• Heavy Rain/Flood KSMOOKAR

    From Mike Powell@618:250/1 to All on Tue Aug 13 09:20:00 2024
    AWUS01 KWNH 131123
    FFGMPD
    MOZ000-ARZ000-OKZ000-KSZ000-131700-

    Mesoscale Precipitation Discussion 0874
    NWS Weather Prediction Center College Park MD
    722 AM EDT Tue Aug 13 2024

    Areas affected...Southeast KS...Southwest MO...Northeast
    OK...Northwest AR...

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

    Valid 131130Z - 131700Z

    SUMMARY...Decaying MCS with a few more hours of WAA training along
    the northern side of strengthening bow echo allowing for 2-4"
    totals and possible flash flooding. Very intense short-term rates
    with 1-2" in 15-30 minutes with the bow may be a flooding concern
    in prone or urban settings.

    DISCUSSION...Regional RADAR mosaic depicts a well defined
    MCV/parent shortwave that has become well displaced in the
    decaying shield precipitation WNW of the strengthening effective
    triple point/new MCV near Marion/Chase county, KS. A impressive
    bowing segment is surging ESE into SE KS, with a broadening
    upstream edge across south-central KS within the MCS anti-cyclonic
    rotor. While strong moisture flux convergence will quickly turn
    with very short-duration resulting in 1-2" of rainfall in 15-30
    minutes likely only resulting in flooding in traditionally prone
    or urban settings.

    Of greater potential for flash flooding are within the bookends of
    the MCS; the upwind southern anti-cyclonic rotor is starting to
    have broadening convective elements being more exposed to the
    southwesterly LLJ and expanding moisture convergence orthogonal to
    the mean motions as the MCS enters a bit more NW to SE motions in
    the 500-1000 thickness pattern (directing toward SW MO/NE OK). VWP
    shows increasingly unidirectional inflow still at 25-35kts from
    925-700mb advecting an axis of enhanced conditionally unstable air
    with MUCAPE of 1500-2000 J/kg across north-central OK. This may
    result in an area of enhanced 2-3" totals into the southern Flint
    Hills and perhaps northern Osage county.

    The other location remains with the stronger WAA along/ahead of
    the MCV on the cyclonic rotor; here, strengthened flow and
    directional convergence results in the greatest moisture flux to
    the system and should support 2-2.5"/hr rates particularly near
    the transferred MCV. However, recent trends show a shortening of
    the downstream convergence and convective development. There may
    be two factors involved, the first: utilizing EAX VWP, downstream
    winds are weaker at less than 10kts with even some lesser than
    desirable southerly component. The second is related to a reduced
    instability pool downstream into MO. RAP analysis suggests values
    of 500-1000 J/kg exist, but strengthening CINH fields in
    combination with weakening isentropic ascent on the effective warm
    front may reduce the length of the WAA wing and therefore
    training/repeating potential as the wave passes. Still, the risk
    of 2-4" totals in 2-3hrs will continue to pose a flash flooding
    risk as the MCS slowly decays through the remainder of the
    morning.

    Gallina

    ATTN...WFO...EAX...ICT...LZK...OUN...SGF...TOP...TSA...

    ATTN...RFC...ABRFC...LMRFC...MBRFC...NWC...

    LAT...LON 38809660 38669435 37999226 36829149 36139183
    35689270 35689382 35919492 36459618 37199736
    38289764
    --- SBBSecho 3.20-Linux
    * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)