000 AXNT20 KNHC 220956 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Sun May 22 2022 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 0600 UTC surface analysis and satellite imagery through 0940 UTC. ...SPECIAL FEATURES... Gulf of Mexico Gale Warning: A large line of thunderstorms persists over the central Gulf of Mexico, roughly 30 nm wide from 24N90W to 25N88W. The thunderstorms are due to divergent flow aloft associated with an upper trough over the north- central Gulf. The thunderstorms are also drawing energy from the warm Loop Current, which flows from the Yucatan Channel into the central Gulf. Winds in the area of the thunderstorms may reach gale force at times early this morning. A ship observation and a pair of recent scatterometer pass confirmed gale force winds along the line of thunderstorms. An outflow boundary was observed moving into the west-central Gulf as far west as 94W, with an estimated speed of 30 kt. In addition to gale force winds, mariners can expect locally higher wave heights and frequent lightning in the central Gulf near this line of thunderstorms. Wave heights may be as high as 13 ft. The thunderstorm activity and associated impacts will diminish through late morning or early afternoon. Heavy Rainfall possible over northern Central America and southern Mexico: Currently, clusters of showers and thunderstorms are active along the coast of Guatemala. Southeast flow following a tropical wave passing west of the region is converging with northerly drainage flow to produce these showers and thunderstorms along the coast. This will likely diminish through the morning. However, although the heavy rainfall that has been impacting parts of Nicaragua and Honduras may taper off through today, broad low pressure off over the far eastern Pacific will continue to pump very moist onshore flow over coastal portions of El Salvador, Guatemala and the Mexican state of Chiapas tonight and Monday, supporting areas of heavy rainfall in those locations. Please refer to bulletins and forecasts that are issued by your local or national meteorological agency for more information. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 58W/59W, from 13N southward, moving westward at 15 to 20 knots. Although this wave is weaker than it was several days ago, low level wind shifts were noted on the past several upper air soundings from Cayenne, French Guiana that are characteristic of a tropical wave passage and this provides some confidence of the position of the wave. This is supported by weak cyclonic turning noted in lower level satellite vector winds near where the tropical wave axis is analyzed. Trade wind convergence is supporting a line of weak showers east of the tropical wave axis, from 07N to 09N between 53W and 58W. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal plains of Guinea-Bissau near 12N16W to 06N20W and to 02N27W. The ITCZ continues from 02N27W to 00N40W. Scattered moderate convection is active from 03N to 05N between 11W and 14W. GULF OF MEXICO... Please refer to the Special Features section for details concerning the gale warning in the Gulf of Mexico. In addition to winds to gale force, recent scatterometer satellite information indicated a broad band of fresh to strong SE winds reaching from the south-central Gulf to parts of the northwest Gulf. In addition to the estimated 11 to 13 ft seas near the line of thunderstorms in the central Gulf, seas 7 to 9 ft may be possible elsewhere in the area of fresh to strong winds based reports from buoys to 7 ft just outside the main area of winds. Moderate to fresh SE winds with 4 to 6 ft seas are noted elsewhere. Several platforms over the northwest Gulf have been reporting visibility limitations due to haze. This may be due to smoke from agricultural fires over southern Mexico impacting the visibility over much of the western Gulf. For the forecast, the thunderstorm activity will diminish later this morning or early afternoon. Winds and seas across the central Gulf will diminish into Mon as the low pressure farther south weakens, except for pulses off fresh to strong winds off the north coast of the Yucatan Peninsula, mainly at night. Looking ahead, a ridge will build from westward from the western Atlantic across the northern Gulf through mid- week. The associated gradient between the ridge and low pressure with a cold front west of the area will support fresh southeast return flow over the western Gulf Tue through late Wed. The cold front is expected to move into the western Gulf on Thu followed by gentle to moderate north to northeast winds. CARIBBEAN SEA... Buoy and ship observations along with scatterometer satellite data indicate pockets of fresh to strong E to SE winds over much of the south-central Caribbean and northwest Caribbean. These winds are due to a tight pressure gradient between a strengthened subtropical ridge north of the area and broad low pressure over the eastern Pacific and northern Central America. Wave heights are likely 8 to 10 ft in the areas of fresh to strong winds, to include the Gulf of Honduras. Elsewhere, moderate to fresh E to SE winds and 5 to 8 ft seas are noted. Convergent low level flow into the monsoon trough is supporting the development of a few showers and thunderstorms about 120 nm off Costa Rica and western Panama. No other significant shower or thunderstorm activity is noted. For the forecast, fresh to strong E to SE winds and rough seas will persist into tonight over parts of the south-central and northwest Caribbean between high pressure to the north and lower pressure over southern Mexico. Winds and seas will diminish tonight through Mon as the pressure areas weaken, although fresh to strong winds will continue to pulse over the Gulf of Honduras and off Colombia into mid week. ATLANTIC OCEAN... 1026 mb high pressure centered near 31N69W west of Bermuda anchors the subtropical ridge east to west along 31N, west of 55W. This pattern is supporting across the basin mainly gentle to moderate breezes north of 22N with 3 to 5 ft seas, and moderate to fresh trade wind flow south of 22N with 5 to 7 ft seas. A few showers and thunderstorm were active earlier this morning over the Gulf Stream off northeast Florida. This activity was ahead of a weak upper disturbance to the northwest, and appears to be rapidly diminishing in the latest satellite images as it moves east of the Gulf Stream. For the forecast for the waters west of 55W, the high pressure ridge along 31N will shift slightly southward today, then change little through mid-week. It will shift eastward Thu ahead of a cold front moving across the southeastern U.S. The associated pressure gradient will allow for mainly gentle to moderate winds across the region through the period, except for pulsing of moderate to fresh east winds between Hispaniola and the southeastern Bahamas through Mon night. Moderate northeast swell may impact the waters east of 60W through Tue, then subside into Wed. $$ Christensen