000 AGXX40 KNHC 220717 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 315 AM EDT MON JUN 22 2009 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. SW N ATLC... THE MAIN FCST ISSUE REMAINS THE EVOLUTION OF THE EXPECTED SWATH OF STRONG SLY WINDS OVER THE FAR NE PORTIONS OF THE ZONE FOR TUE INTO WED. ALL MODELS LATCH UNTO A STRONG VORT MAX NOW OVER UPSTATE NY WHICH IS FCST TO DIVE SWD ON THE W SIDE OF THE VERY DEEP TROUGH JUST OFF THE E COAST. THIS IS THE CULPRIT WHICH ALLOWS A SFC LOW TO DEVELOP ALONG AN EXISTING SFC TROUGH OVER THE N CENTRAL PORTION OF THE ZONE ON TUE AND MOVES ACROSS 31N BETWEEN 68W AND 70W...DEPENDING ON THE MODEL OF CHOICE. AM NOW MORE CONFIDENT THAT THERE WILL...NOT...BE SUSTAINED GALE FORCE WINDS OVER FORECAST WATERS IN THE ZONE ON TUE GIVEN THE OUTPUT FROM THE 00Z MODELS. THE 00Z UKMET/ECMWF HAS TRENDED WEAKER WITH ONLY 25 LOCALLY 30 KT WINDS DEPICTED. THE 00Z GFS NO LONGER SHOWS GALE CONDITIONS WITH THE DEVELOPING SURFACE LOW NEAR 31N69W TUE AFTN IN OUR WATERS...WITH ONLY A POCKET OF GALE FORCE WINDS N OF 31N. THUS WILL FCST 20-30 KT WINDS WITH HIGHER GUSTS THIS PACKAGE. IN ADDITION...THE LATEST UKMET AND NAM HINT AT ANOTHER WAVE DEVELOPING FURTHER S ALONG THE TROUGH ON WED WITH A ANOTHER SURGE OF WINDS. DETAILS OF THE ULTIMATE EVOLUTION OF THE WIND FIELD ARE HIGHLY RELIANT UPON THE SPEED...INTENSITY...AND TRACK OF THE SHORTWAVE ENERGY DROPPING SOUTH ALONG THE BACKSIDE OF THIS AMPLIFIED TROUGH THROUGH THE SOUTHEAST U.S...SOMETHING THE MODELS RARELY HANDLE WELL...BUT THE CURRENT TREND WOULD SUPPORT A BROADENED TROUGH WITH MOVING MULTIPLE SHORTWAVE SYSTEMS PASSING QUICKLY THROUGH THE BASE OF THE TROUGH...MAKING ANY SIGNIFICANT SURFACE DEVELOPMENT LESS LIKELY...AND HENCE ANY SUSTAINED GALE FORCE WINDS. CARIBBEAN... LATEST HI RES QUIKSCAT INDICATED A MUCH SMALLER AREA OF 15 TO 20 KT WINDS OVER THE CARIBBEAN GENERALLY S OF 14N BETWEEN 68W AND 76W. TROPICAL WAVE CURRENTLY ALONG 56W AND S OF 12N WILL MOVE INTO THE EASTERN CARIBBEAN TUE. AT THE SAME TIME...THE DEEPENING SURFACE TROUGH OVER THE SW NORTH ATLC WILL VEER WINDS OVER THE E CARIBBEAN TO MORE SOUTHEASTERLY TUE AND WED...WITH THE REMNANTS OF THE TROPICAL WAVE BEING STEERED NORTHWESTWARD AS IT MOVES ACROSS THE CARIBBEAN. WEAKER LOW LEVEL FLOW NEAR THE BROAD SURFACE TROUGH WILL SLOW THE WAVE/S MOTION MID WEEK. ON THU AND FRI A BUILDING SUBTROPICAL RIDGE OVER THE CENTRAL ATLC WILL INTRODUCE MODERATE TO FRESH TRADE WINDS ACROSS THE E AND CENTRAL CARIBBEAN. GULF OF MEXICO... SURFACE HIGH PRES OVER THE N CENTRAL GULF WILL AFFECT MUCH OF THE GULF EARLY THIS WEEK...WHILE DRIFTING WESTWARD. AS THE HIGH DRIFTS WEST...WINDS WILL BECOME NW AT 15 TO 20 KT TUE AND WED IN RESPONSE TO THE DEEPENING LAYER LOW IN THE WESTERN N ATLC. RIDGE BUILDS WWD OVER THE GULF ALONG 25N THU AND FRI. WARNINGS ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FORECASTER COBB. TROPICAL PREDICTION CENTER.