000 AXNT20 KNHC 010541 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON JUN 01 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. ...TROPICAL WAVES... A TROPICAL WAVE IS LOCATED OVER THE WINDWARD ISLANDS ALONG 61W S OF 14N MOVING W 15-20 KT. THIS WAVE IS ASSOCIATED WITH A NARROW MAXIMUM IN TOTAL PRECIPITABLE WATER AHEAD OF DRY LOW-MID LEVEL AIR IN PART ASSOCIATED WITH SAHARAN DUST. THE POSITION OF THE WAVE IS BASED MAINLY ON THIS TPW FIELD...AS LITTLE SIGNATURE IS APPARENT IN THE LOW-MID LEVEL CLOUDS OR IN SFC OBSERVATIONS. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 7N12W 4N22W 1N40W TO THE EQUATOR 52W. SCATTERED MODERATE CONVECTION IS WITHIN 240 NM EITHER SIDE OF THE AXIS E OF 22W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN 26W-36W. ...DISCUSSION... GULF OF MEXICO... THE REMNANTS OF A FRONT ARE MEANDERING OVER THE SE AND S CENTRAL GULF FROM NEAR NAPLES FLORIDA TO 25N87W TO THE NW CORNER OF THE YUCATAN PENINSULA. THIS BOUNDARY IS ASSISTING IN PRODUCING SCATTERED SHOWERS AND TSTMS ALONG AND TO THE S OF THE TROUGH AXIS. WEAK HIGH PRESSURE IS LOCATED OVER THE N MIDDLE GULF ALLOWING WINDS TO BE LIGHT AND VARIABLE ACROSS MUCH OF THE N WATERS AND PROMOTING GENERALLY FAIR WEATHER. MOISTURE INCREASES OVER THE FAR WRN WATERS IN RESPONSE TO DEEP LAYER TROUGHING OVER THE WESTERN CONUS. HOWEVER...DOPPLER RADAR AND LIGHTNING DATA SUGGEST THAT MOST OF THE TSTM ACTIVITY IS LOCATED INLAND OVER MEXICO AND TEXAS. LOOKING AHEAD A DAY OR TWO...NWP MODELS SUGGEST THAT THE OLD FRONT WILL GRADUALLY DISSIPATE ALLOWING SFC RIDGING TO BECOME BETTER ESTABLISHED ACROSS THE AREA. CARIBBEAN SEA... THE MID-UPPER PATTERN IS QUITE AMPLIFIED OVER THE CARIBBEAN WITH A RIDGE OVER THE WRN HALF AND TROUGHING OVER THE ERN HALF. DIFFLUENCE ALOFT COUPLED WITH LOW-LEVEL CONVERGENCE ALONG A OLD FRONTAL BOUNDARY OVER THE SE GULF OF MEXICO IS PRODUCING SCATTERED SHOWERS AND TSTMS OVER THE YUCATAN PENINSULA...YUCATAN CHANNEL...AND CUBA. SIMILAR ACTIVITY IS OCCURRING OVER PORTIONS OF CENTRAL AMERICA ENHANCED BY THE ITCZ. THE ATMOSPHERE IS MORE STABLE OVER THE CENTRAL CARIBBEAN IN AN UPPER CONFLUENT AREA BETWEEN THE TROUGH AND RIDGE. SW FLOW ALOFT E OF THE TROUGH AXIS IS ADVECTING MOISTURE ACROSS THE SE CARIBBEAN...THOUGH IT IS NOT RESULTING IN ANY SIGNIFICANT SHOWER OR TSTM ACTIVITY. IN THE LOWER LEVELS...SHORTWAVE IR IMAGERY AND QUIKSCAT DATA SHOW EVIDENCE OF A WEAK TROUGH OVER AND N OF THE VIRGIN ISLANDS... GENERATING ISOLATED SHOWERS AND TSTMS IN ITS VICINITY. TRADE WINDS REMAIN 20-30 KT ACROSS THE S CENTRAL PORTION DUE TO THE PRESSURE GRADIENT BETWEEN HIGH PRES OVER THE SUBTROPICAL CENTRAL ATLC AND LOWER PRES OVER NRN SOUTH AMERICA. WINDS NEAR 20 KT ARE OCCURRING OVER THE TOPOGRAPHICALLY ENHANCED GULF OF HONDURAS. LITTLE CHANGE IN THESE FLOWS ARE FORECAST OVER THE NEXT COUPLE OF DAYS. ATLANTIC OCEAN... MUCH OF THE ATLC DISCUSSION ZONE IS QUIET TONIGHT...ONLY A FEW AREAS OF UNSETTLED WEATHER TO MENTION. SCATTERED SHOWERS AND TSTMS ARE LOCATED OVER THE WRN BAHAMAS ASSOCIATED WITH AN UPPER JET AND AN OLD FRONTAL BOUNDARY. THE ASSOCIATED THINNING DEBRIS MOISTURE HAS SPREAD WELL TO THE NE TO BERMUDA. HIGHLY AMPLIFIED DEEP LAYER RIDGING DOMINATED THE CENTRAL ATLC...THOUGH AN UPPER LOW AND SFC TROUGH NEAR THE VIRGIN ISLANDS ARE INTERRUPTING THE RIDGE SLIGHTLY. NONETHELESS...FAIR WEATHER DOMINATES THE MAJORITY OF THE REGION WITH THE EXCEPTION OF NEAR THE SFC TROUGH...S OF 22N BETWEEN 61W-66W WHERE ISOLATED SHOWERS AND TSTMS ARE LIKELY. THE E ATLC IS MAINLY UNDER AN UPPER TROUGH WITH A RELATED WEAK SFC BOUNDARY EXTENDING FROM 30N25W TO 27N37W. LITTLE SIGNIFICANT SHOWER ACTIVITY IS ALONG THE BOUNDARY. IN FACT...CONVECTION APPEARS CONFINED TO THE ITCZ. $$ CANGIALOSI