• Flooding Possible TXLAMS

    From Mike Powell@618:250/10 to All on Fri May 8 08:09:36 2026
    AWUS01 KWNH 081146
    FFGMPD
    MSZ000-LAZ000-TXZ000-081700-

    Mesoscale Precipitation Discussion 0163
    NWS Weather Prediction Center College Park MD
    745 AM EDT Fri May 08 2026

    Areas affected...Southeast Texas...Southern Louisiana...Southwest Mississippi...

    Concerning...Heavy rainfall...Flash flooding possible

    Valid 081145Z - 081700Z

    SUMMARY...Early morning elevated thunderstorms with potential to
    train this morning pose narrow axis of 2-4" totals and isolated
    flash flooding concerns near urban and areas of recent heavy rainfall.

    DISCUSSION...GOES-E WV suite depicts a broad positive tilt closed
    low across the southwest with a nicely shaped anti-cyclonic
    downstream shortwave ridge across central TX into confluent flow
    regime across the Lower Mississippi Valley into the Tennessee
    Valley. This places the surface front stalled along south and
    parallel of the Texas Gulf Coast before angling northward to a
    weak surface wave south of Houma, LA. CIRA LPW denotes the
    anomalously high sfc to 850mb moisture pooled along and north of
    the front generating a very tight gradient across southeast TX and
    across central LA. The 850-700 and 700-500mb layers are also
    complimentary to total PW values aligned across the area of
    concern that values of 1.75-2" exist between the surface front and
    the surface coastal pressure trof that goes from KNOG to KTME
    before crossing that tight PW gradient near KJAS to KAQV in western LA.

    Surface to boundary layer onshore flow is providing weak but
    sufficient WAA before veering to the southwest through the 850mb
    layer to provide sufficient convergence and isentropic ascent
    across the boundary to access the larger well of conditionally
    unstable air with MUCAPES of 1000-1500 J/kg...which extends
    eastward along and south of the PW gradient along and north of
    I-10 through E LA into S MS. As such, RADAR and GOES-E 10.3um
    depicts solid convective initiation along and south of the tight
    gradient which further helps to steepen vertical ascent plane.
    The overall depth of moisture is already supporting isolated to
    scattered .5-1"/hr rates but this will continue to increase with
    coverage and moistening of the mid-level profiles. Additionally,
    with some surface heating, a few nearer surface based cells with
    higher rate potentials to 1.75-2"/hr may develop over the next 3-4
    hours along or even south of the I-10 corridor.

    As mentioned, the deeper layer flow flattens west to east into the
    confluence downstream generally parallel to the boundary/ascent
    plane to support a favorable opportunity for repeating/training
    (especially further east into LA). This may allow for narrow
    streaks of 2-3+", with an isolated 4" total not out of the realm
    of possibility. Generally sandy soils and naturally high FFG in
    the region from overall drought should help to mitigate most of
    the heavy rainfall. However, there are is a axis of reduced FFG
    values especially from Vernon to Rapides to Concordia parish in LA
    and portions of SW MS that are recovering from heavy rainfall
    36-48rs ago as well as a number of prone urban centers along the
    area of concern that would be more susceptible to possible
    incident or two of localized flash flooding this morning.

    Gallina

    ATTN...WFO...FWD...HGX...JAN...LCH...LIX...SHV...

    ATTN...RFC...FWR...ORN...NWC...

    LAT...LON 31669219 31519034 31208953 30788938 30308968
    30129069 30159225 30159283 30059469 30149581
    30449631 30959639 31329594 31559489 31629321

    $$
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    * Origin: Capitol City Online (618:250/10)