000 AXNT20 KNHC 281031 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED MAY 28 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... TROPICAL WAVE IS ALONG 22W S OF 14N MOVING W NEAR 15 KT BASED ON SATELLITE IMAGERY AND MODEL MOISTURE FIELDS. ANY CONVECTION IS WITHIN THE ITCZ. TROPICAL WAVE IS ANALYZED ALONG ALONG 37W S OF 8N MOVING W NEAR 10 KT BASED ON SATELLITE IMAGERY AND MODEL MOISTURE FIELDS. NO ASSOCIATED CONVECTION. TROPICAL WAVE IS FROM 8N61W TO 21N63W MOVING W NEAR 15 KT. WELL DEFINED HIGH AMPLITUDE WAVE IS PASSING OVER THE LESSER ANTILLES. THE UPPER LEVEL FEATURES CONTINUE TO ENHANCE THIS TROPICAL WAVE. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 150 NM E OF THE WAVE AXIS MAINLY N OF 14N. TROPICAL WAVE IS ANALYZED ALONG 78W/79W S OF 18N MOVING W NEAR 15 KT. WAVE IS EMBEDDED WITHIN A BROAD AREA OF LOWER PRESSURE AND AN AREA OF CONVECTION ASSOCIATED WITH THE ITCZ. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 4N3W 1N12W 6N25W 3N32W 5N40W 4N53W AND ACROSS THE SW CARIBBEAN ALONG 10N74W ACROSS COSTA RICA/ NICARAGUA INTO THE E PACIFIC REGION. CLUSTERS OF SCATTERED/ NUMEROUS STRONG CONVECTION ARE FROM 2N TO INLAND OVER SW AFRICA E OF 10W ACROSS THE PRIME MERIDIAN AND FROM 2N TO S OF THE EQUATOR BETWEEN 10W-20W. SMALL CLUSTERS OF SCATTERED MODERATE/ STRONG CONVECTION ARE FROM 1N-7N BETWEEN 17W-28W AND WITHIN 60 NM OF THE ITCZ AXIS W OF 40W TO INLAND OVER SOUTH AMERICA. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 3N-6N BETWEEN 28W-35W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL RIDGE COVERS THE GULF W OF 91W ANCHORED ALONG THE COAST OF SW MEXICO. A SMALL UPPER LOW IS CENTERED NEAR 27N90W WITH A NARROW UPPER TROUGH COVERING THE CENTRAL GULF EXTENDING S TO THE W YUCATAN PENINSULA. A SECOND UPPER RIDGE EXTENDS FROM THE W ATLC OVER THE E GULF E OF 85W. THESE ARE RELATIVELY BENIGN FEATURES AS THE ENTIRE GULF IS DOMINATED BY MODERATE/STRONG SUBSIDENCE AND DRY UPPER AIR. WEAK SURFACE RIDGE EXTENDS ACROSS THE N GULF FROM THE W ATLC TO LOUISIANA WITH MODERATE EASTERLY SURFACE WINDS. THE ONLY AREA OF CONCERN REMAINS THE SE GULF WHERE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 26N E OF 87W TO THE FLORIDA COAST...OVER THE FLORIDA KEYS AND THROUGH THE FLORIDA STRAITS DUE TO A SURFACE TROUGH IN THE W ATLC AND FAR NW CARIBBEAN. OTHERWISE THE REMAINDER OF THE GULF IS RATHER CLEAR AGAIN THIS MORNING. CARIBBEAN SEA... BROAD UPPER RIDGE DOMINATES MUCH OF THE CARIBBEAN WITH A SHEAR AXIS EXTENDING ACROSS W CUBA TO OVER CENTRAL AMERICA IN THE GULF OF HONDURAS. THE REMNANTS OF A SURFACE TROUGH EXTENDING FROM THE W ATLC ACROSS CENTRAL CUBA TO THE ISLE OF YOUTH GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 19N FROM 76W TO THE E COAST OF THE YUCATAN. THE SW UPPER FLOW ACROSS THE S CARIBBEAN IS DRAWING UPPER LEVEL MOISTURE ACROSS CENTRAL AMERICA INTO THE CARIBBEAN AND COUPLED WITH THE ITCZ AXIS IN THE SW CARIBBEAN AND THE PRESENCE OF A TROPICAL WAVE ARE PRODUCING A BROAD AREA OF DENSE CLOUDINESS WITH SCATTERED SHOWERS/ THUNDERSTORMS S OF 16N W OF 71W TO OVER COLOMBIA AND CENTRAL AMERICA. A TROPICAL WAVE IS MOVING E OF THE LESSER ANTILLES CONTINUING TO GIVE THE ISLANDS SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER THE NEXT FEW HOURS. ATLANTIC... AN UPPER RIDGE IS OVER THE FAR W ATLC INTO THE E GULF OF MEXICO WITH A WELL DEFINED ELONGATED UPPER LOW NEAR 33N65W TO 26N68W THEN A EXTENDING A SHEAR AXIS S OF THE UPPER RIDGE ALONG 23N77W ACROSS CUBA INTO THE NW CARIBBEAN. A REMNANT SURFACE TROUGH EXTENDS THROUGH 32N65W TO THE BAHAMAS NEAR 24N75W ACROSS CENTRAL CUBA NEAR 21N78W. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 25N W OF 70W INTO THE FLORIDA STRAITS INCLUDING THE TURKS AND CAICOS. SIMILAR ACTIVITY IS ASSOCIATED WITH THE UPPER LOW WITHIN 90 NM OF THE SURFACE TROUGH N OF 28N. AN UPPER RIDGE EXTENDS FROM THE BROADER UPPER RIDGE OVER THE CARIBBEAN ACROSS THE LEEWARD ISLANDS NE TO BEYOND 32N51W. THE A SURFACE TROUGH EXTENDING FROM 23N61W TO 28N58W WITH SCATTERED SHOWERS/THUNDERSTORMS COVERING THE AREA FROM 22N-28N BETWEEN 57W-63W. BROAD UPPER TROUGH IS IN THE E/CENTRAL ATLC EXTENDING FROM AN ELONGATED UPPER LOW NEAR 31N33W SW INTO THE TROPICAL ATLC TO NEAR 13N48W WITH A SECOND UPPER TROUGH OVER THE FAR E ATLC E OF 18W OVER THE CANARY ISLANDS AND WESTERN SAHARA AFRICA. THE E AND CENTRAL ATLC IS DOMINATED BY A SURFACE RIDGE N OF 15N BRIDGING THE SURFACE TROUGHS IN THE W AND CENTRAL ATLC ACROSS THE N GULF OF MEXICO ANCHORED BY A 1026 MB HIGH NEAR 33N41W. THE RESULT IS CALM WEATHER FOR THE ATLC E OF 55W. $$ WALLACE