Alert archive / California / Flash Flood Warnings in 2023

Flash Flood Warning 4, NWS Sacramento, CA

March 11, 2023Calaveras County, Stanislaus County, Tuolumne County, California

NWS Sacramento, CA issued this flash flood warning at Mar 11, 2023, 3:08 PM PST for Calaveras County, Stanislaus County, Tuolumne County, California. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Mar 11, 2023, 3:08 PM PST (23:08 UTC)
Expired: Mar 11, 2023, 6:15 PM PST
In force: 3 hr
Issued by: NWS Sacramento, CA
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Calaveras County, CA, Stanislaus County, CA, Tuolumne County, CA

The radar

The Sacramento radar (KDAX), 121 km from the middle of the area, began a volume at 23:08 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Oakland, CA (KOAK), launched 12:00Z, 11.1 hours before the alert went out and 151 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1105 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 70 m²/s²
0-3 km storm-relative helicity: 159 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Sacramento, CA wrote its last area forecast discussion before this flash flood warning went out at Mar 11, 2:48 PM PST, 20 minutes earlier.

Area forecast discussion, Mar 11, 2:48 PM PST, 20 minutes before

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In the hours before

Special weather statement, Mar 11, 12:36 PM PST, 2 hours 32 minutes before

Special Weather Statement
National Weather Service Sacramento CA
1236 PM PST Sat Mar 11 2023

CAZ018-019-112115-
Carquinez Strait and Delta CA-Northern San Joaquin Valley CA-
1236 PM PST Sat Mar 11 2023

...A strong thunderstorm will impact portions of central San Joaquin
County through 115 PM PST...

At 1235 PM PST, Doppler radar was tracking a strong thunderstorm near
ear Stockton, moving east norteast at 25 mph.

HAZARD...Winds in excess of 40 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible. Funnel clouds are possible.

Locations impacted include...
Stockton, Waterloo, Country Club, Taft Mosswood, Garden Acres,
Kennedy, August, Linden, Morada, Lincoln Village and Lockeford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3791 12145 3798 12148 3815 12115 3788 12103
TIME...MOT...LOC 2035Z 254DEG 21KT 3795 12141

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

EK

Local storm report, Mar 11, 1:33 PM PST, 1 hour 35 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SACRAMENTO CA
133 PM PST SAT MAR 11 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1242 PM     HAIL             COUNTRY CLUB            37.97N 121.33W
03/11/2023  M1.00 INCH       SAN JOAQUIN        CA   PUBLIC

            REPORT OF HAIL WITH HAIL STONES UP TO
            QUARTER SIZE IN STOCKTON. TIME ESTIMATED
            FROM RADAR.

&&

CP

The office that day

Everything else NWS Sacramento, CA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 11, 12:36 PM PST	Special Weather Statement	STO	San Joaquin	39 min
Mar 11, 12:42 PM PST	Severe Thunderstorm Warning	STO	San Joaquin, Stanislaus	63 min
Mar 11, 1:32 PM PST	Severe Thunderstorm Warning	STO	Calaveras, San Joaquin, Stanislaus, Tuolumne	10 min
Mar 11, 1:46 PM PST	Severe Thunderstorm Warning	STO	Calaveras, San Joaquin, Stanislaus, Tuolumne	59 min
Mar 11, 2:37 PM PST	Tornado Warning	STO	Calaveras, Tuolumne	38 min
Mar 11, 3:09 PM PST	Severe Thunderstorm Warning	STO	Calaveras, Stanislaus	51 min
Mar 11, 3:23 PM PST	Severe Thunderstorm Warning	STO	Calaveras, Stanislaus, Tuolumne	67 min
Mar 11, 3:32 PM PST	Flood Watch	STO		3 days

Nearby

Flash Flood Warnings in California, 2023 Every flash flood warning in 2023

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.