000 AXNT20 KNHC 231552 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Tue May 23 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 1550 UTC. ...SPECIAL FEATURES... Caribbean and Gulf of Mexico Ashfall Advisory: The Popocatepetl Volcano in Mexico continues to erupt this morning. Volcanic ash has moved E across the Bay of Campeche, reaching as far as 85W in the NW Caribbean. Ash is observed as high as 30000 ft. The area impacted by ashfall is expected to gradually recede through the day. Mariners who encounter volcanic ash or floating volcanic debris are encouraged to report this observation to the National Hurricane Center, by calling +1-305-229-4424. ...TROPICAL WAVES... An eastern Atlantic tropical wave has its axis along 27W, south of 12N. It is moving west at 10 kt. Scattered moderate convection is observed from 05N to 10N and between 20W and 33W. A central Atlantic tropical wave has its axis along 43W, south of 12N. It is moving westward at 10 kt. Scattered moderate convection is observed from 03N to 09N between 35W and 48W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coastal border of Guinea and Guinea-Bissau near 11N15W to 07N20W. The ITCZ continues from 07N20W to 06N25W, then resumes from 06N29W to 04N41W, and resumes again from 06N45W to 07N58W. All significant convection in this area was described in the tropical wave section. GULF OF MEXICO... Please read the Special Features section for information on the Ashfall Advisory for the SW Gulf of Mexico. A new 1013 mb low pressure center is analyzed on the coastal border between Mississippi and Alabama near 30N88W with an associated stationary boundary that straddles the Gulf coast from New Orleans, LA to Apalachicola, FL. A surface trough extends from the low pressure center to the SE Gulf near 23N84W. Scattered weak convection is observed north of 26N between 82W and 88W. Otherwise, a 1015 mb high pressure center near 25N92W with a weak gradient dominates the pattern. Winds are light to gentle across the basin with smooth seas of 2 ft or less. For the forecast, a modest cold front will move S through the eastern Gulf Wed through Fri, followed by moderate to locally fresh N to NE winds E of 90W through Sat morning. Otherwise, weak high pressure will generally dominate the basin through the week, yielding light to gentle winds through tonight, and gentle to moderate thereafter. Seas will be slight, but building with the increasing winds behind the front. CARIBBEAN SEA... Please read the Special Features section for information on the Ashfall Advisory for the NW Caribbean Sea. A few isolated showers and thunderstorms are observed within 120 nm south of Puerto Rico and in the Mona Passage. The presence of low pressure in the subtropical Atlantic is maintaining a weak pressure gradient across the basin. Winds are gentle to moderate across the basin. 1-3 ft seas prevail across the majority of the basin, with areas of 2-4 ft seas north of Panama and in the eastern Caribbean. For the forecast, elongated low pres N of the basin will help to maintain a weak pres gradient across the central and western Caribbean through Thu, supporting light to gentle winds. A pre- frontal trough will move into the NW Caribbean Thu night where it will stall and linger through the end of the week, leading to a slight increase in winds and seas there. Over the E Caribbean, the Azores High will support gentle to moderate SE trade winds through the forecast period, locally fresh offshore northern Venezuela. Expect scattered showers and tstms across the waters E of 65W through this evening. ATLANTIC OCEAN... A well defined surface low pressure of 1009 mb is observed near 27N72W. This feature is roughly 30 nm south of NDBC buoy 41047, which is reporting 12 kt ESE winds and 6 ft seas in a 9 second easterly swell. Scattered moderate convection is observed from 25N to 31N between 67W and 71W with widely isolated convection extending as far east as 62W. An associated surface trough extends from 31N70W to 22N75W. West of the trough, winds are moderate to fresh from the NE with 4-6 ft seas. East of the trough, winds are fresh from the SE with 6-8 ft seas. In the central Atlantic, high pressure north of the area is supporting moderate to fresh NE-E winds and 5-7 ft seas. In the eastern Atlantic, winds are moderate to locally fresh from the N-NE with 5-7 ft seas. For the forecast W of 55W, the low will move N-NE and reach just N of the area near 31.5N69.5W Wed morning where it will interact with a weak cold front approaching from the NW, then move well NE and exit the region Wed night. Fresh to strong SE winds, rough seas, with scattered showers and tstms will prevail E of the low and trough through Wed. New low pres is forecast to develop over central Florida late Wed, move N-NE off the peninsula Thu, and across the far NW waters through Sat. The pres gradient between high pres over the eastern U.S. and the low will support fresh to locally strong NE winds and large NE swell across the NE Florida offshore waters beginning Thu night through Sat, with possible gales offshore Jacksonville, Florida Fri night. $$ Flynn