000 AXNT20 KNHC 161152 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI MAY 16 2008 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 29W S OF 11N MOVING W 15-20 KT. SATELLITE IMAGERY SHOWS A BROAD AREA OF LOW LEVEL CYCLONIC TURNING ALONG THE WAVE NEAR 5N. SCATTERED SHOWERS AND TSTMS ARE WITHIN 150 NM ON EITHER SIDE OF THE WAVE AXIS. MORE SHOWER AND TSTM ACTIVITY IS OBSERVED BEHIND THE WAVE AXIS FROM 2N-7N BETWEEN 22W AND 25W. THIS CONVECTIVE ACTIVITY IS BEING ENHANCED BY UPPER DIFFLUENCE ASSOCIATED WITH AN UPPER-LEVEL HIGH LOCATED NEAR 7N21W. A TROPICAL WAVE IS ALONG 49W/50W S OF 11N MOVING W 10-15 KT. AN INVERTED-V PATTERN IS FAIRLY WELL DEFINED ON SATELLITE IMAGERY WITH SOME LOW-LEVEL CYCLONIC TURNING ALONG THE WAVE AXIS NEAR 6N. SCATTERED SHOWERS AND TSTMS ARE WITHIN 160 NM ON EITHER SIDE OF THE AXIS BETWEEN 4N-8N. THE SSMI-DERIVED TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS SHOWS A FAIR LOW-LEVEL MOISTURE SURGE NORTH ALONG 49W SUPPORTING THE POSITION OF THE WAVE. AN ILL-DEFINED TROPICAL WAVE IS ALONG 73W/74W OVER N COLOMBIA S OF 13N MOVING W 10-15 KT. A SMALL BULGE OF MOISTURE ON THE MIMIC TPW ANIMATION N OF THE GUAJIRA PENINSULA SUGGESTS THE PRESENCE OF THIS WAVE THAT IS ENHANCING SOME SHOWER/TSTM ACTIVITY ACROSS N COLOMBIA. HOWEVER...NO OTHER AVAILABLE DATA CAN CURRENTLY CONFIRM OR DENY THE PRESENCE OF THIS FEATURE ESPECIALLY AS IT MOVES OVER THE HIGH TERRAIN OF W COLOMBIA. FOR THE TIME BEING...THE WAVE HAS BEEN EXTRAPOLATED WESTWARD IN ORDER TO KEEP CONTINUITY WITH PREVIOUS MOTION. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 9N13W 9N20W 6N27W 3N31W 2N36W 4N47W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 60 NM OF A LINE FROM 2N10W TO 3N19W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-7N BETWEEN 11W-15W. SIMILAR CONVECTION IS WITHIN 90 NM OF A LINE FROM 9N19W TO 3N25W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL RIDGE CENTERED IN THE NW CARIBBEAN SEA CONTINUES TO TRANSPORT MOISTURE FROM THE EPAC ACROSS MEXICO AND S TEXAS INTO THE W GULF. UPPER LEVEL TROUGH OVER THE SW CONUS SUPPORTS COLD FRONT WHICH ENTERS THE GULF NEAR ATCHAFALAYA BAY LOUISIANA AND EXTENDS ACROSS THE NW GULF INLAND S OF BROWNSVILLE. SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE ACROSS THE NW GULF AS FRONT CONTINUES TO SLOWLY MOVE EASTWARD. A PRE-FRONTAL TROUGH EXTENDS FROM NEAR 26N94W TO NEAR TUXPAN MEXICO AND IS AIDING IN CONVECTIVE ACTIVITY AS WELL. THIS PATTERN IS PRODUCING SOUTHERLY 15-20 KT WINDS ACROSS MUCH OF THE GULF AHEAD OF FRONTAL BOUNDARY. A 1020 MB SURFACE HIGH PRESSURE CENTERED IN THE W ATLC WITH ASSOCIATED RIDGE ACROSS THE STRAITS OF FLORIDA AND THE SE GULF IS PROVIDING FAIR WEATHER E OF 85W. THE FRONT CURRENTLY IN THE NW GULF IS FORECAST TO EXTEND FROM NORTH FLORIDA TO NEAR 27N86W BY FRIDAY NIGHT AND BECOME STATIONARY WEAKENING ON SATURDAY. CARIBBEAN SEA... THE TAIL END OF A COLD FRONT FROM THE CENTRAL ATLC REMAINS ACROSS PUERTO RICO AND S HISPANIOLA WHERE IT IS PRODUCING BROKEN LOW/MID CLOUDS AND MAINLY LIGHT SHOWERS. THE REMAINDER OF THE BASIN IS FAIRLY TRANQUIL DUE TO THE PRESENCE OF A MID/UPPER RIDGE OVER THE W AND CENTRAL CARIBBEAN AND UPPER TROUGHING OVER THE E CARIBBEAN. THIS UPPER PATTERN IS PRODUCING MODERATE TO STRONG SUBSIDENCE SUPPRESSING THE DEVELOPMENT OF ANY SIGNIFICANT CONVECTION. FRESH TRADE WINDS REMAIN ACROSS MUCH OF THE CARIBBEAN SEA AND ARE EXPECTED TO INCREASE SLIGHTLY DURING THE WEEKEND AS W ATLC RIDGE GRADUALLY BUILDS IN ACROSS THE GREATER ANTILLES. ATLANTIC OCEAN... AN UPPER-LEVEL TROUGH EXTENDS ALONG 54W N OF 20N OVER THE CENTRAL ATLC. THIS SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N50W THROUGH 25N52W TO S OF SAINT CROIX. LOW-LEVEL CONVERGENCE ALONG THE FRONTAL BOUNDARY COUPLED WITH A DIFFLUENT PATTERN ALOFT IS PRODUCING A 200 NM WIDE BAND OF SCATTERED SHOWERS AND TSTMS E OF THE FRONT N OF 23N. A 1020 MB SURFACE HIGH PRESSURE LOCATED NEAR 29N71W IS BEHIND THE FRONT PRODUCING MOSTLY FAIR WEATHER ACROSS THE BAHAMAS AND CUBA. THIS HIGH IS FORECAST TO MOVE ESE OVER THE W ATLC DURING THE NEXT 24 HOURS. THE REMAINDER OF THE CENTRAL AND E ATLC IS DOMINATED BY A 1023 MB SURFACE HIGH LOCATED NEAR 32N38W. THE TIGHT PRESSURE GRADIENT BETWEEN THE HIGH AND THE AFOREMENTIONED FRONT IS PRODUCING SOUTHERLY WINDS OF 20-30 KT WITHIN 300 NM E OF THE COLD FRONT N OF 27N. IN THE UPPER LEVELS...A RIDGE/TROUGH/RIDGE PATTERN DOMINATES THE DISCUSSION AREA. IN THE DEEP TROPICS...AN ELONGATED RIDGE REMAINS BETWEEN AFRICA AND THE WINDWARD ISLANDS WITH AXIS ALONG 10N ENHANCING CONVECTION ALONG THE ITCZ. $$ HUFFMAN