• STRMDISC: Tropical Storm Jerry Discussion Number 15

    From COD Weather Processor@1:2320/105 to [email protected] on Sat Oct 11 02:40:31 2025
    584
    WTNT45 KNHC 110240
    TCDAT5

    Tropical Storm Jerry Discussion Number 15
    NWS National Hurricane Center Miami FL AL102025
    1100 PM AST Fri Oct 10 2025

    Jerry's low-level circulation remains rather ill-defined especially
    on the northwest side of the cyclone, where a surface trough extends northwestward from Jerry. The SHIPS guidance is showing about 15-20
    kt of northwesterly deep-layer vertical wind shear in Jerry's
    environment, which is displacing convection to the southeast of the
    center. Scattered moderate to heavy showers and thunderstorms are
    still occurring over the Virgin Islands, but the rainband that was
    producing the persistent heavy rain over the northeastern Caribbean
    Islands has weakened from earlier and is starting to move away. A
    recent ASCAT pass shows maximum winds around 50 kt, so the intensity
    has been raised to 50 kt for this advisory, which is slightly higher
    than the latest TAFB Dvorak estimate. The tropical-storm-force
    winds are limited to the eastern semicircle of Jerry.

    The initial motion estimate is northward, or 350 degrees at 13 kt.
    This general motion should continue through Saturday night because a north-south-oriented mid-level ridge is currently located to the
    east of the cyclone. By Sunday night, Jerry should turn eastward as
    it becomes embedded in the mid-latitude westerlies. Only minor
    adjustments have been made to the previous NHC track forecast, which
    generally lies in between the simple and corrected consensus models.

    Jerry is likely to continue battling moderate to strong shear during
    the next couple of days, and global model fields (with the exception
    of the GFS) suggest that the storm will maintain an elongated
    circulation through this period. Although the shear might decrease
    a bit after 48 hours, at that point Jerry will be moving over more
    marginal sea surface temperatures and into a more stable
    environment. No changes were made to the previous NHC intensity
    forecast, which is near, or slightly below the middle of the
    guidance envelope. The global model fields (with the exception of
    the GFS) show Jerry interacting with a front by Sunday night, and
    the NHC forecast shows Jerry becoming post-tropical by Monday
    evening, with dissipation along the front a day or two later. The
    GFS maintains Jerry as a tropical cyclone through day 5, but that
    solution is considered an outlier.

    It should be noted that the circulation of Jerry is quite
    ill-defined on the northwest side. Therefore, it is possible that
    Jerry could dissipate at any time this weekend. However, given that
    most of the global and regional models hold on to the circulation
    into Sunday, the most likely scenario seems to be that Jerry will
    stick around for at least another 2 days or so until it begins
    interacting with the front.


    KEY MESSAGES:

    1. Heavy rainfall from Jerry will lift north of the Leeward Islands,
    Virgin Islands, and Puerto Rico overnight. As a result, the risk for
    flash flooding will diminish.

    2. Swells generated by Jerry are affecting the Leeward Islands,
    Windward Islands, the Virgin Islands, Puerto Rico, the Dominican
    Republic, and the Turks and Caicos Islands and are likely to cause life-threatening surf and rip current conditions. These swells are
    expected to spread toward the Bahamas by Saturday.


    FORECAST POSITIONS AND MAX WINDS

    INIT 11/0300Z 22.7N 63.9W 50 KT 60 MPH
    12H 11/1200Z 24.6N 63.3W 50 KT 60 MPH
    24H 12/0000Z 27.4N 62.7W 50 KT 60 MPH
    36H 12/1200Z 29.6N 62.0W 45 KT 50 MPH
    48H 13/0000Z 31.3N 60.8W 45 KT 50 MPH
    60H 13/1200Z 32.0N 58.9W 45 KT 50 MPH
    72H 14/0000Z 31.4N 56.4W 45 KT 50 MPH...POST-TROPICAL
    96H 15/0000Z 29.8N 51.6W 50 KT 60 MPH...POST-TROP/EXTRATROP
    120H 16/0000Z...DISSIPATED

    $$
    Forecaster Hagen


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