000 AGXX40 KNHC 120621 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 130 AM EST SAT JAN 12 2008 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. MID LEVEL HEIGHTS CONTINUE TO FALL TONIGHT OVER THE ERN CONUS AND NRN GULF AS COLD AIR ALOFT SPILLS SWD. AN OLD CUTOFF LOW NEAR 26N58W IS BEGINNING TO FEEL THE INFLUENCE OF THE DECREASING HEIGHTS AND IS LIFTING SLOWLY NWD. ON THE SURFACE TONIGHT A WEAK 1010 MB LOW WAS BENEATH THE CUTOFF LOW. PRES GRADIENT BETWEEN THE LOW AND A RIDGE TO THE N CONTINUES TO PRODUCE WINDS 20 TO 25 KT. A STATIONARY FRONT OVER THE CENTRAL GULF HAS NO SUPPORT ALOFT AND WILL GRADUALLY DISSIPATE. LATER DAY 1 A PAIR OF SHORTWAVES MOVE INTO THE PLAINS. ONE IN THE NRN BRANCH OF THE WESTERLIES OVER IOWA AND A SECOND ONE OVER TX IN THE SRN BRANCH. BOTH WILL MERGE AS THEY MOVE EWD WITH THE RESULT OF BRINGING COLDER AIR SWD. ON THE SURFACE LATER DAY 1 A COLD FRONT MOVES INTO CENTRAL TX WITH THE ADVANCING COLD AIR. THE WEAK LOW OVER THE ATLC DRIFTS NWD AND WEAKENS FURTHER. GULF WINDS MOSTLY LIGHT. CARIB WINDS MODERATE IN THE CENTRAL PORTION. ATLC TRADES 20 KT E OF 50W. FOR DAY 2 THE PHASED IN DOUBLE SHORTWAVE SCENARIO MOVES TO THE OH VALLEY TIGHTENING THE MID LEVEL FLOW OVER THE NRN GULF AND EJECTING THE OLD CUTOFF LOW OVER THE ATLC. ON THE SURFACE DAY 2 THE TX COLD FRONT MOVES RAPIDLY SE TO THE E CENTRAL GULF WITH WINDS OF 20 KT. WINDS E OF THE FRONT OVER THE ATLC INCREASE TO SWLY 20 KT. ELSEWHERE REMAINS THE SAME. OUTLOOK PERIOD... FOR DAY 3 A SECONDARY POOL OF COLD AIR ALOFT DROPS SWD OVER THE WRN GREAT LAKES AND WILL HELP CARVE OUT A LARGE UPPER TROUGH OVER THE ERN CONUS. MID LEVEL RIDGE HOLDS FIRM OVER NW CARIB BUT MID LEVEL FLOW VERY STRONG OVER THE REGION W OF 70W. ON THE SURFACE DAY 3 A 1030 MB POLAR HIGH MOVES TO SE TX WITH GUSTY NE WINDS OF 20 TO 25 KT OVER THE GULF. THE COLD FRONT MOVES E TO THE CENTRAL BAHAMAS WITH 20 KT WINDS CONFINED TO N OF 27N. CARIB WINDS INCREASE OVER NW SECTIONS TO 20 KT. LITTLE CHANGE ELSEWHERE. FOR DAY 4 SPLIT FLOW IN THE WESTERLIES SETS UP AS THE COLD POOL OF AIR ALOFT MOVES TO THE ERN GREAT LAKES AND A SRN BRANCH SETS UP OVER THE GULF. ON THE SURFACE DAY 4 CYCLOGENESIS BEGINS TO TAKE SHAPE OVER THE SW GULF WITH THE STRONG JET ALOFT OVER THE AREA. GUSTY NE WINDS 20 TO 30 KT EXPECTED OVER THE NW PORTION. WEAKENING COLD FRONT CONTINUES EWD TO 65W BUT GRADUALLY DISSIPATING. CARIB WINDS REMAIN MODERATE. ATLC TRADES MOSTLY LIGHT TO MODERATE. FOR DAY 5 WHILE THE STRONG SRN BRANCH CONTINUES OVER THE GULF..A NEW SURGE OF COLD AIR ALOFT DROPS INTO THE NRN PLAINS. ON THE SURFACE DAY 5 THE GFS MODEL SHOWS ONLY A WEAK LOW OVER THE SRN GULF AND STRONGEST WINDS SHIFT TO THE N AND NE PORTION WHERE THE OLD POLAR HIGH SLIDES EWD. CARIB WINDS MODERATE E OF 80W. POSSIBLE INCREASE IN WINDS N OF 30N W OF 50W AS A NEW FRONT DROPS SWD OVER THE ATLC. ATLC TRADES S OF 20N INCREASE TO 20 KT. WARNINGS... ATLANTIC... NONE. CARIBBEAN... GALE WARNING... GULF OF MEXICO... NONE. FORECASTER RRG