000 AGXX40 KNHC 290500 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 130 AM EDT SUN APR 29 2007 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. A LARGE MID LEVEL TROUGH IS SWINGING EWD ALONG 80W TONIGHT LOWERING HEIGHTS W OF 70W. MID LEVEL RIDGING IS BUILDING OVER THE MID ATLC ALONG 50W AND BACK OVER THE WRN PLAINS. ON THE SURFACE TONIGHT THE ATLC RIDGE IS CENTERED OVER MID OCEAN WITH MODERATE ELY TRADES E OF 60W. CARIB WINDS MOSTLY 20 KT E OF 78W. A WEAKENING COLD FRONT EXTENDS FROM 31N74W TO S FL AND SHOULD CONTINUE EWD WITH SUPPORT OF THE MID LEVEL TROUGH. LATER DAY 1 A PROGRESSIVE MID LEVEL PATTERN WITH THE TROUGH AXIS SHIFTING TO 70W. ON THE SURFACE LATER DAY 1 THE ATLC RIDGE MAINLY E OF 70W WITH LITTLE CHANGE TO TRADES. WEAKENING COLD FRONT 31N70W TO FL STRAITS WITH A 1023 MB HIGH FOLLOWING BACK OVER SRN LA. FOR DAY 2 MOST OF THE MID LEVEL ENERGY CONTINUES E TO 60W WITH THE MID LEVEL TROUGH. SOME WEAK TROUGHING HOLDS BACK ALONG THE SE COAST. A NEW SHORTWAVE CLOSES OFF IN THE SRN BRANCH ALONG 102W. ON THE SURFACE DAY 2 THE ATLC RIDGE CONTINUES TO RECEDE EWD OF 65W. ELY TRADES CONFINED TO S OF 24N E OF 60W. CARIB WINDS DECREASE TO 15 TO 20 KT E OF 80W. WEAKENING COLD FRONT BEGINS TO DISSIPATE ALONG 31N64W BACK TO CENTRAL BAHAMAS WITH A 1019 MB HIGH FOLLOWING BACK OVER THE NE GULF AND CENTRAL FL. RETURN SE WINDS BEGIN W OF 90W TO 20 KT. OUTLOOK PERIOD... FOR DAY 3 THE FIRST DAY OF MAY..NRN BRANCH OF WESTERLIES DIVING ESE OVER WRN ATLC BUT STAYING N OF 31N AS SEASON WARMS. CLOSED SHORTWAVE IN SRN BRANCH DRIFTING E TO 97W SLOWED BY A SHORTWAVE RIDGE ALONG 85W. ON THE SURFACE DAY 3 THE OLD FRONT DISSIPATES AND THE WEAK HIGH FOLLOWING BEGINS TO MERGE WITH EWD WITH THE WEAK EXTENSION OF THE ATLC RIDGE ALONG 29N. LITTLE CHANGE ELSEWHERE. FOR DAY 4 WEAK MID LEVEL TROUGHING OVER THE SW ATLC AS A STRONG CLOSED SYSTEM WELL N OF THE REGION ALONG 70W DIVES SE OFF THE NEW ENGLAND COAST. FURTHER W THE CLOSED SHORTWAVE BACK OVER THE LOWER MS VALLEY IS CAUGHT IN A DEVELOPING MID LEVEL RIDGE OVER THE PLAINS. THE RIDGE IS IN RESPONSE TO A STRONG TROUGH OVER THE WRN CONUS. ON THE SURFACE DAY 4 A BASIC SUMMER PATTERN BEGINS TO EMERGE WITH THE ATLC RIDGE ALONG 29N WWD TO THE N CENTRAL GULF. WINDS N OF 20N MOSTLY LIGHT AND MODERATE S OF 20N. FOR DAY 5 SRN BRANCH REMAINS ACTIVE WITH SMALL SCALE MID LEVEL SHORTWAVES EMERGING OUT OF THE SRN ROCKIES AND MOVING EWD. PROBLEM IS THEY ENCOUNTER THE LARGE AMPLITUDE RIDGE ALONG 90W AND HAVE TROUBLE MAINTAINING THEIR IDENTITY. LARGE SCALE UPPER TROUGH OVER SE CANADIAN MARITIMES DOMINATES REGION N OF 30N W OF 50W WITH WEAK IMPULSES ROTATING AROUND THE SRN PERIMETER. ON THE SURFACE DAY 5 ATLC RIDGE CENTERED OVER MID ATLC NEAR 33N35W AT 1027 MB WITH AXIS EXTENDING WSW TO 28N62W THEN WEAKLY WWD ALONG 30N TO A 1018 MB HIGH OVER THE NE GULF. SE WINDS INCREASE SOME W OF 90W AS SURFACE PRES FALLS OVER SE TX. CARIB WINDS MOSTLY 15 TO 20 KT S OF 17N E OF 80W. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER RRG