000 AXNT20 KNHC 130455 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON AUG 13 2007 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 0415 UTC. ...SPECIAL FEATURE... A 1006 MB LOW...ASSOCIATED WITH A TROPICAL WAVE ALONG 26W/27W S OF 18N...IS LOCATED SW OF THE CAPE VERDE ISLANDS NEAR 12N MOVING W 15 KT. THE LAST VISIBLE SATELLITE IMAGERY SHOWED A LOW LEVEL CIRCULATION PARTIALLY EXPOSED TO THE E OF THE CONVECTION. SCATTERED MODERATE/STRONG CONVECTION IS FROM 10N-14N BETWEEN 29W-33W. . ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 37W S OF 15N MOVING W 10-15 KT. THIS IS A WEAK LOW AMPLITUDE WAVE. THE CONVECTION WITH THE ABOVE WAVE/LOW IS BEGINNING TO OVERRUN THE INVERTED-V CURVATURE. NO ASSOCIATED SHOWERS/CONVECTION. TROPICAL WAVE IS ALONG 45W S OF 18N MOVING W 10-15 KT. WEAK LOW LEVEL INVERTED-V CURVATURE IS NOTED WITH A BETTER DEFINED MID LEVEL ROTATION EMBEDDED WITHIN THE ITCZ. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM OF THE WAVE AXIS FROM 10N-12N. TROPICAL WAVE IS IN THE CENTRAL CARIBBEAN ALONG 78W/79W S OF 18N MOVING W NEAR 20 KT. WAVE SIGNATURE IS MASKED BY UPPER LEVEL RIDGE WITH ANY SHOWER ACTIVITY/CONVECTION ASSOCIATED WITH UPPER LEVEL FEATURES. TROPICAL WAVE IS APPROACHING THE YUCATAN PENINSULA ALONG 87W/88W S OF 23N MOVING W 15-20 KT. WAVE SIGNATURE IS MASKED BY AN UPPER LEVEL TROUGH WITH ANY SHOWER ACTIVITY/CONVECTION ASSOCIATED WITH UPPER LEVEL FEATURES. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 16N16W 10N32W 8N52W 9N62W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS MOVING OFF W AFRICA FROM 13N-17N E OF 19W AND FROM 5N-7N BETWEEN 28W-33W. DISCUSSION... GULF OF MEXICO... AN UPPER LOW OVER THE E GULF DOMINATES THE GULF TONIGHT CENTERED NEAR 25N86W EXTENDING AN UPPER TROUGH S INTO THE NW CARIBBEAN. CLUSTERS OF SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 120 NM ALONG THE E GULF COAST E OF THE MISSISSIPPI DELTA AROUND THE FLORIDA PENINSULA TO ACROSS CUBA. SOME ISOLATED SHOWERS ARE WITHIN 225 NM OF THE UPPER LOW. THE W GULF REMAINS DRY TONIGHT. CARIBBEAN SEA... THE UPPER LOW OVER THE E GULF OF MEXICO EXTENDS AN UPPER TROUGH S OVER THE NW CARIBBEAN N OF 16N W OF 84W. A WEAK UPPER RIDGE EXTENDS FROM NICARAGUA/HONDURAS N TO ACROSS CENTRAL CUBA WITH ENOUGH DIFFLUENCE AND TROPICAL MOISTURE TO GENERATE SCATTERED MODERATE/STRONG CONVECTION WITHIN 90/120 NM OF LINE FROM 15N80W 20N80W TO 22N85W AND A LARGE AREA OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS COVERING THE ENTIRE W CARIBBEAN W OF 76W. AN UPPER TROUGH FROM THE CENTRAL ATLC EXTENDS OVER THE E CARIBBEAN THROUGH AN UPPER LOW OVER THE VIRGIN ISLANDS SW TO 14N70W. THIS HAS DRIED OUT THE E CARIBBEAN E OF 75W. ATLANTIC OCEAN... AN UPPER RIDGE EXTENDS INTO THE W ATLC ACROSS CENTRAL CUBA TO NEAR 32N73W ESSENTIALLY DRYING OUT THE W ATLC WITH THE EXCEPTION OF THE SCATTERED MODERATE/STRONG CONVECTION OVER CUBA AND WITHIN 75 NM ALONG THE N COAST W OF 77W. AN UPPER TROUGH IS OVER THE CENTRAL ATLC EXTENDING THROUGH 32N47W TO AN UPPER LOW NEAR 26N51W TO A SECOND UPPER LOW OVER THE VIRGIN ISLANDS AND INTO THE E CARIBBEAN GENERATING A SMALL AREA OF SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS FROM 23N-26N BETWEEN 57W-63W. AN UPPER RIDGE DOMINATES THE E ATLC EXTENDING E/W FROM OVER AFRICA NEAR 25N15W TO NEAR 20N43W. A WEAK UPPER LOW IS IN THE NE ATLC NW OF THE CANARY ISLANDS NEAR 31N20W. DRY STABLE AIR COVERS THE ATLC E OF 55W WITH A BROAD SURFACE RIDGE EXTENDING FROM A 1025 MB HIGH S OF THE AZORES NEAR 35N30W SW THROUGH A 1020 MB HIGH S OF BERMUDA NEAR 27N64W TO OVER THE FLORIDA PENINSULA. $$ WALLACE