Alert archive / California / Flash Flood Warnings in 1997

Flash Flood Warning 45, NWS San Diego, CA

December 6, 1997Riverside County, San Diego County, California

NWS San Diego, CA issued this flash flood warning at Dec 6, 1997, 7:55 PM PST for Riverside County, San Diego County, California. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Dec 6, 1997, 7:55 PM PST (03:55 UTC)
Expired
Dec 6, 1997, 10:00 PM PST
In force
2 hr
Issued by
NWS San Diego, CA
Area
Whole counties

Counties Riverside County, CA, San Diego County, CA

The nearest sounding before it

San Diego, CA (KNKX), launched 00:00Z, 3.9 hours before the alert went out and 100 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 1997-12-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 554 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 00:00Z on 1997-12-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 58 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
554 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
731 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
58 m²/s²
0-3 km storm-relative helicity
88 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.9

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

The local office's own words before this flash flood 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 flash flood warning went out at Dec 6, 2:51 PM PST, 5 hours 4 minutes earlier.

Area forecast discussion, Dec 6, 2:51 PM PST, 5 hours 4 minutes before
SOUTHWESTERN CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
250 PM PST SAT DEC 6 1997

                          ...SYNOPSIS...
THE CENTER OF A MAJOR STORM SYSTEM WILL MOVE THROUGH SOUTHERN
CALIFORNIA TONIGHT. THIS WILL BRING SHOWERS AND THUNDERSTORMS
TONIGHT...SOME WITH HEAVY RAIN. A FLASH FLOOD WATCH COVERS ALL AREAS
EXCEPT THE LOWER DESERTS TONIGHT...AND A WINTER STORM WARNING COVERS
THE RIVERSIDE AND SAN BERNARDINO COUNTY MOUNTAINS ABOVE 6500 FEET
TONIGHT FOR 8 TO 14 INCHES OF SNOW. AS THE SYSTEM MOVES EAST OF SAN
DIEGO SUNDAY...THE PRECIPITATION SHOULD TAPER TO SOME SHOWERS. A
DISTURBANCE ON THE BACK SIDE OF THE TROUGH COULD BRING MORE SHOWERS
MONDAY.

                         ...DISCUSSION...
THE BIGGEST CONCERN RIGHT NOW IS THE SQUALL LINE ABOUT 80 MILES
OFFSHORE. NKX DOPPLER RADAR INDICATES ONE CELL HAVING AN INTENSITY
GREATER THAN 50 DBZ ALREADY...AND WITH THE HISTORY OF THE STORMS
TODAY...THE INTENSITIES GENERALLY INCREASED AS THE APPROACHED THE
COAST...SO WARNINGS OF SOME SORT MAY HAVE TO BE ISSUED WHEN THIS
SQUALL LINE HITS LAND. ALSO...LEFTOVER RAIN IN EASTERN ORANGE COUNTY
AND WESTERN RIVERSIDE COUNTY CONTINUES TO BE LOCALLY HEAVY SO THOSE
AREAS WILL NOT GET MUCH...IF ANY...OF A BREAK BEFORE THE SQUALL LINE.

ANOTHER MAJOR CONCERN IS SNOW ABOVE 6500 FEET. BIG BEAR HAS ALREADY
HAD 2 TO 6 INCHES...AND WITH THIS SQUALL LINE WITH DEEP CELLS MOVING
TOWARDS LAND...HEAVY SNOW SHOULD OCCUR WITH THE UPSLOPE IN THE SAN
BERNARDINO/RIVERSIDE COUNTY MOUNTAINS.

THE 12Z MODELS PLUS 15Z MSO SEEMED TO BE ON TRACK FOR MOVING THE
500MB VORT MAX RIGHT TOWARDS SAN DIEGO. THE TIMING OF THE VORT
MAX...NOW ABOUT 150 SOUTH OF PT CONCEPTION...IS FOR LANDFALL AROUND
12Z SUN. AFTER THAT...THE PRECIPITATION SHOULD DECREASE...BUT
RESIDUAL MOISTURE ABOVE 70 PERCENT AT 850MB WILL KEEP SCATTERED
SHOWERS IN THE AREA THROUGH MONDAY. SOME TROUGHING AT 850 AND 700MB
WILL HELP KEEP A CHANCE OF SHOWERS MONDAY TOO. AT LEAST...SKIES WILL
REMAIN MOSTLY CLOUDY...AND WITH STRONG HEIGHT GRADIENTS
ALOFT...BREEZY TO LOCALLY WINDY CONDITIONS ARE LIKELY.

SAN WE 056/064 054/064 052 07+433

MAXWELL

In the hours before

Local storm report, Dec 6, 4:24 PM PST, 3 hours 31 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO, CA
430 PM PDT SAT DEC 6 1997

TIME(PST)  .....CITY LOCATION.....STATE    ...EVENT/REMARKS...
           ....COUNTY LOCATION....
825 AM     WRIGHTWOOD                CA    FLOODING.
12/6/97    SAN BERNARDINO                  HWY 2 FLOODED.

855 AM     ELSINORE                  CA    FLOODING.
12/6/97    RIVERSIDE                       2 TO 3 FEET OF WATER IN
                                           CITY STREETS.

855 AM     NORCO                     CA    FLOODING.
12/6/97    RIVERSIDE                       2 TO 3 FEET OF WATER IN
                                           CITY STREETS.

1015 AM    EL TORO                   CA    HEAVY RAIN.
12/6/97    ORANGE                          1/2 INCH IN 10 MINUTES.

1100 AM    WOODBRIDGE LAKE           CA    FLOODING.
12/6/97    ORANGE                          WOODBRIDGE LAKE
                                           OVERFLOWED.

1145 AM    SILVERADO CANYON          CA    MUDSLIDE.
12/6/97    ORANGE                          SILVERADO ROAD CLOSED.

1155 AM    ORANGE COUNTY             CA    HEAVY RAIN.
12/6/97    ORANGE                          5 ROOFS COLLAPSED

1155 AM    ORANGE COUNTY             CA    FLOODING.
12/6/97    ORANGE                          128 EVACUATIONS IN COUNTY.
                                           SOME PEOPLE WERE STRANDED
                                           ON TOP OF THEIR CARS.

230 PM     EL TORO                   CA    HEAVY RAIN.
12/6/97    ORANGE                          .42 INCHES IN 15 MINUTES.

300 PM     MORENO VALLEY             CA    MUDSLIDE.
12/6/97    RIVERSIDE                       MUDSLIDE CLOSED ROAD.

400 PM     LAGUNA BEACH              CA    HEAVY RAIN.
12/6/97    ORANGE                          24 HOUR RAINFALL 6.81 IN
                                           WITH MAJOR FLOODING MOST
                                           OF SATURDAY. LAGUNA CYN
                                           ROAD CLOSED BY MUDSLIDES.

400 PM     IRVINE                    CA    HEAVY RAIN.
12/6/97    ORANGE                          24 HOUR RAINFALL 6.73 IN
                             `              AT NEARBY GAUGE WITH MAJOR
                                           FLOODING MOST OF SATURDAY.

MAXWELL

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 6, 6:24 PM PSTFlash Flood WarningSGXSan Diego66 min
Dec 6, 7:30 PM PSTFlash Flood WarningSGXSan Diego60 min
Dec 6, 7:55 PM PSTFlash Flood WarningSGXOrange, San Bernardino2 hr

Nearby

Flash Flood Warnings in California, 1997Every flash flood warning in 1997

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.