000 AXNT20 KNHC 160604 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0545 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 27W 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 120 NM AHEAD OF THE WAVE AXIS. MORE SHOWER AND TSTM ACTIVITY IS OBSERVED BEHIND THE WAVE AXIS FROM 2N-8N BETWEEN 17W AND 23W. THIS CONVECTIVE ACTIVITY IS BEING ENHANCED BY UPPER DIFFLUENCE ASSOCIATED WITH AN UPPER-LEVEL HIGH LOCATED NEAR 8N21W. A TROPICAL WAVE IS ALONG 49W 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 3N-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 OVER W VENEZUELA/E COLOMBIA WITH AXIS ALONG 72W. A SMALL BULGE OF MOISTURE ON THE MIMIC TPW ANIMATION BETWEEN THE ABC ISLANDS AND THE GUAJIRA PENINSULA SUGGESTS THE PRESENCE OF THIS WAVE THAT IS ENHANCING SOME SHOWER/TSTM ACTIVITY ACROSS CENTRAL COLOMBIA. HOWEVER...NO OTHER AVAILABLE DATA CAN CURRENTLY CONFIRM OR DENY THE PRESENCE OF THIS FEATURE. FOR THE TIME BEING...THE WAVE WILL BE EXTRAPOLATED WESTWARD IN HOPES THAT MORNING DATA WILL SHED SOME LIGHT ON ITS EXISTENCE. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N11W 6N15W 8N21W 4N29W 2N35W 5N48W. SCATTERED MODERATE TO STRONG CONVECTION IS DIRECTLY OFF THE SIERRA LEONE AND LIBERIA COAST FROM 4N-6N BETWEEN 9W-13W. CLUSTERS OF MODERATE CONVECTION ARE FROM 2N-8N BETWEEN 17W-24W. SCATTERED MODERATE CONVECTION IS ALSO FROM 4N-6N BETWEEN 30W-33W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL RIDGE CENTERED ACROSS W CUBA 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 THE TEXAS/LOUISIANA BORDER AND EXTENDS ACROSS THE NW GULF INLAND S OF CORPUS CHRISTI. SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE ACROSS THE GULF W OF 92W AS FRONT CONTINUES TO SLOWLY MOVE EASTWARD. A PRE-FRONTAL TROUGH EXTENDS FROM NEAR 28N92W TO NEAR TAMPICO MEXICO. THIS PATTERN IS PRODUCING SOUTHERLY 10-15 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 CENTRAL FLORIDA AND THE E GULF IS PROVIDING FAIR WEATHER E OF 90W. 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 WELL DEFINED ACROSS S HISPANIOLA AND JAMAICA 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. HIGH LEVEL CLOUDINESS AND POSSIBLE SCATTERED SHOWERS ARE LOCATED WITHIN 60 NM N OF THE PANAMA COAST DUE TO THE CLOSE PROXIMITY OF THE EPAC ITCZ. ELSEWHERE 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 59W OVER THE CENTRAL ATLC. THIS SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N49W THROUGH 25N53W 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 30N73W 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 1025 MB SURFACE HIGH LOCATED NEAR 32N37W. THE TIGHT PRESSURE GRADIENT BETWEEN THE HIGH AND THE AFOREMENTIONED FRONT IS PRODUCING SLY 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 9N ENHANCING CONVECTION ALONG THE ITCZ. $$ HUFFMAN