000 AGXX40 KNHC 081217 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 820 AM EDT SUN AUG 08 2010 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... THE NORTHERN EXTENSION OF A TROPICAL WAVE CURRENTLY EXTENDS INTO THE BAY OF CAMPECHE. THE GFS CONTINUES TO INCREASE WINDS TO 20 KT BEHIND THE WAVE OVERNIGHT TONIGHT. GIVEN THE HISTORY OF THIS SYSTEM BEING STRONGER THAN THE MODELS HAVE ADVERTISED...WILL MENTION WINDS TO 20 KT IN THE ATLC HIGH SEAS FORECAST LATER THIS MORNING. SIGNIFICANT CHANGES IN THE MODELS SINCE THIS TIME YESTERDAY WITH THE LOW EXPECTED TO PINCH OFF THE FRONTAL TROUGH OVER CENTRAL FLORIDA. THE CMC..ECMWF...AND UKMET ALL SHOW A MUCH MORE ORGANIZED LOW PRES SYSTEM DEEPENING OVER THE EASTERN GULF MON AND MOVING WEST-NORTHWEST TOWARD LOUISIANA BY THU COMPARED TO THEIR RUNS THIS TIME YESTERDAY. THE GFS IS SIGNIFICANTLY WEAKER AND FARTHER E WITH THE TRACK IN THE GULF...BUT IT HAS BEEN SLOWLY TRENDING TOWARD THE OTHER MODELS THE LAST FEW DAYS. THE HPC/NHC NOON MEDIUM RANGE CALL SAT CALLED FOR A COMPROMISE BETWEEN THE ECMWF AND GFS TRACK WHICH CARRIES A TUE MORNING LOW POSITION NEAR 29N82W AND BRIEFLY MOVES IT INTO THE FAR NE GULF BEFORE CARRYING IT INTO THE FLORIDA PANHANDLE NEAR 30N85W WED MORNING. THESE POINTS WERE TWEAKED TOWARD THE CONSENSUS OF THE ECMWF...UKMET...AND CMC WHICH WERE FARTHER SOUTHWEST WITH THE TRACK AND ALLOWED THE LOW MORE TIME OVER THE GULF WATERS. SW N ATLC AND TROPICAL N ATLC... TROPICAL STORM COLIN WAS AT 30.7N 65.6W AT 0900 UTC THIS MORNING WITH MAXIMUM SUSTAINED WINDS OF 35 KT. COLIN IS FORECAST TO MOVE SLIGHTLY NORTH THROUGH THE NORTHEASTERN EDGE OF THE SW N ATLC ZONE TODAY AND FINALLY EXIT THE SW N ATLC ZONE THIS EVENING. SEE THE TROPICAL CYCLONE DISCUSSION...TCDAT4 OR WTNT44 KNHC...ON T.S. COLIN FOR MORE DETAILS. EARLY MORNING OBSERVATIONS OVER NORTH FLORIDA SHOW A CLEAR WIND SHIFT SUGGESTING THE PASSAGE OF A FRONTAL TROUGH. THE SATELLITE SIGNATURE NEAR BUOY 41010 THIS MORNING SUGGESTS THERE MAY BE A WAVE DEVELOPING ALONG THE BOUNDARY. THE MODELS SUGGEST THE DEVELOPMENT OF A MID LEVEL LOW SOMEWHERE OVER CENTRAL FLORIDA TONIGHT OR MON...BUT THEY ARE NOT SURE OF THE DETAILS. BY TUE...THE UKMET...ECMWF...AND CMC COME INTO EXCELLENT AGREEMENT ON A RETROGRADING AND DEEPENING LOW PRES SYSTEM IN THE GULF OF MEXICO BORN FROM THE ENERGY ASSOCIATED WITH THIS FRONTAL TROUGH WHILE THE GFS IS WEAKER AND MORE NORTHERLY WITH THE SYSTEM. THE GFS HAS BEEN PLAYING CATCH UP HERE. GIVEN THE CURRENT SATELLITE IMAGERY...IT APPEARS THE ECMWF HAS THE BEST HANDLE ON THE DEVELOPMENT NEAR FLORIDA FOR NOW. PLEASE SEE THE DISCUSSION IN THE GULF OF MEXICO SECTION FOR MORE DETAILS ON THIS SYSTEM. THE LOW PRES SYSTEM THAT HAD BEEN EMBEDDED IN THE TROPICAL WAVE OVER THE CENTRAL ATLC HAS FINALLY BROKEN FREE. IT IS FOLLOWING A SLIGHTLY MORE NORTHERLY TRACK THAN WAS SUGGESTED BY THE NOON CONFERENCE CALL YESTERDAY. THIS IS CONSISTENT WITH THE CURRENT MODEL CONSENSUS WHICH IS NOW TO THE RIGHT OF THE PREVIOUS COORDINATED FORECAST. CONFIDENCE IS SOMEWHAT LOW IN THE FASTER TURN. COLIN HAS BEEN SLOW TO BE PICKED UP BY THE TROUGHING CURRENTLY OVER THE WESTERN ATLC THAT IS ALSO EXPECTED TO PICK UP THIS SYSTEM. FOR NOW...WILL HEDGE MOST CLOSELY TO THE COORDINATED POINTS FOR THE SYSTEM RATHER THAN THE NEW GUIDANCE. THIS LARGELY KEEPS THE SYSTEM OUTSIDE OF THE OFFSHORE ZONES THROUGH THE PERIOD. THIS SYSTEM COULD BECOME A TROPICAL CYCLONE IN THE NEXT 48 HOURS. CARIBBEAN SEA... ASIDE FROM SOME RESIDUAL FUNNELING EASTERLY WINDS INTO THE GULF OF HONDURAS BEHIND THE TROPICAL WAVE THAT HAS MOVED INTO THE BAY OF CAMPECHE...THE CARIBBEAN IS QUIET THIS MORNING WITH WINDS LESS THAN 20 KT AND SEAS LESS THAN 8 FT. THE PRES GRADIENT SHOULD REMAIN RELATIVELY WEAK ACROSS THE CARIBBEAN OVER THE NEXT FEW DAYS AS THE RIDGE THAT HAS BUILT S OF COLIN IS COMPROMISED BY THE LOW CURRENTLY IN THE CENTRAL ATLC. THE TROUGH IN THE EASTERN CARIBBEAN IS EXPECTED TO PASS W AND WEAKEN AS IT CROSSES 75W ON TUE AND THE TROPICAL WAVE THAT SPAWNED THE LOW PRES SYSTEM IN THE CENTRAL ATLC WILL ENTER THE CARIBBEAN BY WED. NEITHER SYSTEM IS EXPECTED TO FORCE WIDESPREAD AREAS OF 20 KT WINDS. WARNINGS... SW N ATLC... .AMZ080...TROPICAL STORM WARNING N OF 29N E OF 66W... CARIBBEAN... .NONE. .GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER