Alert archive / California / Red Flag Warnings in 2008
Red Flag Warning 21, NWS San Diego, CA
NWS San Diego, CA issued this red flag warning at May 20, 2008, 3:55 AM PDT for Riverside County, San Bernardino County, San Diego County, California. It took effect at May 20, 2008, 8:36 AM PDT. It was in force for 13 hr. 1 report 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
- May 20, 2008, 3:55 AM PDT (10:55 UTC)
- In effect from
- May 20, 2008, 8:36 AM PDT
- Expired
- May 20, 2008, 9:10 PM PDT
- In force
- 13 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 10:51 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 |
|---|---|---|---|
| May 20, 8:54 PM PDT | NON-TSTM WND GST 59 | 30 W Baker, CA | MEASURED AT THE 4-CORNERS MESOWEST SITE. ELEVATION 2484 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 00:00Z, 10.9 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
- 2693 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- -14 m²/s²
- 0-3 km storm-relative helicity
- 60 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 WWUS86 KSGX 201055 RFWSGX RED FLAG WARNING NATIONAL WEATHER SERVICE SAN DIEGO CA 355 AM PDT TUE MAY 20 2008 ...DRY AND WINDY FOR THE MOUNTAINS AND DESERTS THIS AFTERNOON AND EVENING... .A TROUGH OF LOW PRESSURE MOVING INLAND THROUGH NORTHERN CALIFORNIA AND THE PACIFIC NORTHWEST INTO THE GREAT BASIN WILL BRING STRONG ONSHORE FLOW TO SOUTHERN CALIFORNIA WITH STRONG GUSTY WINDS IN THE MOUNTAINS AND DESERTS AT TIMES THROUGH WEDNESDAY. HUMIDITIES WILL BE LOWEST TODAY. WINDS ARE NOT EXPECTED TO BE QUITE AS STRONG NOR HUMIDITIES QUITE AS LOW WEDNESDAY. CAZ260-202100- /O.CAN.KSGX.FW.A.0003.080521T1800Z-080522T0300Z/ /O.UPG.KSGX.FW.A.0002.080520T2100Z-080521T0600Z/ /O.NEW.KSGX.FW.W.0021.080520T1900Z-080521T0300Z/ VICTOR VALLEY-APPLE VALLEY-LUCERNE VALLEY-YUCCA VALLEY- MORONGO VALLEY- 355 AM PDT TUE MAY 20 2008 ...RED FLAG WARNING IN EFFECT FROM NOON TODAY TO 8 PM PDT THIS EVENING FOR WINDS GUSTING OVER 35 MPH AND RELATIVE HUMIDITY BELOW 15 PERCENT FOR MORE THAN SIX HOURS... ...FIRE WEATHER WATCH IS CANCELLED... THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A RED FLAG WARNING...WHICH IS IN EFFECT FROM NOON TODAY TO 8 PM PDT THIS EVENING. THE FIRE WEATHER WATCH HAS BEEN CANCELLED. THE FIRE WEATHER WATCH IS NO LONGER IN EFFECT. WIND GUSTS GREATER THAN 35 MPH COMBINED WITH RELATIVE HUMIDITIES LESS THAN 15 PERCENT ARE EXPECTED FOR A PERIOD OF 6 TO 8 HOURS THIS AFTERNOON AND EARLY EVENING. WINDS ARE EXPECTED TO BE SLIGHTLY WEAKER AND HUMIDITIES SLIGHTLY HIGHER FOR WEDNESDAY. A RED FLAG WARNING MEANS THAT CRITICAL FIRE WEATHER CONDITIONS ARE EITHER OCCURRING NOW...OR WILL SHORTLY. A COMBINATION OF STRONG WINDS...LOW RELATIVE HUMIDITY...AND WARM TEMPERATURES WILL CREATE EXPLOSIVE FIRE GROWTH POTENTIAL. $$ CAZ256-258-261-262-201200- /O.CAN.KSGX.FW.A.0002.080520T2100Z-080521T0600Z/ RIVERSIDE COUNTY MOUNTAINS- INCLUDING THE SAN JACINTO RANGER DISTRICT OF THE SAN BERNARDINO NATIONAL FOREST-SAN DIEGO COUNTY MOUNTAINS- INCLUDING THE PALOMAR AND DESCANSO RANGER DISTRICTS OF THE CLEVELAND NATIONAL FOREST-COACHELLA VALLEY- INCLUDING THE PALM SPRINGS SOUTH COAST DESERT DISTRICT- SAN DIEGO COUNTY DESERTS- INCLUDING THE ANZA BORREGO DESERT STATE PARK- 355 AM PDT TUE MAY 20 2008 ...FIRE WEATHER WATCH IS CANCELLED... THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS CANCELLED THE FIRE WEATHER WATCH. WIND GUSTS GREATER THAN 35 MPH COMBINED WITH RELATIVE HUMIDITIES LESS THAN 15 PERCENT ARE EXPECTED FOR A PERIOD OF LESS THAN 6 HOURS THIS AFTERNOON AND EARLY EVENING. WINDS ARE EXPECTED TO BE SLIGHTLY WEAKER AND HUMIDITIES SLIGHTLY HIGHER FOR WEDNESDAY. $$ CAZ255-256-202100- /O.UPG.KSGX.FW.A.0002.080520T2100Z-080521T0600Z/ /O.NEW.KSGX.FW.W.0021.080520T1900Z-080521T0300Z/ SAN BERNARDINO COUNTY MOUNTAINS- INCLUDING THE MOUNTAIN TOP AND FRONT COUNTRY RANGER DISTRICTS OF THE SAN BERNARDINO NATIONAL FOREST- 355 AM PDT TUE MAY 20 2008 ...RED FLAG WARNING IN EFFECT FROM NOON TODAY TO 8 PM PDT THIS EVENING FOR RIDGES AND DESERT SLOPES DUE TO WINDS GUSTING OVER 35 MPH AND RELATIVE HUMIDITY BELOW 15 PERCENT FOR MORE THAN SIX HOURS... THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A RED FLAG WARNING...WHICH IS IN EFFECT FROM NOON TODAY TO 8 PM PDT THIS EVENING. THE FIRE WEATHER WATCH IS NO LONGER IN EFFECT. WIND GUSTS GREATER THAN 35 MPH COMBINED WITH RELATIVE HUMIDITIES LESS THAN 15 PERCENT ARE EXPECTED FOR A PERIOD OF 6 TO 8 HOURS THIS AFTERNOON AND EARLY EVENING FOR RIDGES AND ON DESERT SLOPES. WINDS ARE EXPECTED TO BE SLIGHTLY WEAKER AND HUMIDITIES SLIGHTLY HIGHER FOR WEDNESDAY. A RED FLAG WARNING MEANS THAT CRITICAL FIRE WEATHER CONDITIONS ARE EITHER OCCURRING NOW...OR WILL SHORTLY. A COMBINATION OF STRONG WINDS...LOW RELATIVE HUMIDITY...AND WARM TEMPERATURES WILL CREATE EXPLOSIVE FIRE GROWTH POTENTIAL. $$ MARTIN
3 follow-up statements
000 WWUS86 KSGX 201536 RFWSGX RED FLAG WARNING NATIONAL WEATHER SERVICE SAN DIEGO CA 836 AM PDT TUE MAY 20 2008 ...DRY AND WINDY FOR THE MOUNTAINS AND DESERTS THIS AFTERNOON AND EVENING... .A TROUGH OF LOW PRESSURE MOVING INLAND THROUGH NORTHERN CALIFORNIA AND THE PACIFIC NORTHWEST INTO THE GREAT BASIN WILL BRING STRONG ONSHORE FLOW TO SOUTHERN CALIFORNIA WITH STRONG GUSTY WINDS IN THE MOUNTAINS AND DESERTS AT TIMES THROUGH WEDNESDAY. HUMIDITY WILL BE LOWEST TODAY. WINDS ARE EXPECTED TO BE STRONGER TONIGHT AND WEDNESDAY BUT HUMIDITY WILL BE HIGHER. CAZ256-201645- /O.CAN.KSGX.FW.W.0021.080520T1900Z-080521T0300Z/ RIVERSIDE COUNTY MOUNTAINS- INCLUDING THE SAN JACINTO RANGER DISTRICT OF THE SAN BERNARDINO NATIONAL FOREST- 836 AM PDT TUE MAY 20 2008 ...RED FLAG WARNING IS CANCELLED... THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS CANCELLED THE RED FLAG WARNING. $$ CAZ261-262-210445- /O.EXB.KSGX.FW.W.0021.080520T2100Z-080521T0500Z/ COACHELLA VALLEY- INCLUDING THE PALM SPRINGS SOUTH COAST DESERT DISTRICT- SAN DIEGO COUNTY DESERTS- INCLUDING THE ANZA BORREGO DESERT STATE PARK- 836 AM PDT TUE MAY 20 2008 ...RED FLAG WARNING IN EFFECT FROM 2 PM THIS AFTERNOON TO 10 PM PDT THIS EVENING... THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A RED FLAG WARNING...WHICH IS IN EFFECT FROM 2 PM THIS AFTERNOON TO 10 PM PDT THIS EVENING. WIND GUSTS GREATER THAN 35 MPH COMBINED WITH RELATIVE HUMIDITIES LESS THAN 15 PERCENT ARE EXPECTED FOR A PERIOD OF 6 TO 8 HOURS THIS AFTERNOON AND EARLY EVENING. WINDS ARE EXPECTED TO BE STRONGER BUT HUMIDITY WILL BE HIGHER TONIGHT AND WEDNESDAY. A RED FLAG WARNING MEANS THAT CRITICAL FIRE WEATHER CONDITIONS ARE EITHER OCCURRING NOW...OR WILL SHORTLY. A COMBINATION OF STRONG WINDS...LOW RELATIVE HUMIDITY...AND WARM TEMPERATURES WILL CREATE EXPLOSIVE FIRE GROWTH POTENTIAL. $$ CAZ255-256-260-210300- /O.CON.KSGX.FW.W.0021.080520T1900Z-080521T0300Z/ SAN BERNARDINO COUNTY MOUNTAINS- INCLUDING THE MOUNTAIN TOP AND FRONT COUNTRY RANGER DISTRICTS OF THE SAN BERNARDINO NATIONAL FOREST-VICTOR VALLEY-APPLE VALLEY- LUCERNE VALLEY-YUCCA VALLEY-MORONGO VALLEY- 836 AM PDT TUE MAY 20 2008 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 8 PM PDT THIS EVENING... A RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 8 PM PDT THIS EVENING. WIND GUSTS GREATER THAN 35 MPH COMBINED WITH RELATIVE HUMIDITIES LESS THAN 15 PERCENT ARE EXPECTED FOR A PERIOD OF 6 TO 8 HOURS THIS AFTERNOON AND EARLY EVENING FOR RIDGES AND ON DESERT SLOPES. WINDS ARE EXPECTED TO BE STRONGER BUT HUMIDITY HIGHER FOR TONIGHT AND WEDNESDAY. A RED FLAG WARNING MEANS THAT CRITICAL FIRE WEATHER CONDITIONS ARE EITHER OCCURRING NOW...OR WILL SHORTLY. A COMBINATION OF STRONG WINDS...LOW RELATIVE HUMIDITY...AND WARM TEMPERATURES WILL CREATE EXPLOSIVE FIRE GROWTH POTENTIAL. $$ BALFOUR
000 WWUS86 KSGX 202032 RFWSGX RED FLAG WARNING NATIONAL WEATHER SERVICE SAN DIEGO CA 132 PM PDT TUE MAY 20 2008 ...RED FLAG WARNING EXTENDED UNTIL 2200 PDT THIS EVENING FOR ALL DESERT AREAS OF SOUTHWEST CALIFORNIA AS WELL AS PORTIONS OF THE SAN BERNARDINO NATIONAL FOREST...DUE TO COMBINATION OF STRONG GUSTY WINDS AND LOW RELATIVE HUMIDITY... .A TROUGH OF LOW PRESSURE MOVING INLAND ACROSS NORTHERN CALIFORNIA IS CREATING STRONG GUSTY WINDS OVER SOUTHERN CALIFORNIA. RELATIVE HUMIDITY WILL REMAIN BELOW 15 PERCENT THROUGH 2200 PDT WHILE WINDS ARE GUSTING OVER 35 MPH IN THE WARNED AREAS. ADJACENT AREAS...INCLUDING THE DESERT PORTIONS OF THE SAN JACINTO RANGER DISTRICT OF THE SAN BERNARDINO NATIONAL FOREST...AND THE DESERT PORTIONS OF THE PALOMAR AND DESCANSO RANGER DISTRICTS MAY ALSO EXPERIENCE SEVERAL HOURS BETWEEN NOW AND 2000 PDT THIS EVENING WITH CRITICAL FIRE WEATHER CONDITIONS. AFTER MIDNIGHT WINDS WILL BECOME EVEN STRONGER...WITH GUSTS TO 70 MPH POSSIBLE THROUGH WEDNESDAY MORNING. RELATIVE HUMIDITY WILL BE ABOVE 15 PERCENT BUT NOT BY MUCH...AND MAXIMUM VALUES WILL ONLY RANGE BETWEEN 25 AND 35 PERCENT FOR A FEW HOURS EARLY WEDNESDAY. CAZ256-202145- /O.CAN.KSGX.FW.W.0021.000000T0000Z-080521T0300Z/ RIVERSIDE COUNTY MOUNTAINS- INCLUDING THE SAN JACINTO RANGER DISTRICT OF THE SAN BERNARDINO NATIONAL FOREST- 132 PM PDT TUE MAY 20 2008 ...RED FLAG WARNING IS CANCELLED... THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS CANCELLED THE RED FLAG WARNING. $$ CAZ255-256-260-210500- /O.EXT.KSGX.FW.W.0021.000000T0000Z-080521T0500Z/ SAN BERNARDINO COUNTY MOUNTAINS- INCLUDING THE MOUNTAIN TOP AND FRONT COUNTRY RANGER DISTRICTS OF THE SAN BERNARDINO NATIONAL FOREST-VICTOR VALLEY-APPLE VALLEY- LUCERNE VALLEY-YUCCA VALLEY-MORONGO VALLEY- 132 PM PDT TUE MAY 20 2008 ...RED FLAG WARNING NOW IN EFFECT UNTIL 10 PM PDT THIS EVENING... THE RED FLAG WARNING IS NOW IN EFFECT UNTIL 10 PM PDT THIS EVENING. WIND GUSTS GREATER THAN 35 MPH COMBINED WITH RELATIVE HUMIDITIES LESS THAN 15 PERCENT ARE EXPECTED TO CONTINUE THROUGH 2200 PDT. WINDS ARE FORECAST TO BE STRONGER LATER TONIGHT AND WEDNESDAY BUT HUMIDITY SHOULD BE ABOVE 15 PERCENT THEN. A RED FLAG WARNING MEANS THAT CRITICAL FIRE WEATHER CONDITIONS ARE EITHER OCCURRING NOW...OR WILL SHORTLY. A COMBINATION OF STRONG WINDS...LOW RELATIVE HUMIDITY...AND WARM TEMPERATURES WILL CREATE EXPLOSIVE FIRE GROWTH POTENTIAL. $$ CAZ261-262-210500- /O.CON.KSGX.FW.W.0021.080520T2100Z-080521T0500Z/ COACHELLA VALLEY- INCLUDING THE PALM SPRINGS SOUTH COAST DESERT DISTRICT- SAN DIEGO COUNTY DESERTS- INCLUDING THE ANZA BORREGO DESERT STATE PARK- 132 PM PDT TUE MAY 20 2008 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 10 PM PDT THIS EVENING... A RED FLAG WARNING REMAINS IN EFFECT UNTIL 10 PM PDT THIS EVENING. WIND GUSTS GREATER THAN 35 MPH COMBINED WITH RELATIVE HUMIDITY LESS THAN 15 PERCENT WILL CONTINUE THROUGH 2200 PDT. WINDS ARE FORECAST TO BE STRONGER LATER TONIGHT AND WEDNESDAY BUT HUMIDITY SHOULD BE ABOVE 15 PERCENT THEN. A RED FLAG WARNING MEANS THAT CRITICAL FIRE WEATHER CONDITIONS ARE EITHER OCCURRING NOW...OR WILL SHORTLY. A COMBINATION OF STRONG WINDS...LOW RELATIVE HUMIDITY...AND WARM TEMPERATURES WILL CREATE EXPLOSIVE FIRE GROWTH POTENTIAL. $$ BALFOUR
000 WWUS86 KSGX 210410 RFWSGX RED FLAG WARNING NATIONAL WEATHER SERVICE SAN DIEGO CA 910 PM PDT TUE MAY 20 2008 CAZ255-256-260>262-210515- /O.CAN.KSGX.FW.W.0021.000000T0000Z-080521T0500Z/ SAN BERNARDINO COUNTY MOUNTAINS- INCLUDING THE MOUNTAIN TOP AND FRONT COUNTRY RANGER DISTRICTS OF THE SAN BERNARDINO NATIONAL FOREST-RIVERSIDE COUNTY MOUNTAINS- INCLUDING THE SAN JACINTO RANGER DISTRICT OF THE SAN BERNARDINO NATIONAL FOREST-VICTOR VALLEY-APPLE VALLEY-LUCERNE VALLEY- YUCCA VALLEY-MORONGO VALLEY-COACHELLA VALLEY- INCLUDING THE PALM SPRINGS SOUTH COAST DESERT DISTRICT- SAN DIEGO COUNTY DESERTS- INCLUDING THE ANZA BORREGO DESERT STATE PARK- 910 PM PDT TUE MAY 20 2008 ...RED FLAG WARNING IS CANCELLED... THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS CANCELLED THE RED FLAG WARNING. WEATHER CONDITIONS ARE STILL EXPECTED TO BE WARM AND DRY IN THE DESERTS THROUGH WEDNESDAY...HOWEVER RED FLAG CONDITIONS ARE NOT EXPECTED TO PERSIST LONG ENOUGH TO MEET RED FLAG WARNING CRITERIA. $$ SCV
The office that day
Everything else NWS San Diego, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 20, 4:03 AM PDT | High Wind Warning | SGX | San Bernardino | 5 hr |
| May 20, 4:03 AM PDT | Wind Advisory | SGX | Riverside, San Bernardino, San Diego | 38 hr |
| May 20, 8:33 AM PDT | High Wind Watch | SGX | Riverside, San Bernardino, San Diego | 13 hr |
| May 20, 1:13 PM PDT | High Wind Warning | SGX | San Bernardino | 29 hr |
Nearby
Red Flag Warnings in California, 2008Every red flag warning in 2008
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.