000 AGXX40 KNHC 090458 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 130 AM EDT MON APR 9 2007 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. A BATTLE GOING ON TONIGHT BETWEEN THE NRN BRANCH OF THE WESTERLIES AND THE SRN BRANCH. COLD AIR WITH A LARGE MID LEVEL TROUGH IS BEING HELD N OF 35N WHILE A NEW SURGE HEADS SE OVER THE NRN PLAINS. THE STRONG TEMP GRADIENT THROUGH MID ATMOS IS SERVING TO INCREASE THE WLY FLOW S OF 35N. WEAK SHORTWAVES IN THE SRN BRANCH WHILE RIDING THE STRONG FLOW ARE HAVING A TOUGH TIME WITHSTANDING THE CONFLUENT MID LEVEL FLOW. ON THE SURFACE TONIGHT A WEAKENING POLAR AIRMASS EXTENDS SE FROM THE SRN PLAINS ACROSS FL TO A 1022 MB HIGH E OF THE BAHAMAS. THE ATLC SUBTROPIC RIDGE IS NAR 30N43W AT 1026 MB. A STATIONARY FRONT SEPARATES THE TWO AIRMASSES ALONG 31N57W TO 20N71W. A WEAK LOW 1014 MB WAS OVER THE NW GULF WITH 20 KT WINDS ALONG THE N COAST. ELY TRADES ARE NEAR 20 KT S OF 18N INTO THE CARIB TO 75W. LATER DAY 1 THE BATTLE CONTINUES WITH THE COLD AIR ALOFT BEING HELD AT BAY. A NEW SHORTWAVE MOVES E INTO THE SRN PLAINS. ON THE SURFACE LATER DAY 1 WEAK HIGH PRES CONSOLIDATES ALONG 26N WHILE THE CENTRAL ATLC FRONT DISSIPATES. A WEAK FRONT REMAINS OVER THE NRN GULF WITH NE WINDS 20 TO 25 KT. LITTLE CHANGE ELSEWHERE. FOR DAY 2 THE COLD AIR ALOFT EXITS THE NE CONUS WITH THE BROAD ZONAL FLOW DOMINATING THE REGION. EMBEDDED SHORTWAVES MOVE RAPIDLY EWD WITH ONE OVER FL AND ANOTHER BACK OVER THE LOWER MS VALLEY. ON THE SURFACE DAY 2 AIRMASSES OVER THE ATLC GET ELONGATED IN THE STRONG ZONAL FLOW. A STATIONARY FRONT CONTINUES OVER THE N GULF WITH SLY WINDS INCREASING TO 20 KT S OF THE FRONT. CARIB WINDS AND ATLC TRADES MOSTLY MODERATE. OUTLOOK PERIOD... FOR DAY 3 A STRONG SHORTWAVE MOVES E OUT OF THE NRN ROCKIES INTO THE N CENTRAL PLAINS. A WEAKER SHORTWAVE IN THE SRN BRANCH MOVES TO 70W. ON THE SURFACE DAY 3 THE GFS MODEL STILL DEVELOPS A WEAK LOW WITH THE SHORTWAVE NEAR 70W. MODEL WINDS LOOK A LITTLE TOO HIGH FOR A 1009 MB LOW WHICH IS WEAKER THAN LAST NIGHTS RUN. THE OLD STATIONARY FRONT OVER THE N GULF MOVES INLAND PUSHED BY THE SLY WINDS. LITTLE CHANGE ELSEWHERE. FOR DAY 4 WITH THE ABSENCE OF ANY LARGE POOL OF COLD AIR ALOFT..THE NRN BRANCH SHORTWAVE HEADS EWD OVER THE NE CONUS. MID LEVEL RIDGING BEGINS TO TAKE SHAPE ALONG 90W AS THE NEXT SYSTEM MOVES INTO THE CENTRAL ROCKIES. A FLAT MID LEVEL RIDGE HOLDS FIRM OVER THE CARIB. ON THE SURFACE DAY 4 THE ATLC LOW WEAKENS AS IT MOVES RAPIDLY EWD TO NEAR 31N53W. MODEL STILL HAS 30 KT ON IT'S S SIDE WHICH LOOK A LITTLE HIGH. NOT MUCH GOING ON ELSEWHERE WITH MOSTLY LIGHT TO MODERATE WINDS ALL LOCATIONS. FOR DAY 5 WITH A BULGING MID LEVEL RIDGE ALONG 83W..A NRN BRANCH SHORTWAVE THAT WAS OVER THE NE CONUS DAY 4 HEADS SE TO NEAR 36N58W. THE BULGING RIDGE IS IN RESONSE TO THE NEXT SHORTWAVE MOVING OUT OF THE CENTRAL ROCKIES INTO THE CENTRAL PLAINS. ON THE SURFACE DAY 5 SLY WINDS INCREASE OVER THE GULF W OF 85W AS SURFACE PRESSURES FALL OVER THE SRN PLAINS. THE ATLC LOW EXITS THE REGION ALONG 38W STILL WITH TRAILING SW WINDS TO 30 KT WHICH STILL LOOKS TO HIGH. NW CARIB WINDS INCREASE TO 20 KT AS HIGH PRES ALONG 70W PUMPS A SELY FLOW WITH HELP FROM THE INCREASING GULF FLOW. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER RRG