Atlantic Discussion

  • NHC Atlantic Tropical Weather Discussion
    by (nhcwebmaster) on February 19, 2018 at 5:19 AM

    000 AXNT20 KNHC 190519 CCA TWDAT Tropical Weather Discussion...Corrected NWS National Hurricane Center Miami FL 705 PM EST Sun Feb 18 2018 Corrected Monsoon Trough/ITCZ Section 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 2345 UTC. ...SPECIAL FEATURES... Caribbean Sea Gale Warning: A tight surface pressure gradient continues between a surface high pressure in the western Atlantic and lower surface pressures in northern sections of South America. This pattern supports winds pulsing to minimal gale force near the coast of Colombia through early next week. Wave heights within the area of gale force winds will range between 12-17 ft. Please read the latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...MONSOON TROUGH/ITCZ...Corrected The monsoon trough axis extends from the coast of Africa near 06N10W southwestward to 03N14W and dips below the Equator at 19W where it transitions to the ITCZ axis to 02S29W and to the coast of S America at 03S39W. The ITCZ continues from that point to 03N39W. Scattered moderate convection is within 30 nm N of the axis between 18W-19W. ...DISCUSSION... GULF OF MEXICO... A surface ridge extends westward from a 1026 mb high centered over the Atlantic near 28N64W to 1023 mb high centered over central Florida, and continues westward to the NW Gulf. The earlier frontal boundary that was along the coastal plains has N of the as a warm front, and is over eastern Texas and the southern portions of Louisiana, Mississippi and Alabama. A rather weak surface trough is over the NE Gulf from 30N86W to 27N88W. Earlier related shower activity has dissipated. Another surface trough has recently emerged off the west coast of the Yucatan Peninsula to over the far eastern Bay of Campeche. Isolated showers are S of 21N and E of 94W. Areas of fog are expected over portions of the northern and central gulf during the overnight hours and into Mon morning. Both buoy observations and latest scatterometer data reveal generally light to gentle east to southeast flow N of of 26N, and gentle to moderate east to southeast winds S of 26N, except for higher winds in the moderate to fresh range E of 88W and W of 94W. Expect increasing winds and building seas by early next week as high pressure strengthens in the western Atlantic Ocean. The thermal trough will develop again over the western Yucatan Peninsula each afternoon, drift westward across the eastern Bay of Campeche during the overnight hours, and then dissipate in the SW Gulf waters by the late morning hours. CARIBBEAN SEA... Please refer to the SPECIAL FEATURES section for details regarding the Gale Warning near the coast of Colombia. A tight pressure gradient across the basin created by the combination of high pressure over the central Atlantic and lower pressure over NW Colombia is producing strong east winds throughout. These winds continue to quickly advect patches of mainly broken low clouds westward along with quick passing isolated showers, except over the far western Caribbean from 14N-18N W of 83W, including the Gulf of Honduras, where patches of overcast low clouds contain scattered showers. This same gradient will continue to support pulsing winds of minimal gale force near the coast of Colombia through early next week. Fresh to locally strong trade winds are expected elsewhere across the Caribbean Sea. The high pressure will be reinforced by a stronger one system on Mon. This stronger system will bring increasing winds and building seas across the eastern and central Caribbean, and the Tropical N Atlantic waters possibly into the middle of next week. ATLANTIC OCEAN... Broad area of high pressure prevails across the basin, centered by a 1026 mb high center near 28N64W and a 1024 mb high center near 31N34W. A weakness in the ridge was analyzed as a surface trough, extending from 28N44W to 19N45W. The tail end of a stationary front is along 32N from 44W-51W, while a cold front is just along 32N W of 72W. The cold front will drop southward over the NW waters tonight and dissipate on Mon. The ridge will be reinforced by a stronger high pressure system through Tuesday. For additional information please visit $$ Aguirr […]