000 AXNT20 KNHC 201127 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST WED DEC 20 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA... CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA... NORTHEASTERN 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 5N7W 4N11W 5N22W 4N44W 3N52W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 2N-6N BETWEEN 36W-48W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE COVERS THE GULF WITH THE AXIS EXTENDING FROM S MEXICO ACROSS THE CENTRAL BAY OF CAMPECHE TO OVER THE SE US NEAR 32N88W. TROPICAL MOISTURE IS BEING ADVECTED ACROSS MEXICO FROM THE E PACIFIC REGION OVER THE GULF WITH ENOUGH DIFFLUENCE TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS W OF 90W. THE NEXT COLD FRONT IS EXPECTED TO MOVE OFF THE TEXAS COAST LATE TONIGHT INTO TOMORROW MORNING BRINGING MORE ACTIVITY SHOWER ACTIVITY TO THE NW GULF THEN MOVING EASTWARD. ISOLATED SHOWERS REMAIN OVER THE FAR SE GULF S OF 26N E OF 84W THROUGH THE STRAITS OF FLORIDA INCLUDING S FLORIDA AND THE FLORIDA KEYS. CARIBBEAN SEA... MID/UPPER LEVEL TROUGH OVER THE SW ATLC DIPS S INTO THE N CARIBBEAN N OF 16N E OF 82W TO OVER THE LEEWARD ISLANDS WITH A SURFACE TROUGH EXTENDING FROM 16N70W ACROSS HISPANIOLA TO 24N66W. THE REMAINDER OF THE CARIBBEAN IS DOMINATED BY UPPER ZONAL WESTERLY FLOW. VERY DRY UPPER AIR AND MODERATE/STRONG SUBSIDENCE COVERS THE ENTIRE AREA GIVING MOST OF THE CARIBBEAN CLEAR SKIES TONIGHT WITH THE EXCEPTION SCATTERED/BROKEN LOW CLOUDS AND ISOLATED SHOWERS WITHIN 75/90 NM OF LINE S OF HAITI NEAR 18N74W ALONG 15N79W TO COSTA RICA NEAR 10N83W AND OVER THE WINDWARD ISLANDS FROM 11N-15N BETWEEN 60W-63W. MODERATE/STRONG TRADE WINDS ALSO DOMINATE MOST OF THE CARIBBEAN. ATLANTIC OCEAN... DEEP LAYERED TROUGH IS OVER THE NW ATLC N OF 29N FROM 60W-80W WITH THE ASSOCIATED COLD FRONT EXTENDING ALONG 32N W OF BERMUDA. THIS FRONT WILL CONTINUE TO DIP SOUTHWARD OVER THE W ATLC BUT BEGIN TO DISSIPATE OVER THE W ATLC AS THE FRONT MOVES INTO THE CENTRAL ATLC TONIGHT INTO TOMORROW. AN UPPER TROUGH IS IN THE SW ATLC EXTENDING FROM AN UPPER LOW N OF THE VIRGIN ISLANDS NEAR 23N64W WSW TO INTO THE W CARIBBEAN OVER E CUBA NEAR 21N76W. THIS IS GIVING THE AREA FROM 21N-25N BETWEEN 57W-67W SCATTERED SHOWERS WHILE THE REMAINDER OF THE W ATLC REMAINS RATHER SHOWER FREE. AN UPPER HIGH IS IN THE CENTRAL ATLC NEAR 27N43W AND A SURFACE RIDGE COVERS THE AREA WITH A 1022 MB HIGH LOCATED NEAR 29N46W. BROAD UPPER TROUGH COVERS THE REMAINDER OF THE ATLC N OF 16N E OF 35W WITH AN UPPER LOW NEAR 28N26W AND A 1016 MB SURFACE LOW NEAR 28N30W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE E OF THE UPPER AND SURFACE LOWS N OF 24N FROM 20W-27W. BROAD UPPER RIDGE COVERS THE TROPICS CENTERED NEAR 2N44W WITH THE MEAN AXIS EXTENDING N TO 16N45W. $$ WALLACE