Alert archive / California / Severe Thunderstorm Warnings in 2022

Severe Thunderstorm Warning 17, NWS San Diego, CA

September 12, 2022San Bernardino County, California

NWS San Diego, CA issued this severe thunderstorm warning at Sep 12, 2022, 1:45 PM PDT for San Bernardino County, California. It was in force for 45 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Sep 12, 2022, 1:45 PM PDT (20:45 UTC)
Expired: Sep 12, 2022, 2:30 PM PDT
In force: 45 min
Issued by: NWS San Diego, CA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County San Bernardino County, CA

The nearest sounding before it

Las Vegas, NV (KVEF), launched 12:00Z, 8.8 hours before the alert went out and 180 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: 25 J/kg
Mixed-layer CIN: -165 J/kg
Mixed-layer LCL: 2221 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: -19 m²/s²
0-3 km storm-relative helicity: 19 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 severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS San Diego, CA wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 12, 10:00 AM PDT, 3 hours 45 minutes earlier.

Area forecast discussion, Sep 12, 10:00 AM PDT, 3 hours 45 minutes before

Area Forecast Discussion
National Weather Service San Diego CA
1000 AM PDT Mon Sep 12 2022

.SYNOPSIS...
Extensive moisture aloft will bring mostly cloudy conditions today
with a chance of thunderstorms mainly this afternoon. Locally heavy
rain and flash flooding will be possible with some thunderstorms. As
moisture decreases, only isolated thunderstorms are expected
Tuesday, with dry weather prevailed Wednesday through next weekend.
Temperatures will mostly be near normal the rest of this week, with
areas of night and morning low clouds near the coast.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

The remnant surface low of Kay was approximately 400 miles southwest
of San Diego, with extensive moisture bringing a broad cloud shield
from the low (and beyond) northeast through a lot of SoCal. A few
showers were occurring this morning. The NKX sounding this morning
had 1.67" of PW. Current SPC analysis shows rather modest surface
and MU CAPE due to the cloud cover, and any instability that could
occur due to clearing is the key to afternoon convection. If
thunderstorms form, heavy rain will be possible as HRRR runs this
morning have shown locally more than 1"/hour rates. Given the
limited clearing so far, thunderstorms will likely be delayed until
mid-late afternoon. Greatest chances, based on surface convergence,
will be in the mountains, though the HRRR indicates some risk in the
far eastern Inland Empire as well. The cloud cover today will result
in lower temperatures, and they are already about 5 deg F lower on
average than 24 hours ago. The muggy conditions will continue,
however.

A drying trend will occur Tuesday and Wednesday as we return to west
flow aloft with moderate troughing over the Pacific Northwest.
Thunderstorm chances are marginal Tuesday, with the most likely
scenario being that thunderstorms will happen only near the higher
peaks. Starting Wednesday, there should be dry weather across the
region. The westerly flow will be favorable for marine layer stratus
near the ocast, which could be extensive on some nights and even
days. Temperatures will mostly be near normal, though highs will be
a bit below normal with lows a bit above normal. Most model/ensemble
solutions show a deeping trough or upper low along the West Coast
this weekend which could bring some cooling but at this point
appears unlikely to bring precipitation.

&&

.AVIATION...
121600Z...Coast/Valleys...SCT-BKN020-030 with local CIGS 005-010 and
isolated -SHRA through 17Z. From 17Z-24Z...SCT030-050 SCT100 with
isolated TSRA, mainly in the valleys/foothills.

Mountains/Deserts...SCT030-050 BKN100 with isolated -SHRA this
morning and scattered -TSRA this afternoon with tops to 40,000 ft.

&&

.MARINE...
Isolated showers this morning. Otherwise, no hazardous marine
conditions through Thursday.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Flood Watch from 11 AM PDT this morning through this evening for
     Apple and Lucerne Valleys-Riverside County Mountains-San
     Bernardino County Mountains-San Gorgonio Pass Near Banning.

PZ...None.

&&

PUBLIC...Maxwell
AVIATION/MARINE...Small

In the hours before

Local storm report, Sep 12, 1:26 PM PDT, 19 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
126 PM PDT MON SEP 12 2022

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

0100 PM     HEAVY RAIN       5 NE RANCHO CUCAMONGA   34.17N 117.51W
09/12/2022  M2.83 INCH       SAN BERNARDINO     CA   MESONET

            MESONET STATION LRAC1 5.5 NE RANCHO
            CUCAMONGA.

&&

AOT

Local storm report, Sep 12, 1:27 PM PDT, 18 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
127 PM PDT MON SEP 12 2022

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

1200 PM     HEAVY RAIN       5 NE RANCHO CUCAMONGA   34.17N 117.51W
09/12/2022  M2.83 INCH       SAN BERNARDINO     CA   MESONET

            MESONET STATION LRAC1 LARSON RANCH.

&&

AOT

Local storm report, Sep 12, 1:28 PM PDT, 17 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
128 PM PDT MON SEP 12 2022

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

0700 AM     HEAVY RAIN       4 W SAN JACINTO         33.80N 117.04W
09/12/2022  M1.33 INCH       RIVERSIDE          CA   COCORAHS

            COCORAHS STATION CA-RV-58 SAN JACINTO 4.2 W.

&&

AOT

Local storm report, Sep 12, 1:29 PM PDT, 16 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
129 PM PDT MON SEP 12 2022

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

0700 AM     HEAVY RAIN       2 WSW RAMONA            33.03N 116.90W
09/12/2022  M0.95 INCH       SAN DIEGO          CA   COCORAHS

            COCORAHS STATION CA-SD-186 RAMONA 1.8 WSW.

&&

AOT

Local storm report, Sep 12, 1:30 PM PDT, 15 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
130 PM PDT MON SEP 12 2022

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

0115 PM     HEAVY RAIN       5 NE RAINBOW            33.46N 117.08W
09/12/2022  M0.48 INCH       RIVERSIDE          CA   MESONET

            MESONET STATION FW9212 ESCONDIDO.

&&

AOT

Local storm report, Sep 12, 1:42 PM PDT, 3 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
142 PM PDT MON SEP 12 2022

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

0141 PM     HEAVY RAIN       3 NW RUNNING SPRINGS    34.24N 117.14W
09/12/2022  M2.68 INCH       SAN BERNARDINO     CA   MESONET

            HEAPS PEAK RAWS - RADAR HAD 2 TO 3 INCHES ON
            SUNDAY.

&&

AOT

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 11, 5:05 PM PDT	Areal Flood Advisory	SGX	Orange, Riverside	115 min
Sep 11, 5:24 PM PDT	Flash Flood Warning Considerable damage threat	SGX	Orange, Riverside	3 hr
Sep 11, 5:41 PM PDT	Areal Flood Advisory	SGX	San Bernardino	2 hr
Sep 11, 5:59 PM PDT	Flash Flood Warning Considerable damage threat	SGX	San Bernardino	3 hr
Sep 11, 6:10 PM PDT	Flash Flood Warning	SGX	San Bernardino	3 hr
Sep 11, 6:30 PM PDT	Areal Flood Advisory	SGX	San Bernardino	3 hr
Sep 11, 6:44 PM PDT	Flash Flood Warning Considerable damage threat	SGX	San Bernardino	3 hr
Sep 11, 6:47 PM PDT	Areal Flood Advisory	SGX	San Bernardino	118 min
Sep 12, 2:46 AM PDT	Flood Watch	SGX	Riverside, San Bernardino	17 hr
Sep 12, 1:27 PM PDT	Flash Flood Warning Considerable damage threat	SGX	Riverside, San Bernardino	5 hr
Sep 12, 1:34 PM PDT	Areal Flood Advisory	SGX	San Bernardino	2 hr
Sep 12, 1:54 PM PDT	Flash Flood Warning Considerable damage threat	SGX	San Bernardino	3 hr
Sep 12, 2:04 PM PDT	Areal Flood Advisory	SGX	San Bernardino	116 min
Sep 12, 2:10 PM PDT	Areal Flood Advisory	SGX	San Bernardino	2 hr
Sep 12, 2:27 PM PDT	Areal Flood Advisory	SGX	San Bernardino	2 hr
Sep 12, 2:37 PM PDT	Flash Flood Warning Considerable damage threat	SGX	Riverside, San Bernardino	3 hr
Sep 12, 3:04 PM PDT	Special Weather Statement	SGX		41 min
Sep 12, 3:06 PM PDT	Flash Flood Warning Considerable damage threat	SGX	San Bernardino	3 hr
Sep 12, 3:23 PM PDT	Special Weather Statement	SGX	Orange	52 min
Sep 12, 3:30 PM PDT	Areal Flood Advisory	SGX	San Diego	3 hr
Sep 12, 3:38 PM PDT	Areal Flood Advisory	SGX	Orange, Riverside	2 hr
Sep 12, 3:51 PM PDT	Flash Flood Warning Considerable damage threat	SGX	Riverside	3 hr
Sep 12, 4:03 PM PDT	Flash Flood Warning Considerable damage threat	SGX	San Bernardino	3 hr
Sep 12, 4:43 PM PDT	Flash Flood Warning Considerable damage threat	SGX	Riverside, San Bernardino	3 hr

Nearby

Severe Thunderstorm Warnings in California, 2022 Every severe thunderstorm warning in 2022

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.