000 AGXX40 KNHC 220629 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 130 AM EST SAT DEC 22 2007 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. WEAKENING SHORTWAVE TROUGH AT MID LEVELS TONIGHT ALONG 73W MOVING ESE AND TRYING TO PHASE WITH A MUCH STRONGER AND LARGER MID LEVEL TROUGH IN THE NRN BRANCH OF THE WESTERLIES N OF 35N. MID LEVEL RIDGE BUILDING RAPIDLY FROM NE GULF TO OH VALLEY IN RESPONSE TO NEXT DOUBLE BARREL SYSTEM MOVING OUT OF ROCKIES. ON THE SURFACE TONIGHT A 1006 MB LOW WAS NEAR 30N78W MOVING E WITH A TRAILING WEAK COLD FRONT OVER THE WRN BAHAMAS TO FL STRAITS. WEAK RIDGE OF HIGH PRES FOLLOWING SYSTEM OVER NE GULF. RETURN FLOW SETTING UP OVER WRN GULF AS PRESSURES FALL OVER PLAINS. HIGH PRES OVER MID ATLC WITH MODERATE TRADES S OF 20N. LATER DAY 1 GFS MODEL SHOWS MID LEVEL TROUGHS OVER ATLC TRYING TO PHASE TOGETHER E OF 65W. DOUBLE BARREL SHORTWAVES OVER PLAINS IN PHASE WITH A STRONG RIDGE FROM NE GULF TO SE CANADA. ON THE SURFACE LATER DAY 1 LOW PRES CENTER MOVES TO NEAR 29N66W AND WEAKENING BUT GRADIENT N OF 20N SUPPORTS 20 TO 30 KT AND SEAS TO 15 FT. NEW COLD FRONT MOVES OFF TX COAST WITH WINDS TO 20 KT. CARIB WINDS MODERATE OVER S CENTRAL SECTION. ATLC TRADES LIGHT TO MODERATE. FOR DAY 2 GFS MODEL SHOWS COLD AIR AT MID LEVELS WORKING IT'S WAY S ALONG 50W AND CAPTURING SHORTWAVE ALONG 60W. RESULT WILL BE A LARGE MID LEVEL TROUGH OVER MID ATLC S OF 30N. VERY STRONG NEG TILT MID LEVEL TROUGH FORECAST TO DEVELOP OVER OH VALLEY WITH VERY STRONG JET OVER SRN CONUS SPELLS SEVERE WX IN THAT AREA. MID LEVEL RIDGE CLOSES OFF OVER CUBA/BAHAMAS AND EXTENDS NE TO CANADIAN MARITIMES. ON THE SURFACE DAY 2 ATLC LOW CONTINUES WEAKENING TREND BUT PRES GRADIENT N OF 28N BETWEEN 50W AND 70W SUFFICIENT FOR NE AND E WINDS 20 TO 30 KT AND SEAS 10 TO 15 FT. GULF COLD FRONT MOVING RAPIDLY SE TO 30N85W 19N92W WITH 1032 MB HIGH MOVING TO S TX. GALE CONDITIONS DEVELOP S OF 25N W OF FRONT TO MEXICAN COAST WITH BUILDING SEAS. ELY TRADES OVER ATLC S OF 20N INCREASE SOME TO 20 KT. CARIB WINDS REMAIN UNCHANGED. OUTLOOK PERIOD... FOR DAY 3 LARGE POS TILTED MID LEVEL TROUGH OVER MID ATLC FROM 35N42W TO 15N60W. MID LEVEL RIDGE HOLDING FIRM OVER CUBA/BAHAMAS EXTENDS NE TO 40N50W. STRONG MID LEVEL TROUGH OVER OH VALLEY LIFTS NE WHILE NEW STRONG SHORTWAVE IN SRN BRANCH MOVES OUT OF SRN ROCKIES. ON THE SURFACE DAY 3 OLD COLD FRONT MOVES E 0VER ATLC TO 30N40W TO 23N50W. NE TO E WINDS OVER ATLC BEHIND FRONT TO 65W CONTINUE 20 TO 25 KT WITH SEAS 10 TO 14 FT. GULF COLD FRONT WEAKENING AS IT PUSHES E OF FL AND INTO NW CARIB BUT WINDS BEHIND FRONT REMAIN MODERATE NELY WITH CENTER OF HIGH PRES MOVING TO LOWER MS VALLEY AT 1028 MB. CARIB WINDS INCREASING SOME AS HIGH PRES BUILDS FROM THE NW. NO CHANGE TO ATLC TRADES. FOR DAY 4..CHRISTMAS DAY..MID LEVEL TROUGH OVER CENTRAL ATLC CLOSES OFF NEAR 30N42W WITH TROUGH EXTENDING SW TO ERN ANTILLES. MID LEVEL RIDGE WEAKENS BUT STILL HANGS ON FROM NE CARIB TO 35N50W. SHORTWAVE IN SRN BRANCH MOVES E TO TN VALLEY BUT WEAKENING DUE TO PRESENCE OF MID LEVEL RIDGE DEVELOPING ALONG SAME LONGITUDE IN NRN BRANCH. ON THE SURFACE DAY 4 LOW PRES ALONG OLD ATLC FRONT CLOSES OFF NEAR 30N42W WITH WINDS 20 TO 25 KT EITHER SIDE N OF 27N. RIDGE OVER ATLC MAINTAINS 20 KT WINDS N OF 22N BETWEEN 50W AND 65W. GULF WINDS DECREASE TO 10 KT WHILE CARIB AND TRPL ATLC WINDS REMAIN ABOUT THE SAME. FOR DAY 5 CLOSED OFF MID LEVEL LOW OVER MID ATLC CUTOFF FROM SOURCE OF COLD AIR WILL GRADUALLY FILL. SHORTWAVE IN SRN BRANCH MOVES OFF DELMARVA HEADING ENE. NEXT STRONG SHORTWAVE MOVES OUT OF ROCKIES INTO MID MS VALLEY TIGHTENING MID LEVEL FLOW ALONG N GULF COAST WITH POSSIBILITY OF SEVERE WX. MID LEVEL RIDGE WEAKENING BUT HOLDING ON OVER WRN CARIB EXTENDING NE TO 30N50W. ON THE SURACE DAY 5 NEW COLD FRONT MOVES OFF TX COAST WITH WINDS TO 25 KT. LOW PRES OVER LOWER MS VALLEY INCREASES SLY WINDS TO 25 KT OVER N GULF COAST. ATLC WINDS WEAKEN AS PRES GRADIENTS DIMINISH. CARIB WINDS ALSO WEAKEN AS HIGH PRES MOVES WEAKENS AND MOVES E. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... GALE WARNING S OF 28N BEHIND COLD FRONT BEGINNING 06Z 23 DEC. FORECASTER RRG