Alert archive / California / Winter Storm Warnings in 2020

Winter Storm Warning 3, NWS San Diego, CA

April 5, 2020Riverside County, San Bernardino County, California

NWS San Diego, CA issued this winter storm warning at Apr 5, 2020, 3:28 AM PDT for Riverside County, San Bernardino County, California. It took effect at Apr 5, 2020, 11:00 PM PDT. It was in force for 5 days. 16 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
Apr 5, 2020, 3:28 AM PDT (10:28 UTC)
In effect from
Apr 5, 2020, 11:00 PM PDT
Expired
Apr 10, 2020, 8:00 PM PDT
In force
5 days
Issued by
NWS San Diego, CA

Counties Riverside County, CA, San Bernardino County, CA

The radar

The Santa Ana Mts radar (KSOX), 152 km from the middle of the area, began a volume at 10:33 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
Apr 7, 7:00 AM PDTHEAVY SNOW 143 Ne Running Springs, CASAN BERNARDINO COUNTY PUBLIC WORKS - 4.15 INCHES WATER AT LAKE ARROWHEAD.
Apr 7, 7:17 AM PDTSNOW 42 Sw Big Bear City, CACURRENTLY SNOW FLURRIES. SNOWFALL STORM TOTAL. YESTERDAY 4/6/20 RECEIVED 0.12 INCHES OF RAIN PRIOR TO CHANGEOVER TO SNOW.
Apr 7, 10:04 AM PDTHEAVY SNOW 9Running Springs, CAAT 6200 FEET BY SAN BERNARDINO PUBLIC WORKS.
Apr 8, 7:00 AM PDTSNOW 62 Sw Big Bear City, CA6 INCHES OF SNOW IN 4 HOURS IN BIG BEAR.
Apr 8, 8:29 AM PDTSNOW 112 E Big Bear City, CA11 INCHES SO FAR AT SHAY MEADOW. SNOW TOTALS THROUGH BIG BEAR VALLEY RANGE FROM 8-12 INCHES, AND UP TO 18 INCHES AT RESORT LEVELS.
Apr 8, 9:15 AM PDTSNOW 123 E Big Bear Lake, CA11 INCHES OF SNOW SINCE TUESDAY NIGHT, BRINGING TOTAL TO 12 INCHES.
Apr 8, 4:21 PM PDTSNOW 32 W Lake Arrowhead, CAHARD TO ESTIMATE THE SNOWFALL, ITS SWITCHED BETWEEN RAIN AND SNOW ALL DAY. ALSO 2 VISIBLE LIGHTNING STRIKES WITHIN THE LAST 10 MINUTES.
Apr 8, 5:00 PM PDTHEAVY SNOW 14.53 E Big Bear Lake, CA2.5 INCHES OF NEW SNOW FROM 3:00 PM PDT TO 5:00 PM PDT BRINGING THE TOTAL TO 14.5 INCHES.
Apr 9, 1:46 PM PDTHEAVY SNOW 17Running Springs, CATOTAL SINCE MONDAY. STILL SNOWING. ABOUT 6200 FEET.
Apr 9, 4:12 PM PDTSNOW 41 Ne Mt Baldy, CASTEADY SNOW ALL DAY. SAN ANTONIO CANYON. NOT A STORM TOTAL AS THERE HAS BEEN MELTING EARLY IN THE WEEK.
Apr 9, 5:30 PM PDTHEAVY SNOW 8Wrightwood, CASTORM TOTAL SO FAR.
Apr 9, 6:00 PM PDTHEAVY SNOW 273 Ne Running Springs, CAREPORTED AT GREEN VALLEY LAKE STORM TOTAL SO FAR.
Apr 9, 7:00 PM PDTHEAVY SNOW 5Idyllwild, CAELEVATION 5600 FEET.
Apr 9, 7:00 PM PDTHEAVY SNOW 121 Nw Idyllwild, CAREPORTED AT PINE COVE, CA STORM TOTAL SO FAR NEAR MARION MOUNTAIN CAMPGROUND.
Apr 10, 12:10 AM PDTHEAVY SNOW 121 Ssw Lake Arrowhead, CACORRECTS PREVIOUS HEAVY SNOW REPORT FROM 1 SSW LAKE ARROWHEAD FOR SPELLING. TREE FELL, KNOCKING DOWN POWER LINES. LIKELY DUE TO WEIGHT OF SNOW (LIGHT WIND AT THE TIME).
Apr 10, 12:10 AM PDTHEAVY SNOW 121 Ssw Lake Arrowhead, CATREE FEEL, KNOCKING DOWN POWER LINES. LIKELY DUE TO WEIGHT OF SNOW (LIGHT WIND AT THE TIME).

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, 10.5 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.

Skew-T log-pSkew-T log-p diagram, San Diego, CA at 00:00Z on 2020-04-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, San Diego, CA at 00:00Z on 2020-04-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -10 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
726 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-10 m²/s²
0-3 km storm-relative helicity
22 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

987 
WWUS46 KSGX 051028
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
328 AM PDT Sun Apr 5 2020

CAZ055-056-052100-
/O.UPG.KSGX.WS.A.0003.200406T0600Z-200409T1200Z/
/O.NEW.KSGX.WS.W.0003.200406T0600Z-200409T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
328 AM PDT Sun Apr 5 2020

...WINTER STORM WARNING IN EFFECT FROM 11 PM THIS EVENING TO 5 AM
PDT THURSDAY ABOVE 5500 FEET...

* WHAT...Heavy snow expected. Travel will be very difficult to
  impossible, including during the morning commute on Monday. Tree
  branches could fall as well. Total snow accumulations will be 4
  to 12 inches between 5000 to 6000 feet, 1 to 2 feet between 6000
  to 7000 feet, and 2 to 4 feet above 7000 feet. 

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet.

* WHEN...11 PM this evening to 5 AM Thursday morning.

* 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.

$$

jmb
18 follow-up statements
898 
WWUS46 KSGX 052023
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
123 PM PDT Sun Apr 5 2020

CAZ055-056-060500-
/O.CON.KSGX.WS.W.0003.200406T0600Z-200409T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
123 PM PDT Sun Apr 5 2020

...WINTER STORM WARNING REMAINS IN EFFECT FROM 11 PM THIS EVENING
TO 5 AM PDT THURSDAY ABOVE 5500 FEET...

* WHAT...Heavy snow expected. Travel will be very difficult to
  impossible, including during the evening commute on Monday. Tree
  branches could fall as well. This could be a record April snow
  event in the San Bernardino mountains with total snow
  accumulations of 18 to 24 inches, and localized amounts to 48
  inches expected.

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet.

* WHEN...11 PM today to 5 AM Thursday.

* ADDITIONAL DETAILS...Be prepared for significant reductions in
  visibility at times in fig and blowing snow. 

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.

$$

10
822 
WWUS46 KSGX 060450
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
950 PM PDT Sun Apr 5 2020

CAZ055-056-061300-
/O.CON.KSGX.WS.W.0003.200406T0600Z-200409T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
950 PM PDT Sun Apr 5 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM PDT THURSDAY
ABOVE 5500 FEET...

* WHAT...Heavy snow expected. Travel will be very difficult to 
  impossible, including during the evening commute on Monday. 
  Tree branches could fall as well. This could be a record April 
  snow event in the San Bernardino mountains with total snow 
  accumulations of 18 to 24 inches, and localized amounts to 48 
  inches expected.

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet.

* WHEN...11 PM tonight to 5 AM Thursday.

* ADDITIONAL DETAILS...Be prepared for significant reductions in 
  visibility at times in fig and blowing snow.

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
396 
WWUS46 KSGX 061037
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
337 AM PDT Mon Apr 6 2020

CAZ055-056-062315-
/O.CON.KSGX.WS.W.0003.000000T0000Z-200409T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
337 AM PDT Mon Apr 6 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM PDT THURSDAY
ABOVE 5500 FEET...

* WHAT...Heavy snow occurring. Travel will be very difficult to
  impossible, including during the evening commute. Tree branches
  could fall as well. Total snow accumulations will range from 6
  to 10 inches between 5,000 and 6,000 feet, 10 to 20 inches
  between 6,000 and 7,000 feet, and from 20 to 36 inches above
  7,000 feet with local amounts up to 48 inches on the highest
  peaks. Areas of south to southwest winds today of 20 to 30 mph
  with gusts to 45 mph. Winds gradually subsiding tonight and
  Tuesday.

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet.

* WHEN...Until 5 AM Thursday.

* ADDITIONAL DETAILS...Be prepared for significant reductions in
  visibility at times in heavy 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.

$$
887 
WWUS46 KSGX 062045
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
145 PM PDT Mon Apr 6 2020

CAZ055-056-070500-
/O.CON.KSGX.WS.W.0003.000000T0000Z-200409T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
145 PM PDT Mon Apr 6 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM PDT THURSDAY
ABOVE 5500 FEET...

* WHAT...Heavy snow occurring. Travel will be very difficult to
  impossible, including during the evening commute. Tree branches
  could fall as well. Additional snow accumulations of 15 to 21
  inches, with localized amounts up to 48 inches, are possible.

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet.

* WHEN...Until 5 AM Thursday.

* 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.

$$

10
598 
WWUS46 KSGX 070315
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
815 PM PDT Mon Apr 6 2020

CAZ055-056-071300-
/O.CON.KSGX.WS.W.0003.000000T0000Z-200409T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
815 PM PDT Mon Apr 6 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM PDT THURSDAY
ABOVE 5500 FEET...

* WHAT...Heavy snow occurring. Travel will be very difficult to
  impossible at times. Additional snow accumulations of 10 to 20
  inches, with local amounts of 30 inches, are possible.

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet.

* WHEN...Until 5 AM Thursday.

* ADDITIONAL DETAILS...Snow amounts through 8 PM Monday included 9
  inches in Wrightwood at Acorn Canyon, 8 inches at Green Valley
  Lake, and 3 inches at Arrowbear.  

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.

$$

Moede
462 
WWUS46 KSGX 070914
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
214 AM PDT Tue Apr 7 2020

CAZ055-056-072200-
/O.CON.KSGX.WS.W.0003.000000T0000Z-200409T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
214 AM PDT Tue Apr 7 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM PDT THURSDAY
ABOVE 5500 FEET...

* WHAT...Heavy snow occurring. Travel will be very difficult to 
  impossible, including during the evening commute on Wednesday. 
  Additional snow accumulations of 10 to 16 inches, with 
  localized amounts up to 32 inches, are expected.

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet.

* WHEN...Until 5 AM Thursday.

* 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
012 
WWUS46 KSGX 072037
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
137 PM PDT Tue Apr 7 2020

CAZ055-056-080445-
/O.EXT.KSGX.WS.W.0003.000000T0000Z-200410T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
137 PM PDT Tue Apr 7 2020

...WINTER STORM WARNING NOW IN EFFECT UNTIL 5 AM PDT FRIDAY ABOVE
5500 FEET...

* WHAT...Heavy snow occurring. Travel will be very difficult to
  impossible. Additional snow accumulations of 11 to 17 inches,
  with localized amounts up to 36 inches on the highest peaks, 
  are expected.

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet.

* WHEN...Until 5 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.

$$

SS
361 
WWUS46 KSGX 080412
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
912 PM PDT Tue Apr 7 2020

CAZ055-056-081300-
/O.CON.KSGX.WS.W.0003.000000T0000Z-200410T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
912 PM PDT Tue Apr 7 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM PDT FRIDAY
ABOVE 5500 FEET...

* WHAT...Heavy snow occurring. Travel will be very difficult.
  Additional snow accumulations will range from 10 to 20 inches,
  with even greater amounts of 30 inches on the highest peaks.

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet.

* WHEN...Until 5 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.

$$

Moede
376 
WWUS46 KSGX 080919
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
219 AM PDT Wed Apr 8 2020

CAZ055-056-082230-
/O.CON.KSGX.WS.W.0003.000000T0000Z-200410T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
219 AM PDT Wed Apr 8 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM PDT FRIDAY
ABOVE 5500 FEET...

* WHAT...Heavy snow occurring. Travel will be very difficult to
  impossible, including during the evening commute on Thursday.
  Additional snow accumulations of 10 to 16 inches, with localized
  amounts up to 24 inches on the highest, are expected.

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet.

* WHEN...Until 5 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.

$$

CAZ058-082230-
/O.NEW.KSGX.WW.Y.0010.200408T0919Z-200409T1900Z/
San Diego County Mountains-
219 AM PDT Wed Apr 8 2020

...WINTER WEATHER ADVISORY IN EFFECT UNTIL NOON PDT THURSDAY
ABOVE 5000 FEET...

* WHAT...Snow expected. Plan on difficult travel conditions, 
  including during the morning commute. Total snow accumulations 
  of 3 to 5 inches, with localized amounts up to 8 inches, are 
  expected.

* WHERE...San Diego County mountains above 5000 feet. Lighter
  accumulations down to around 4500 feet.

* WHEN...2 AM today to noon 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.

$$

17
196 
WWUS46 KSGX 082017
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
117 PM PDT Wed Apr 8 2020

CAZ055-056-090500-
/O.CON.KSGX.WS.W.0003.000000T0000Z-200410T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
117 PM PDT Wed Apr 8 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM PDT FRIDAY
ABOVE 5500 FEET...

* WHAT...Heavy snow occurring. Travel will be very difficult to
  impossible. Additional snow accumulations of 6 to 12 inches,
  with isolated amounts up to 24 inches, are expected.

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet.

* WHEN...Until 5 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.

$$

CAZ058-090500-
/O.CON.KSGX.WW.Y.0010.000000T0000Z-200409T1900Z/
San Diego County Mountains-
117 PM PDT Wed Apr 8 2020

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL NOON PDT
THURSDAY ABOVE 5000 FEET...

* WHAT...Snow occurring. Plan on difficult travel conditions. 
  Additional snow accumulations of 2 to 4 inches, with localized 
  amounts up to 6 inches, are expected.

* WHERE...San Diego County mountains above 5000 feet. Lighter 
  accumulations down to around 4500 feet.

* WHEN...Until noon 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.

$$

SS
022 
WWUS46 KSGX 090701
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
1201 AM PDT Thu Apr 9 2020


CAZ055-056-091515-
/O.CON.KSGX.WS.W.0003.000000T0000Z-200410T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
1201 AM PDT Thu Apr 9 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM PDT FRIDAY
ABOVE 5500 FEET...

* WHAT...Heavy snow occurring. Travel will be very difficult to
  impossible, including during the evening commute. Additional
  snow accumulations of 6 to 12 inches, with localized amounts up
  to 20 inches on the highest peaks, are expected.

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet.

* WHEN...Until 5 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.

$$

CAZ058-091515-
/O.CON.KSGX.WW.Y.0010.000000T0000Z-200409T1900Z/
San Diego County Mountains-
1201 AM PDT Thu Apr 9 2020

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL NOON PDT
THURSDAY ABOVE 5000 FEET...

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

* WHERE...San Diego County mountains above 5000 feet. Lighter 
  accumulations down to around 4500 feet.

* WHEN...Until noon 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.

$$

17
060 
WWUS46 KSGX 090931
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
231 AM PDT Thu Apr 9 2020

CAZ055-056-091915-
/O.CON.KSGX.WS.W.0003.000000T0000Z-200410T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
231 AM PDT Thu Apr 9 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM PDT FRIDAY
ABOVE 5500 FEET...

* WHAT...Heavy snow occurring. Travel will be very difficult to 
  impossible, including during the evening commute. Additional 
  snow accumulations of 6 to 12 inches, with localized amounts 
  up to 20 inches on the highest peaks, are expected.

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet.

* WHEN...Until 5 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.

$$

CAZ058-091900-
/O.CON.KSGX.WW.Y.0010.000000T0000Z-200409T1900Z/
San Diego County Mountains-
231 AM PDT Thu Apr 9 2020

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL NOON PDT TODAY
ABOVE 5000 FEET...

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

* WHERE...San Diego County mountains above 5000 feet. Lighter 
  accumulations down to around 4500 feet.

* WHEN...Until noon 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.

$$

17
071 
WWUS46 KSGX 091539
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service San Diego CA
Issued by National Weather Service San Francisco CA
839 AM PDT Thu Apr 9 2020

CAZ058-091645-
/O.CAN.KSGX.WW.Y.0010.000000T0000Z-200409T1900Z/
San Diego County Mountains-
839 AM PDT Thu Apr 9 2020

...WINTER WEATHER ADVISORY IS CANCELLED...

The National Weather Service in San Diego has cancelled the
Winter Weather Advisory for the San Diego County Mountains.

$$

CAZ055-056-100000-
/O.CON.KSGX.WS.W.0003.000000T0000Z-200410T1200Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
839 AM PDT Thu Apr 9 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM PDT FRIDAY...

* WHAT...Heavy snow occurring. Travel will be very difficult to 
  impossible, including during the evening commute. Additional 
  snow accumulations of 6 to 12 inches, with localized amounts 
  up to 20 inches on the highest peaks, are expected. 

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet. 

* WHEN...Until 5 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.

$$
471 
WWUS46 KSGX 091954
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
Issued by National Weather Service San Francisco CA
1254 PM PDT Thu Apr 9 2020

CAZ055-056-100500-
/O.EXT.KSGX.WS.W.0003.000000T0000Z-200411T0300Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
1254 PM PDT Thu Apr 9 2020

...WINTER STORM WARNING NOW IN EFFECT UNTIL 8 PM PDT FRIDAY ABOVE
5500 FEET...

* WHAT...Heavy snow occurring. Travel will be very difficult to
  impossible. Additional snow accumulations of 6 to 12 inches, 
  with localized amounts up to 18 inches, are expected.

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet.

* WHEN...Until 8 PM 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.

$$
183 
WWUS46 KSGX 100450
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
950 PM PDT Thu Apr 9 2020

CAZ055-056-101300-
/O.CON.KSGX.WS.W.0003.000000T0000Z-200411T0300Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
950 PM PDT Thu Apr 9 2020

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 8 PM PDT FRIDAY
ABOVE 5500 FEET...

* WHAT...Heavy snow occurring. Plan on difficult if not impossible
  travel conditions. Additional snow accumulations of 6 to 12 
  inches, with localized amounts up to 16 inches, are expected.

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet.

* WHEN...Until 8 PM Friday.

* ADDITIONAL DETAILS...Be prepared for significant reductions in
  visibility at times. Snow levels will fluctuate between 5000 to
  6000 feet. 

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.

$$

jmb
323 
WWUS46 KSGX 101019
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
319 AM PDT Fri Apr 10 2020

CAZ055-056-102230-
/O.CON.KSGX.WS.W.0003.000000T0000Z-200411T0300Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
319 AM PDT Fri Apr 10 2020

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

* WHAT...Heavy snow occurring. Travel will be very difficult to
  impossible, including during the morning commute. Additional
  snow accumulations of 3 to 6 from 5500 to 6500 feet, 6 to 19 
  inches from 6500 to 7500 feet, and 10 to 16 inches above 7500 
  feet. 

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet.

* 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.

$$

CAZ058-102230-
/O.NEW.KSGX.WW.Y.0011.200410T1019Z-200411T0300Z/
San Diego County Mountains-
319 AM PDT Fri Apr 10 2020

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 8 PM PDT THIS EVENING
ABOVE 5000 FEET...

* WHAT...Wet snow occurring. Plan on difficult travel 
  conditions, including during the morning commute. Additional 
  wet snow accumulations of 2 to 4 inches, with localized 
  amounts up to 8 inches, are expected.

* WHERE...The San Diego County mountains above 5000 feet.

* WHEN...Until 8 PM today.

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

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.

$$

17
292 
WWUS46 KSGX 102049
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
149 PM PDT Fri Apr 10 2020

CAZ055-056-110300-
/O.CON.KSGX.WS.W.0003.000000T0000Z-200411T0300Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
149 PM PDT Fri Apr 10 2020

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

* WHAT...Heavy snow occurring. Plan on difficult travel
  conditions, including during the evening commute. Additional
  snow accumulations of 1 to 4 inches are expected.

* WHERE...Mountains of San Bernardino and Riverside Counties, 
  above 5500 feet. The heaviest snow will occur above 6500 feet.

* 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.

$$

CAZ058-110300-
/O.CON.KSGX.WW.Y.0011.000000T0000Z-200411T0300Z/
San Diego County Mountains-
149 PM PDT Fri Apr 10 2020

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 8 PM PDT THIS
EVENING ABOVE 5000 FEET...

* WHAT...Wet snow occurring. Plan on slippery road conditions,
  including during the evening commute. Additional wet snow
  accumulations of one to three inches, are expected.

* WHERE...The San Diego County mountains above 5000 feet.

* WHEN...Until 8 PM today.

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

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.

$$

10
573 
WWUS46 KSGX 110319
WSWSGX

URGENT - WINTER WEATHER MESSAGE
National Weather Service SAN DIEGO CA
819 PM PDT Fri Apr 10 2020

CAZ055-056-110430-
/O.EXP.KSGX.WS.W.0003.000000T0000Z-200411T0300Z/
San Bernardino County Mountains-Riverside County Mountains-
Including the cities of Big Bear City, Big Bear Lake, 
Running Springs, and Wrightwood
819 PM PDT Fri Apr 10 2020

...WINTER STORM WARNING HAS EXPIRED...

Isolated snow showers will be possible overnight, however the
threat for heavy snow has ended. Please be alert for snow covered
and treacherous mountain highways!

$$

CAZ058-110430-
/O.EXP.KSGX.WW.Y.0011.000000T0000Z-200411T0300Z/
San Diego County Mountains-
819 PM PDT Fri Apr 10 2020

...WINTER WEATHER ADVISORY HAS EXPIRED...

Isolated snow showers will be possible overnight, however the
threat for heavy snow has ended. Please be alert for snow covered
and treacherous mountain highways!

$$

jmb

What forecasters said that day

The local office's own words before this winter storm 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 winter storm warning went out at Apr 4, 9:55 PM PDT, 5 hours 33 minutes earlier.

Area forecast discussion, Apr 4, 9:55 PM PDT, 5 hours 33 minutes before
Area Forecast Discussion
National Weather Service San Diego CA
955 PM PDT Sat Apr 4 2020

.SYNOPSIS...
A slow-moving winter-like storm will bring cold weather and periods
of rain and mountain snow through Wednesday night. Light rain
showers could begin late tonight or Sunday morning, but the most
widespread rain and mountain snow will be on Monday and Tuesday.
Heavy snow will impact the San Bernardino mountains. The storm will
exit the region Thursday followed by dry and warmer weather Friday
and Saturday.

&&

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

A strong winter-like storm with high impact potential will move
across Southern California next week. This deep closed low will
bring periods of rain, significant mountain snow, gusty winds and
unseasonable cold. Temperatures will be 15 degrees below average
Monday through Wednesday. For example, the forecast highs in Palm
Springs M/T/W are 67/67/67. The average high is 82. The forecast
highs in Riverside are 58/61/61. The average high is 73.

Spotty light rain or drizzle from a deep eddy-enhanced marine layer
is possible later tonight into Sunday. But the significant rain will
hold off until Monday when an Atmospheric River (IVT values of 300-
500 kg/m/s) moves in from the Pacific. Moist southwest flow ahead of
the trough off the coast is perfectly aligned to bring moderate to
heavy rain to the southwest slopes of the Orange, San Bernardino and
Riverside County mountains. WPC has a slight risk of excessive
rainfall and a risk of flash flooding in these areas Monday and
Monday night. Rain amounts of 2-4" are possible on the southwest
facing slopes of the San Bernardino Mountains through Monday night.

Tuesday and Wednesday will be cold days with scattered showers and
perhaps a few thunderstorms just about anywhere as the cold core low
slowly meanders from Pt Conception Tuesday to near Yuma, AZ on
Wednesday. The airmass will be somewhat unstable with 500 mb
temperatures falling to -25C and -28C during that time. Several
shortwaves in the broad cyclonic flow will add to the instability.
Snow will be heavy at times above 5500 FT in the San Bernardino and
Riverside County mountains Monday through Wednesday night where a
Winter Storm Watch will be in effect.

By Thursday, there is quite a spread in the model solutions, but
both the ECMWF/GFS 00Z runs have the storm center to the east of the
forecast area, suggesting an end to most precip west of the mts, but
with wrap-around possibilities, mts and deserts could still be
getting significant amounts of rain/snow. So far, next weekend looks
dry and warmer.

&&

.AVIATION...
050330Z...Coast/Valleys...BKN-OVC low clouds with bases mostly
ranging between 2000-3000 ft MSL will continue to fill into the
valleys overnight. Visibility will remain 6+ miles at TAF sites. Low
clouds will lift to around 3000 ft MSL after 16Z. Partial clearing
is possible in the valleys after 18Z, but low confidence in clearing
at the coast.

Mountains/Deserts...Mostly clear with unrestricted vis through
Sunday morning. Areas of low clouds and fog will impact the
mountains overnight, dropping visibility down to 1 mile at times.
Partial clearing is likely in the mountains after 18Z. Locally gusty
NW winds possible Sunday afternoon through Sunday night at KPSP/KTRM
with gusts to 20-25 kts.

&&

.MARINE...
An incoming storm system will produce showers and gusty winds over
the coastal waters starting Sunday afternoon. There is a slight
chance of thunderstorms Monday night, and again Wednesday afternoon
and evening. The cold front will produce gusty southwest winds 20-25
kt over the coastal waters on late Sunday night through Monday
evening, which could be hazardous to small craft.

&&

.HYDROLOGY...

A blend of model QPF solutions was used to achieve our current
rain and snowfall outlook for this event. Hopefully the disparate
model track projections for this storm will coalesce, giving higher
confidence for parsing out the most significant precip and timing
impacts. For now, Precip totals Sunday night through Thursday night
are as follows:

High deserts...1-1.5 inches. Isolated thunderstorms could produce
localized excessive runoff, otherwise most of the rain will be of
the light to moderate variety.

Low Deserts: 0.5-1.00 inches. No significant runoff issues forecast
at this time, although inflow into the Whitewater River will need to
be monitored and may cause low-water crossing impacts in the
Coachella Canal by Tuesday.

Coast/Valley: 1.00-2.25 inches. Some urban and small stream flooding
issues are possible later Monday through Tuesday morning when the
more widespread and heavier rainfall is expected.

Mountains: 3.00-6.00 inches with isolated heavier amounts possible
on the coastal slopes of the San Bernardino Mts. Less expected south
through Riverside and the San Diego County Mts where less upslope
enhancement is likely. A very significant April snowfall event looks
likely in the San Bernardino Mts and the San Jacinto Mts where feet
of snow are likely to fall above 6000 FT. Small streams may overflow
their banks for a time later Monday into Tuesday on the coastal
slopes when the most widespread moderate rainfall is expected.

River flooding is not expected, but flow will be higher than normal,
even for the Mojave. The Whitewater will need to be monitored. For
the San Diego River, any amounts greater than currently forecast
would cause sharp rises and will be monitored.

.SKYWARN...
Skywarn activation may be requested Monday. H

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Winter Storm Watch from Sunday evening through late Wednesday
     night for Riverside County Mountains-San Bernardino County
     Mountains.

PZ...NONE.
&&

PUBLIC...Moede
HYDROLOGY...10
AVIATION/MARINE...Connolly

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 5, 1:55 AM PDTSmall Craft AdvisorySGX40 hr

Nearby

Winter Storm Warnings in California, 2020Every winter storm warning in 2020

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.