Mesoscale Precipitation Discussion 0014
NWS Weather Prediction Center College Park MD
603 PM EST Sun Feb 02 2025

Areas affected...Shasta County / northern CA

Concerning...Heavy rainfall...Flash flooding likely

Valid 022302Z - 030200Z

SUMMARY...A narrow and focused band of heavy rain is expected to
result in a localized area of flash flooding for portions of
Shasta County in and around the Redding metro area. Peak hourly
rainfall of 1-2 inches will be possible with localized additional
totals of 3-5 inches through 02Z.

DISCUSSION...Local radar imagery from KBBX at 2240Z showed a
narrow band (just 2-4 miles wide) of stationary heavy rain
occurring just south of downtown Redding, CA. This band has been
present for the past 2 to 3 hours and has resulted in 4 to 6
inches of rain, most of which has occurred since 20Z. These
rainfall reports have been sourced from a number of
Wunderground.com observations with the band just recently shifting
south to Redding Regional Airport.

The band of heavy rain was located along an axis of strong
surface/near-surface convergence co-located with a
quasi-stationary front that extended SW to NE across the northern
Sacramento Valley. Weak instability may be present with RAP
estimates of near 100 J/kg. Little change to the pattern on the
regional scale is expected to keep the quasi-stationary front in
roughly the same position over the next few hours though some
minor wavering of the rainfall axis is expected over the next
couple of hours along with possible weakening of the little
instability that could be in place. Given the presence of this
band of heavy rain across the I-5 corridor near Redding and into
the higher terrain of eastern Shasta County, a localized area of
flash flooding appears likely with this band. Due to the highly
mesoscale nature of this feature, confidence is below average in
its longevity but it seems likely to persist for at least another
1-2 hours.

Otto

ATTN...WFO...STO...

ATTN...RFC...CNRFC...NWC...

LAT...LON   41082185 40972166 40772163 40642187 40262256
            40462268 40972208