765 AXNT20 KNHC 120527 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 127 AM EDT Thu Jul 12 2018 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 0000 UTC surface analysis and satellite imagery through 0515 UTC. ...SPECIAL FEATURES... ...Hurricane Chris... The center of Hurricane Chris is located near 39.6N 63.0W at 12/03Z, or about 300 nm south of Halifax, Nova Scotia. Chris is moving toward the northeast, or 50 degrees, at 25 knots. On the forecast track, the center of Chris will pass near southeastern Newfoundland on Thursday. The estimated minimum central pressure is 980 mb. The maximum sustained wind speed is 75 kt with gusts to 90 kt. Additional weakening is forecast fro Chris during the next few days, and it will become a post-tropical cyclone by Thursday afternoon. Numerous moderate convection is observed from 37N-44N between 60W-66W. Please read the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMAT3/WTNT23 KNHC for more details. ...Gale in the Caribbean... A tight pressure gradient will develop across the southern Caribbean inducing gale-force winds from 11N-13N between 70W- 76W in 24 hours. These conditions will continue through the next 12 hours. Fresh to strong winds will prevail across the area after this. Refer to the High Seas Forecast product, under the AWIPS/WMO headers HSFAT2/FZNT02 KNHC, for more details. ...TROPICAL WAVES... A tropical wave extends its axis along 27W from 05N-15N. The wave is moving west at 20-25 kt. Scattered showers are noted along the wave's axis. This wave coincides with a good surge of moisture based on the TPW product, and model diagnostic guidance also confirms its presence. A tropical wave has its axis along 43W from 07N-20N, moving west at 15-20 kt. Saharan dust follows this wave inhibiting convection at this time. Satellite imagery indicates some inverted-V pattern in the cloud field associated with this wave. A low amplitude tropical wave extends its axis along 63W from 08N-15N, moving west 10-15 kt. Saharan dust surrounds the wave inhibiting convection. GFS computer model suggests an increase in moisture in association with this wave reaching the central Caribbean by Friday. Another tropical wave is moving across the western Caribbean. Its axis along 84W from 10N-21N, moving west at 10-15 knots. GOES-16 RGB Geocolor shows African dust behind the wave's axis covering the basin all the way to the Lesser Antilles. Scattered moderate convection prevails from 11N-18N between 82W-88W. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of The Gambia near 13N17W to 09N40W. The ITCZ extends from 10N46W to 08N54W to 10N62W. Aside from the showers related to the tropical wave along 27W, no significant convection is observed at this time. ...DISCUSSION... GULF OF MEXICO... A surface trough is analyzed over the southwestern Gulf and extends from 22N93W to 19N93W. A surface ridge prevails across the remainder of the basin anchored by a 1018 mb high centered over the NW Gulf near 27N94W. Scattered showers are noted over the far east Gulf waters along 26N enhanced by an upper-level low. High pressure is forecast to prevail across the northern Gulf waters through the upcoming weekend. A surface trough will move westward off the Yucatan Peninsula each evening through Sun, and enhance nocturnal winds over the SW Gulf, producing moderate to fresh NE-E winds and seas of 3-4 ft. Winds and seas will slightly increase in association with this trough by Sat night. CARIBBEAN SEA... Two tropical waves are moving across the basin. Refer to the Tropical Waves section above for details. A gale warning is in effect for the south-central Caribbean. Refer to the section above for details. Scatterometer data depicts moderate to fresh winds across the basin, with fresh to strong winds over the central portion of the basin south of 14N between 72W-74W. The Atlantic high pressure will build across the region behind the tropical wave with axis along 84W to freshen tradewinds across the central Caribbean waters. Convection will continue to flare-up during the day over the SW Caribbean, mainly south of 11N, due to the presence of the monsoon trough. This convective activity is affecting parts of Panama and Costa Rica. ATLANTIC OCEAN... As of 0300 UTC, Hurricane Chris is centered north of the forecast area near 39.6N 63.0W. Swells generated by Hurricane Chris are expected to affect portions of the coasts of North Carolina and the mid-Atlantic states during the next few days. These swells could cause life-threatening surf and rip current conditions. Refer to the section above for more details. A large area of cloudiness and disorganized showers and thunderstorms associated with the remnants of Beryl is located over the Bahamas and extends northwestward over the western Atlantic for a few hundred miles. A surface trough is analyzed in this area from 29N72W to 27N76W. Little or no tropical cyclone development is expected today, but conditions could become a little more favorable later in the week and over the weekend while the disturbance moves slowly northward and northeastward over the western Atlantic. The latest Tropical Weather Outlook gives this system a low chance of tropical cyclone formation during the next 48 hours. A recent scatterometer pass clearly indicates the wind shift associated with the aforementioned surface trough. Wind and seas could be higher near tstms. Lightning density indicates frequent lightning within the observed convection. Surface ridge prevails across the remainder of the Atlantic forecast area, anchored by a 1037 mb high pressure centered near NW of the Azores near 43N33W. The ridge extends into the NE Caribbean. The Saharan Air Layer (SAL) from CIMSS shows a new surge of African dust over the eastern Atlantic, and behind the tropical wave along 43W. For additional information please visit http://www.hurricanes.gov/marine $$ ERA