000 AGXX40 KNHC 090618 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 130 AM EST SAT DEC 9 2006 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. STRONG UPPER TROUGH OVER WRN ATLC BEGINNING TO LIFT AWAY FROM THE REGION ACCORDING TO THE LATEST WATER VAPOR IMAGERY. STRONG SRN BRANCH OF WESTERLIES STILL EVIDENT FROM OVER SRN GULF NE TO NRN BAHAMAS THEN NE OF AREA. A LARGE MID LEVEL RIDGE IS ANCHORED NEAR 30N47W EXTENDS BACK SW ACROSS THE CARIB. ON THE SURFACE TONIGHT A COLD FRONT EXTENDS FROM 31N63W TO THE SE BAHAMAS THEN STATIONARY TO 17N85W. AN ARCTIC AIRMASS IS OVER THE SRN US AND IS PRODUCING STRONG NE WINDS OVER THE MARINE AREA W OF THE FRONT. A MODERATELY STRONG HIGH IS OVER THE ERN ATLC E OF 60W WITH MODERATE TO FRESH ELY TRADES E OF 60W. LATER DAY 1 THE STRONG UPPER TROUGH CONTINUES EWD TO 60W WHILE A SMALLER SHORTWAVE TROUGH DROPS SE OFF THE SE COAST. MID LEVEL RIDGING BEGINS BULGING NWD ALONG 90W. THE ATLC MID LEVEL RIDGE HOLDS FIRM WHILE TROUGHING DEVELOPS S OF 30N E OF 40W. ON THE SURFACE LATER DAY 1 THE CENTER OF THE ARCTIC AIR MOVES EWD TO THE N CAR COAST WHILE THE COLD FRONT MOVES SLOWLY EWD. STRONG NE WINDS CONTINUE OVER ALL SECTIONS W OF THE FRONT. MODERATE ELY TRADES WILL CONTINUE OVER THE CARIB AND ATLC WATERS E OF 60W. FOR DAY 2 THE OVERALL MID LEVEL FLOW BECOMES MORE SWLY WITH THE SHORTWAVE TROUGH MOVING E TO 65W. A WEAKER SHORTWAVE MOVES TO 90W. OVER THE ERN ATLC THE TROUGH CLOSES OFF S OF THE MID LEVEL HIGH AND FORMS A BLOCKING PATTERN KNOWN AS A REX BLOCK. ON THE SURFACE DAY 2 THE OLD COLD FRONT BECOMES STATIONARY FROM 31N55W TO 20N72W. HIGH PRESSURE N OF 30N MAINTAINS A FAIRLY STRONG GRADIENT OVER THE REGION W OF THE FRONT AND NE WINDS TO 25 KT CONTINUE OVER THE ATLC WHILE GULF WINDS E OF 90W REMAIN AT 20 KT. CARIB WINDS REMAIN THE SAME AT 20 TO 25 KT. W GULF WINDS BECOME E AND SE AT 10 TO 15 KT. OUTLOOK PERIOD... FOR DAY 3 THE SHORTWAVE TROUGH IN THE MID LEVELS MOVES EWD TO NEAR 55W. A BROAD MID LEVEL RIDGE BUILDS OVER THE WRN CARIB BULGING NWD ALONG 85W. A NEW STRONG MID LEVEL TROUGH DROPS INTO THE SRN PLAINS. THE REX BLOCK CONTINUES OVER THE ERN ATLC. ON THE SURFACE DAY 3 THE OLD FRONT BEGINS TO DISSIPATE INTO A FRONTAL TROUGH ALONG 31N52W TO 24N62W TO THE SE BAHAMAS. HIGH PRESSURE REMAINS W OF THE FRONT WITH GUSTY NE WINDS TO 25 KT. ATLC TRADES E OF 60W DECREASE TO 10 TO 15 KT. LITTLE CHANGE ELSEWHERE. FOR DAY 4 THE MID LEVELS BEGIN TO TAKE ON MORE AMPLITUDE AS COLD AIR SPILLS SWD ALONG 50W AND OVER THE PLAINS. THE REX BLOCK WEAKENS AS THE RIDGE PORTION GETS KICKED OUT BY THE DEVELOPING TROUGH AND MOVES NE. ON THE SURFACE DAY 4 THE OLD FRONTAL TROUGH MOVES SLOWLY EWD TO ALONG 31N45W TO 21N52W. THE OLD ARCTIC AIRMASS STILL HOLDS ON W OF 60W WITH GUSTY NE AND E WINDS TO 25 KT CONTINUING. A WEAK COLD FRONT MOVES TO SE TX. ELSEWHERE ABOUT THE SAME. FOR DAY 5 A LARGE UPPER TROUGH BEGINS TO DROP SWD ALONG 45W WHILE RIDGING BULGES NWD ALONG 65W. THE STRONG TROUGH OVER THE PLAINS WASHES OUT AS IT LIFTS NE ALONG 80W. THE MID LEVEL FLOW W OF 80W BECOMES VERY STRONG WLY. ON THE SURFACE DAY 5 THE WEAK COLD FRONT LOOSES SUPPORT AS THE MID LEVEL TROUGH WASHES OUT AND BARELY MAKES IT TO THE NW GULF. THE OLD FRONTAL TROUGH MOVES EWD TO 31N40W 20N45W. THE OLD ARCTIC AIRMASS NOW MODIFIED STILL CREATES ENOUGH GRADIENT TO PRODUCE NE AND E WINDS TO 25 KT BETWEEN 50W AND 70W N OF 20N. GULF WINDS BECOME MORE LIGHT AND CARIB WINDS ELY 10 TO 15 KT. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER RRG