Alert archive / California / Winter Storm Warnings in 2021
Winter Storm Warning 6, NWS San Diego, CA
NWS San Diego, CA issued this winter storm warning at Dec 24, 2021, 9:00 PM PST for Riverside County, San Bernardino County, California. It took effect at Dec 25, 2021, 6:00 PM PST. It was in force for 11 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
- Dec 24, 2021, 9:00 PM PST (05:00 UTC)
- In effect from
- Dec 25, 2021, 6:00 PM PST
- Expired
- Dec 26, 2021, 4:35 AM PST
- In force
- 11 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 05:03 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
San Diego, CA (KNKX), launched 00:00Z, 5.0 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
- 856 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 19 m²/s²
- 0-3 km storm-relative helicity
- 101 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
023 WWUS46 KSGX 250500 WSWSGX URGENT - WINTER WEATHER MESSAGE National Weather Service SAN DIEGO CA 900 PM PST Fri Dec 24 2021 ...WINTER STORM SYSTEM TO BRING SNOW TO THE SAN BERNARDINO AND RIVERSIDE COUNTY MOUNTAINS SATURDAY NIGHT THROUGH SUNDAY MORNING... CAZ055-056-251300- /O.UPG.KSGX.WS.A.0005.211226T0200Z-211226T1800Z/ /O.NEW.KSGX.WS.W.0006.211226T0200Z-211226T1800Z/ 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 900 PM PST Fri Dec 24 2021 ...WINTER STORM WARNING IN EFFECT FROM 6 PM SATURDAY TO 10 AM SUNDAY... * WHAT...Heavy snow expected. Total snow accumulations of 3 to 6 inches, with localized amounts of 6 to 12 inches. * WHERE...San Bernardino and Riverside County Mountains. * WHEN...6 PM Saturday to 10 AM Sunday. * ADDITIONAL DETAILS...Significant reductions in visibility in snow and fog. Snow level will be mostly be around 5000 feet with this storm. 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. $$ Moede
4 follow-up statements
690 WWUS46 KSGX 251122 WSWSGX URGENT - WINTER WEATHER MESSAGE National Weather Service SAN DIEGO CA 322 AM PST Sat Dec 25 2021 CAZ055-056-252300- /O.CON.KSGX.WS.W.0006.211226T0200Z-211226T1800Z/ San Bernardino County Mountains-Riverside County Mountains- Including the cities of Lake Arrowhead, Big Bear City, Big Bear Lake, Running Springs, Wrightwood, and Idyllwild-Pine Cove 322 AM PST Sat Dec 25 2021 ...WINTER STORM WARNING REMAINS IN EFFECT FROM 6 PM THIS EVENING TO 10 AM PST SUNDAY ABOVE 5000 FEET... * WHAT...Heavy snow expected. Plan on difficult travel conditions. Tree branches could fall as well. Total snow accumulations of 4 to 8 inches, with localized amounts up to 12 inches, are expected. * WHERE...San Bernardino and Riverside County Mountains above 5000 feet. * WHEN...6 PM today to 10 AM Sunday. * ADDITIONAL DETAILS...Be prepared for significant reductions in visibility at times. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Storm Warning for snow means severe winter weather conditions are expected. If you must travel, keep an extra flashlight, food and water in your vehicle in case of an emergency. For road condition information in California...enter 8 0 0 4 2 7 7 6 2 3 if inside california or 9 1 6 4 5 5 7 6 2 3 if outside California. $$ 17
453 WWUS46 KSGX 252140 WSWSGX URGENT - WINTER WEATHER MESSAGE National Weather Service SAN DIEGO CA 140 PM PST Sat Dec 25 2021 ...Heavy snow at times in the mountains tonight, especially in San Bernardino County and Riverside County... ...Another winter storm to bring heavy snow to the mountains late Monday and Monday night... CAZ055-056-260600- /O.NEW.KSGX.WS.A.0006.211227T2200Z-211228T1100Z/ /O.CON.KSGX.WS.W.0006.211226T0200Z-211226T1800Z/ 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 140 PM PST Sat Dec 25 2021 ...WINTER STORM WARNING REMAINS IN EFFECT FROM 6 PM THIS EVENING TO 10 AM PST SUNDAY ABOVE 5000 FEET... ...WINTER STORM WATCH IN EFFECT FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT... * WHAT...Heavy snow expected. Plan on difficult travel conditions. Tree branches could fall as well. Total snow accumulations of 4 to 8 inches, with localized amounts up to 12 inches, are expected above 5000 feet through early Sunday morning. Similar additional snowfall amounts are possible late Monday and Monday night, except with much lower snow levels, falling to 3000 feet or lower. * WHERE...San Bernardino County and Riverside County Mountains. * WHEN...For the Winter Storm Warning, 6 PM today to 10 AM Sunday. For the Winter Storm Watch, from 2 PM Monday through 3 AM Tuesday. * ADDITIONAL DETAILS...Be prepared for significant reductions in visibility at times in snow and fog. 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. A Winter Storm Watch means there is potential for significant snow, sleet or ice accumulations that may impact travel. Continue to monitor the latest forecasts. $$ CAZ058-260600- /O.NEW.KSGX.WW.Y.0010.211226T0600Z-211226T1800Z/ /O.NEW.KSGX.WS.A.0006.211227T2200Z-211228T1100Z/ San Diego County Mountains- Including the cities of Julian and Pine Valley 140 PM PST Sat Dec 25 2021 ...WINTER WEATHER ADVISORY IN EFFECT FROM 10 PM THIS EVENING TO 10 AM PST SUNDAY... ...WINTER STORM WATCH IN EFFECT FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT... * WHAT...Snow expected. Total accumulations of 2 to 5 inches are expected above 5500 feet late tonight and early Sunday. Additional accumulations of 4 to 8 inches are possible late Monday and Monday night, with snow levels falling to around 3500 feet. * WHERE...San Diego County Mountains. * WHEN...For the Winter Weather Advisory, 10 PM today to 10 AM Sunday. For the Winter Storm Watch, from 2 PM Monday afternoon through 3 AM Tuesday. * ADDITIONAL DETAILS...Significant reductions in visibility are likely in snow and fog. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Storm Watch means there is potential for significant snow, sleet or ice accumulations that may impact travel. Continue to monitor the latest forecasts. $$ Maxwell
733 WWUS46 KSGX 260518 WSWSGX URGENT - WINTER WEATHER MESSAGE National Weather Service SAN DIEGO CA 918 PM PST Sat Dec 25 2021 CAZ055-056-261400- /O.CON.KSGX.WS.W.0006.000000T0000Z-211226T1800Z/ /O.CON.KSGX.WS.A.0006.211227T2200Z-211228T1100Z/ 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 918 PM PST Sat Dec 25 2021 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 AM PST SUNDAY ABOVE 5000 FEET... ...WINTER STORM WATCH REMAINS IN EFFECT FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT... * WHAT...Heavy snow and strong southwest winds expected. Plan on difficult travel conditions. Tree branches could fall as well. Total snow accumulations of 4 to 8 inches, with localized amounts up to 12 inches, are expected above 5000 feet through early Sunday morning. Heavy snow and strong southwest winds are possible again Monday and Monday night, with lower snow levels. * WHERE...San Bernardino County and Riverside County Mountains. * WHEN...For the Winter Storm Warning, through 10 AM Sunday. For the Winter Storm Watch, from 2 PM Monday through 3 AM Tuesday. * ADDITIONAL DETAILS...Southwest winds of 20 to 35 mph with gusts 50 to locally 60 mph. Be prepared for significant reductions in visibility at times in snow, blowing snow and fog. 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. A Winter Storm Watch means there is potential for significant snow, sleet or ice accumulations that may impact travel. Continue to monitor the latest forecasts. $$ CAZ058-261400- /O.CON.KSGX.WW.Y.0010.211226T0600Z-211226T1800Z/ /O.CON.KSGX.WS.A.0006.211227T2200Z-211228T1100Z/ San Diego County Mountains- Including the cities of Julian and Pine Valley 918 PM PST Sat Dec 25 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 AM PST SUNDAY... ...WINTER STORM WATCH REMAINS IN EFFECT FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT... * WHAT...Snow and strong southwest to west winds expected. Total accumulations of 2 to 5 inches are expected above 5300 feet late tonight and early Sunday. Additional accumulations of 4 to 8 inches are possible late Monday and Monday night, with snow levels falling to between 3500 and 4000 feet. * WHERE...San Diego County Mountains. * WHEN...For the Winter Weather Advisory, through 10 AM Sunday. For the Winter Storm Watch, from 2 PM Monday afternoon through 3 AM Tuesday. * ADDITIONAL DETAILS...Southwest winds of 20 to 40 mph, with gusts 50 to locally 60 mph. Be prepared for significant reductions in visibility at times in snow, blowing snow and fog. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Weather Advisory for blowing snow means that visibilities will be limited due to strong winds blowing snow around. Use caution when traveling, especially in open areas. For road condition information in California...enter 8 0 0 4 2 7 7 6 2 3 if inside california or 9 1 6 4 5 5 7 6 2 3 if outside California. A Winter Storm Watch means there is potential for significant snow, sleet or ice accumulations that may impact travel. Continue to monitor the latest forecasts. $$
148 WWUS46 KSGX 261235 WSWSGX URGENT - WINTER WEATHER MESSAGE National Weather Service SAN DIEGO CA 435 AM PST Sun Dec 26 2021 CAZ055-056-262300- /O.CAN.KSGX.WS.W.0006.000000T0000Z-211226T1800Z/ /O.EXT.KSGX.WS.A.0006.211227T2000Z-211228T1100Z/ 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 435 AM PST Sun Dec 26 2021 ...WINTER STORM WATCH NOW IN EFFECT FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT... ...WINTER STORM WARNING IS CANCELLED... * WHAT...Heavy snow possible. Plan on difficult travel conditions, including during the evening commute on Monday. Tree branches could fall as well. Total snow accumulations of 4 to 8 inches above 4000 to 4500 feet, with localized amounts up to 16 inches above 6500 feet, are possible. * WHERE...San Bernardino County and Riverside County Mountains. * WHEN...From Monday afternoon through late Monday night. * ADDITIONAL DETAILS...Significant reductions in visibility are possible. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Storm Watch means there is potential for significant snow, sleet or ice accumulations that may impact travel. Continue to monitor the latest forecasts. $$ CAZ058-262300- /O.EXT.KSGX.WW.Y.0010.000000T0000Z-211226T1400Z/ /O.EXT.KSGX.WS.A.0006.211227T2000Z-211228T1100Z/ San Diego County Mountains- Including the cities of Julian and Pine Valley 435 AM PST Sun Dec 26 2021 ...WINTER WEATHER ADVISORY NOW IN EFFECT UNTIL 6 AM PST EARLY THIS MORNING ABOVE 5000 FEET... ...WINTER STORM WATCH NOW IN EFFECT FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT... * WHAT...Wet snow occurring above 5000 feet. Heavy wet snow possible on Monday and Monday night. Plan on slippery road conditions. Damage to trees and power lines is possible. Above 5000 feet, additional wet snow accumulations of up to one inch are expected early this morning. Total wet snow accumulations of up to 3 inches on Monday afternoon and night, with localized amounts up to 9 inches above 5000 feet, are possible. * WHERE...San Diego County Mountains. * WHEN...For the Winter Weather Advisory, until 6 AM today. For the Winter Storm Watch, from Monday afternoon through late Monday night. * ADDITIONAL DETAILS...Be prepared for reduced visibilities at times. Significant reductions in visibility are possible. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Weather Advisory for wet snow means periods of wet snow will cause primarily travel difficulties. Be prepared for snow covered roads and limited visibilities, and use caution while driving. For road condition information in California...enter 8 0 0 4 2 7 7 6 2 3 if inside california or 9 1 6 4 5 5 7 6 2 3 if outside California. A Winter Storm Watch means there is potential for significant snow, sleet or ice accumulations that may impact travel. Continue to monitor the latest forecasts. $$ 17
The office that day
Everything else NWS San Diego, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 25, 2:25 AM PST | Small Craft Advisory | SGX | 32 hr | |
| Dec 25, 1:40 PM PST | Winter Storm Watch | SGX | Riverside, San Bernardino, San Diego | 24 hr |
| Dec 25, 1:40 PM PST | Winter Weather Advisory | SGX | San Diego | 16 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.