Atlantic Tropical Weather Discussion

National Hurricane Center - Tropical Weather Discussion (Atlantic)

  1. 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