• STRMDISC: Potential Tropical Cyclone One Discussion Number 4

    From COD Weather Processor@1:2320/107 to wx-atlan@lists.illinois.edu on Wed Jun 17 08:35:54 2026
    850
    WTNT41 KNHC 170835
    TCDAT1

    Potential Tropical Cyclone One Discussion Number 4
    NWS National Hurricane Center Miami FL AL012026
    400 AM CDT Wed Jun 17 2026

    The center of the low pressure area is very near the Middle Texas
    coast, and offshore buoy observations indicate that maximum winds
    remain 25 kt. A line of deep convection has formed over the
    northwestern Gulf waters since the last advisory, but due to strong
    westerly shear, this activity is located more than 120 n mi to the east/southeast of the low-level center. As a result, the latest
    Dvorak classification from TAFB is Too Weak To Classify, meaning
    the system does not have the convective organization necessary to
    be designated as a tropical cyclone.

    The current motion is northeastward, or 045/5 kt. The system is
    embedded in strengthening low- to mid-level southwesterly flow, and
    with another trough approaching from the northwest, it is expected
    to accelerate northeastward today. The track guidance has shifted
    slightly westward on this cycle, and the center of the low is
    therefore likely to straddle the Texas coast for much of the day,
    before moving farther inland over eastern Texas or Louisiana
    tonight. The NHC official track has been nudged westward, close to
    the TVCN and HCCA consensus aids.

    The prospects for this system to become a tropical cyclone may be
    decreasing. With the low-level center unlikely to fully emerge
    over the Gulf waters for an appreciable amount of time, and 25-30
    kt of westerly shear expected to continue for the next 12 hours, it
    will be difficult for the system to gain the convective
    organization necessary to become a tropical cyclone before it moves
    inland tonight. Even if the system doesn't become a tropical
    cyclone, there could still be some strengthening of the wind field
    well east of the center during the day, and the NHC official
    forecast will continue to show a peak of 35 kt in 12 hours. After
    that, all of the global models now show the system opening up into a
    trough over Louisiana by tonight. The official forecast shows the
    system as a remnant low at 24 hours, but it's entirely possible it
    will have dissipated by then.

    The global models show the remnant low-level vorticity continuing
    eastward across the Southeast U.S. on Thursday and Friday, and the
    ECMWF, Canadian, and UKMET models indicate that a low pressure
    system could redevelop, especially once the system moves offshore
    over the western Atlantic. The exact nature of this low is unclear
    at this time, but we will monitor model trends for the possibility
    of tropical cyclone formation over the western Atlantic late this
    week or this weekend.

    Regardless of whether the system becomes a tropical cyclone, heavy
    rainfall and life-threatening flash flooding will be the primary
    hazards with this system.


    KEY MESSAGES:

    1. Potentially life-threatening flash flooding and urban flooding
    are likely through Thursday across southern Louisiana, southern
    Mississippi, southern Alabama, southwestern Georgia and the Florida
    Panhandle, with possible flooding near the Upper Texas coast.
    Ongoing heavy rainfall could prolong the flood threat into the
    weekend.

    2. Tropical-storm-force winds are expected along the Louisiana
    coast today from Sabine Pass to Morgan City where a Tropical
    Storm Warning is in effect.

    3. Minor to moderate coastal flooding is expected along portions of
    the Upper Texas and Louisiana coastlines today.


    FORECAST POSITIONS AND MAX WINDS

    INIT 17/0900Z 28.0N 96.7W 25 KT 30 MPH...POTENTIAL TROP CYCLONE
    12H 17/1800Z 29.1N 95.2W 35 KT 40 MPH...TROPICAL STORM
    24H 18/0600Z 31.1N 92.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
    36H 18/1800Z...DISSIPATED

    $$
    Forecaster Berg


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