000 AXNT20 KNHC 071109 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST FRI DEC 07 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 6N8W 4N14W 5N25W 6N40W 3N51W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM THE COAST OF SW AFRICA TO S OF THE EQUATOR E OF 12W TO ACROSS THE PRIME MERIDIAN. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 180 NM OF THE AXIS FROM 16W-33W. DISCUSSION... GULF OF MEXICO... THE REMNANTS OF A FRONTAL BOUNDARY EXTENDING ACROSS THE N GULF FROM 28N86W ALONG THE COAST OF LOUISIANA TO INLAND OVER ENE TEXAS. EVEN THOUGH THERE IS ABUNDANCE OF UPPER LEVEL TROPICAL MOISTURE THERE IS NO ASSOCIATED SHOWERS. AN UPPER LEVEL SHORTWAVE TROUGH EXTENDS FROM SE LOUISIANA SW TO AN UPPER LOW OFF THE COAST OF MEXICO NEAR 23N96W. OTHERWISE THE GULF IS DOMINATED BY AN UPPER RIDGE ANCHORED OVER SOUTH AMERICA COVERING THE CARIBBEAN AND W ATLC. SOME ISOLATED SHOWERS REMAIN IN THE FLORIDA STRAITS AND OVER THE FLORIDA KEYS. CARIBBEAN SEA... BROAD UPPER RIDGE DOMINATES THE CARIBBEAN ANCHORED OVER SOUTH AMERICA AND EXTENDS TO OVER THE GULF OF MEXICO AND THE W ATLC. WEAK SURFACE PRESSURE GRADIENT REMAINS OVER THE CARIBBEAN BUT IS EXPECTED TO INCREASE THROUGH SUN. MODERATE NE TO E TRADE WINDS DOMINATE THE CARIBBEAN USHERING IN ISOLATED LOW LEVEL SHOWERS S OF 18N E OF 78W. OTHERWISE THE CARIBBEAN REMAINS RATHER TRANQUIL TONIGHT. ATLANTIC OCEAN... UPPER TROUGH IS OVER THE NW ATLC EXTENDING A COLD FRONT INTO THE REGION NEAR 32N58W TO NEAR 28N67W WHERE IT CONTINUES AS A STATIONARY FRONT TO 28N75W. A WEAK SURFACE TROUGH EXTENDS OFF THE COAST OF THE CAROLINAS THROUGH 32N79W ALONG THE FLORIDA COAST TO NEAR VERO BEACH. THE AIR IS SOMEWHAT DRY AND STABLE OVER THE REGION WITH SOME LOW LEVEL ISOLATED SHOWERS OVER THE N BAHAMA ISLANDS FROM 25N-28N BETWEEN 73W-79W. SIMILAR SHOWERS ARE S OF 22N TO OVER HISPANIOLA BETWEEN 68W-73W INCLUDING THE TURKS AND CAICOS. OTHERWISE THE BROAD UPPER RIDGE ANCHORED OVER SOUTH AMERICA AND COVERING THE GULF OF MEXICO AND CARIBBEAN EXTENDS OVER THE W ATLC W OF 60W. A REMNANT SURFACE TROUGH REMAINS INT HE CENTRAL ATLC EXTENDING FROM 22N61W TO BEYOND 32N51W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 60 NM OF THE TROUGH. BROAD UPPER RIDGE ANCHORED OVER THE AZORES IS INDUCING AN UPPER TROUGH IN THE CENTRAL ATLC EXTENDING FROM 23N51W TO BEYOND 32N48W WITH A SURFACE TROUGH LOCATED ALONG 28N48W 21N50W TO 14N49W AND SCATTERED SHOWERS FROM 16N-28N BETWEEN 43W-53W. A RATHER LARGE UPPER LOW COVERS THE E ATLC E OF 40W CENTERED NEAR 24N28W MOVING WESTWARD WHILE A SURFACE RIDGE COVERS THE E ATLC E OF 45W ANCHORED BY A 1038 MB HIGH S OF THE AZORES. AN E/W UPPER RIDGE COVERS THE E TROPICAL ATLC WITH THE AXIS ALONG 6W/7W TO NEAR 35W ADVECTING TROPICAL MOISTURE N ACROSS THE TROPICS INCLUDING THE CAPE VERDE ISLANDS. $$ WALLACE