000 AGXX40 KNHC 050804 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 400 AM EDT Fri May 5 2017 Marine Weather Discussion for the Gulf of Mexico, Caribbean Sea, and Tropical North Atlantic from 07N to 19N between 55W and 64W and the Southwest North Atlantic including the Bahamas ...GULF OF MEXICO... A strong cold front for this time of the yea has pushed to across the eastern portion of the Gulf along a position from near 30N83W to 24.5N87W to the central Bay of Campeche near 18N94.5W. A tight pressure gradient behind the front with cold air advection is bringing strong offshore winds in its wake as noted in the buoy observations and in reports from a few ship observations. Strong northwest winds with gusts to gale force where captured by the 0320Z Ascat pass from last night. Seas west of the front are in the range of 8 to 10 ft. Over the far western Gulf west of 95W, northerly flow has diminished to moderate to fresh and is veering to the northeast in direction. Seas west of 95W have lowered to 5 to 7 ft. A pre-frontal trough extending from near 22N85W to the northwest Caribbean Sea is producing, with the aid of mid/upper short wave trough, scattered showers and isolated thunderstorms to its east. This activity has already begun to move onshore the southwest portion of Florida, and is approaching the vicinity of the lower Florida Keys. The front is on track to move southeast of the area this he Gulf region reaching the southeast waters by Friday morning, and move southeast of the area by early this evening. Winds and seas will diminish through tonight over much of the Gulf, and through Saturday over the northeast Gulf as high pressure builds over the western Gulf in the wake of the front. The high pressure will slide eastward through Sunday before it becomes stationary over the central Gulf waters on Monday and Tuesday. With the high shifting eastward, fresh east to southeast winds will develop over the western Gulf through Monday and briefly increase to strong category on Tuesday. Seas will build with these winds. Strong northeast to east winds will develop briefly off the western coast of the Yucatan peninsula at night beginning on Sunday as the typical thermal trough migrates off the Yucatan Peninsula to the southwest Gulf late at night into the morning hours. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... A series of late season cold fronts is keeping the subtropical ridge north of the area relatively week and displaced eastward. This will result in only moderate trade winds, and 3 to 5 ft seas across most of the Caribbean Sea through the weekend. Local drainage effects off Colombia will allow moderate to fresh trades mainly during the overnight and early morning hours. Long period northeast swell will begin to propagate into the tropical north Atlantic waters west of 55W this afternoon, and continue southward to east of about 59W tonight into Saturday, with resultant seas in the 6 to 7 ft range. The swell will decay Sunday afternoon and evening allowing for these seas to subside to 5 to 6 ft. A cold front moving across the eastern Gulf of Mexico today will reach the Yucatan Channel by early this afternoon, then reach a position from near Matanzas Cuba to the Gulf of Honduras by early Saturday morning. Moderate northerly winds and seas of 4 to 5 ft are expected behind the front before it stalls and dissipates late Saturday into Sunday. ...SW N ATLANTIC INCLUDING THE BAHAMAS... Gentle to moderate southeast winds and seas generally under 6 ft are observed across the region under the influence of ridge that is anchored by a 1024 mb high pressure located near 32N53W, while over the far western portion, the latest pressure analysis suggests that pressures are lowering in advance of an approaching strong frontal system for this time of year currently advancing across the eastern Gulf of Mexico as described above. The pressure gradient between the ridging and the lower pressures is supporting increasing southerly flow over the far western waters. This is increasing the seas there as well. Scattered showers and thunderstorms in lines moving quickly north are observed over the far northwest waters. The aforementioned cold front will move off the northeast Florida coast this morning followed by strong west winds with possible frequent gusts to gale force. The southerly flow ahead of the front will increase to strong category this afternoon. Seas will build to 8 to 10 ft this afternoon ahead and behind the front as it reaches from near 31N77W to southeast Florida. Scattered showers and thunderstorms in lines will precede the front mainly north of about 28N. Winds and seas will diminish through Saturday as the front moves eastward while gradually weakening. The front will eventually stall and weaken from roughly from near 29N65W to the Central Bahamas and Central Cuba by Tuesday. A weak pressure pattern will dominate the region on Tuesday with gentle to moderate winds and seas of 3 to 5 ft east of the Bahamas, and 1 to 3 ft off east Florida and across the Old Bahama Channel. A weak reinforcing cold front may move south of 31N and east of 70W late Tuesday, then shift eastward of the area late Wednesday. At that time, another cold front may enter the northern waters. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... .GMZ013...N CENTRAL GULF INCLUDING FLOWER GARDEN BANKS MARINE SANCTUARY... Gale Warning for frequent gusts east of 89W through this evening. .GMZ015...NE GULF N OF 25N E OF 87W... Gale Warning for frequnet gusts through early this evening. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... .AMZ111 and AMZ115 Gale warning for frequent gusts north of 30N tonight into Saturday. $$ *For detailed zone descriptions, please visit: http://www.nhc.noaa.gov/abouttafbprod.shtml#OWF Note: gridded marine forecasts are available in the National Digital Forecast Database (NDFD) at: http://www.nhc.noaa.gov/marine/grids.php For additional information, please visit: http://www.nhc.noaa.gov/marine $$ .Forecaster Aguirre. National Hurricane Center.