Alert archive / California / Flash Flood Warnings in 2018
Flash Flood Warning 9, NWS San Diego, CA
NWS San Diego, CA issued this flash flood warning at Jul 12, 2018, 11:51 AM PDT for Riverside County, San Bernardino County, California. It was in force for 3 hr. 3 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Jul 12, 2018, 11:51 AM PDT (18:51 UTC)
- Expired
- Jul 12, 2018, 2:45 PM PDT
- In force
- 3 hr
- Issued by
- NWS San Diego, CA
- Area
- Storm-based polygon
- Flood severity
- None
The radar
The Santa Ana Mts radar (KSOX), 80 km from the middle of the area, began a volume at 18:53 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 12, 1:00 PM PDT | FLASH FLOOD | 7 Ne Yucaipa, CA | CALTRANS AND CHP REPORT VALLEY OF THE FALLS CLOSED DUE TO DEBRIS OR MUD FLOWS FROM HEAVY RAIN AND CONCERNS FOR MORE MOVEMENT. THIS IS JUST EAST OF HIGHWAY 38. |
| Jul 12, 1:11 PM PDT | FLASH FLOOD | 7 N Big Bear City, CA | FLASH FLOODING ON HIGHWAY 18 MILE MARKER 65 NEAR MITSUBISHI CEMENT CORPORATION PLANT. NUMEROUS VEHICLES STRANDED DUE TO SIGNIFICANT FLOW OF WATER AND DEBRIS. HIGHWAY 18 CLOSED IN BOTH DIRECTIONS. |
| Jul 12, 1:19 PM PDT | FLASH FLOOD | 4 Ne Big Bear City, CA | STATE ROUTE 18 WILL BE CLOSED BETWEEN BIG BEAR AND LUCERNE VALLEY UNTIL FUTHER NOTICE DUE TO FLOODING. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
San Diego, CA (KNKX), launched 12:00Z, 6.9 hours before the alert went out and 157 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1276 m above ground
- 0-6 km bulk shear
- 7 kt
- 0-1 km storm-relative helicity
- 37 m²/s²
- 0-3 km storm-relative helicity
- 43 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
586
WGUS56 KSGX 121851
FFWSGX
CAC065-071-122145-
/O.NEW.KSGX.FF.W.0009.180712T1851Z-180712T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Diego CA
1151 AM PDT THU JUL 12 2018
The National Weather Service in San Diego has issued a
* Flash Flood Warning for...
San Bernardino County in southern California...
Riverside County in southern California...
* Until 245 PM PDT
* At 1144 AM PDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area over Onyx Peak. Flash flooding
will likely begin shortly in creeks around south Big Bear City,
Raywood Flats and draining into the south fork Whitewater River.
Urban flooding is likely as well. Rainfall rates of up to 0.75
inches per hour are expected. Heavy rain could cause rock or
debris slides on highways 38 and 18.
* Some locations that will likely experience flooding include...
Yucaipa, Big Bear City, Mount San Gorgonio, Onyx Summit, Forest
Falls, Lucerne Valley, Banning, Big Bear Lake, Seven Oaks, Mountain
Home Village, Hwy 38 Between Onyx Summit And Sugarloaf, Baldwin
Lake, Angelus Oaks, Hwy 18 Between Baldwin Lake And Lucerne Valley,
Hwy 38 Between Yucaipa And Onyx Summit, Hwy 18 Between Running
Springs And Big Bear, Woodlands, Fawnskin, Heart Bar Campground and
Barton Flats Campground.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3403 11705 3438 11708 3442 11689 3425 11650
3401 11678
$$
Tardy2 follow-up statements
358
WGUS76 KSGX 122053
FFSSGX
Flash Flood Statement
National Weather Service San Diego CA
153 PM PDT THU JUL 12 2018
CAC065-071-122145-
/O.CON.KSGX.FF.W.0009.000000T0000Z-180712T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-Riverside CA-
153 PM PDT THU JUL 12 2018
...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 245 PM PDT FOR SAN
BERNARDINO AND RIVERSIDE COUNTIES...
At 146 PM PDT, emergency management reported large rock and mud
debris flows from heavy rain on Highway 38, 18 and Valley of the
Falls road. Caltrans has closed both highway 18 north of Big Bear
and Valley of the Falls entrance. Radar and gages show 1 to 2 inches
of rain fell in less than 2 hours. Rainfall has tapered off to
showers but isolated heavy rain is still possible.
Some locations that will experience flooding or debris flows include...
Yucaipa, Big Bear City, Mount San Gorgonio, Onyx Summit, Forest
Falls, Lucerne Valley, Heart Bar Campground and Barton Flats
Campground.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3403 11705 3438 11708 3442 11689 3425 11650
3401 11678
$$
Tardy241
WGUS76 KSGX 122149
FFSSGX
Flash Flood Statement
National Weather Service San Diego CA
249 PM PDT THU JUL 12 2018
CAC065-071-122157-
/O.EXP.KSGX.FF.W.0009.000000T0000Z-180712T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-Riverside CA-
249 PM PDT THU JUL 12 2018
...THE FLASH FLOOD WARNING FOR SAN BERNARDINO AND RIVERSIDE COUNTIES
HAS EXPIRED...
The heavy rain has ended. Flooding is no longer expected to pose a
threat at this time. However, roadways remain closed and significant
debris is still in place. Please continue to heed any remaining road closures
such as Highway 18 and Valley of the Falls road.
There is still a threat for new thunderstorms with heavy rain so be aware
of changing skies.
LAT...LON 3403 11705 3438 11708 3442 11689 3425 11650
3401 11678
$$
TardyThe office that day
Everything else NWS San Diego, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 11, 5:06 PM PDT | Flash Flood Warning | SGX | San Diego | 3 hr |
| Jul 11, 6:33 PM PDT | Flash Flood Warning | SGX | Riverside | 117 min |
| Jul 11, 6:40 PM PDT | Severe Thunderstorm Warning | SGX | Riverside | 65 min |
| Jul 12, 12:29 PM PDT | Areal Flood Advisory | SGX | San Bernardino | 3 hr |
| Jul 12, 12:54 PM PDT | Flash Flood Warning | SGX | San Bernardino | 3 hr |
| Jul 12, 1:09 PM PDT | Severe Thunderstorm Warning | SGX | San Bernardino | 47 min |
| Jul 12, 1:36 PM PDT | Flash Flood Warning | SGX | San Diego | 2 hr |
| Jul 12, 1:53 PM PDT | Severe Thunderstorm Warning | SGX | San Diego | 67 min |
Nearby
Flash Flood Warnings in California, 2018Every flash flood warning in 2018
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.