• STRMDISC: Hurricane Melissa Discussion Number 21

    From COD Weather Processor@1:2320/105 to wx-atlan@lists.illinois.edu on Sunday, October 26, 2025 14:59:46
    944
    WTNT43 KNHC 261459
    TCDAT3

    Hurricane Melissa Discussion Number 21
    NWS National Hurricane Center Miami FL AL132025
    1100 AM EDT Sun Oct 26 2025

    After rapidly intensifying over the past day or so, NOAA-P3 aircraft
    data indicates that Melissa's intensity has leveled off this
    morning. Melissa remains a very formidable hurricane on satellite
    imagery, with a clearing eye quite evident on morning visible
    imagery, and the eye temperature has warmed to +15-20C. Meanwhile
    the eyewall convection continues to remain robust with cloud tops as
    low as -75 to -80C encircling the core. With that said, the eye
    presentation from the Kingston, Jamaica radar is not as pristine,
    with the eyewall occasionally open on the east side, and some
    evidence of concentric bands forming off and on. Zooming out a bit,
    there still remains some evidence of light to moderate westerly
    shear undercutting the expanding storm outflow, and Melissa's
    primarily rainbands are distributed mostly on the eastern side of
    the circulation. NOAA-P3 aircraft data this morning had a peak 700-
    mb flight level wind of 120 kt, and Tail Doppler Radar (TDR) wind
    retrievals were up to 129 kt at 0.5 km, and 129 kt in the 500 m
    average of a dropsonde launched in the north eyewall. While this
    data would support a somewhat lower intensity, the subjective and
    objective satellite based intensity estimates are mostly higher,
    ranging from 115 to 140 kt. The initial intensity will be held at
    120 kt, on the lower end of those estimates, and this value could be
    a little generous based on the aircraft data.

    The major hurricane is moving westward this morning, from aircraft
    fixes estimated at 270/3 kt. This motion is expected to continue for
    the next 24-36 h as a narrow mid-level ridge to the north of Melissa
    imparts the majority of the steering. Thereafter, a short-wave
    trough moving into the southeastern United States is expected to
    erode this ridge, allowing Melissa to turn sharply to the northeast,
    with gradual acceleration. On the forecast track, Melissa's core
    is expected to be near the Jamaica coastline by Tuesday morning,
    moving across the island and then approaching and moving over
    eastern Cuba by Tuesday night. While the track guidance has become
    tightly clustered over the first 24-48 hours, the along-track spread
    starts to increase significantly after that time period, with Google
    DeepMind ensemble solutions on Wednesday morning ranging from
    between Jamaica and eastern Cuba in the Caribbean Sea, over eastern
    Cuba, or in the Southwestern Atlantic near the Southeastern Bahamas
    and Turks and Cacaos Islands. The latest NHC track forecast was
    nudged just a little westward of the prior track, once again
    blending the reliable track aids HFIP Corrected Consensus Approach
    (HCCA), and Google DeepMind ensemble mean (GDMI).

    It is unclear if the current pause in Melissa's intensification is
    temporary. While there have not been obvious indications of a
    secondary eyewall formation yet, there are some concentric
    reflectivity bands appearing on both Jamaica and NOAA-P3 TDR data
    occasionally, though the inner eyewall remains strong. Some of the
    guidance this morning has actually increased from yesterday at this
    time, and notably both the HAFS-A/B explicitly forecast a Category 5
    hurricane shortly before they show landfall in Jamaica. The latest
    NHC intensity forecast will continue to show a peak intensity of 140
    kt. However, inner-core fluctuations like eyewall replacement cycles
    could occur at any time. Regardless, Melissa is forecast to reach
    Jamaica as an upper-end category 4 hurricane, which will only
    exacerbate any damages caused by heavy rainfall and flooding over
    the next 2 days. Melissa will likely weaken some as it traverses
    over the higher terrain of Jamaica, but it is still forecast to be a
    major hurricane when it subsequently moves over eastern Cuba in
    60-72 hours. Thereafter, increasing southwesterly shear should
    cause gradual weakening, but Melissa could still be near hurricane
    intensity when it makes it closest approach to Bermuda in about 5
    days. The latest NHC intensity forecast is on the high end of the
    intensity guidance, but not far off the GDMI, and HAFS-A/B intensity
    aids.

    Key Messages:

    1. Jamaica: Seek shelter now. Damaging winds and heavy rainfall
    today and Monday will cause catastrophic and life-threatening flash
    flooding and numerous landslides before potentially devastating
    winds arrive Monday night and Tuesday morning. Extensive
    infrastructural damage, long-duration power and communication
    outages, and isolation of communities are expected. Life-threatening
    storm surge is likely along portions of the southern coast Monday
    night and Tuesday morning.

    2. Haiti: Catastrophic and life-threatening flash flooding and
    landslides are expected across southwestern Haiti through midweek,
    likely causing extensive infrastructural damage and isolation of
    communities. Although winds are temporarily decreasing on the
    Tiburon peninsula, they could increase again across much of western
    Haiti on Tuesday.

    3. Dominican Republic: Heavy rainfall through midweek could produce catastrophic flash flooding and numerous landslides in southern
    portions of the country.

    4. Eastern Cuba, Southeast Bahamas, and the Turks and Caicos:
    Monitor Melissa closely. There is an increasing risk of a
    significant storm surge, damaging winds, and heavy rainfall Tuesday
    and Wednesday. In eastern Cuba, the risk of life-threatening flash
    flooding and landslides is increasing. A Hurricane Watch is in
    effect for portions of eastern Cuba.



    FORECAST POSITIONS AND MAX WINDS

    INIT 26/1500Z 16.4N 76.6W 120 KT 140 MPH
    12H 27/0000Z 16.4N 77.1W 130 KT 150 MPH
    24H 27/1200Z 16.6N 77.8W 140 KT 160 MPH
    36H 28/0000Z 16.9N 78.0W 140 KT 160 MPH
    48H 28/1200Z 17.8N 77.7W 135 KT 155 MPH
    60H 29/0000Z 19.2N 76.6W 110 KT 125 MPH
    72H 29/1200Z 20.9N 75.1W 95 KT 110 MPH
    96H 30/1200Z 25.5N 71.0W 85 KT 100 MPH
    120H 31/1200Z 32.0N 65.5W 75 KT 85 MPH

    $$
    Forecaster Papin



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