000 AXNT20 KNHC 172348 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0805 PM EDT MON OCT 17 2016 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 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2130 UTC. ...SPECIAL FEATURES... Hurricane Nicole is centered near 42.7N 42.6W at 2100 UTC or about 500 nm ESE of Cape Race Newfoundland and is accelerating toward the NE at 22 kt. Estimated minimum central pressure is 962 mb. Maximum sustained wind speed is 65 kt with gusts to 80 kt. Widely scattered moderate convection is within 180 nm of center. See latest Forecast/Advisory under AWIPS/WMO headers MIATCMAT5/WTNT25 KNHC for more details. Nicole has developed a very large wind field over the past weekend which has generated a tremendously large wave field. Large swell from Nicole is propagating in all directions from the system center and will spread across most of the North Atlantic Basin during the next few days. Large NNE to NE swell is reaching the coasts of the Bahamas, Hispaniola, Puerto Rico and the Lesser Antilles late this afternoon, is expected to build further overnight through Tuesday. These large swells will create very high and powerful breaking waves along the coasts and local reefs, and produce extremely dangerous rip currents in the surf zone. Wave runup along the beaches will also have the potential to cause beach erosion and coastal flooding. Consult the local meteorological service in your area for specific details on these hazards. ...TROPICAL WAVES... Tropical wave is in the vicinity of 24N-25N southward of 14n moving W at 10-15 kt. A 1010 mb low is centered at the southern extend of the wave near 07.5N25W and remains embedded within the Monsoon Trough. Scattered moderate to strong convection is from 08.5N-14.5N between 20W-28W, and is brushing across southern portions of the Cabo Verde Islands. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 09.5N14W to 10N18W to low pressure near 07.5N25W to 06N31W to 07N39W. Scattered moderate isolated strong convection is from 00N-05N between 15W-18W. Widely scattered moderate isolated strong convection is from 01N-07N between 24W-33W. ...DISCUSSION... GULF OF MEXICO... Water vapor imagery indicates dry sinking air aloft covering the NE two-thirds of the basin as an upper level trough continues to sink S across the Florida peninsula and portions of the SW North Atlc. Strong NE to ENE prevailing across the Atlantic coastal waters of Florida are spreading across the peninsula and into far eastern Gulf to near 85W, where skies are mostly cloud free. A weak low level trough extends from near the mouth of the Mississippi River to near 24N88W. Low level convergence along the E side of this trough is producing short narrow lines of shallow convection that is shifting slowly W. Mostly fair conditions prevail W of this trough as a surface ridge axis extends from the Carolinas SW across the remainder of the northern Gulf. Gentle to moderate anticyclonic winds continue and are expected to persist through Tuesday as they increase slightly Tuesday night into Wednesday. The next cold front is expected to emerge off the Texas and Louisiana coasts by Thursday night into early Friday. CARIBBEAN SEA... An upper level anticyclonic circulation is anchored over the SW Caribbean this evening near 11N77W. Mostly clear skies and fair conditions are noted on satellite imagery E of 68W, however W of 68W moisture and cloudiness increase as a broad cyclonic circulation is developing in the low levels from central America to Jamaica. A diffluent upper level environment continues to allow for scattered showers and isolated strong tstms from 09N- 18N between 76W-88W...including large portions of Panama and Costa Rica. A large cluster of showers and tstms is across portions of the south-central Caribbean S of 16N between 68W and 72W extending into coastal portions of Venezuela and Colombia. Gentle to moderate S to SE winds have developed this afternoon across the E half of the Caribbean, while light trades generally prevail elsewhere E of 80W this evening. On Tuesday, global models are suggesting cyclogenesis to occur N of Hispaniola and Puerto Rico, which is already resulting in a disruption of the usual trade wind flow across the eastern Caribbean. As a low center organizes Tuesday through Wednesday and lifts generally northward, lingering weak surface troughing will extend across the Greater Antilles into the SW Caribbean through Saturday. ...HISPANIOLA... SE low level winds across the eastern Caribbean this afternoon have led to seabreeze convergence across the northern coastal areas of the Dominican Republic where scattered moderate isolated strong convection is occurring. To the north of Hispaniola, a shear line extends from near 21.5N60W to 24N74W. This low-level flow regime in tandem with an upper level trough noted on water vapor imagery over the SW North Atlc is likely to maintain some of this active convection well into the night timehours as the upper trough shifts slightly ESE. The island is expected to remain within an area of weak surface troughing through Wednesday as cyclogenesis occurs across the SW North Atlc waters overnight through Wednesday. ATLANTIC OCEAN... A middle to upper level trough is noted on water vapor imagery over the SW North Atlc, NW Bahamas to Cuba, with a relatively broad base reaching to near 20N80W. The troughing aloft is generating maximum diffluence to the east and inducing a surface trough analyzed from 28N74W to 23N73W. At the base of this surface trough, a 1008 mb surface low looks to have developed, where surface obs from the Grand Turks have reported W to NW winds since this afternoon. A large area of scattered showers and tstms is occurring from 20N-30N between 60W-72W, with the strongest convection occurring along the shearline described above, extending from 21N53W to the surface low. The low pressure near 23N73W will shift ENE tonight, then attempt to become better organized Tuesday as it begins to lift northward. Strong easterly winds are expected to occur within 240 nm across northern portions of this low and the shearline in its vicinity during the next 24 hours. Farther east, the central Atlc is under the influence of a stationary front extending from the circulation associated with Hurricane Nicole well to the N of the discussion area. The front extends from 32N38W SW to 22N46W to 21N53W where the shear line begins. Widely scattered showers and isolated tstms are occurring within 90 nm either side of the front. Finally, across the eastern Atlc, a middle to upper level cyclone is noted in water vapor imagery in the vicinity of 29N12W. This low supports widely scattered convection aloft across portions of Morocco. To the NW of this, a 1012 mb low centered W-SW of the Iberian peninsula near 37N16W with a cold front extending SW from the low center to 32N19W the stationary into a weak 1017 mb low centered near 30N23W. The frontal troughing then extends to the SW with another surface trough analyzed from 24N27W to 16N35W. For additional information please visit http://www.hurricanes.gov/marine $$ Stripling