• HVYRAIN: Excessive Rainfall Discussion...corrected

    From COD Weather Processor@1:2320/105 to wx-storm@lists.illinois.edu on Wednesday, February 18, 2026 19:44:52
    FOUS30 KWBC 181944 CCA
    QPFERD

    Excessive Rainfall Discussion...CORRECTED
    NWS Weather Prediction Center College Park MD
    244 PM EST Wed Feb 18 2026

    Corrected for typo in last sentence of Day 2 text

    Day 1
    Valid 16Z Wed Feb 18 2026 - 12Z Thu Feb 19 2026

    The probability of rainfall exceeding flash flood guidance is less
    than 5 percent.

    Otto


    Day 2
    Valid 12Z Thu Feb 19 2026 - 12Z Fri Feb 20 2026

    A potent mid-level shortwave/closed low is forecast to bring
    another round of heavier precipitation to southern CA beginning
    Thursday morning, ahead of a progressive cold front. Peak model=20
    consensus of MUCAPE no greater than 250 J/kg and IVT values of=20
    300-400 kg/m/s appear to be slightly weaker than what was=20
    associated with the round of heavier rain which impacted the=20
    Transverse Ranges early Wednesday morning. However, locally high=20
    48-72 rainfall totals have impacted portions of southern CA along=20
    with a number of flooding reports since Monday.

    The next round to affect southern California's Transverse and=20
    Peninsular Ranges is expected to bring peak hourly rainfall values
    in the 0.5 to 1.0 inch range on Thursday (12Z HREF probs for=20
    greater than 0.5 inches in 1 hour were 30-40 percent), from roughly
    15Z/18 to 03Z/19, advancing southward along the coast with time.=20
    Given the progressive nature, peak total rainfall is forecast to=20
    fall in the 1 to 2 inch range for the Transverse and Peninsula=20
    Ranges but could be a bit higher for the Peninsular Ranges given a=20
    longer and more favorable fetch of low level moisture into the
    region. While the 12Z NAM_nest is likely overdone, it does show 3+
    inch potential for localized areas below snow levels which look to
    briefly rise in the 5000-6000 foot range. Any flood related=20
    impacts should remain isolated and minor in magnitude.

    Otto


    Day 3
    Valid 12Z Fri Feb 20 2026 - 12Z Sat Feb 21 2026

    The probability of rainfall exceeding flash flood guidance is less
    than 5 percent.

    Otto


    Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!5N6V9V2B7mOBPkkk83gviV1QOp-KPIThnoDtotJCDSMp= Oxs1D9J8KAZl4bq-GQtCL1HCHu6xjK6pCKGFmVnr3otuy5g$=20
    Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!5N6V9V2B7mOBPkkk83gviV1QOp-KPIThnoDtotJCDSMp= Oxs1D9J8KAZl4bq-GQtCL1HCHu6xjK6pCKGFmVnrzXQnRvQ$=20
    Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!5N6V9V2B7mOBPkkk83gviV1QOp-KPIThnoDtotJCDSMp= Oxs1D9J8KAZl4bq-GQtCL1HCHu6xjK6pCKGFmVnrxLulBk0$=20

    =3D =3D =3D
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    * Origin: Capitol City Online (1:2320/105)