Alert archive / California / Winter Storm Warnings in 2021
Winter Storm Warning 4, NWS San Diego, CA
NWS San Diego, CA issued this winter storm warning at Dec 13, 2021, 3:53 AM PST for Riverside County, San Bernardino County, California. It took effect at Dec 14, 2021, 4:00 AM PST. It was in force for 20 hr. 2 reports came from inside the area while it was in force.
The area
The counties it named, with what was reported inside it.
The facts
- Issued
- Dec 13, 2021, 3:53 AM PST (11:53 UTC)
- In effect from
- Dec 14, 2021, 4:00 AM PST
- Expired
- Dec 15, 2021, 12:08 AM PST
- In force
- 20 hr
- Issued by
- NWS San Diego, CA
The radar
The Santa Ana Mts radar (KSOX), 152 km from the middle of the area, began a volume at 11:56 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 |
|---|---|---|---|
| Dec 14, 7:48 AM PST | SNOW 1 | 1 E Running Springs, CA | CHAIN CONTROL HIGHWAY 18 RIM OF THE WORLD STARTING NEAR 6500 FEET. |
| Dec 14, 9:00 PM PST | HEAVY SNOW 12 | 3 Ne Running Springs, CA | 12 INCHES OF NEW SNOW ON DECEMBER 14. |
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 00:00Z, 11.9 hours before the alert went out and 195 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
- 1661 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- 41 m²/s²
- 0-3 km storm-relative helicity
- 94 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
575 WWUS46 KSGX 131153 WSWSGX URGENT - WINTER WEATHER MESSAGE National Weather Service SAN DIEGO CA 353 AM PST Mon Dec 13 2021 CAZ055-056-132200- /O.UPG.KSGX.WS.A.0004.211214T1200Z-211215T1000Z/ /O.NEW.KSGX.WS.W.0004.211214T1200Z-211215T1000Z/ San Bernardino County Mountains-Riverside County Mountains- Including the cities of Big Bear City, Big Bear Lake, Running Springs, and Wrightwood 353 AM PST Mon Dec 13 2021 ...WINTER STORM WARNING IN EFFECT FROM 4 AM TUESDAY TO 2 AM PST WEDNESDAY ABOVE 6000 FEET... * WHAT...Heavy snow expected. Travel will be very difficult to impossible, including during the evening commute on Tuesday. Expect damage to trees and power lines as well. Total snow accumulations of 6 to 14 inches above 6,000 feet, with localized amounts up to 24 inches above 8,000 feet. * WHERE...Mountains of San Bernardino and Riverside Counties above 6,000 feet elevation. * WHEN...4 AM Tuesday to 2 AM Wednesday. * ADDITIONAL DETAILS...Be prepared for significant reductions in visibility at times. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Storm Warning for snow means severe winter weather conditions are expected. If you must travel, keep an extra flashlight, food and water in your vehicle in case of an emergency. For road condition information in California...enter 8 0 0 4 2 7 7 6 2 3 if inside california or 9 1 6 4 5 5 7 6 2 3 if outside California. $$
7 follow-up statements
066 WWUS46 KSGX 131207 AAA WSWSGX URGENT - WINTER WEATHER MESSAGE...UPDATED National Weather Service SAN DIEGO CA 407 AM PST Mon Dec 13 2021 CAZ055-056-132200- /O.CON.KSGX.WS.W.0004.211214T1200Z-211215T1000Z/ San Bernardino County Mountains-Riverside County Mountains- Including the cities of Crestline, Lake Arrowhead, Big Bear City, Big Bear Lake, Running Springs, Wrightwood, and Idyllwild-Pine Cove 407 AM PST Mon Dec 13 2021 ...WINTER STORM WARNING REMAINS IN EFFECT FROM 4 AM TUESDAY TO 2 AM PST WEDNESDAY... * WHAT...Heavy snow expected. Plan on difficult travel conditions, including during the evening commute on Tuesday. Damage to trees and power lines is possible. Total snow accumulations of 3 to 7 inches, with localized amounts 8 to 24 inches above 8,000 feet are expected. * WHERE...Mountains of San Bernardino and Riverside Counties above 6,000 feet elevation. * WHEN...4 AM Tuesday to 2 AM Wednesday. * ADDITIONAL DETAILS...Be prepared for significant reductions in visibility at times. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Storm Warning for snow means severe winter weather conditions are expected. If you must travel, keep an extra flashlight, food and water in your vehicle in case of an emergency. For road condition information in California...enter 8 0 0 4 2 7 7 6 2 3 if inside california or 9 1 6 4 5 5 7 6 2 3 if outside California. $$
024 WWUS46 KSGX 132108 WSWSGX URGENT - WINTER WEATHER MESSAGE National Weather Service SAN DIEGO CA 108 PM PST Mon Dec 13 2021 CAZ055-056-140615- /O.CON.KSGX.WS.W.0004.211214T1200Z-211215T1000Z/ San Bernardino County Mountains-Riverside County Mountains- Including the cities of Crestline, Lake Arrowhead, Big Bear City, Big Bear Lake, Running Springs, Wrightwood, and Idyllwild-Pine Cove 108 PM PST Mon Dec 13 2021 ...WINTER STORM WARNING REMAINS IN EFFECT FROM 4 AM TUESDAY TO 2 AM PST WEDNESDAY... * WHAT...Heavy snow expected. Plan on difficult travel conditions, including during the evening commute on Tuesday. Expect damage to trees and power lines as well. Total snow accumulations of 5 to 12 inches between 5000-7000 feet, with locally higher amounts up to 3 feet in the Riverside County mountains and 3 to 4 feet in the San Bernardino county mountains. Highest amounts will accumulate on the highest peaks, above 8000 feet. * WHERE...Mountains of San Bernardino and Riverside Counties above 5,000 feet elevation. * WHEN...4 AM Tuesday to 2 AM Wednesday. * ADDITIONAL DETAILS...Be prepared for significant reductions in visibility at times. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Storm Warning for snow means severe winter weather conditions are expected. If you must travel, keep an extra flashlight, food and water in your vehicle in case of an emergency. For road condition information in California...enter 8 0 0 4 2 7 7 6 2 3 if inside california or 9 1 6 4 5 5 7 6 2 3 if outside California. $$ CO
020 WWUS46 KSGX 140502 WSWSGX URGENT - WINTER WEATHER MESSAGE National Weather Service SAN DIEGO CA 902 PM PST Mon Dec 13 2021 CAZ055-056-141400- /O.CON.KSGX.WS.W.0004.211214T1200Z-211215T1000Z/ San Bernardino County Mountains-Riverside County Mountains- Including the cities of Crestline, Lake Arrowhead, Big Bear City, Big Bear Lake, Running Springs, Wrightwood, and Idyllwild-Pine Cove 902 PM PST Mon Dec 13 2021 ...WINTER STORM WARNING REMAINS IN EFFECT FROM 4 AM TUESDAY TO 2 AM WEDNESDAY... * WHAT...Heavy snow expected. Plan on difficult travel conditions. Expect damage to trees and power lines as well. Total snow accumulations of 5 to 12 inches between 5000-7000 feet, with locally higher amounts up to 3 feet in the Riverside County mountains and 3 to 4 feet in the San Bernardino mountains above 8000 feet. * WHERE...Mountains of San Bernardino and Riverside Counties above 5,000 feet elevation. * WHEN...4 AM Tuesday to 2 AM Wednesday. * ADDITIONAL DETAILS...Significant reductions in visibility at times. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Storm Warning for snow means severe winter weather conditions are expected. If you must travel, keep an extra flashlight, food and water in your vehicle in case of an emergency. $$ Moede
477 WWUS46 KSGX 141208 WSWSGX URGENT - WINTER WEATHER MESSAGE National Weather Service SAN DIEGO CA 408 AM PST Tue Dec 14 2021 CAZ055-056-142230- /O.CON.KSGX.WS.W.0004.000000T0000Z-211215T1000Z/ San Bernardino County Mountains-Riverside County Mountains- Including the cities of Crestline, Lake Arrowhead, Big Bear City, Big Bear Lake, Running Springs, Wrightwood, and Idyllwild-Pine Cove 408 AM PST Tue Dec 14 2021 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 2 AM PST WEDNESDAY... * WHAT...Heavy snow. Plan on difficult travel conditions, including during the evening commute. Damage to trees and power lines is possible. Storm total snowfall of 4 to 12 inches between 5000-7000 feet. Higher amounts up to 3 feet in the Riverside County mountains and 3 to 4 feet in the San Bernardino mountains above 8000 feet. * WHERE...Mountains of San Bernardino and Riverside Counties above 5,000 feet elevation. * WHEN...Until 2 AM Wednesday. * ADDITIONAL DETAILS...Be prepared for significant reductions in visibility at times. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Storm Warning for snow means severe winter weather conditions are occurring. If you must travel, keep an extra flashlight, food and water in your vehicle in case of an emergency. For road condition information in California...enter 8 0 0 4 2 7 7 6 2 3 if inside california or 9 1 6 4 5 5 7 6 2 3 if outside California. $$
765 WWUS46 KSGX 142034 WSWSGX URGENT - WINTER WEATHER MESSAGE National Weather Service SAN DIEGO CA 1234 PM PST Tue Dec 14 2021 CAZ055-056-150615- /O.CON.KSGX.WS.W.0004.000000T0000Z-211215T1000Z/ San Bernardino County Mountains-Riverside County Mountains- Including the cities of Crestline, Lake Arrowhead, Big Bear City, Big Bear Lake, Running Springs, Wrightwood, and Idyllwild-Pine Cove 1234 PM PST Tue Dec 14 2021 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 2 AM PST WEDNESDAY... * WHAT...Heavy snow occurring. Plan on difficult travel conditions, including during the evening commute. Expect damage to trees and power lines as well. Additional snow accumulations of 4 to 12 inches, with localized amounts up to 28 inches. * WHERE...Mountains of San Bernardino and Riverside Counties above 5,000 feet elevation. * WHEN...Until 2 AM Wednesday. * ADDITIONAL DETAILS...Be prepared for significant reductions in visibility at times. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Storm Warning for snow means severe winter weather conditions are occurring. If you must travel, keep an extra flashlight, food and water in your vehicle in case of an emergency. For road condition information in California...enter 8 0 0 4 2 7 7 6 2 3 if inside california or 9 1 6 4 5 5 7 6 2 3 if outside California. $$ CO
408 WWUS46 KSGX 150427 WSWSGX URGENT - WINTER WEATHER MESSAGE National Weather Service SAN DIEGO CA 827 PM PST Tue Dec 14 2021 CAZ055-056-151000- /O.CON.KSGX.WS.W.0004.000000T0000Z-211215T1000Z/ San Bernardino County Mountains-Riverside County Mountains- Including the cities of Crestline, Lake Arrowhead, Big Bear City, Big Bear Lake, Running Springs, Wrightwood, and Idyllwild-Pine Cove 827 PM PST Tue Dec 14 2021 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 2 AM WEDNESDAY... * WHAT...Snow showers and strong winds. Additional snow accumulations of 4 to 6 inches. * WHERE...Mountains of San Bernardino and Riverside Counties above 5,000 feet elevation. * WHEN...Until 2 AM Wednesday. * ADDITIONAL DETAILS...Be prepared for significant reductions in visibility at times. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Storm Warning for snow means severe winter weather conditions are occurring. If you must travel, keep an extra flashlight, food and water in your vehicle in case of an emergency. $$ Moede
357 WWUS46 KSGX 150808 WSWSGX URGENT - WINTER WEATHER MESSAGE National Weather Service SAN DIEGO CA 1208 AM PST Wed Dec 15 2021 CAZ055-056-150915- /O.CAN.KSGX.WS.W.0004.000000T0000Z-211215T1000Z/ San Bernardino County Mountains-Riverside County Mountains- 1208 AM PST Wed Dec 15 2021 ...WINTER STORM WARNING IS CANCELLED... Snow has ended and winds have decreased. However, roads will remain icy through the morning. $$
The office that day
Everything else NWS San Diego, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 12, 5:03 PM PST | Gale Warning | SGX | 59 hr | |
| Dec 13, 3:50 AM PST | High Wind Warning | SGX | Riverside, San Bernardino, San Diego | 44 hr |
| Dec 13, 3:50 AM PST | Wind Advisory | SGX | Orange, Riverside, San Bernardino, San Diego | 44 hr |
| Dec 13, 10:42 AM PST | Flood Watch | SGX | Orange, Riverside, San Bernardino, San Diego | 34 hr |
| Dec 13, 1:07 PM PST | High Surf Advisory | SGX | Orange, San Diego | 49 hr |
Nearby
Winter Storm Warnings in California, 2021Every winter storm warning in 2021
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.