Major Hurricane Sam is centered near 15.2N 51.4W at 27/0900 UTC or 700 nm ESE of the Northern Leeward Islands moving NW at 7 kt. Estimated minimum central pressure is 952 mb. Maximum sustained wind speed is 115 kt with gusts to 140 kt. Peak seas are near 40 ft near the center with 12 ft seas extending 120 nm of the center except 90 nm in the SE quadrant. Numerous moderate to strong convection is seen within 90 nm of the center. Scattered moderate convection is within 150 nm of the center. Sam is moving toward the northwest, and this general motion is expected to continue for the next several days, with an increase in forward speed beginning on Thursday. Little change in strength is expected during the next day or so. Thereafter, some slow weakening is forecast through midweek, although Sam should remain a major hurricane. Sam is expected to pass well NE of the Leeward Islands. Swells generated by Sam will reach the Lesser Antilles today and impact these islands for the next several days. These swells could cause life- threatening surf and rip current conditions. Please read the latest High Seas Forecast issued by NHC at http://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest NHC Public Advisory and Forecast/Advisory at https://hurricanes.gov for more details.
Satellite-derived wind data indicate an elongated area of low pressure associated with the remnants of Peter is located a few hundred miles southeast of Bermuda. Showers and thunderstorms have become a little better organized since last night, and environmental conditions are marginally conducive for some further development of this system. Peter could briefly become a tropical depression again during the next day or two while it moves northeastward at about 10 mph. By midweek, environmental conditions are expected to become unfavorable for further development. This disturbance has a medium chance of development over the next 48 hours. Please visit hurricanes.gov for more details.
An Atlantic tropical wave has its axis along 30W, south of 17N, and it is moving W near 15 kt. Interaction between the wave and the monsoon trough allows for scattered moderate to isolated strong convection from 03N to 10N and between 28W and 32W. The northern portion of the wave is devoid of deep convection.
Another Atlantic tropical wave has its axis along 40W, south of 16N and it is moving W at 10-15 kt. Interaction between the wave and the monsoon trough results in scattered moderate convection E of the wave axis to 30W and between 04N and 11N. The northern portion of the wave is devoid of deep convection.
A Caribbean tropical wave has its axis along 73W, south of 19N, extending from Haiti to Colombia and it is moving W near 10 kt. The wave is enhancing the thunderstorm activity over Hispaniola. No deep convection is noted near the wave axis over the Caribbean Sea.
The monsoon trough enters the Atlantic through the coast of The Gambia/Senegal near 13N17W to 08N20W to 09N32W and to 07N43W. There is no ITCZ at this time. Scattered moderate to strong convection is observed south of the monsoon trough from 01N to 09N and east of 24W to the coast of Africa.
The E Pacific monsoon trough enters the Caribbean Sea through the coast of Costa Rica near 11N83W and continues to the coast of NW Colombia. Scattered moderate to isolated strong is S of 13N between 78W to 84W.
Gulf Of Mexico
A tenacious surface trough remains in the W Gulf, extending from 28N90W to 23N96. Showers and thunderstorms continue to flare up near the trough axis. A few showers and isolated thunderstorms are also noted over the E Bay of Campeche and off W Florida. However, this activity is quickly losing strength and should dissipate soon. The rest of the basin is under the dominance of dry air, leading to fairly tranquil weather conditions. An overnight scatterometer satellite pass indicated fresh NE winds in the Florida Straits, while gentle to moderate anticyclonic winds prevail in the remainder of the Gulf. Seas in the SE Gulf are 2-4 ft, with the highest seas occurring in the Florida Straits. Elsewhere, seas are 1-3 ft.
The aforementioned surface trough will continue to drift westward toward the Texas coast through tonight. High pressure presently over the area will remain in place trough Thu, then be replaced by slighter stronger high pressure that will build southward over the area Fri and Fri night. This will bring moderate to fresh winds over most of the Gulf on Fri through Sat..
Favorable upper-level atmospheric dynamics and diurnal heating in the northern Caribbean allowed for the development of afternoon and evening thunderstorms across the Greater Antilles. A few showers and thunderstorms are seen in the E Caribbean, near the Lesser Antilles with isolated thunderstorms in the NW Caribbean. While fairly tranquil conditions prevail in the rest of the basin. Overnight satellite- derived wind data show fresh trades within 100 nm of the coast of Colombia and NW Venezuela, including the waters surrounding the ABC islands. Moderate to locally fresh trades are present elsewhere in the Caribbean Sea. Sea of 3-6 ft are occurring in the central Caribbean, with the highest seas materializing in the south- central and SW Caribbean. Elsewhere, seas are 1-3 ft.
Hurricane Sam was near 15.2N 51.4W 952 mb at 5 AM EDT moving NW at 7 kt. Maximum sustained winds 115 kt gusts 140 kt. Sam will move to 15.9N 52.2W this afternoon, 16.8N 53.3W Tue morning, 17.7N 54.4W Tue afternoon, 18.6N 55.6W Wed morning, 19.6N 57.1W Wed afternoon, and 21.0N 58.8W Thu morning. Sam will change little in intensity as it moves near 24.9N 61.6W early Fri. Meanwhile, moderate trades will continue over much of the Caribbean through Tue. Fresh trades over the south- central Caribbean will diminish to gentle to moderate speeds today. Gentle trades will then prevail over the Caribbean through Fri. Fresh trades will follow in the wake of Sam across the Tropical N Atlantic waters. Swells generated by Sam are forecast to reach the Lesser Antilles by later today through the middle of the week.
Please read the Special Features section above for details on Hurricane Sam.
The Cumbre Vieja volcano on the island of La Palma in the Canary Islands has been erupting since 19/1410 UTC. Significant volcanic ash is mainly in the vicinity of the volcano below 5000 ft. ANother cloud mainly composed of SO2 is drifting to the NE. Marine and aviation interests should monitor this on-going situation by reading Volcanic Ash Advisory issued by Meteo-France at http://vaac.meteo.fr/volcanoes/la-palma/. The next advisory will be issued no later than 27/1500 UTC.
A cold front traversing the NW Atlantic enters the tropical Atlantic near 31N68W and extends to 28N77W, about 100 nm NE of the NW Bahamas. A pre-frontal trough is analyzed from 29N68W to 25N74W. Scattered moderate convection is noted from 24N to 30N between 66W and 75W. Satellite- derived wind data depict moderate to fresh cyclonic winds surrounding the trough, with the highest winds occurring near the convection.
Farther east, a cold front extends from a 1013 mb low pressure SW of the Azores and enters the tropical Atlantic near 31N28W and transitions into a stationary front that extends from 28N30W to 22N46W. Showers and thunderstorms are noted along this boundary from 19N to 30N between 25W and 37W. Overnight satellite- derived wind data indicated that fresh to strong southerly winds are occurring N of 25N and within 150 nm to the E of the frontal boundary. The scatterometer satellite data also depicted fresh to locally strong NE winds N of 22N and E of 20W, with the strongest winds occurring near the coast of NW Africa. Outside of the influence of Hurricane Sam, the rest of the basin experiences moderate or weaker winds. Seas are 4-8 ft with the highest seas occurring near the areas described above.
A cold front is pressing southward across the Bahamas with a trough stretching from 30N68W to 25N74W. This front will weaken by tonight. Expect showers and thunderstorms along this boundary through Mon night. Gentle to moderate winds will prevail through most of the week. Stronger high pressure will build southward over the NW and north- central offshore waters late in the week, bringing moderate to locally fresh winds across the northern SW Atlantic. Meanwhile, Hurricane Sam was near 15.2N 51.4W 952 mb at 5 AM EDT moving NW at 7 kt. Maximum sustained winds 115 kt gusts 140 kt. Sam is forecast to continue on its current motion over the next few days as it slowly weakens reaching near 25N62W by late Fri, with maximum sustained winds 105 kt gusts 130 kt. Swells generated by Sam are expected to spread westward across the forecast waters late in the week.
Posted 48 minutes ago by NHC Forecaster Areinhart