000 AXNT20 KNHC 251045 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED JUN 25 2008 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. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 46W S OF 9N MOVING W 15 KT. WEAK INVERTED-V CURVATURE IN THE MID LEVELS. THE MIMIC-TPW ANIMATION CONTINUES TO SHOW A SURGE IN MOISTURE IN THE VICINITY OF THIS WAVE SOUTH OF THE ITCZ WITH NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE IS ALONG 77W S OF 21N MOVING W 15-20 KT. WEAK SATELLITE SIGNATURE AS THE WAVE IS MOVING BENEATH AN UPPER TROUGH LIMITING DIFFLUENCE ALOFT THUS LIMITING DEEP CONVECTION. HOWEVER A SMALL AREA OF ISOLATED THUNDERSTORMS ARE FROM 18N TO INLAND OVER CUBA BETWEEN 75W-80W. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 9N12W 8N18W 6N27W 6N54W TO 10N62W. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 75/90 NM OF LINE FROM 9N55W ACROSS THE WINDWARD ISLANDS INTO THE SE CARIBBEAN TO 13N72W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-8N E OF 22W TO THE COAST OF W AFRICA. SCATTERED MODERATE CONVECTION IS FROM 1N TO S OF THE EQUATOR BETWEEN 47W-49W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER TROUGH EXTENDS FROM AN UPPER LOW IN THE NW ATLC ACROSS THE SE US AND OVER THE W HALF OF THE GULF TO S MEXICO AND THE W BAY OF CAMPECHE. AN UPPER LEVEL RIDGE EXTENDS FROM THE CARIBBEAN OVER THE REMAINDER OF THE GULF INTO THE W ATLC ACROSS THE N BAHAMA ISLANDS. THIS CONTINUES TO SUPPLY THE E GULF WITH ABUNDANCE OF TROPICAL MOISTURE AS WELL AS DIFFLUENCE ALOFT. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS DOT THE E GULF SW OF A LINE FROM TAMPA FLORIDA TO THE W BAY OF CAMPECHE WITH THE HEAVIEST ACTIVITY JUST N OF THE YUCATAN PENINSULA. A SHORTWAVE UPPER TROUGH EXTENDS FROM LOUISIANA TO JUST OFF THE TEXAS COAST GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 28N TO INLAND OVER TEXAS BETWEEN 94W-96W. SURFACE RIDGE REMAINS ACROSS THE GULF TO THE COAST OF MEXICO AND TEXAS BUT DUE TO THE LOWERING PRESSURE OVER THE CENTRAL US WINDS WILL BE INCREASING THROUGH THU. CARIBBEAN... AN UPPER RIDGE ANCHORED IN THE E PACIFIC REGION EXTENDS ACROSS HONDURAS/NICARAGUA ACROSS W/CENTRAL CUBA INTO THE W ATLC COVERING THE AREA W OF 80W WHILE A SECOND UPPER RIDGE ANCHORED E OF THE WINDWARD ISLANDS COVERS THE E CARIBBEAN. THE WEAK UPPER TROUGH REMAINS BETWEEN THESE UPPER RIDGES EXTENDING FROM THE W ATLC INTO THE CARIBBEAN OVER E CUBA SW TO 12N78W. UPPER LEVEL DIFFLUENCE CONTINUES TO GENERATE SCATTERED SHOWERS/THUNDERSTORMS OVER THE NW CARIBBEAN NW OF A LINE FROM CUBA NEAR 20N80W TO THE NICARAGUA/HONDURAS BORDER. THE ITCZ CROSSES THE N PORTION OF SOUTH AMERICA ACROSS COSTA RICA INTO THE E PACIFIC REGION GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE AREA S OF 11N BETWEEN COLOMBIA AND PANAMA. MODERATE/STRONG EASTERLY TRADE WINDS CONTINUE TO DOMINATE MOST OF THE CARIBBEAN DUE TO THE TIGHT PRESSURE GRADIENT BETWEEN THE SURFACE RIDGE OVER THE ATLC AND LOWER PRESSURE OVER SOUTH AMERICA. ATLANTIC... AN UPPER RIDGE EXTENDS FROM THE CARIBBEAN ACROSS W/CENTRAL CUBA OVER THE N BAHAMA ISLANDS TO NEAR 30N75W PROVIDING UPPER DIFFLUENCE GENERATING CLUSTERS OF SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS W OF 75W. AN UPPER LOW IS OVER THE W/CENTRAL ATLC NEAR 26N61W EXTENDING AN UPPER TROUGH SW ACROSS TURKS AND CAICOS INTO THE CARIBBEAN OVER E CUBA. LARGE UPPER RIDGE DOMINATES THE REMAINDER OF THE CENTRAL ATLC ANCHORED BY AN UPPER HIGH NEAR 32N49W. AN UPPER TROUGH IS OVER THE E ATLC EXTENDING THROUGH 32N30W TO 21N35W. UPPER HIGH IS E OF THE WINDWARD ISLANDS NEAR 12N57W WITH THE RIDGE COVERING THE AREA E OF 43W INTO THE CARIBBEAN WITH A SECOND UPPER RIDGE EXTENDS OFF AFRICA ALONG 12N TO 35W COVERING THE E TROPICS. THE SURFACE RIDGE REMAINS IN CONTROL OF THE ATLC BASIN FROM AFRICA INTO THE GULF OF MEXICO ANCHORED BY A 1029 MB HIGH CENTERED NEAR 31N54W. MODERATE/STRONG SUBSIDENCE AND A FAIR AMOUNT OF DRY STABLE AIR ALSO DOMINATES THE ATLC E OF 70W GIVING THE AREA FAIR WEATHER AGAIN THIS MORNING. THE FIRST VISIBLE SATELLITE IMAGES CONTINUE TO SHOW AFRICAN DUST COMING OFF THE COAST AND TRANSVERSING THE ATLC S OF 21N FROM AFRICA TO THE CARIBBEAN AND A NARROWER SWATH EXTENDING N OF THE CARIBBEAN OVER THE W ATLC FROM 20N-30N BETWEEN 60W AND THE BAHAMA ISLANDS. $$ WALLACE