000 AXNT20 KNHC 072314 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Thu Jun 8 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 1800 UTC surface analysis and satellite imagery through 2300 UTC. ...SPECIAL FEATURES... Excessive Rainfall - Cuba and Bahamas: Moist southerly mid-level flow combined with enhanced rising air motion due to a strong upper-level jet positioned just northwest of this area will increase the potential for heavy rain and strong thunderstorms. The heaviest rainfall is expected to occur from this afternoon through Sat afternoon across portions of eastern and central Cuba and the central Bahamas. These rains could cause flooding, especially over mountainous areas in eastern and central Cuba. Please see the latest forecast from your national meteorological service for more information. Locally heavy rain has been reported in central and east Cuba, with a maximum rainfall amount of around 4 inches (108.1 mm) in Jiquima, Holguin in the past 24 hours. ...TROPICAL WAVES... The axis of an Atlantic Ocean tropical wave is near 30W, from 13N southward, moving westward at 15-20 knots. Scattered moderate to isolated strong convection is noted where the wave meets the ITCZ from 03N-07N between 28W-32W. The axis of an Atlantic Ocean tropical wave is near 51W/52W, from 12N southward, moving westward at 15-20 knots. Scattered showers are near the wave axis. The axis of a Caribbean Sea tropical wave is near 68W/69W, from 13N southward, moving westward at 10 to 15 knots. The wave appears to enhance convection over western Venezuela. The axis of a Caribbean Sea tropical wave is near 79W, from 14N southward extending into the eastern Pacific region, and moving westward at 10 knots. A cluster of moderate to strong convection is near the northern end of the wave axis, covering the waters from 12N-14N between 79W-82W. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coast of Guinea near 10N14W then continues to 09N16W. The ITCZ extends from 09N16W to 06N35W to 04N51W on the coast of Brazil. A large cluster of moderate to strong convection is seen from 03.5N-07N between 08W-12W. This convective activity, likely associated with the next tropical wave, is affecting much of Liberia. Scattered moderate and isolated strong convection exists from 05N-08N between 22W-30W, and from 06N-09N between 40W and 45W. Scattered moderate convection is also noted from 02N-05N from 32W-40W. ...GULF OF MEXICO... A weak pressure pattern dominates the Gulf waters supporting mainly light to gentle winds, with seas in the 1-2 ft range. A 1009 mb low pressure is analyzed near 27N89W with a surface trough extending westward to near Brownsville, Texas. Numerous showers and thunderstorms are noted over the eastern Gulf, particularly E of 88W, and over parts of Florida in association with an upper-level trough that extends from SE Louisiana to the central Bay of Campeche. For the forecast, high pressure will generally prevail across the basin through the end of the week, with mainly gentle to moderate winds. Moderate return flow will develop across the western Gulf over the upcoming weekend. ...CARIBBEAN SEA... See Special Feature above for heavy rainfall to affect Cuba through Sat afternoon. Numerous showers and thunderstorms are noted over Central America, mainly from western Panama to Honduras. A diffluent patter aloft is helping to induce this convective activity. Shower and thunderstorms are also noted over eastern Cuba, the Cayman Islands, and Jamaica. A dry and stable air mass dominates the eastern Caribbean, where African dust is observed on the Saharan Air Layer (SAL) tracking product from CIMSS. The dry weather is forecast to persist throughout the weekend. As a result, excessive heat conditions will persist along locations in the N coast of Puerto Rico where heat indices over 112 degrees are expected. San Juan, was one degree from tying the record temperature of 94 degrees on Wed. Winds are increasing over the eastern Caribbean due to the pressure gradient between the 1009 mb Colombian Low and high pressure northeast of the Caribbean Sea. Latest satellite derived wind data provide observations of fresh to strong trades S of 15N between 69W and 73W, with moderate to fresh winds elsewhere between Hispaniola and northern Colombia/NW Venezuela. Light to gentle E to SE winds are seen over the NW Caribbean. Seas are 4-6 ft over the central and E Caribbean and 2-4 ft in the NW Caribbean. For the forecast, weak high pressure across the central Tropical Atlantic will shift NW and strengthen through Thu, producing increasing winds and seas over the eastern and central Caribbean through early Fri. Active weather is expected across N central portions through Fri. Atlantic high pressure will shift NE and weaken Fri night through the weekend, with winds and seas across the basin diminishing modestly. A return to a more typical easterly trade wind regime is expected Mon. ...ATLANTIC OCEAN... Please, see Special Features above for heavy rainfall to affect the Bahamas through Sat afternoon. A weak cold front extends from a 1008 mb low pressure located near 33N47W to 28N57W, where it transitions to a stationary front to 28N64W. Convection is limited near the front. Farther east, a cold front enters the forecast waters near 31N15W, then crosses the Canary Islands and continues SW to 21N27W, where it transitions to a stationary front to a 1012 mb low near 20N34W. A weakening cold front extends westward from the low center to 17N40W. These frontal boundaries and associated low pressure systems farther north have displaced the Bermuda/Azores High down to 22N62W with a 1019 mb central pressure. Winds ahead of the easternmost cold front north of 27N and east of 20W are SW fresh to locally strong with seas of 6-8 ft. Similar wind speeds are noted between the Canary Islands. Elsewhere across the entire subtropical N Atlantic, the winds are moderate or weaker with seas generally in the 4-6 ft range. For the forecast west of 55W, the aforementioned high pressure will move NW and build across the forecast waters tonight through late Fri. Active weather is expected across the Bahamas and adjacent Atlantic to 70W though Fri. The high pressure will then drift NE over the upcoming weekend, leading to a decreasing trend in winds and seas across the area. $$ GR