000 AGXX40 KNHC 270458 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 130 AM EDT THU APR 27 2006 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. ONE WEAKENING SHORTWAVE EXITING THE AREA ALONG 45W OVER MID OCEAN TONIGHT WHILE A STRONGER SHORTWAVE MOVES SE OVER THE SERN US. THE SECOND SHORTWAVE IS SUPPLYING THE ENERGY FOR A COLD FRONT OVER THE GULF OF MEXICO WHICH IS MOVING EWD. THE STRONG SHORTWAVE IS IN THE SRN BRANCH OF THE WESTERLIES AND WILL MOVE TO THE SE COAST DAY 1. IN THE NRN BRANCH A MUCH LARGER TROUGH WILL DIVE SWD OVER THE GREATLAKES AND BEGIN TO INTERACT WITH THE SRN BRANCH. ON THE SURFACE DAY 1 THE COLD FRONT MOVES OFF THE NE FL COAST WITH WINDS 20 TO 25 KT MAINLY AHEAD OF THE FRONT. THE AIRMASS FOLLOWING THE FRONT IS WEAK AND GULF WINDS WILL BE MOSTLY LIGHT. WEAK GRADIENT OVER THE CARIB DAY 1 WITH MOSTLY LIGHT WINDS. THE ATLC RIDGE IS CENTERED OVER MID OCEAN. THE TROUGH IN THE NRN BRANCH RAPIDLY MOVES IN BEHIND THE SHORTWAVE IN THE SRN BRANCH DAY 2 SENDING IT TO NEAR 32N70W. A SURFACE LOW DEVELOPS AS A RESULT BUT IT'S CENTER IS N OF OUR REGION NEAR 33N69W AT 1007 MB. A COLD FRONT FROM THE LOW MOVES SE OVER THE BAHAMAS BUT GUSTY WINDS ARE CONFINED N OF 27N. RETURN FLOW SETS UP DAY 2 W OF 90W TO 20 KT. CARIB WINDS REMAIN MOSTLY LIGHT TO MODERATE ALONG THE S AMERICAN COAST. OUTLOOK PERIOD... THE GFS MODEL SHOWS THE TWO UPPER TROUGHS MERGING INTO ONE DAY 3 ALONG 70W WITH A GOOD SUPPLY OF COLD AIR ALOFT. A NEW STRONG VORTEX IN THE SRN BRANCH MOVES INTO THE SRN PLAINS DAY 3. THIS LOWERS SURFACE PRESSURES OVER THE PLAINS AND INCREASES THE RETURN FLOW AND SPREADS IT OVER THE ERN GULF DAY 3. THE LOW PRES IN THE ATLC MOVES TO NEAR 33N67W AT 1005 MB WITH A COLD FRONT DRAGGING EWD TO ALONG 65W. GUSTY WINDS TO 25 KT OVER THE ATLC EITHER SIDE OF THE FRONT N OF 28N. CARIB WINDS REMAIN MOSTLY LIGHT BUT INCREASE OVER THE NW PORTION TO 20 KT FROM THE NE AND E. LARGE UPPER VORTICIES DOMINATE THE HEMISPHERE THE FOURTH DAY. ONE OVER THE ERN ATLC..THE SECOND ALONG 65W AND THE THIRD OVER THE MID MS VALLEY. THE ATLC LOW PRES CENTER 1004 MB DRIFTS E TO NEAR 33N65W DAY 4 WITH THE FRONT MOVING E TO NEAR 60W. WINDS REMAIN A PROBLEM N OF 26N ON EITHER SIDE OF THE FRONT. GULF WINDS DECREASE EXCEPT FOR THE ERN PORTION WHERE THEY REMAIN SE 20 TO 25 KT. CARIB WINDS MOSTLY MODERATE NE AND E DAY 4. THE FIRST OF MAY FINDS THE CENTRAL ATLC UPPER VORTEX BEGINNING TO LIFT NE ALONG 60W WHILE THE ONE OVER THE MID MS VALLEY WEAKENS SLIGHTLY DAY 5. THE ATLC FRONT MOVES TO NEAR 60W WITH WINDS DECREASING SOME AS THE LOW PRES CENTER MOVES FURTHER N. W OF 70W N OF 20N WINDS SHOULD BE MOSTLY LIGHT DAY 5 WHILE S OF 20N W OF 70W WINDS WILL BE NE TO E 15 TO 20 KT. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER RRG