000 AXNT20 KNHC 231047 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU APR 23 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 5N9W 1N19W CROSSING THE EQUATOR NEAR 27W TO 1S39W TO NE BRAZIL NEAR 3S43W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 1N-5N BETWEEN 14W-25W. SCATTERED MODERATE CONVECTION IS FROM 2N-4N BETWEEN 27W-32W. SCATTERED MODERATE CONVECTION IS ALSO S OF 1N BETWEEN 43W-46W. ...DISCUSSION... GULF OF MEXICO... SFC HIGH PRESSURE...CURRENTLY CENTERED OVER THE NE WATERS NEAR 27N85W...IS SHIFTING E. WINDS ARE LIGHT AND VARIABLE ACROSS MUCH OF THE AREA...BUT SLY WINDS HAVE INCREASED TO 20 KT OVER THE FAR NW WATERS IN RESPONSE TO LOW PRESSURE OVER THE S CENTRAL PLAINS. E TO SE WINDS ARE EXPECTED TO INCREASE TO 20-25 KT OVER MUCH OF THE AREA TONIGHT AND FRI AS HIGH PRESSURE STRENGTHENS OFF THE SE CONUS COAST. DRY AIR IN THE MID AND UPPER LEVELS IS SUPPORTING FAIR WEATHER ACROSS THE ENTIRE REGION. MAINLY FAIR WEATHER IS EXPECTED TO CONTINUE OVER THE NEXT COUPLE OF DAYS...THOUGH ISOLATED SHOWERS WILL LIKELY DEVELOP IN THE STRONG LOW-LEVEL FLOW. THE CARIBBEAN SEA... SCATTERED MODERATE TO STRONG CONVECTION IS LOCATED OVER THE EXTREME SW CARIBBEAN S OF 11N W OF 80W. LOW-LEVEL LIFT FROM CONVERGENCE ALONG THE ITCZ AND UPPER DIFFLUENCE APPEAR TO BE THE PRIMARY FACTORS FUELING THE CONVECTION. HOWEVER...LOCAL AND SMALL SCALE EFFECTS OVER COLOMBIA ARE PROVIDING ENHANCEMENT FOR THE DEEPER ACTIVITY NOTED INLAND. SWLY FLOW ALOFT IS SPREADING SOME MOISTURE NE THOUGH IT APPEARS TO BE ONLY IN THE FORM OF MID-HIGH LEVEL CLOUDINESS. MORE DENSE CLOUDINESS IS EVIDENT OVER HISPANIOLA ASSOCIATED WITH A WEAK LOW-LEVEL TROUGH AND LIKELY ENHANCED BY UPSLOPE FLOW. TRADE WINDS ARE IN THE 20-25 KT RANGE OVER THE S CARIBBEAN...EXCEPT 25-30 KT NEAR THE COAST OF COLOMBIA...AND MAINLY 15-20 KT ELSEWHERE. WINDS ARE EXPECTED TO INCREASE OVER THE WRN HALF OF THE REGION AS HIGH PRESSURE STRENGTHENS OVER THE W ATLC TIGHTENING THE PRESSURE GRADIENT. THE ATLANTIC OCEAN... SCATTERED SHOWERS AND TSTMS ARE WITHIN 300 NM E OF A COLD FRONT EXTENDING FROM 32N66W TO 25N71W THEN STATIONARY TO THE WINDWARD PASSAGE. THIS ACTIVITY IS BEING ENHANCED BY STRONG SWLY UPPER FLOW AND A DIFFLUENT PATTERN BETWEEN THE ASSOCIATED TROUGH OVER THE NE CONUS AND A RIDGE OVER THE CENTRAL ATLC. A POST-FRONTAL TROUGH EXTENDS 31N70W TO 29N72W. FARTHER TO THE W...SURFACE HIGH PRESSURE IS DRIFTING SOUTHEASTWARD...BRINGING FAIR WEATHER CONDITIONS IN THE WAKE OF THE FRONTS AND TROUGH. OVER THE CENTRAL ATLC...DEEP LAYER TROUGHING REMAINS WELL DEFINED PROVIDING SOME SUPPORT FOR A WEAKENING STATIONARY FRONT EXTENDING FROM 32N34W TO 27N50W AND A WEAK TROUGH ALONG 35W N OF 26N. THE COMBINATION OF LOW-LEVEL CONVERGENCE AND INSTABILITY ALONG THE UPPER TROUGH AXIS IS PRODUCING SCATTERED SHOWERS AND TSTMS FROM 29N-32N BETWEEN 35W-38W. THE TIGHT PRESSURE GRADIENT BETWEEN THE FRONT AND HIGH PRES TO ITS N IS CAUSING STRONG NE 20-30 KT FLOW WITH HIGHER GUSTS N OF THE FRONT. AN UPPER JET EXTENDING NE FROM 9N41W TO THE CAPE VERDE ISLANDS IS ADVECTING SOME MOISTURE WITHIN 240 NM E OF THE JET AXIS. $$ CANGIALOSI