Alert archive / California / Winter Storm Warnings in 2021

Winter Storm Warning 8, NWS San Diego, CA

December 28, 2021Riverside County, San Bernardino County, San Diego County, California

NWS San Diego, CA issued this winter storm warning at Dec 28, 2021, 1:26 PM PST for Riverside County, San Bernardino County, San Diego County, California. It took effect at Dec 29, 2021, 1:00 AM PST. It was in force for 43 hr. 25 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 28, 2021, 1:26 PM PST (21:26 UTC)
In effect from
Dec 29, 2021, 1:00 AM PST
Expired
Dec 30, 2021, 8:00 PM PST
In force
43 hr
Issued by
NWS San Diego, CA

Counties Riverside County, CA, San Bernardino County, CA, San Diego County, CA

The radar

The Santa Ana Mts radar (KSOX), 122 km from the middle of the area, began a volume at 21:28 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

TimeReportWhereRemark
Dec 29, 1:46 PM PSTHEAVY SNOW 41 Se Lake Arrowhead, CAHEAVY SNOW AND DOWNED TREES BLOCKING KUFFEL CANYON ROAD IN BOTH DIRECTIONS AT HIGHWAY 18.
Dec 29, 1:46 PM PSTHEAVY SNOW 61 Se Lake Arrowhead, CAHEAVY SNOW AND DOWNED TREES BLOCKING KUFFEL CANYON ROAD AT HWY 18 IN BOTH DIRECTIONS.
Dec 29, 6:11 PM PSTSNOW 42 Wnw Crestline, CAPOWERLINE DOWN ON ROADWAY. 21611 SAWPIT CANYON RD. AREA HAS WET SNOW ON TREES AND CURRENTLY AT SNOW LEVEL 5000 FEET WITH TEMPERATURES 33-35F. 0.5 TO 1 INCH OF PRECIPITATION PAST 6 HOURS.
Dec 29, 6:17 PM PSTSNOW 53 Wsw Lake Arrowhead, CATREE AND POWERLINES DOWN ON HIGHWAY 189 AND VEHICLES TRAPPED. NEAR STRAWBERRY PEAK. TEMPERATURES 30-32F AT 5500 FEET AND SNOW LEVEL AT 5000 FEET. AREA HAS RECEIVED 5 INCHES OF SNOW AND RIME ICING PAST 36 HOURS. PRECIPITATION ONGOING AT THE TIME OF INCIDENT. EL
Dec 29, 6:32 PM PSTSNOW 71 Se Lake Arrowhead, CAOAKMOUNT LANE HAS TREE DOWN WHICH TOOK OUT 2 POWERLINES AT OF 922 PM. TEMPERATURES 31 TO 32F AT 5500 FEET. AREA HAS RECEIVED 5-7 INCHES OF SNOW MONDAY NIGHT AND 24-30 HOURS OF RIME ICING. HUMIDITY 100 PERCENT AND WET SNOW FALLING WITH SNOW LEVEL NEAR 5000 FEET
Dec 29, 6:46 PM PSTSNOW 72 W Lake Arrowhead, CAPOWERLINE DOWN ON LAKE FOREST ROAD. TWIN PEAKS AND LAKE ARROWHEAD. TEMPERATURES 31 TO 32F AT 5500 FEET. AREA HAS RECEIVED 5-7 INCHES OF SNOW AND 24-30 HOURS OF RIME ICING. HUMIDITY 100 PERCENT AND WET SNOW FALLING WITH SNOW LEVEL NEAR 5000 FEET AT THE TIME.
Dec 29, 6:48 PM PSTSNOW 71 Se Lake Arrowhead, CAOAK ROAD HAS POWER LINE DOWN. NUMEROUS CALLS TO SCE FOR POWER OUTAGES AND LINES DOWN. TEMPERATURES 31 TO 32F AT 5500 FEET. AREA HAS RECEIVED 5-7 INCHES OF SNOW MONDAY NIGHT AND 24-30 HOURS OF RIME ICING. HUMIDITY 100 PERCENT AND WET SNOW FALLING WITH SNOW LEVE
Dec 29, 7:29 PM PSTSNOW 72 Wsw Lake Arrowhead, CABEAR SPRINGS ROAD AND LAKEVIEW LANE. POWERLINE DOWN ON LAKEVIEW ROAD. TEMPERATURES 31 TO 32F AT 5500 FEET. AREA HAS RECEIVED 5-7 INCHES OF SNOW AND ABOUT 24 HOURS OF RIME ICING. HUMIDITY 100 PERCENT AND LIGHT WET SNOW FALLING WITH SNOW LEVEL NEAR 5000 FEET AT
Dec 29, 7:43 PM PSTSNOW 7Lake Arrowhead, CALIVE WIRE DOWNED ON WEST VICTORIA COURT ON VEHICLE AS OF 956 PM. INCIDENTS BEGAN 2 PM IN THIS AREA. TEMPERATURES 31 TO 32F AT 5500 FEET. AREA HAS RECEIVED 5-7 INCHES OF SNOW AND 24-30 HOURS OF RIME ICING. HUMIDITY 100 PERCENT AND WET SNOW FALLING WITH SNOW LEV
Dec 29, 7:49 PM PSTSNOW 51 Ssw Lake Arrowhead, CAMEADOW BROOK DRIVE AND MECHAM DRIVE. LANES BLOCKED BY TREE AND SNOW. CREST PARK IS 32F CURRENTLY. TEMPERATURES 31 TO 32F AT 5500 FEET. AREA HAS RECEIVED 5-7 INCHES OF SNOW MONDAY NIGHT AND 24-30 HOURS OF RIME ICING. HUMIDITY 100 PERCENT AND WET SNOW FALLING WI
Dec 29, 8:02 PM PSTSNOW 72 Wsw Lake Arrowhead, CAHIGHWAY 189 LIVE WIRE DOWN ON ROADWAY TO BLUE JAY. CHP HAS CLOSED HIGHWAY 189. NUMEROUS WIRES AND TREES DOWN IN AREA TO LAKE ARROWHEAD. TEMPERATURES 31 TO 32F AT 5500 FEET. AREA HAS RECEIVED 5-7 INCHES OF SNOW AND 24-30 HOURS OF RIME ICING. HUMIDITY 100 PERCEN
Dec 29, 8:04 PM PSTSNOW 9Running Springs, CAOCEAN VIEW DRIVE AND CITY CREEK ROAD. TREE DOWNED AND COVERED IN SNOW BLOCKING LANE. TEMPERATURES 30 TO 31F AT 5800 TO 6200 FEET. AREA HAS RECEIVED 7-9 INCHES OF SNOW MONDAY NIGHT AND 24-30 HOURS OF RIME ICING. HUMIDITY 100 PERCENT AND WET SNOW FALLING WITH SN
Dec 29, 8:52 PM PSTSNOW 53 W Lake Arrowhead, CALA CASITA DR A TREE REPORTED DOWN BLOCKING ROAD. AREA HAS HAD 0.5 TO 0.75 PRECIPITATION WATER EQUIVALENT (SNOW) PAST 6 HOURS AND IS 32F WITH SNOW LEVEL AT 5000 FEET. RECENT SNOWFALL OF 5 TO 8 INCHES AND RIME ICING CAUSING HEAVY LOADING ON TREES PAST 36 HOURS.
Dec 29, 9:37 PM PSTSNOW 9Running Springs, CAVALLEY RIDGE DRIVE AND WILDERNESS ROAD. POWERLINE DOWN ON ROAD. TEMPERATURES 30 TO 31F AT 5800-6500 FEET. AREA HAS RECEIVED 9 INCHES OF SNOW MONDAY NIGHT AND 24-30 HOURS OF RIME ICING. HUMIDITY 100 PERCENT AND WET SNOW FALLING WITH SNOW LEVEL NEAR 5000 FEET AT
Dec 29, 9:52 PM PSTSNOW 72 Wsw Lake Arrowhead, CAPOWERLINE DOWN ON SUGAR CONE LANE. TEMPERATURES 31 TO 32F AT 5500 FEET. AREA HAS RECEIVED 5-7 INCHES OF SNOW AND 24-30 HOURS OF RIME ICING. HUMIDITY 100 PERCENT AND WET SNOW FALLING WITH SNOW LEVEL NEAR 5000 FEET AT THE TIME. 0.5 TO 0.75 NEW PRECIPITATION PAST
Dec 30, 7:35 AM PSTSNOW 11.51 W Wrightwood, CASPOTTER REPORT AT 6275 FEET. STILL SNOWING.
Dec 30, 8:00 AM PSTSNOW 144 Ne Mt Baldy, CAEND OF BALDY ROAD REPORTED 14 INCHES NEW SNOW. 2.3 INCHES SNOW WATER EQUIVALENT. ELEVATION OF REPORT IS 6400 FEET MSL. STILL SNOWING.
Dec 30, 8:09 AM PSTSNOW 71 Wnw Running Springs, CATREE BLOCKING OAK GLEN DRIVE AND WILD OAK DRIVE SO CAN NOT PLOW ROAD. TREE FELL ON WIRES AND WIRES HANGING LOW. 6 TO 7 INCHES OF SNOW OVERNIGHT AND 1 INCH SNOW WATER EQUIVALENT. HEAVY SNOW LOADING DUE TO 36 HOURS OF RIME ICING AND PRIOR 7 INCHES OF SNOWFALL FR
Dec 30, 8:28 AM PSTSNOW 51 Nw Lake Arrowhead, CAPIONEER ROAD, POWERLINE DOWN. 5 INCHES OF SNOW OVERNIGHT AND 1 INCH SNOW WATER EQUIVALENT. HEAVY SNOW LOADING DUE TO 36 HOURS OF RIME ICING AND PRIOR 5 INCHES OF SNOWFALL FROM MONDAY NIGHT. MANY TREES DOWNED OR HANGING LOW. TEMPERATURES ARE 33F AT 5700 FEET.
Dec 30, 8:49 AM PSTSNOW 6Running Springs, CARIM OF THE WORLD DRIVE AT HIGHWAY 330 POWER POLE DOWN ALONG WITH LINES. 6 INCHES NEW SNOW OVERNIGHT AND 1 INCH WATER (HEAVY SNOW) ADDED TO 36 HOURS OF RIME ICING AND SIMILAR SNOWFALL FROM MONDAY NIGHT. TREES FALLING ON ROADS AND POWERLINES IN RUNNING SPRINGS.
Dec 30, 9:24 AM PSTSNOW 52 W Lake Arrowhead, CAWALNUT HILLS DRIVE AND SPYGLASS DRIVE. POWERLINES DOWN ON ROAD AND VEHICLES DRIVING ON THEM. TREE FELL ON WIRES. 6 INCHES OF SNOW OVERNIGHT AND 1 INCH SNOW WATER EQUIVALENT. HEAVY SNOW LOADING DUE TO 36 HOURS OF RIME ICING AND PRIOR 5 INCHES OF SNOWFALL FROM M
Dec 30, 9:27 AM PSTSNOW 61 Nw Running Springs, CANOB HILL DRIVE. TREE FELL ON WIRES AND WIRES HANGING LOW. 6 INCHES OF SNOW OVERNIGHT AND 1 INCH SNOW WATER EQUIVALENT. HEAVY SNOW LOADING DUE TO 36 HOURS OF RIME ICING AND PRIOR 7 INCHES OF SNOWFALL FROM MONDAY NIGHT. MANY TREES DOWNED OR HANGING LOW. TEMPERAT
Dec 30, 9:44 AM PSTSNOW 52 Wsw Lake Arrowhead, CAUPDATE FROM PRIOR LSR. BLUE JAY AREA REMAINS CUT OFF AT HIGHWAY 189 FROM ACCESS DUE TO TREES AND POWERLINES DOWN. SCE SOCAL EDISON IN AREA BUT NO ETA TO RESTORE POWERLINES. THIS AFFECTS NOAA WEATHER RADIO TRANSMITTER LIKELY. MUTUAL AID BEING REQUESTED IN THIS
Dec 30, 10:47 AM PSTSNOW 10Wrightwood, CA10 INCHES NEW SNOW OVERNIGHT. ELEVATION 5900 FEET. STILL SNOWING. 8 WEATHER STATIONS REPORT CURRENT TEMPERATURE 32-33F.
Dec 30, 12:07 PM PSTSNOW 151 Nne Mt Baldy, CAMT BALDY ROAD CLOSED AT ICE HOUSE CANYON. 34F AT 5000 FEET. PRECIPITATION CONTINUES IN THIS AREA WITH SNOW LEVEL 5000-5500 FEET.

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, 9.4 hours before the alert went out and 145 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-pSkew-T log-p diagram, San Diego, CA at 12:00Z on 2021-12-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 28 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, San Diego, CA at 12:00Z on 2021-12-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
28 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
646 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
14 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

274 
WWUS46 KSGX 282126
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
126 PM PST Tue Dec 28 2021

CAZ055-056-058-290615-
/O.UPG.KSGX.WS.A.0007.211229T0900Z-211231T1200Z/
/O.NEW.KSGX.WS.W.0008.211229T0900Z-211231T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
San Diego County Mountains-
Including the cities of Lake Arrowhead, Big Bear City, 
Big Bear Lake, Running Springs, Wrightwood, 
and Idyllwild-Pine Cove
126 PM PST Tue Dec 28 2021

...WINTER STORM WARNING IN EFFECT FROM 1 AM WEDNESDAY TO 4 AM PST
FRIDAY...

* WHAT...Heavy snow expected. Travel will be very difficult to
  impossible. Total snow accumulations of 6 to 12 inches, with
  localized amounts up to 56 inches above 8000 feet possible.
  Areas of southwest winds 25 to 35 mph with local gusts to 55 mph
  in the San Bernardino Mountains.

* WHERE...Above 5,000 feet in the San Bernardino County 
  Mountains, Riverside County Mountains and San Diego County 
  Mountains.

* WHEN...1 AM Wednesday to 4 AM Friday.

* 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
7 follow-up statements
502 
WWUS46 KSGX 290529
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
929 PM PST Tue Dec 28 2021


CAZ055-056-058-291400-
/O.CON.KSGX.WS.W.0008.211229T0900Z-211231T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
San Diego County Mountains-
Including the cities of Lake Arrowhead, Big Bear City, 
Big Bear Lake, Running Springs, Wrightwood, 
and Idyllwild-Pine Cove
929 PM PST Tue Dec 28 2021

...WINTER STORM WARNING REMAINS IN EFFECT FROM 1 AM WEDNESDAY TO
4 AM PST FRIDAY...

* WHAT...Heavy snow expected. Travel will be very difficult to
  impossible. Total snow accumulations of 6 to 12 inches between
  5000-6000 ft and 12-24 inches between 6000-7000 ft. Localized
  amounts of 3-4 ft or more above 8000 feet possible in the San
  Bernardino Mountains. For the San Diego County Mountains, snow
  accumulations of 1-2 inches. Southwest winds 20-30 mph with 
  gusts 35-50 mph.

* WHERE...Above 5,000 feet in the San Bernardino County 
  Mountains, Riverside County Mountains and San Diego County 
  Mountains.

* WHEN...1 AM Wednesday to 4 AM Friday.

* 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.

$$

SS
097 
WWUS46 KSGX 291147
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
347 AM PST Wed Dec 29 2021

CAZ058-300000-
/O.CAN.KSGX.WS.W.0008.000000T0000Z-211231T1200Z/
/O.NEW.KSGX.WW.Y.0011.211229T1147Z-211230T0000Z/
San Diego County Mountains-
347 AM PST Wed Dec 29 2021

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 4 PM PST THIS
AFTERNOON ABOVE 5000 FEET...
...WINTER STORM WARNING IS CANCELLED...

* WHAT...Wet snow occurring. Plan on slippery road conditions. 
  Tree branches could fall as well. Wet snow accumulations of 2 to
  4 inches are expected.

* WHERE...San Diego County Mountains above 5000 feet.

* WHEN...Until 4 PM today.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at
  times. Snow levels will rise for this afternoon and tonight with
  most of the precipitation in the form of rain after this
  afternoon.

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.

$$

CAZ055-056-300015-
/O.CON.KSGX.WS.W.0008.000000T0000Z-211231T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
347 AM PST Wed Dec 29 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 4 AM PST FRIDAY
ABOVE 6000 FEET...

* WHAT...Heavy snow occurring. Travel will be very difficult to
  impossible. Tree branches could fall as well. Snow accumulations 
  of 12 to 24 inches above 6000 to 6500 feet and 2 to 4 feet above
  7500 feet, are expected.

* WHERE...San Bernardino County Mountains and Riverside County
  Mountains above 5000 feet today, above 5500 feet this evening, 
  and above 6000 feet after this evening.

* WHEN...Until 4 AM Friday.

* ADDITIONAL DETAILS...Be prepared for significant reductions in
  visibility at times. Snow level around 4000 feet rising to 5000
  feet in the evening and 5500 to 6000 feet late tonight. The 
  most widespread and heaviest snowfall is expected for tonight 
  into early Thursday.

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.

$$

17
424 
WWUS46 KSGX 292123
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
123 PM PST Wed Dec 29 2021

CAZ055-056-300630-
/O.CON.KSGX.WS.W.0008.000000T0000Z-211231T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
123 PM PST Wed Dec 29 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 4 AM PST FRIDAY 
ABOVE 6000 FEET...

* WHAT...Heavy snow occurring. Travel will be very difficult to
  impossible. Tree branches could fall as well. Snow accumulations 
  of 12 to 24 inches above 6000 to 6500 feet and 2 to 4 feet above
  7500 feet, are expected.

* WHERE...San Bernardino County Mountains and Riverside County
  Mountains above 5000 feet today, above 5500 feet overnight, and
  above 6000 feet Thursday morning

* WHEN...Until 4 AM Friday.

* ADDITIONAL DETAILS...Be prepared for significant reductions in
  visibility at times. Snow level around 4500 to 5000 feet, rising
  to 5500 tonight, and 6000 feet Thursday morning. The most
  widespread and heaviest snowfall is expected for tonight into 
  Thursday.

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.

$$

CAZ058-300630-
/O.EXT.KSGX.WW.Y.0011.000000T0000Z-211230T1700Z/
San Diego County Mountains-
123 PM PST Wed Dec 29 2021

...WINTER WEATHER ADVISORY NOW IN EFFECT UNTIL 9 AM PST THURSDAY
ABOVE 5000 FEET...

* WHAT...Snow occurring. Plan on slippery road conditions,
  including during the evening commute tonight and morning commute
  Thursday. Additional snow accumulations of two to four inches 
  are expected.

* WHERE...San Diego County Mountains above 5000 feet.

* WHEN...Until 9 AM Thursday.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of 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.

$$

CO
606 
WWUS46 KSGX 300603
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
1003 PM PST Wed Dec 29 2021

CAZ055-056-301400-
/O.CON.KSGX.WS.W.0008.000000T0000Z-211231T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
1003 PM PST Wed Dec 29 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 4 AM FRIDAY ABOVE
6000 FEET...

* WHAT...Heavy snow occurring. Travel will be very difficult to
  impossible. Snow accumulations of 12 to 24 inches above 6000 to
  6500 feet and 2 to 4 feet above 7500 feet.

* WHERE...San Bernardino County Mountains and Riverside County 
  Mountains above 5000 feet today, above 5500 feet overnight, 
  and above 6000 feet Thursday morning

* WHEN...Until 4 AM Friday.

* 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.

$$

CAZ058-301400-
/O.CON.KSGX.WW.Y.0011.000000T0000Z-211230T1700Z/
San Diego County Mountains-
1003 PM PST Wed Dec 29 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM THURSDAY 
ABOVE 5000 FEET...

* WHAT...Snow occurring. Plan on slippery road conditions, 
  including during the evening commute tonight and morning 
  commute Thursday. Additional snow accumulations of two to four 
  inches are expected.

* WHERE...San Diego County Mountains above 5000 feet.

* WHEN...Until 9 AM Thursday.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

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.

$$

Moede
763 
WWUS46 KSGX 301050
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
250 AM PST Thu Dec 30 2021

CAZ056-302300-
/O.CAN.KSGX.WS.W.0008.000000T0000Z-211231T1200Z/
/O.NEW.KSGX.WW.Y.0012.211230T1050Z-211231T0400Z/
Riverside County Mountains-
250 AM PST Thu Dec 30 2021

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 8 PM PST THIS EVENING
ABOVE 6000 FEET...
...WINTER STORM WARNING IS CANCELLED...

* WHAT...Snow occurring. Plan on slippery road conditions. 
  Additional snow accumulations of 1 to 3 inches are expected.

* WHERE...Riverside County Mountains above 6000 feet with the
  greater totals above 7500 feet.

* WHEN...Until 8 PM today.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of 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.

$$

CAZ058-301200-
/O.CAN.KSGX.WW.Y.0011.000000T0000Z-211230T1700Z/
San Diego County Mountains-
250 AM PST Thu Dec 30 2021

...WINTER WEATHER ADVISORY IS CANCELLED...

Most precipitation will remain to the west early this morning.
Once precipitation does return, snow levels will have risen to
5000 to 5500 feet with any snow limited to the highest peaks.

$$

CAZ055-302300-
/O.EXT.KSGX.WS.W.0008.000000T0000Z-211231T0400Z/
San Bernardino County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
250 AM PST Thu Dec 30 2021

...WINTER STORM WARNING NOW IN EFFECT UNTIL 8 PM PST THIS EVENING
ABOVE 5500 FEET...

* WHAT...Heavy snow occurring. Plan on difficult travel 
  conditions, including during the morning commute. Additional 
  snow accumulations of 4 to 8 inches, with localized amounts up 
  to 20 inches, are expected.

* WHERE...San Bernardino County Mountains above 5500 feet. Snow
  levels will rise from 4500 to 5000 feet early this morning to
  5500 feet in the afternoon. The heaviest snowfall is expected
  west of the Cajon Pass and above 5500 feet with amounts
  decreasing toward the east.

* WHEN...Until 8 PM today.

* 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.

$$

17
760 
WWUS46 KSGX 301932
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
1132 AM PST Thu Dec 30 2021

|.

CAZ056-302045-
/O.CAN.KSGX.WW.Y.0012.000000T0000Z-211231T0400Z/
Riverside County Mountains-
1132 AM PST Thu Dec 30 2021

...WINTER WEATHER ADVISORY IS CANCELLED...

Only periods of light snow showers are expected through tonight.

$$

CAZ055-310400-
/O.CON.KSGX.WS.W.0008.000000T0000Z-211231T0400Z/
San Bernardino County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
1132 AM PST Thu Dec 30 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 8 PM PST THIS
EVENING ABOVE 5500 FEET...

* WHAT...Heavy snow occurring. Plan on difficult travel
  conditions, including during the evening commute. Additional
  snow accumulations of 2 to 4 inches are expected.

* WHERE...San Bernardino County Mountains above 5500 feet. The 
  heaviest snowfall is expected west of the Cajon Pass and above 
  5500 feet with amounts decreasing toward the east.

* WHEN...Until 8 PM today.

* 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.

$$
271 
WWUS46 KSGX 310350
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
750 PM PST Thu Dec 30 2021

CAZ055-310500-
/O.EXP.KSGX.WS.W.0008.000000T0000Z-211231T0400Z/
San Bernardino County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
750 PM PST Thu Dec 30 2021

...WINTER STORM WARNING WILL EXPIRE AT 8 PM THIS EVENING ABOVE 
5500 FEET...

The heavy snow has ended. The warning will expire at 8 PM. 

$$

Moede

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 27, 7:39 PM PSTWind AdvisorySGXRiverside, San Bernardino, San Diego7 hr
Dec 27, 8:03 PM PSTSmall Craft AdvisorySGX13 hr
Dec 28, 3:00 AM PSTWinter Storm WatchSGXRiverside, San Bernardino, San Diego10 hr
Dec 28, 11:07 AM PSTFlood WatchSGXOrange, Riverside, San Bernardino, San Diego48 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.