• TROPDISC: Tropical Weather Discussion...update

    From COD Weather Processor@1:2320/105 to wx-atlan@lists.illinois.edu on Friday, December 12, 2025 10:33:14
    644
    AXNT20 KNHC 121033 AAA
    TWDAT

    Tropical Weather Discussion...Update
    NWS National Hurricane Center Miami FL
    0615 UTC Fri Dec 12 2025

    Tropical Weather Discussion for North America, Central America
    Gulf of America, Caribbean Sea, northern sections of South
    America, and Atlantic Ocean to the African coast from the
    Equator to 31N. The following information is based on satellite
    imagery, weather observations, radar and meteorological analysis.

    Based on 0000 UTC surface analysis and satellite imagery through
    0600 UTC.

    Updated to add Special Features Section

    ...SPECIAL FEATURES...
    East Atlantic Gale Warnings:
    MeteoFrance issued Gale Warnings for their MADEIRA and CANARIAS
    Marine Zones. For Madeira, it is through 13/12Z and for Canarias,
    it is from 12/15Z to 13/12Z. Please visit website: wwmiws.wmo.int/ index.php/metareas/display/2 for more information.

    ...MONSOON TROUGH/ITCZ...

    A monsoon trough enters the Atlantic near the coastal border of
    Guinea-Bissau and Sierra Leone, then runs southwestward to
    05N18W. An ITCZ meanders westward from 05N18W to 04N31W to 05N47W.
    Scattered moderate to isolated strong convection is noted up to
    110 nm along either side of the ITCZ between 21W and 30W, and
    south of the monsoon trough from 02N to 07N east of 16W. Widely
    scattered moderate convection is seen up to 50 nm along either
    side of the ITCZ west of 30W.

    ...GULF OF AMERICA...

    A weak cold front extends westward from the Great Bahama Bank
    across the Florida Straits to 25N87W, then continues as a
    stationary front to 25N96W. Patchy showers are present near and up
    to 85 nm north of this boundary. A surface trough is causing
    widely scattered showers at the southwestern Gulf. A 1021 n mb
    high just south of the Florida Panhandle is supporting mainly
    gentle NE to SSE winds and seas of 1 to 3 ft at the north-central
    and northeastern Gulf. Gentle to moderate with locally fresh NE to
    SE winds and 3 to 5 ft seas prevail for the rest of the Gulf.

    For the forecast, the front will stall overnight and dissipate.
    Elsewhere, moderate to occasionally fresh E to NE winds will
    prevail in the eastern Bay of Campeche and offshore of the Yucatan
    Peninsula each night through Sat. Otherwise, moderate or weaker
    winds and slight seas are expected over the remainder of the Gulf
    through Sat. Looking ahead, the next cold front is expected to
    enter the northern Gulf on Sun morning, bringing increasing winds
    and building seas behind the front. The front is expected to reach
    the southern Gulf along 23N by Mon morning and move south of the
    Gulf late Mon night.

    ...CARIBBEAN SEA...

    Two surface trough embedded within the trade-wind flow are
    triggering scattered showers and isolated thunderstorms at the
    Gulf of Honduras, and the southwestern basin. Convergent trades
    are producing similar conditions near the Mona Passage. Fresh to
    strong ENE to E trades and seas at 7 to 9 ft are occurring at the south-central, and part of the southwestern basin. Moderate to
    fresh ENE to E trades and 5 to 7 ft seas are found at the north-
    central basin. Gentle to moderate with locally fresh NE to E winds
    and seas of 3 to 6 ft prevail elsewhere in the Caribbean Sea.

    For the forecast, widespread fresh trade winds are expected over
    the central and eastern Caribbean through Sun morning as a
    moderate pressure gradient prevails between the Colombian low and
    migrating high pressure to the north along 29N. Strong E winds
    will pulse to near gale-force at night offshore of northern
    Colombia. Elsewhere, fresh to locally strong trade winds and rough
    seas in large E swell will prevail over the Atlantic waters and
    through the passages into the eastern basin through this weekend.
    Looking ahead, a cold front will approach the northwestern
    basin on Mon, accompanied by increasing winds and building seas
    behind the front. This front may reach from central Cuba to Belize
    Tue morning and begin to stall.

    ...ATLANTIC OCEAN...

    A cold front curves southwestward from northwest of Bermuda
    across 31N69W and the northwest Bahamas to beyond the Florida
    Straits. Patchy showers are found near and up to 50 nm southeast
    of this feature. Another stronger cold front reaches
    southwestward from northeast of Bermuda across 31N64W to
    northeast of the southeast Bahamas. Scattered showers and isolated thunderstorms are seen near and up to 175 nm southeast of this
    front. Scattered showers are noted at the central Atlantic near
    the western end of a frontal boundary, north of 26N between 35W
    and 40W. Refer to the Monsoon Trough/ITCZ section at the very
    beginning for additional convection in the Atlantic Basin.

    Fresh to strong with locally near-gale NW to SW winds and 8 to 10
    ft seas are evident near the two cold fronts, north of 27N
    between 51W and 72W. Farther east, moderate to fresh ENE to ESE
    winds with 10 to 12 ft seas in large NW swell. For the rest of the
    Atlantic waters north of 24N between 35W and the Florida/souther
    Georgia, gentle to moderate SE to S to SW winds and seas of 6 to
    10 ft in large northerly swell. For the tropical waters from 05N
    to 20N/23N between 35W and the Lesser Antilles, fresh to strong NE
    to ESE trades with 8 to 11 ft seas exist. For the remainder of
    the Atlantic west of 35W, gentle to moderate with locally strong
    NE to E winds with 6 to 8 ft seas prevail.

    For the forecast, the two cold fronts will rapidly progress
    eastward and merge across the central Atlantic through Fri.
    Widespread strong to locally near gale-force SW winds will occur
    ahead of the leading front, generally north of 28N and east of
    70W, into Fri afternoon. West of the cold fronts, fresh to locally
    strong W to NW winds are anticipated, north of 28N from offshore
    of Florida to 70W through late tonight. Rough seas in SW swell and
    then NW swell are expected north of 27N, with seas slowly
    subsiding from west to east into this weekend. Elsewhere in the
    central Atlantic, rough seas in mixed N and SE swell will prevail
    through Fri morning, with a new mixed swell reinforcing rough seas
    this weekend. Looking ahead, the next cold front is slated to
    push off the coast of the southeastern United States on Sun, with
    increasing winds and building seas expected behind the front.

    $$

    Chan

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