000 AGXX40 KNHC 231755 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 200 PM EST THU DEC 23 2004 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. SW N ATLC... SLY RETURN FLOW 15-20 KT AND EXPECTED TO INCREASE TO 20-25 KT OVER W PORTION JUST IN ADVANCE OF FRONT EXPECTED TO MOVE OFFSHORE IN A FEW HOURS PRECEDED BY SQUALL LINE. GRADIENT ELSEWHERE SUPPORTING 15-20 KT PER QSCAT PASS WITH NE SWELLS 9-12 FT BETWEEN 65W-55W. STILL SOME UNCERTAINTY OVER LOCATION WHERE FRONT WILL TEMPORARILY STALL OR BEGIN TO DRIFT SE...IN RESPONSE TO WAVE DEVELOPING ALONG FRONT IN SW GULF OF MEXICO...FRI NIGHT AND SAT BUT I LIKE GFS/ETA/UKMET POSITION AS NOGAPS DOESNT STALL FRONT AT ALL. ANYWAY...I AM FORECASTING FRONTAL WAVE TO MOVE ACROSS S FLORIDA OR STRAITS SAT AFTERNOON DRAGGING FRONT THROUGH CENTRAL BAHAMAS BY MON...AND DIFFUSE ACROSS SE BAHAMAS TUE. ONSET OF STRONGER POST-FRONTAL WINDS LATE FRI WITH MODELS BACK TO SHOWING 25-30 KT AFTER BACKING OFF TO 25 KT ON YESTERDAYS RUNS. BY SUNRISE SUN GFS INDICATING POSSIBILITY OF VERY SMALL AREA GALE WINDS OFFSHORE WATERS E OF CENTRAL FLORIDA...AND PREVIOUS RUN OF ETA AS WELL BUT NOT TILL MID DAY SUN. NOTE THAT MY 5 DAY FORECAST A FEW DAYS AGO MENTIONED GALE POSSIBILITY... BUT LATER MODEL RUNS SUGGESTED WINDS WELL BELOW GALE...THUS WORDING WAS REMOVED FROM TEXT PRODUCTS. WILL GO WITH 30 KT MAX FOR NOW AS BEYOND 48 HOURS. NNW3 RESPONDS WITH SEAS TO 18 FT MID DAY MONDAY ALONG 30N. CARIBBEAN AND TROPICAL N ATLC... HIGH PRES REMAINS IN CONTROL WITH WINDS DECREASING AS HIGH PRES N OF AREA WEAKENS AND FRONT APPROACHES YUCATAN CHANNEL. THE FRONT WILL MOVE INTO NW CARIBBEAN BY SUNRISE SUN...BUT THEN STALL OVER NW PART WITH N WINDS BEHIND FRONT ABOUT 20 KT. NLY SWELL AFFECTING TROPICAL N ATLC WATERS WITH BUOY E OF GUADELOUPE REPORTING 9 FT SEAS FOR PAST SEVERAL HOURS. THESE SWELLS WILL CONTINUE AFFECTING LESSER ANTILLES AND CARIBBEAN PASSAGES FOR THE NEXT 2 DAYS WITH SEA HEIGHTS SLOWLY DECREASING. ANOTHER SWELL FIELD AFFECTS N PART OF TROPICAL N ATLC SUN FROM DEVELOPING CENTRAL ATLC GALE... WITH EXPECTED SEA HEIGHTS SIMILAR TO WHAT ARE BEING OBSERVED WITH CURRENT SWELL. GULF OF MEXICO... WINDS E AND W OF FRONT 25 KT WITH A FEW 30 KT REPORTS WITH A 14 FT SEAS SHIP REPORT THIS MORNING. EXPECT A DECREASE IN CONDITIONS TONIGHT AS FRONT SLOWS DOWN OVER S GULF. FRONTAL WAVE EXPECTED TO DEVELOP SW GULF LATE TONIGHT AND SHIFT E ALONG FRONT TO FLORIDA COAST ON SAT. EVEN IF LOW DEVELOPMENT IS OVER- FORECAST...THE COMBINATION OF STRONG PRES GRADIENT AND COLD AIR ADVECTION SHOULD BE ENOUGH FOR NLY WINDS TO INCREASE TO GALE STRENGTH. STRONGEST WINDS WILL BE OVER SW GULF WHERE WINDS COULD REACH 40 KT. SINCE MODELS COULD BE UNDERESTIMATING STRENGTH OF THIS COLD AIR ADVECTION...35 KT WINDS MAY BE MEASURED IN THE NW AND N CENTRAL COASTAL WATERS AS WELL. EXPECT WINDS TO BECOME NE-E MON-TUE AND CONTINUE AT1 15-20 KT OVER E PORTION. WILL TWEAK NWW3 GUIDANCE DOWNWARD A LITTLE. CONTINUE PREVIOUS FORECASTS MENTION OF WINTRY PRECIP NEAR COAST IN NW AND MIDDLE GULF TO MATCH UP WITH COASTAL OFFICES. WARNINGS... ATLC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. GALE WARNING EXPECTED FRI NW/SW/MIDDLE GULF...GMZ080-082-084. GALE CONDITIONS POSSIBLE SAT FOR GMZ080-082-084 $$ FORECASTER NELSON