000 AXNT20 KNHC 221805 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 105 PM EST Thu Feb 22 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 1200 UTC surface analysis and satellite imagery through 1745 UTC. ...SPECIAL FEATURES... Caribbean Sea Gale Warning: A tight surface pressure gradient continues to exist, between comparatively higher surface pressures in the western Atlantic Ocean and lower surface pressures in northern sections of S America. This pattern is supporting winds reaching gale force strength from 11N to 13N between 74W and 77W. Waveheights within the area of gale force winds will range from 12-14 feet. These winds are forecast to diminish below gale force early this afternoon, then develop again tonight and Fri night. Please read the latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. Please refer to the METEO-FRANCE High Seas Forecast, that is listed on the website: WWW.METEOFRANCE.COM/PREVISIONS-METEO- MARINE/BULLETIN/ GRANDLARGE/METAREA2. Gale-force winds are forecast for the areas: IRVING and METEOR. The OUTLOOK, for the 24 hours that follow the forecast that is valid until 23/0000 UTC, consists of: the threat of NW near gale or gale in IRVING and in METEOR. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from the coastal sections of Guinea near 10N14W to 03N19W, where latest scatterometer data indicated it transitions to the ITCZ dropping below the equator at 24W. Scattered moderate to strong convection is within 30 nm of the axis between 11W-15W. Scattered moderate isolated strong convection is seen S of 04N between 30W- 42W. Scattered moderate convection is S of 03N between 24W-26W. ...DISCUSSION... GULF OF MEXICO... A weak cold front that moved into the far NW Gulf during the overnight hours has become stationary along a position from near the Texas/SW Louisiana border to a 1020 mb low at 27N96W and to inland the coast of Mexico at 24N98W as of 15Z this morning. Isolated showers and small patches of rain are along and NW of the front and low per latest NWS radar imagery. Stratus clouds and areas of dense fog with visibility 1 nm or less are observed along the coast of Texas, and east from there to within about 75 nm of that coast. Similar areas of dense fog are along the coast of Mexico N of 19N. The fog is expected to linger into this evening. A terrain induced weak low of 1019 mb is near Tuxpan with a trough extending southeastward to 20N96W, and another trough extending northward to 23N97W. The stationary front is forecast to begin to lift back N as a warm front today. A weak cold front is expected to slowly move to the Texas coastal late on Sun, then move southeastward reaching from the Florida panhandle to Veracruz by Mon afternoon. The gradient associated with strong high pressure that extends from the western Atlantic to over the eastern and central gulf waters will maintain fresh east to southeast winds to the E of the front and low, with the exception of strong east winds across the Straits of Florida through tonight before diminishing to mainly fresh winds on Friday as the ridge weakens. CARIBBEAN SEA... Please read the SPECIAL FEATURES section for details regarding the Gale Warning that is in effect for the waters near the coast of Colombia. Scattered to broken low clouds with scattered showers and isolated thunderstorms are associated with a shear line, and are noted from 15N-17N east of about 67W. Gusty winds can be expected with these showers. Strong surface high pressure across the NW Atlantic Ocean will dominate the region, settling across the Bermuda area through Sat. Fresh to strong trade winds will prevail across the Caribbean Sea and the Tropical N Atlantic Ocean today, with nocturnal winds expected along the coast of Colombia expected to diminish to just below gale force early this afternoon, then pulse back to gale force tonight and Fri night. Surface high pressure will weaken through the weekend leading to diminishing winds and seas. ATLANTIC OCEAN... An upper level trough extends from an upper low dropping southward N of the area at 34N28W through 32N29W to 24N38W, then continues as a cyclonic shear axis to 23N46W to 21N56W and to the NE Caribbean Sea. The trough supports a cold front that enters the area at 32N23W, and continues to 25N24W to 18N33W, where it transitions to a shear line to 17N38W to 16N48W to just S of Martinque and to the eastern Caribbean Sea at 17N71W. Broken low level clouds with scattered showers are within 45 nm either side of the shear line. The surface low associated with the upper low at 32N28W is forecast to intensify as it quickly drops southward reaching to near 29N26W with a pressure of 998 mb by early on Fri. Strong to gale force winds will accompany the low along with large seas. An associated cold front is forecast to extend from near 25N35W to 25N44W to 28N49W by early on Sat. Strong to near gale force NW to N winds and seas of 10-17 ft are expected to the north of a line from 25N35W TO 25N44W TO 28N49W at that time. A western Atlantic ridge will persist along 33N/34N through Fri, then slowly move southwestward and weaken slowly through the weekend. Patches of low clouds moving quickly westward with isolated showers will continue to the S of 26N and west of 50W outside those associated with the aforementioned shear line. Gentle to moderate winds will prevail N of 25N, with fresh to strong winds S of 25N through Thursday. NNE swell will move through the waters that are to the E of 65W through Friday night. It is possible that a weak cold front may move off the NE Florida coast early next week. For additional information please visit http://www.hurricanes.gov/marine $$ Aguirre