000 AGXX40 KNHC 180500 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 130 AM EDT MON JUNE 18 2007 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. NEW SURGE OF COLD AIR SPILLING SE IN THE NRN BRANCH OF THE WESTERLIES TONIGHT OFF THE NE COAST WILL RE-INFORCE THE OLD CUTOFF THAT HAS LINGERED OFF THE MID ATLC FOR SOME TIME. STRONG MID LEVEL RIDGE HAS DEVELOPED ALONG 85W EXTENDING INTO CANADA. A SHORTWAVE OVER THE SRN PLAINS IS TRYING TO CLIMB OVER THE RIDGE BUT WILL HAVE TO WAIT FOR SOME HELP FROM A NEW SHORTWAVE IN THE NRN BRANCH EMERGING INTO THE NRN PLAINS. A SECOND MID LEVEL RIDGE CENTERED NEAR 26N45W EXTENDS NWD. ON THE SURFACE TONIGHT A 1023 MB HIGH ANCHORES THE ATLC RIDGE NEAR 27N47W WHILE A CONTINENTAL HIGH 1020 MB WAS OFF THE SE COAST. IN BETWEEN AN OLD TROUGH LINGERS FROM 31N65W TO 27N75W BUT IS GRADUALLY DISSIPATING. RETURN FLOW W OF 90W HAS INCREASED TONIGHT WHILE TRADES IN THE CARIB REMAIN MODERATE. ATLC TRADES NOT QUITE AS STRONG. TRPL WAVE ALONG 48W MOVING WNW 15 TO 20 KT. SOME INDICATION IN GFS MODEL OF WAVE. LATER DAY 1 UPPER TROUGH N OF AREA ALONG 60W CONTINUES EWD WHILE NEW STRONG SHORTWAVE MOVES INTO NRN PLAINS. WEAK SHORTWAVE OVER SRN PLAINS BEGINNING TO LIFT NE. MID LEVEL RIDGES HOLDING ALONG 80W AND 45W. ON THE SURFACE LATER DAY 1 AS ATLC TROUGH WEAKENS THE TWO HIGH CELLS BEGIN TO MERGE INTO AN ELONGATED RIDGE ALONG 28N. RETURN FLOW OVER THE WRN GULF WEAKENS SOME WHILE CARIB WINDS REMAIN 20 TO 25 KT. ATLC WINDS S OF 20N 15 TO 20 KT WITH WAVE WEAKLY DEPICTED BY GFS ALONG 55W. FOR DAY 2 STRONG PROGRESSIVE PATTERN IN NRN BRANCH WITH SYSTEMS CONTINUING TO BRUSH BY OUR REGION. SHORTWAVE THAT WAS TRYING TO LIFT NE WEAKENS SIGNIFICANTLY ALONG 85W NO MATCH FOR THE STRONG RIDGE ALONG 76W. ON THE SURFACE DAY 2 ATLC TROUGH WEAKLY HANGS ON NEAR 63W WHILE BOTH CENTERS TRY TO CONNECT. WRN GULF WINDS REMAIN 15 TO 20 KT WHILE CARIB WINDS 20 TO 25 KT IN USUAL S CENTRAL PORTION. ATLC TRADES 15 TO 20 KT WITH WAVE ALONG 60W. OUTLOOK PERIOD... FOR DAY 3 MID LEVEL RIDGE ALONG 76W GETS CAUGHT UP THE STRONG WNW FLOW AND GETS PINCHED BETWEEN THE OLD UPPER TROUGH ALONG 47W AND THE SECOND STRONG SHORTWAVE BARRELING OVER NEW ENGLAND. THE WEAK SHORTWAVE OVER THE SE MOVES TO 80W AND KIND OF PHASES IN WITH THE STRONGER ONE OVER NEW ENGLAND. ON THE SURFACE DAY 3 WINDS INCREASE SOME OVER ATLC WATERS N OF 29N BETWEEN 50W AND 60W WITH PASSING LOW PRES TO THE N. ATLC RIDGE REMAINS WEAK WITH TWO HIGH CENTERS STILL TRYING TO MERGE. GULF WINDS DIMINISH WHILE CARIB WINDS REMAIN AB0UT THE SAME. TRPL WAVE WEAKENS AS IT HEADS NW ALONG 63W. FOR DAY 4 MID LEVEL RIDGING OVER SRN PLAINS DIVERTS NRN BRANCH INTO MORE OF A SELY TRACK AND PICKS UP THE WEAK SHORTWAVE OVER THE SE AND SWINGS IT OVER OUR NRN WATERS. OTHERWISE A FLAT MID LEVEL RIDGE COVERS THE AREA. ON THE SURFACE DAY 4 GFS MODEL DEVELOPS LOW PRES OVER N FL IN RESPONSE TO SHORTWAVE. SLY WINDS INCREASE W OF 75W TO 20 KT WHILE GULF WINDS REMAIN LIGHT. CARIB WINDS CHANGE LITTLE. TRPL WAVE WEAKLY DEPICTED OVER SE BAHAMAS. ATLC RIDGE REMAINS WEAK MAINLY E OF 70W. FOR DAY 5 WEAK SHORTWAVE NEARLY STATIONARY OFF SE COAST WHILE ANOTHER WEAK SHORTWAVE IN THE NRN BRANCH HEADS SE OVER THE UPPER MS VALLEY. WEAK INVERTED MID LEVEL TROUGHING DEVELOPS ALONG 45W OTHERWISE FLAT MID LEVEL RIDGE S OF 28N. ON THE SURFACE DAY 5 GFS MODEL CONTINUES WITH A 1011 MB LOW NEAR JAX SUPPORTED BY THE STATIONARY SHORTWAVE. WITH A 1023 MB HIGH PARKED NEAR 28N62W THE PRES GRADIENT TIGHTENS SOME BETWEEN 70W AND 80W WITH AN INCREASE IN SLY WINDS. CARIB WINDS REMAIN STRONG IN CENTRAL PORTION WHILE ATLC TRADES MOSTLY 15 TO 20 KT S OF 20N. WARNINGS... ATLANTIC...NONE. CARIBBEAN...NONE. GULF OF MEXICO...NONE. FORECASTER RRG