000 AXNT20 KNHC 172249 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST SUN DEC 17 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...THE ITCZ... 8N12W 4N23W 3N34W 2N46W 1N52W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM OF THE AXIS BETWEEN 23N AND 40W....DISCUSSION... THE GULF OF MEXICO... A MID/UPPER TRIDGE DOMINATES THE GULF. THE TAIL END OF A TROUGH THRU CENTRAL FLORIDA AFFECTS PORTIONS OF THE EASTERN GULF. A LOW LEVEL REFLECTED TROUGH IS ALONG 85W. A FEW SCATTERED SHOWERS AND OVERCAST LOW MID CLOUDS ARE AFFECTING MOST OF THE SE GULF AND AREAS E OF 90W. AS THE RIDGE ANCHORS BETTER INTO THE AREA MUCH BETTER CONDITONS ARE EXPECTED AS THE WEEK PROGRESSES. AHEAD AND ELSEWHERE FORECAST MODEL DATA INDICATES THAT WEAK HIGH PRES N OF THE AREA WILL BE REINFORCED LATE TUESDAY WITH INCREASING WINDS ACROSS THE N AND E GULF. A COLD FRONT IS EXPECTED TO MOVE OFF THE TEXAS COAST THURSDAY THEN EXTEND FROM THE FLORIDA PANHANDLE TO THE SW GULF ON FRIDAY. THE CARIBBEAN SEA... MOSTLY WESTERLY FLOW ALOFT OVER THE AREA. A MASS OF TROPICAL MOISTURE COVERS AREAS N OF 15N. LOW MIDDLE CLOUDS WITH SCATTERED SHOWERS ARE W OF 80W AND E OF 70W AFFECTING THE COASTS OF CENTRAL AMERICA AND THE EASTERN ANTILLES THE CLOUD COVER SEEMS QUITE THICK OVER PUERTO RICO HISPANIOLA AND THE LESSER ANTILLES. AHEAD AND ELSEWHERE FORECAST MODEL DATA INDICATES THAT HIGH PRES N OF THE AREA WILL MAINTAIN MODERATE TRADES ACROSS THE AREA THROUGH TONIGHT THEN WEAKEN SLIGHTLY MON THROUGH WED. WINDS WILL INCREASE AGAIN OVER THE FAR NW CARIBBEAN WED AND NE OF PUERTO RICO FRI AS STRONGER HIGH PRES RE-BUILDS N OF THE AREA. THE ATLANTIC OCEAN... A LARGE UPPER CYCLONE N OF THE AREA HAS A TROUGH EXTENDING THROUGH 32N30W TO 20N33W TO 10N50W. A STRONG SW TO NE JET IS WITHIN 180 NM E OF THE TROUGH AXIS. A SECOND TROUGH IS N OF 27N BETWEEN 50W AND 60W DIGGIN RAPIDLY ESE. A LARGE UPPER RIDGE IS TILTING SE W OF 70W..A SURFACE FRONT EXTENDS THROUGH 32N50W TO 26N60W AND 22N80W. SCATTERED SHOWERS AND THUNDERSTORMS ARE EMBEDDED IN HEAVY MULTILAYRED CLOUDS WITHIN 300 NM SE OF THE FRONT E OF 70W. THICK LAYRED CLOUDS ARE ELSEWHERE N OF 20N W OF 40W. SCATTERED SHOWERS ARE EMBEDDED IN THESE CLOUDS. LOOKING AHEAD AT FORECAST MODEL DATA...THE FRONTAL TROUGH WILL MOVE EAST AND GRADUALLY DISSIPATE. SURFACE HIGH PRES OFF THE CAROLINAS WILL KEEP MODERATE TO FRESH EASTERLIES OVER THE AREA THROUGH TUESDAY. A STRONG COLD FRONT WILL MOVE INTO THE N PART WITH INCREASING WINDS TUESDAY NIGHT AND EXTEND FROM 28N65W TO CENTRAL FLORIDA WEDNESDAY AFTERNOON THEN BECOME DIFFUSE T THURSDAY. WINDS WILL BECOME SLY OVER THE W PART FRIDAY AS HIGH PRES BEHIND THE FRONT SLIDES E. $$ TORRES-SUAREZ