Graphic for MPD #0048

Mesoscale Precipitation Discussion 0048
NWS Weather Prediction Center College Park MD
605 PM EST Sun Feb 04 2024

Areas affected...Central and Northern CA Coastal Ranges and the
Central Valley

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

Valid 042305Z - 050800Z

SUMMARY...Additional areas of heavy rainfall are expected going
through the evening and into the overnight hours. Runoff problems
and areas of flooding will remain possible given the very wet and
locally saturated soil conditions.

DISCUSSION...The afternoon GOES-W visible satellite imagery shows
a strong area of low pressure associated with today's West Coast
atmospheric river lifting gradually north up off the central CA
coast. Focused moisture transport continuing to ride up across the
coastal ranges and into the Central Valley around the eastern
flank of this low coupled with the arrival of additional shortwave
energy/forcing rounding the base of the deeper layer
cyclone/trough will maintain at least pockets of heavy rainfall
heading through the evening hours.

The 18Z HREF supports some increase in instability this evening
across coastal areas of central and northern CA given the arrival
of steepening mid-level lapse rates, and the latest HRRR guidance
supports the potential for some localized small-scale linear
convective bands which will not only impact the coastal ranges,
but may affect the Bay Area and at least portions of the
Sacramento Valley.

Rainfall rates with these stronger convective elements, in
addition to any areas of orographic enhancement, may reach a 0.50"
to 1"/hour. Additional rainfall totals going through the late
evening hours may locally be as much as 2 to 4 inches over the
higher terrain, with spotty 1 to 2 inch amounts in the lower
elevations/valley areas.

Given the already very wet and locally saturated soil conditions,
additional runoff problems and flooding will remain a concern.

Orrison

ATTN...WFO...EKA...HNX...LOX...MFR...MTR...STO...

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

LAT...LON   41432233 41332190 40822173 40162149 39342069
            38642034 37861983 37151919 36431868 35871849
            35491855 35411874 35601917 35512011 35372063
            35462116 35882162 36242204 36782236 37032247
            37732284 38242322 38922382 39692424 40272437
            40682400 40842335 41252272
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Last Updated: 605 PM EST Sun Feb 04 2024