• MESO: Heavy rain Flash flooding possible FL Peninsula

    From Mike Powell@618:250/6 to All on Thu Apr 9 08:32:20 2026
    AWUS01 KWNH 091025
    FFGMPD
    FLZ000-091500-

    Mesoscale Precipitation Discussion 0085
    NWS Weather Prediction Center College Park MD
    624 AM EDT Thu Apr 09 2026

    Areas affected...east-central FL Peninsula

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

    Valid 091017Z - 091500Z

    Summary...Slow moving showers with possible embedded thunderstorms
    are expected to focus isolated areas of heavy rain along the Space
    and Treasure coasts through late morning. Localized hourly
    rainfall of 2+ inches will be possible with storm totals of 2 to
    4+ inches through 15Z, which may result in isolated flash flooding.

    Discussion...Regional radar imagery at 10Z showed scattered
    showers between southern Brevard County and southern St. Lucie
    County. 10.3 micron satellite imagery indicated cloud tops over
    land were relatively warm at -20 to -35 C, with an estimated cloud
    depth of 9 km AGL based on RAP analysis soundings over the region.
    Easterly winds of 20-30 kt in the 925-850 mb layer were oriented
    perpendicular to the coast while mid-upper level flow was from the
    west at a similar magnitude. This has set up favorable effective
    shear profiles for organized cells although 0-8 km AGL mean layer
    winds were about 5 kt or less, resulting in slow cell movement. In
    addition, the alignment of showers with the low level wind has
    also resulted in slow movement of heavy rain cores at times with
    recent development near Vero Beach showing signs of a weak MCV
    over eastern Indian River County. MRMS-derived and KVRB hourly
    rainfall of 2-2.5 inches has been observed with nearly 2 inches of
    rain in 32 minutes at KVRB ending 0940Z. Speed and weak
    directional convergence near the surface was allowing for the
    formation of quasi-transient bands of heavy rain within an
    expanding pocket of MLCAPE between 500-1000 J/kg (06Z-10Z SPC
    mesoanalyses) over the east coast of FL.

    While the future existence of the weak meso-vortex near Vero Beach
    is unknown, convergence in the surface to near-surface layer is
    expected to continue a threat for slow moving showers with
    embedded thunderstorms from Brevard County down to St. Lucie
    County over the next 3-5 hours. However, the concentration of
    heavy rain is expected to remain limited in spatial extent through
    the morning hours. Any areas of flash flooding that develop are
    likely to focus across urban and other areas of poor draining,
    remaining localized in coverage.

    Otto

    ATTN...WFO...MLB...

    ATTN...RFC...ALR...NWC...

    LAT...LON 28608054 27788010 27008004 26998066 27908111
    28528112

    =3D =3D =3D
    --- MultiMail/DOS
    * Origin: Project Scorpio TEST (618:250/6)