000 AXNT20 KNHC 181728 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sat Feb 18 2023 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...SPECIAL FEATURES... CARIBBEAN SEA Gale-FORCE WIND WARNING: A tight pressure gradient between the Bermuda high and lower pressure in northwestern Colombia will induce NE to ENE strong to near-gale force winds during the daytime hours, and gale-force winds during the late night and early morning hours, in the south central Caribbean Sea, through at least Wednesday. The sea heights, during the moments of the comparatively fastest wind speeds, will be ranging from 11 feet to 14 feet. CENTRAL ATLANTIC OCEAN LARGE SWELL EVENT: Large long-period northerly swell, that is behind a stationary front, is generating sea heights that are ranging from 11 feet to 13 feet from 25N northward between 40W and 47W, through today. Subsiding swell should allow the sea heights to go down, to less than 12 feet later this evening. Please, read the latest High Seas Forecast, at the website: https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, for more details. ...MONSOON TROUGH/ITCZ... A surface trough passes through the Prime Meridian along 03N/04N, to 15W. The ITCZ continues from 04N15W, to 02N23W, crossing the Equator along 26W, to 02S28W, to 02S43W. Precipitation: widely scattered moderate to isolated strong is from 08N southward from 60W eastward. ...GULF OF MEXICO... A cold front is passing through 31N73W, to the Florida east coast near Deerfield Beach, to the NE Yucatan Peninsula, to northern Guatemala. A surface ridge is to the north and northwest of the cold front, from central Louisiana, to 20N96W in the SW corner of the Gulf of Mexico. Precipitation: rainshowers are possible: from the NW Bahamas into the Straits of Florida, and from 84W westward, in the broken to overcast multilayered clouds. Strong to near gale-force northerly winds have been following the cold front. Gale-force winds were near Veracruz in Mexico during the late night and early morning hours. Those gale-force winds have slowed down. The sea heights have been ranging from 8 feet to 14 feet from 28N southward from 86W westward. The comparatively highest sea heights have been in the SW corner of the area. The sea heights range from 5 feet to 7 feet elsewhere. A strong cold front extends from extreme south Florida SW to the NE Yucatan peninsula. Strong to near gale force northerly winds persist behind the front S of 21N. These winds will begin to diminish later this morning as the front moves E and exits the basin. Elsewhere winds and seas associated with the front will diminish this afternoon through early Sun. Surface high pressure and associated ridging will develop across the gulf on Sun providing mainly light to gentle variable winds basin-wide through Mon night. Moderate to fresh SE winds will develop across the western half of the gulf on Tue ahead of the next frontal system. ...CARIBBEAN SEA... Please, read the SPECIAL FEATURES section, for details about the ongoing Gale-Force Wind Warning. A 1027 mb high pressure center is in the Atlantic Ocean near 32N51W. A subtropical ridge extends to Andros Island in the Bahamas. Expect the continuation of fresh to near gale-force trade winds in most of the areas. The exception will be moderate to fresh winds in the SE part, and in the NW corner. The sea heights have been ranging from: 7 feet to 10 feet in the E, in the SW, and in the central Caribbean. The exception is for the range from 11 feet to 14 feet offshore Colombia. Expect the sea heights to range from 3 feet to 6 feet elsewhere. 1027 mb high pressure centered just NE of the area and the associated subtropical ridge extend to the Straits of Florida. The high will weaken through Mon as a cold front moves into the western Atlantic, with reinforcing high pressure building behind it, and due north of the Caribbean basin. This pattern will sustain fresh to strong easterly trades across most of the basin through Wed, including the Windward Passage. Winds will pulse nightly to gale force off the coast of Colombia through Mon night, however strong to near gale force winds will continue through the remainder forecast period. High seas in mixed N and NE swell across the tropical Atlantic waters will subside Mon night. Strong trade winds prevailing east of the Leeward Islands will diminish to fresh speeds Sun night. ...ATLANTIC OCEAN... Please, read the SPECIAL FEATURES section, for details about the large northerly swell and the rough seas. A cold front is passing through 31N73W, to the Florida east coast near Deerfield Beach, to the NE Yucatan Peninsula, to northern Guatemala. Fresh to strong N to NW winds, and and sea heights that have been reaching 9 feet, are to the northwest of the cold front. Fresh to strong SW winds have been to the east and southeast of the cold front from 28N northward to 63W. Precipitation: rainshowers are possible to the north of the line that passes through 31N67W, to the NW Bahamas, to the Straits of Florida. A surface ridge passes through a 1027 mb high pressure center that is near 32N51W, to 28N63W, to the NW Bahamas and Andros Island. The surface pressure gradient, that is between the 31N73W-to- Deerfield Beach Florida cold front and the surface ridge is helping to sustain fresh to locally strong winds and sea heights that have been ranging from 8 feet to 11 feet, are from 23N southward. A 1016 mb low pressure center is near 25N42W. An occluded front extends from the 1016 mb low pressure center to 29N42W. A stationary front continues from 29N42W beyond 31N39W. A cold front continues from 29N42W, curving to 25N40W and 20N42W. A shear line continues from 20N42W to 16N50W, beyond 15N60W, into the Caribbean Sea near 15N69W. Fresh to strong winds, and sea heights reaching 12 feet, have been to the west of the front to 50W. Moderate to fresh winds, and sea heights reaching 10 feet, have been to the east of the front. Precipitation: widely scattered moderate to isolated strong is from 21N northward between 35W and 45W. 1027 mb high pressure centered near 31N51W extends a ridge SW to the Straits of Florida. A cold front extends across the Atlantic from 31N71W to the extreme south Florida and is moving SE. Fresh to strong trade winds will prevail S of 22N through early Mon as the high drifts NE and weakens. The pressure gradient between the ridge and the front will support strong SW winds ahead of the frontal boundary, N of 29N through today as the frontal boundary continues southeastward. Strong northerly winds will prevail behind the front through this morning then winds will begin to veer and gradually diminish as the front reaches from 31N57W to the NW Bahamas Sun morning, and then stalls. Weak high pressure then will prevail through early next week. $$ mt