000 AXNT20 KNHC 131758 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED AUG 13 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. ...SPECIAL FEATURES... TROPICAL WAVE IS IN THE W TROPICAL ATLANTIC EXTENDING FROM 22N54W THROUGH A 1010 MB LOW NEAR 17N56W TO 11N57W MOVING WNW 10-15 KT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION SURROUNDS TO THE LOW FROM 16N-19N BETWEEN 54W-58W. ENVIRONMENTAL CONDITIONS ARE ONLY MARGINALLY FAVORABLE FOR DEVELOPMENT AND ALTHOUGH THE POTENTIAL FOR TROPICAL CYCLONE FORMATION HAS DECREASED IT STILL HAS THE POSSIBILITY FOR FURTHER DEVELOPMENT. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 34W S OF 20N MOVING W 15-20 KT. A 1012 MB LOW IS JUST TO THE W OF THE WAVE AXIS NEAR 16N35W FORMING AN ELONGATED AREA OF LOWER PRESSURE AND IN AN AREA OF DEEP LAYERED MOISTURE INDICATED BY MIMIC-TPW ANIMATION. SCATTERED MODERATE CONVECTION IS FROM 17N-19N BETWEEN 31W-36W AND FROM 14N-16N BETWEEN 37W-39W. TROPICAL WAVE IS IN THE W CARIBBEAN ALONG 84W S OF 18N MOVING W 15-20 KT. MID LEVEL ROTATION IS OBSERVED INLAND OVER CENTRAL AMERICA AND AN INVERTED-V CURVATURE IS IN THE E PACIFIC REGION. NO ASSOCIATED SHOWERS/DEEP CONVECTION. ...THE ITCZ... THE ITCZ IS CENTERED ALONG 10N12W 9N20W 15N30W 9N39W 13N53W. ITCZ AXIS IS DISTORTED BY THE TROPICAL WAVES/LOWS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 8N-11N BETWEEN 17W-22W AND FROM 7N-11N BETWEEN 45W-48W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 125 NM OF LINE FROM 6N37W TO 8N45W. ...DISCUSSION... GULF OF MEXICO... AN UPPER TROUGH IS PUSHING S OVER THE MISSISSIPPI VALLEY MOVING OVER THE SE U.S. WITH THE ASSOCIATED COLD FRONT EXTENDING FROM A 1010 MB LOW OVER E ALABAMA ALONG THE COAST OF LOUISIANA INTO E TEXAS. SCATTERED SHOWERS/THUNDERSTORMS ARE IN THE GULF WATERS FROM 27N-30N W OF 90W TO JUST INLAND OVER THE TEXAS COAST WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS N OF 27N FROM OVER FLORIDA TO TEXAS. AN UPPER LEVEL RIDGE EXTENDS ACROSS THE REMAINDER OF THE GULF ANCHORED OVER THE BIG BEND AREA OF TEXAS GIVING MOST OF THE GULF E TO SE UPPER FLOW. THE SURFACE RIDGE HAS WEAKENED OVER THE PAST 24 HOURS COVERING THE FAR E GULF. THIS IS PRODUCING RETURN FLOW CONSISTING OF MODERATE/ STRONG S TO SW WINDS ACROSS THE E GULF AND LIGHT/MODERATE WINDS OVER THE W GULF. OTHERWISE...THE REMAINDER OF THE GULF IS RELATIVELY CLEAR THIS AFTERNOON. CARIBBEAN SEA... THE BROAD UPPER RIDGE OVER THE GULF OF MEXICO COVERS THE NW GULF WITH UPPER NE FLOW. AN UPPER LOW IS ALONG THE N COAST OF HAITI COVERING THE N CARIBBEAN N OF 15N FROM THE LEEWARD ISLANDS TO THE CAYMAN ISLANDS. AN UPPER RIDGE IS ANCHORED ALONG N COAST OF COLOMBIA COVERING THE S/CENTRAL CARIBBEAN S OF 15N BETWEEN THE ABC ISLANDS AND THE COAST OF CENTRAL AMERICA. UPPER LEVEL DIFFLUENCE IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 15N-18N BETWEEN 70W-73W AND WITHIN 45 NM OF LINE FROM COLOMBIA NEAR 9N76W TO 13N81W. ISOLATED SHOWERS ARE OVER THE E CARIBBEAN FROM 14N-17N BETWEEN 60W-65W PRECEDING THE TROPICAL WAVE/LOW E OF THE LESSER ANTILLES. OTHERWISE THE REMAINDER OF THE CARIBBEAN HAS CLEAR SKIES THIS AFTERNOON WITH MODERATE EASTERLY TRADE WINDS ACROSS THE AREA. ATLANTIC OCEAN... THE UPPER RIDGE OVER THE GULF OF MEXICO EXTENDS ACROSS FLORIDA NE OVER THE W ATLC TO BEYOND 32N73W. AN UPPER LOW ALONG THE N COAST OF HAITI COVERS THE AREA S OF 26N BETWEEN 60W-80W. THIS SCENARIO IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 26N BETWEEN 67W-77W WITH ISOLATED SHOWERS N OF 28N W OF 79W TO INLAND OVER NE FLORIDA AND SE GEORGIA. A SERIES OF BENIGN UPPER LOWS ARE ACROSS THE REMAINDER OF THE ATLC WITH THE FIRST ALONG THE COAST OF WESTERN SAHARA NEAR 27N14W TO A SECOND NEAR 29N33W TO A THIRD NEAR 30N50W. THESE UPPER LOWS ARE EMBEDDED WITHIN MODERATE/STRONG SUBSIDENCE AND DRY STABLE AIR...THUS FAIR WEATHER THIS AFTERNOON ACROSS THE REMAINDER OF THE ATLC. A SURFACE RIDGE COVERS THE ATLC ANCHORED BY A 1025 MB HIGH N OF THE REGION NEAR 36N38W AND EXTENDS TO JUST E OF THE BAHAMA ISLANDS WEAKENING AS IT EXTENDS OVER THE FAR E GULF OF MEXICO. $$ WALLACE