Alert archive / California / Winter Storm Warnings in 2018
Winter Storm Warning 2, NWS San Diego, CA
NWS San Diego, CA issued this winter storm warning at Feb 26, 2018, 1:42 PM PST for Riverside County, San Bernardino County, San Diego County, California. It took effect at Feb 26, 2018, 7:00 PM PST. It was in force for 27 hr. 11 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
- Feb 26, 2018, 1:42 PM PST (21:42 UTC)
- In effect from
- Feb 26, 2018, 7:00 PM PST
- Expired
- Feb 27, 2018, 10:00 PM PST
- In force
- 27 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 21:45 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 |
|---|---|---|---|
| Feb 27, 6:55 AM PST | HEAVY SNOW 2 | 9 Ese Wrightwood, CA | CHP REPORTS HIGHWAY 138 CLOSED DUE TO SNOW COVERED ROADS AND VEHICLES SPIN OUTS. THIS IS EXIT ON I-15 IN CAJON PASS AT CAJON JUNCTION. |
| Feb 27, 7:43 AM PST | SNOW 5.5 | Wrightwood, CA | |
| Feb 27, 7:55 AM PST | SNOW 5 | Idyllwild-Pine Cove, CA | |
| Feb 27, 7:56 AM PST | SNOW 4.5 | Julian, CA | |
| Feb 27, 7:57 AM PST | SNOW 5 | Big Bear Lake, CA | |
| Feb 27, 7:59 AM PST | HEAVY SNOW 4 | 9 Ne Rancho Cucamonga, CA | CHP REPORTS 4 INCHES OF SNOW ON LYTLE CREEK ROAD, ELEVATION ESTIMATED 3000 FEET. |
| Feb 27, 8:02 AM PST | SNOW 4 | 2 Ene Idyllwild-Pine Co, CA | FERN VALLEY. |
| Feb 27, 8:05 AM PST | HEAVY SNOW 1 | Aguanga, CA | CHP HAS SET UP CHAIN CONTROL AT AGUANGA AT INTERSECTION OF 79 AND 371. |
| Feb 27, 8:17 AM PST | HEAVY SNOW 0.5 | 7 Wsw Hesperia, CA | SNOWING AT OAK HILLS AT 3300 FEET IN HIGH DESERT. TRAFFIC IS STAND STILL ON I-15. |
| Feb 27, 8:27 AM PST | SNOW 5 | Laguna Mountain Lodge, CA | |
| Feb 27, 9:42 AM PST | HEAVY SNOW 1 | 2 Nne Yucaipa, CA | 1 INCH OF SNOW REPORTED ON COCORAHS ELEVATION ESTIMATE 2500 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, 9.7 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2092 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 29 m²/s²
- 0-3 km storm-relative helicity
- 97 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
191 WWUS46 KSGX 262142 WSWSGX URGENT - WINTER WEATHER MESSAGE National Weather Service SAN DIEGO CA 142 PM PST Mon Feb 26 2018 ...WINTER STORM SYSTEM TO BRING HEAVY SNOW IN THE MOUNTAINS... .A winter storm system will bring snow to the mountains tonight, beginning in the San Bernardino County Mountains early this evening, spreading south overnight and reaching the San Diego County Mountains by midnight. Heaviest snowfall will be overnight tonight, with periodic snow showers Tuesday with brief heavy snow rates. The snow will end Tuesday evening. Snow levels will fall from 5000 feet early tonight to 2500 to 3000 feet Tuesday morning. Local snowfall over the highest mountains will be 12 to 18 inches. CAZ055-056-058-270600- /O.UPG.KSGX.WW.Y.0003.180227T0300Z-180228T0600Z/ /O.NEW.KSGX.WS.W.0002.180227T0300Z-180228T0600Z/ San Bernardino County Mountains-Riverside County Mountains- San Diego County Mountains- Including the cities of Crestline, Lake Arrowhead, Big Bear City, Big Bear Lake, Running Springs, Wrightwood, Idyllwild-Pine Cove, Julian, and Pine Valley 142 PM PST Mon Feb 26 2018 ...WINTER STORM WARNING IN EFFECT FROM 7 PM THIS EVENING TO 10 PM PST TUESDAY... * WHAT...Heavy snow expected. Plan on difficult travel conditions. Total snow accumulations of 6 to 12 inches, with localized amounts up to 18 inches, are expected. Locally strong winds will bring gusts 40 to 50 mph near mountain crests. * WHERE...Heaviest snow above 6000 feet with accumulations with locally over one foot. Snow accumulations between 4000 and 6000 feet will be 4 to 8 inches. Between 3000 and 4000 feet, amounts will be 2 to 4 inches. * WHEN...7 PM today to 10 PM Tuesday. * ADDITIONAL DETAILS...Travel along Interstate 15 through Cajon Pass and Interstate 8 in the San Diego County Mountains will be hazardous late tonight and Tuesday. Be prepared for significant reductions in visibility at times across the mountains. 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. $$ CAZ057-060-270600- /O.CON.KSGX.WW.Y.0003.180227T0600Z-180228T0600Z/ Santa Ana Mountains and Foothills-Apple and Lucerne Valleys- Including the cities of Victorville, Hesperia, and Apple Valley 142 PM PST Mon Feb 26 2018 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 10 PM THIS EVENING TO 10 PM PST TUESDAY... * WHAT...Snow expected. Plan on slippery road conditions. Total snow accumulations of 1 to 4 inches, with localized amounts up to 5 inches, are expected. Locally gusty winds will occur, especially in the high deserts with local gusts around 40 mph. * WHERE...Snowfall in the Santa Ana mountains above 3000 feet will be 3 to 5 inches. Snow in the high desert between 2500 to 3500 feet will accumulate from a half inch at 2500 feet, up to 4 inches near the mountains. * WHEN...10 PM today to 10 PM Tuesday. * ADDITIONAL DETAILS...Be prepared for reduced visibilities at times. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Weather Advisory for snow means periods of snow will cause primarily travel difficulties. Be prepared for snow covered roads and limited visibilities, and use caution while driving. For road condition information in California...enter 8 0 0 4 2 7 7 6 2 3 if inside california or 9 1 6 4 5 5 7 6 2 3 if outside California. $$ Maxwell
4 follow-up statements
837 WWUS46 KSGX 270437 WSWSGX URGENT - WINTER WEATHER MESSAGE National Weather Service SAN DIEGO CA 837 PM PST Mon Feb 26 2018 ...WINTER STORM SYSTEM TO BRING HEAVY SNOW AND HAZARDOUS TRAVEL CONDITIONS IN THE MOUNTAINS... .A winter storm system will bring snow to the mountains, beginning in the San Bernardino County Mountains this evening, spreading south overnight and reaching the San Diego County Mountains by midnight. Heaviest snowfall will be overnight tonight, with periodic snow showers Tuesday with brief heavy snow rates. The snow will end Tuesday evening. Snow levels will fall from 4000 feet this evening to 2000 to 2500 feet Tuesday morning. Local snowfall over the highest mountains will be 12 to 18 inches. CAZ055-056-058-271400- /O.CON.KSGX.WS.W.0002.000000T0000Z-180228T0600Z/ San Bernardino County Mountains-Riverside County Mountains- San Diego County Mountains- Including the cities of Crestline, Lake Arrowhead, Big Bear City, Big Bear Lake, Running Springs, Wrightwood, Idyllwild-Pine Cove, Julian, and Pine Valley 837 PM PST Mon Feb 26 2018 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 PM PST TUESDAY... * WHAT...Heavy snow expected. Plan on difficult travel conditions. Total snow accumulations of 6 to 12 inches, with localized amounts up to 18 inches, are expected. Locally strong winds will bring gusts 40 to 50 mph near mountain crests. * WHERE...Heaviest snow above 6000 feet with accumulations locally over one foot. Snow accumulations between 4000 and 6000 feet will be 4 to 8 inches. Between 3000 and 4000 feet, amounts will be 2 to 4 inches. * WHEN...Until 10 PM Tuesday. * ADDITIONAL DETAILS...Travel along Interstate 15 through the Cajon Pass and Interstate 8 in the San Diego County Mountains will be hazardous late tonight and Tuesday. Be prepared for significant reductions in visibility at times across the mountains. 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. $$ CAZ057-060-271400- /O.CON.KSGX.WW.Y.0003.180227T0600Z-180228T0600Z/ Santa Ana Mountains and Foothills-Apple and Lucerne Valleys- Including the cities of Victorville, Hesperia, and Apple Valley 837 PM PST Mon Feb 26 2018 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 PM PST TUESDAY... * WHAT...Snow expected. Plan on slippery road conditions. Total snow accumulations of 1 to 4 inches, with localized amounts up to 5 inches, are expected. Locally gusty winds will occur, especially in the high deserts with local gusts around 40 mph. * WHERE...Snowfall in the Santa Ana mountains above 3000 feet will be 3 to 5 inches. Snow in the high desert between 2500 to 3500 feet will accumulate from a half inch at 2500 feet, up to 4 inches near the mountains. * WHEN...10 PM today to 10 PM Tuesday. * ADDITIONAL DETAILS...Be prepared for reduced visibilities at times. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Weather Advisory for snow means periods of snow will cause primarily travel difficulties. Be prepared for snow covered roads and limited visibilities, and use caution while driving. For road condition information in California...enter 8 0 0 4 2 7 7 6 2 3 if inside california or 9 1 6 4 5 5 7 6 2 3 if outside California. $$ Gregoria
957 WWUS46 KSGX 271051 WSWSGX URGENT - WINTER WEATHER MESSAGE National Weather Service SAN DIEGO CA 251 AM PST Tue Feb 27 2018 ...WINTER STORM SYSTEM TO BRING HEAVY SNOW AND HAZARDOUS TRAVEL CONDITIONS IN THE MOUNTAINS... .Steady snow will continue to accumulate in the mountains early this morning, but then turn to snow showers after sunrise. The snow level we be as low as 2000 feet, which would include the foothills and the high desert. Showers will continue all day, with brief heavy snow rates possible. The snow will taper off tonight. Local snowfall over the highest mountains will exceed one foot. CAZ055-056-058-272200- /O.CON.KSGX.WS.W.0002.000000T0000Z-180228T0600Z/ San Bernardino County Mountains-Riverside County Mountains- San Diego County Mountains- Including the cities of Crestline, Lake Arrowhead, Big Bear City, Big Bear Lake, Running Springs, Wrightwood, Idyllwild-Pine Cove, Julian, and Pine Valley 251 AM PST Tue Feb 27 2018 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 PM PST THIS EVENING... * WHAT...Heavy snow early this morning becoming showery after sunrise. Plan on difficult travel conditions. * WHERE...Above 6000 feet, snow accumulations up to 10 inches, and could exceed a foot above 7000 feet. Up to 6 inches below 6000 feet. Snow accumulations between 4000 and 6000 feet will be 3 to 6 inches, and between 2500 and 4000 feet, up to 3 inches. * WHEN...Heaviest and steadiest snow early this morning. Occasional bursts of heavy snow in showers possible through this evening. * 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. $$ CAZ057-060-272200- /O.CON.KSGX.WW.Y.0003.000000T0000Z-180228T0600Z/ Santa Ana Mountains and Foothills-Apple and Lucerne Valleys- Including the cities of Victorville, Hesperia, and Apple Valley 251 AM PST Tue Feb 27 2018 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 PM PST THIS EVENING... * WHAT...Snow showers through this evening. Plan on slippery road conditions, including during both commutes. * WHERE...Snowfall in the Santa Ana mountains above 3000 feet will be 3 to 6 inches. Snow in the high desert between 2500 to 3500 feet will accumulate from a half inch at 2500 feet, up to 4 inches near the mountains. * WHEN...through this evening. * ADDITIONAL DETAILS...Be prepared for reduced visibilities at times. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Weather Advisory for snow means periods of snow will cause primarily travel difficulties. Be prepared for snow covered roads and limited visibilities, and use caution while driving. For road condition information in California...enter 8 0 0 4 2 7 7 6 2 3 if inside california or 9 1 6 4 5 5 7 6 2 3 if outside California. $$
103 WWUS46 KSGX 272159 WSWSGX URGENT - WINTER WEATHER MESSAGE National Weather Service SAN DIEGO CA 159 PM PST Tue Feb 27 2018 ...SNOW SHOWERS CONTINUING THIS EVENING... .Most of the snow has already fallen, with numerous reports of six to eight inches on the ground above 5500 feet elevation. Additional snow showers will bring light accumulations this evening, but with temperatures falling again this evening, roads that had some melting of snow will refreeze and be treacherous. Travel will continue to be hazardous tonight in the mountains and some adjacent foothill areas. CAZ055-056-058-280600- /O.CON.KSGX.WS.W.0002.000000T0000Z-180228T0600Z/ San Bernardino County Mountains-Riverside County Mountains- San Diego County Mountains- Including the cities of Crestline, Lake Arrowhead, Big Bear City, Big Bear Lake, Running Springs, Wrightwood, Idyllwild-Pine Cove, Julian, and Pine Valley 159 PM PST Tue Feb 27 2018 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 PM PST THIS EVENING... * WHAT...Snow expected. Snow showers will gradually diminish tonight. * WHERE...Above 6000 feet, total snow accumulations, including that which had already fallen, up to 10 inches. Up to 6 inches below 6000 feet. Snow accumulations between 4000 and 6000 feet will be 3 to 6 inches, and between 2500 and 4000 feet, up to 3 inches. * WHEN...Occasional bursts of moderate to heavy snow in showers possible through this evening. * 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. $$ CAZ057-060-280600- /O.CON.KSGX.WW.Y.0003.000000T0000Z-180228T0600Z/ Santa Ana Mountains and Foothills-Apple and Lucerne Valleys- Including the cities of Victorville, Hesperia, and Apple Valley 159 PM PST Tue Feb 27 2018 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 10 PM PST THIS EVENING... * WHAT...Snow expected. Snow showers will gradually diminish tonight. * WHERE...Total snowfall, including that had already fallen, in the Santa Ana mountains above 3000 feet will be 3 to 6 inches. Total snow in the high desert will be up to 4 inches near the mountains. * WHEN...through this evening. * ADDITIONAL DETAILS...Be prepared for reduced visibilities at times. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Weather Advisory for blowing snow means that visibilities will be limited due to strong winds blowing snow around. Use caution when traveling, especially in open areas. For road condition information in California...enter 8 0 0 4 2 7 7 6 2 3 if inside california or 9 1 6 4 5 5 7 6 2 3 if outside California. $$ Maxwell
934 WWUS46 KSGX 280556 WSWSGX URGENT - WINTER WEATHER MESSAGE National Weather Service SAN DIEGO CA 956 PM PST Tue Feb 27 2018 CAZ055-056-058-280700- /O.EXP.KSGX.WS.W.0002.000000T0000Z-180228T0600Z/ San Bernardino County Mountains-Riverside County Mountains- San Diego County Mountains- Including the cities of Crestline, Lake Arrowhead, Big Bear City, Big Bear Lake, Running Springs, Wrightwood, Idyllwild-Pine Cove, Julian, and Pine Valley 956 PM PST Tue Feb 27 2018 ...WINTER STORM WARNING WILL EXPIRE AT 10 PM PST THIS EVENING... No additional accumulating snowfall is expected. As such, the Winter Storm Warning will be allowed to expire at 10 PM. $$ CAZ057-060-280700- /O.EXP.KSGX.WW.Y.0003.000000T0000Z-180228T0600Z/ Santa Ana Mountains and Foothills-Apple and Lucerne Valleys- Including the cities of Victorville, Hesperia, and Apple Valley 956 PM PST Tue Feb 27 2018 ...WINTER WEATHER ADVISORY WILL EXPIRE AT 10 PM PST THIS EVENING... No additional accumulating snowfall is expected. As such, the Winter Weather Advisory will expire at 10 PM. $$ Gregoria
The office that day
Everything else NWS San Diego, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 25, 5:33 PM PST | Winter Weather Advisory | SGX | Orange, Riverside, San Bernardino, San Diego | 52 hr |
Nearby
Winter Storm Warnings in California, 2018Every winter storm warning in 2018
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.