Alert archive / California / Flash Flood Watches in 2010
Flash Flood Watch 7, NWS San Diego, CA
NWS San Diego, CA issued this flash flood watch at Dec 20, 2010, 4:52 AM PST for 4 counties in California. It took effect at Dec 20, 2010, 12:00 PM PST. It was in force for 54 hr.
The area
The counties it named.
The facts
- Issued
- Dec 20, 2010, 4:52 AM PST (12:52 UTC)
- In effect from
- Dec 20, 2010, 12:00 PM PST
- Expired
- Dec 22, 2010, 6:00 PM PST
- In force
- 54 hr
- Issued by
- NWS San Diego, CA
- Flood severity
- None
Counties Orange County, CA, Riverside County, CA, San Bernardino County, CA, San Diego County, CA
The radar
The Santa Ana Mts radar (KSOX), 88 km from the middle of the area, began a volume at 12:52 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
San Diego, CA (KNKX), launched 12:00Z, 0.9 hours before the alert went out and 124 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
- 170 J/kg
- Mixed-layer CIN
- -14 J/kg
- Mixed-layer LCL
- 447 m above ground
- 0-6 km bulk shear
- 65 kt
- 0-1 km storm-relative helicity
- 126 m²/s²
- 0-3 km storm-relative helicity
- 164 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.4
What forecasters said that day
The local office's own words before this flash flood watch 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 flash flood watch went out at Dec 20, 3:00 AM PST, 1 hour 52 minutes earlier.
Area forecast discussion, Dec 20, 3:00 AM PST, 1 hour 52 minutes before
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</html>Hazardous weather outlook, Dec 20, 4:00 AM PST, 52 minutes before
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SAN DIEGO CA 400 AM PST MON DEC 20 2010 CAZ042-043-048-050-055>058-060>062-211200- ORANGE COUNTY COASTAL AREAS- SAN DIEGO COUNTY COASTAL AREAS- SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE- SAN DIEGO COUNTY VALLEYS- SAN BERNARDINO COUNTY MOUNTAINS- RIVERSIDE COUNTY MOUNTAINS- SANTA ANA MOUNTAINS AND FOOTHILLS- SAN DIEGO COUNTY MOUNTAINS- APPLE AND LUCERNE VALLEYS- COACHELLA VALLEY- SAN DIEGO COUNTY DESERTS- 400 AM PST MON DEC 20 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR ALL OF EXTREME SOUTHWESTERN CALIFORNIA. .DAY ONE...TODAY THROUGH TONIGHT A LARGE PACIFIC PLUME OF MOISTURE AHEAD OF AN ADVANCING TROUGH OF LOW PRESSURE IS EXPECTED TO BRING HEAVY RAINS AND THE POTENTIAL FOR SERIOUS FLOODING BETWEEN LATE THIS AFTERNOON THROUGH WEDNESDAY AFTERNOON. A FLASH FLOOD WATCH IS IN EFFECT FOR ENTIRE AREA. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY HEAVY RAINS AND THE POTENTIAL FOR SERIOUS FLOODING WILL CONTINUE TUESDAY THROUGH WEDNESDAY AFTERNOON. THE SAN BERNARDINO AND RIVERSIDE COUNTY MOUNTAINS COULD GET HEAVY SNOW DOWN TO 6000 FEET TUESDAY NIGHT INTO WEDNESDAY AS THE COLD FRONT COMES IN...AND A WINTER STORM WARNING MAY BE NEEDED THEN. MODELS ALSO INDICATE THAT STRONG THUNDERSTORMS AND WATERSPOUTS COULD ACCOMPANY THE COLD FRONT ON WEDNESDAY. STRONG SOUTH WINDS ARE EXPECTED IN ADVANCE OF THE FRONT SO WIND ADVISORIES IN THE COASTS AND VALLEYS MAY BE REQUIRED ON TUESDAY AND WEDNESDAY. .SPOTTER INFORMATION STATEMENT... SKYWARN SPOTTER ACTIVATION IS NOT REQUESTED FOR THIS AREA...HOWEVER WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS. MACKECHNIE
In the hours before
Special weather statement, Dec 20, 3:33 AM PST, 1 hour 19 minutes before
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</html>The office that day
Everything else NWS San Diego, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 19, 4:11 PM PST | Areal Flood Advisory | SGX | Orange, Riverside, San Bernardino, San Diego | 5 hr |
| Dec 19, 4:45 PM PST | Flash Flood Warning | SGX | San Bernardino | 4 hr |
| Dec 19, 9:00 PM PST | Areal Flood Advisory | SGX | Orange, Riverside, San Bernardino, San Diego | 4 hr |
| Dec 20, 2:26 PM PST | Areal Flood Advisory | SGX | Orange, Riverside, San Bernardino, San Diego | 6 hr |
| Dec 20, 3:14 PM PST | Wind Advisory | SGX | Orange, Riverside, San Bernardino, San Diego | 10 hr |
| Dec 20, 3:25 PM PST | Flash Flood Warning | SGX | Riverside, San Bernardino | 7 hr |
Nearby
Flash Flood Watches in California, 2010Every flash flood watch in 2010
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.