDGE COVERS CUBA...THE NW CARIBBEAN AND THE MAJORITY OF CENTRAL AMERICA WHILE A TROUGH STRETCHES FROM HISPANIOLA TO THE SW CARIBBEAN. CONFLUENCE ALOFT IS ENHANCING SUBSIDENCE NEAR AND W OF THE TROUGH AXIS...WHILE DIFFLUENCE IS CAUSING ONLY SLIGHT MOISTENING E OF THE AXIS. THE OVERALL WEATHER PATTERN ACROSS THE BASIN WILL CHANGE LITTLE OVER THE NEXT DAY OR SO. ATLANTIC OCEAN... AN OCCLUDED 994 MB LOW PRES SYSTEM IS CENTERED NEAR 32N52W. THIS LOW IS FORECAST TO MOVE SE...AND INTO THE DISCUSSION AREA IN ABOUT 24 HOURS. THE ATTENDANT COLD FRONT EXTENDS FROM THE TRIPLE POINT NEAR 32N57W SW THEN MAINLY W ALONG 24N54W 23N65W 25N70W THEN DISSIPATING TO 27N74W. A NARROW BAND OF MAINLY LOW-LEVEL CLOUDS IS NOTED ALONG MUCH OF THE FRONTAL BOUNDARY WHILE A BAND OF SCATTERED SHOWERS AND TSTMS IS WITHIN 200 NM AHEAD OF THE FRONT N OF 26N. A DIFFLUENT PATTER ALOFT IS HELPING TO INDUCE THIS CONVECTIVE ACTIVITY. WINDS TO STORM FORCE ARE ESTIMATED W OF THE FRONT IN THE COLD SECTOR OF THE LOW DUE THE TIGHT PRES GRADIENT BETWEEN THE LOW AND A SFC RIDGE OVER THE W ATLC. ANOTHER LOW PRES SYSTEM...CURRENTLY CENTERED JUST WEST OF THE AZORES...CONTINUES TO PULL AWAY FROM THE AREA. A SFC TROUGH... REMNANTS OF THE ASSOCIATED COLD FRONT OVER THE FORECAST REGION IS ANALYZED FROM 31N31W TO NEAR 20N40W. ANOTHER SFC TROUGH IS OBSERVED OVER THE DEEP TROPICS AND RUNS FROM 15N43W TO THE COAST OF FRENCH GUIANA. AN AREA OF SCATTERED SHOWERS IS NEAR THE TAIL END OF THIS SECOND TROUGH. BOTH TROUGHS SHOW UP WELL ON THE TPW PRODUCT WITH A DECENT MOISTURE SURGE. THE E ATLC IN UNDER THE INFLUENCE OF A WEAK SFC RIDGE. IN THE DEEP TROPICS...STRONG WLY FLOW ALOFT ON THE N SIDE OF A BROAD UPPER-LEVEL RIDGE IS TRANSPORTING MID-HIGH LEVEL CLOUDINESS FROM THE LESSER ANTILLES TO WEST AFRICA. THE RIDGE IS ALSO ENHANCING CONVECTION ALONG THE ITCZ AXIS...PARTICULARLY E OF 20W. $$ GR