000 AXNT20 KNHC 071754 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU AUG 07 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 25W S OF 14N WITH A 1010 MB LOW ALONG THE WAVE NEAR 12N MOVING W 15-20 KT. WAVE WAS RELOCATED BASED ON SATELLITE CLASSIFICATION AND VISIBLE SATELLITE IMAGERY. BROAD AREA OF LOWER PRESSURE IS ASSOCIATED WITH THIS LOW/WAVE. ANY CONVECTION IS W OF THE WAVE AND ASSOCIATED WITH THE ITCZ. TROPICAL WAVE IS ALONG 43W/44W FROM 15N-25N MOVING W NEAR 20 KT. HIGH AMPLITUDE WAVE WELL N OF THE ITCZ WITH WELL DEFINED INVERTED-V CURVATURE OBSERVED ON SATELLITE IMAGERY. THE MIMIC TPW PRODUCT SHOWS A WEAK AREA OF DEEP LAYERED MOISTURE FIELD WELL N OF THE ITCZ AS WELL. NO ASSOCIATED SHOWERS/CONVECTION. TROPICAL WAVE IS ALONG 59W S OF 13N MOVING W NEAR 15 KT. LOW AMPLITUDE WAVE MOSTLY INLAND OVER SOUTH AMERICA. SHOWER ACTIVITY IS INLAND OVER GUYANA SOUTH AMERICA. TROPICAL WAVE IS ALONG 78W S OF 21N MOVING W 10-15 KT. BROAD AREA OF DEEP LAYERED MOISTURE FIELD IS OBSERVED ON MIMIC TPW PRODUCT COVERING MOST OF THE CARIBBEAN. WAVE IS AT THE LEADING EDGE OF A SURGE OF AFRICAN DUST THAT COVERS THE E CARIBBEAN AND AND N OF THE GREATER ANTILLES MOVING INTO THE TURKS AND CAICOS. NO ASSOCIATED SHOWERS/CONVECTION. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 13N16W 11N27W 10N42W 8N53W 8N62W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 75 NM OF LINE FROM 7N45W TO 6N47W. SCATTERED MODERATE CONVECTION IS WITHIN 60/75 NM OF ITCZ FROM 25W-30W. ...DISCUSSION... GULF OF MEXICO... UPPER RIDGES DOMINATE MOST OF THE GULF WITH ONE EXTENDING FROM TEXAS OVER THE NW GULF...SECOND OVER THE SE U.S. INTO THE W ATLC COVERING THE NE GULF...AND A THIRD EXTENDING FROM THE E PACIFIC REGION ACROSS S MEXICO OVER THE SW GULF AND THE BAY OF CAMPECHE. THE SE GULF IS DOMINATED BY AN UPPER LOW CENTERED ALONG THE SW COAST OF CUBA. THIS SCENARIO IS LEAVING THE CENTRAL GULF IN AN AREA OF WEAKNESS. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 120 NM ALONG THE COAST OF MEXICO S OF 24N INTO THE BAY OF CAMPECHE W OF 93W. CLUSTERS OF SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 75 NM OF LINE FROM 27N85W TO THE NE YUCATAN NEAR 21N88W. SCATTERED CLUSTERS OF ISOLATED SHOWERS/THUNDERSTORMS DOT THE REMAINDER OF THE CENTRAL GULF FROM 23N-27N BETWEEN FLORIDA AND TEXAS/NE MEXICO. OTHERWISE AT THE SURFACE IS A RIDGE THAT COVERS THE N GULF AND PORTIONS OF THE SE U.S. WITH A 1018 MB HIGH LOCATED NEAR 27N85W. A FRONTAL BOUNDARY IS EXPECTED TO DIP OVER THE SE U.S. LATE TONIGHT/FRI MORNING THEN MOVE E INTO THE W ATLC. HOWEVER...ASSOCIATED SHOWERS/THUNDERSTORM ACTIVITY WILL BE OVER THE NE GULF ON FRI THROUGH SUN. THE SURFACE RIDGE WILL WEAKEN AND MOVE S WITH THE APPROACHING FRONT BUT MAINTAIN THROUGH THE WEEKEND. CARIBBEAN SEA... THE UPPER LOW COVERING THE SE GULF IS ANCHORED ALONG THE SW COAST OF CUBA NEAR THE ISLE OF YOUTH COVERING THE NW CARIBBEAN WITH A BROAD UPPER HIGH COVERING THE REMAINDER OF THE CARIBBEAN. UPPER LEVEL DIFFLUENCE COUPLED WITH THE ITCZ THAT EXTENDS INTO THE E PACIFIC REGION JUST S OF PANAMA ARE GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE SW CARIBBEAN S OF 12N W OF 76W TO INLAND OVER CENTRAL AMERICA. SCATTERED CLUSTERS OF ISOLATED SHOWERS/THUNDERSTORMS DOT THE FAR NW CARIBBEAN N OF 18N W OF 82W TO OVER W CUBA AND THE YUCATAN PENINSULA. MODERATE/ STRONG EASTERLY TRADE WINDS DOMINATE THE ENTIRE CARIBBEAN. SURGE OF AFRICAN DUST IS TRAILING THE TROPICAL WAVE ALONG 78W COVERING THE E CARIBBEAN TO OVER THE WINDWARD ISLANDS BUT IS THINNING OVER THE LEEWARD ISLANDS. THE TROPICAL WAVE ALONG 59W WILL BE MOVING OVER THE WINDWARD ISLANDS LATER TONIGHT BRINGING SHOWERS AND ISOLATED THUNDERSTORMS TO THE ISLANDS INTO FRI. ATLANTIC OCEAN... A WEAK 1014 MB LOW HAS DEVELOPED NEAR 25N76.5W ALONG THE SURFACE TROUGH THAT EXTENDS FROM 27N75W OVER THE N BAHAMA ISLANDS TO 23N78W GENERATING SCATTERED SHOWERS/THUNDERSTORMS FROM 23N-27N BETWEEN 75W-79W. AN UPPER LOW IS TO THE E NEAR 25N75W COVERING THE W ATLC W OF 70W. A SERIES OF UPPER LOWS EXTENDS FROM THE E ATLC INTO THE S/CENTRAL ATLC WITH THE UPPER LOWS CENTERED NEAR 33N22W 23N43W AND 19N56W AND THE UPPER TROUGH EXTENDING TO JUST OVER THE LEEWARD ISLANDS. AN UPPER HIGH IS IN THE SE ATLC NEAR 18N35W. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE IN THE CENTRAL ATLC WITHIN 60/75 NM OF LINE FROM 27N60W TO 23N70W. OTHERWISE THE ATLC IS DOMINATED BY MODERATE/STRONG SUBSIDENCE AND DRY SOMEWHAT STABLE AIR AND A SURFACE RIDGE THAT EXTENDS FROM A HIGH NE OF THE AZORES THROUGH A 1020 MB HIGH NEAR 31N47W TO JUST E OF THE BAHAMAS NEAR 25N73W...THUS GIVING THE REMAINDER OF THE ATLC FAIR WEATHER THIS AFTERNOON. THE FRONTAL BOUNDARY EXPECTED OVER THE SE U.S. LATE TONIGHT/FRI IS EXPECTED TO MOVE INTO THE FAR W ATLC FRI INTO SAT BUT WILL REMAIN N OF 30N. $$ WALLACE