Alert archive / California / Flash Flood Watches in 2007

Flash Flood Watch 7, NWS San Diego, CA

September 1, 20074 counties in California

NWS San Diego, CA issued this flash flood watch at Sep 1, 2007, 5:49 PM PDT for 4 counties in California. It took effect at Sep 2, 2007, 10:00 AM PDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued: Sep 1, 2007, 5:49 PM PDT (00:49 UTC)
In effect from: Sep 2, 2007, 10:00 AM PDT
Expired: Sep 2, 2007, 7:00 PM PDT
In force: 9 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 00:51 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.

The nearest sounding before it

San Diego, CA (KNKX), launched 00:00Z, 0.8 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 860 J/kg
Mixed-layer CIN: -265 J/kg
Mixed-layer LCL: 2571 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: 33 m²/s²
0-3 km storm-relative helicity: 44 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

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 Sep 1, 2:00 PM PDT, 3 hours 49 minutes earlier.

Area forecast discussion, Sep 1, 2:00 PM PDT, 3 hours 49 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
200 PM PDT SAT SEP 1 2007

.SYNOPSIS...
HIGH PRESSURE OVER ARIZONA WILL BRING HOT HUMID WEATHER THROUGH
LABOR DAY. MOISTURE IN SOUTHEAST FLOW ALOFT WILL BRING A CHANCE OF
MAINLY AFTERNOON AND EVENING THUNDERSTORMS...AND MAINLY IN THE
MOUNTAINS AND DESERTS. SOME THUNDERSTORMS WILL PRODUCE HEAVY
RAINFALL AND LOCAL FLOODING. COOLER AND LESS HUMID WEATHER IS
EXPECTED TUESDAY AND THROUGH THE MIDDLE OF NEXT WEEK.

&&

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

THUNDERSTORMS HAVE FIRED ALL ALONG THE PENINSULAR RANGE OF SOCAL
WITH SOME DRIFT INTO THE FAR INLAND VALLEYS. RAIN IS HEAVY BUT THE
STORMS ARE NOT LONG LASTING. EVEN SO...MANY CAN PRODUCE FLASH
FLOODING IN A VERY SHORT TIME. THE FLOW...THE DYNAMICS AND THE
MOISTURE LOOK NEARLY IDENTICAL THROUGH THE HOLIDAY MON. SO THE
TSTORMS AND THE THREAT OF FLASH FLOODING WILL CONTINUE. SMALL
CHANCES OF PRECIP WILL CONTINUE EVEN DURING SUN AND MON NIGHTS. WEAK
EASTERLY FLOW WILL NUDGE SOME OF THOSE TSTORMS WESTARD INTO THE
VALLEYS ON SUN. THE HEAT LOOKS THE SAME TOO THROUGH THE HOLIDAY
EXCEPT FOR PERHAPS A COUPLE DEGREES OF COOLING ON MON. A TROUGH OF
LOW PRESSURE COMING OUT OF THE NORTHWEST TUE AND WED IS LOOKING MORE
CONSISTENT LATELY ON THE STRENGTH AND THE TIMING. THIS WILL BRING A
COOLING TREND AND MORE COASTAL CLOUDS. AS THE TROUGH PASSES...JUST A
TOUCH OF OFFSHORE FLOW DEVELOPS WED AND THU MORNINGS. NOT ENOUGH FOR
REALLY STRONG OFFSHORE WINDS...BUT MAYBE ENOUGH TO DRY OUT THE AIR
AND INCREASE THE FIRE POTENTIAL BRIEFLY. ANOTHER FEATURE TO WATCH IS
THE MOISTURE ASSOCIATED WITH THE REMNANTS OF HENRIETTE. EXTENDED
MODELS SHOW MOST OF THAT MOISTURE GOING INTO AZ ON THU AND FRI...BUT
ENOUGH TO CLIP AT LEAST THE SOUTHEAST PART OF OUR REGION AND BRING
SHOWERS AND/OR TSTORMS.

&&

.AVIATION...
011930..TWO MAIN PROBLEMS THROUGH SUNDAY WILL BE THE AFTERNOON
THUNDERSTORM ACTIVITY OVER THE MOUNTAINS AND ADJACENT VALLEY AND
DESERT AREAS AND THE MAXIMUM TEMPERATURES AT THE AREA AIRPORTS.

ISOLATED TO SCATTERED THUNDERSTORMS OVER THE MOUNTAINS THIS
AFTERNOON SHOULD END BY SUNSET BUT SHOULD DEVELOP BY NOON ON SUNDAY
AND CONTINUE THROUGH THE AFTERNOON. BASES SHOULD BE AT OR ABOVE
FL080 WITH TOPS TO FL450 AT TIMES.

MAXIMUM TEMPERATURES FOR SUNDAY SHOULD BE SIMILAR. MAXIMUM
TEMPERATURES AT KSAN AND KSNA SHOULD BE BETWEEN 28 AND 32 DEGREES
C...NEAR 43 DEGREES C AT KONT AND BETWEEN 45 AND 47 DEGREES C AT
KPSP AND KTRM.

THE MARINE LAYER REMAINS VERY SHALLOW SO MARINE LAYER STRATUS/FOG IS
NOT EXPECTED TO BE A FACTOR AT ANY OF THE COASTAL AIRPORTS THROUGH
SUNDAY.  HORTON

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 7 PM THIS EVE FOR MTNS AND UPPER DESERT...
SEE LAXFFASGX.
EXCESSIVE HEAT WARNING FROM 10 AM TO 7 PM TODAY AND SUNDAY FOR
INLAND AREAS...SEE LAXNPWSGX.

&&

PUBLIC...MM
AVIATION/MARINE...HORTON

NWS ON THE WEB AT WEATHER.GOV/SANDIEGO

Hazardous weather outlook, Sep 1, 4:00 PM PDT, 1 hour 49 minutes before

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In the hours before

Local storm report, Sep 1, 2:25 PM PDT, 3 hours 24 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
225 PM PDT SAT SEP 01 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0220 PM     FLASH FLOOD      WRIGHTWOOD              34.36N 117.63W
09/01/2007                   SAN BERNARDINO     CA   TRAINED SPOTTER

            FLASH FLOOD IN PROGRESS AT LONE PINE AND SHEEP CREEK WASH

&&

MANU

Local storm report, Sep 1, 2:27 PM PDT, 3 hours 22 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
227 PM PDT SAT SEP 01 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0203 PM     FLASH FLOOD      FOREST FALLS            34.09N 116.92W
09/01/2007                   SAN BERNARDINO     CA   TRAINED SPOTTER

            FLASH FLOOD IN PROGRESS AT MT HOME JUST S OF FOREST
            FALLS.

&&

MANU

Local storm report, Sep 1, 2:30 PM PDT, 3 hours 19 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
230 PM PDT SAT SEP 01 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0203 PM     FLASH FLOOD      OAK GROVE               33.38N 116.79W
09/01/2007                   SAN DIEGO          CA   NWS EMPLOYEE

            FLASH FLOOD IN OAK GROVE. 3-4 INS. ACROSS HWY 79. DOWNED
            TREES AND MANY LARGE LIMBS BLOCKING ROAD.

&&

MANU

Local storm report, Sep 1, 2:33 PM PDT, 3 hours 16 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
233 PM PDT SAT SEP 01 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0129 PM     TSTM WND DMG     PALOMAR MOUNTAIN        33.36N 116.83W
09/01/2007                   SAN DIEGO          CA   NWS EMPLOYEE

            DOWNED TREE LIMBS 6-8 INS. DIAMETER CAUSED A 2 CAR
            ACCIDENT ON HWY 76.

&&

MANU

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 2, 3:17 AM PDT	Excessive Heat Warning	SGX	Riverside, San Bernardino, San Diego	40 hr
Sep 2, 12:26 PM PDT	Flash Flood Warning	SGX	San Bernardino	64 min
Sep 2, 1:18 PM PDT	Flash Flood Warning	SGX	San Bernardino	72 min
Sep 2, 1:49 PM PDT	Severe Thunderstorm Warning	SGX	Riverside	56 min
Sep 2, 2:17 PM PDT	Severe Thunderstorm Warning	SGX	San Diego	28 min
Sep 2, 2:23 PM PDT	Flash Flood Warning	SGX	San Bernardino	3 hr
Sep 2, 2:25 PM PDT	Severe Thunderstorm Warning	SGX	Orange, Riverside	45 min
Sep 2, 3:44 PM PDT	Severe Thunderstorm Warning	SGX	Riverside, San Diego	61 min

Nearby

Flash Flood Watches in California, 2007 Every flash flood watch in 2007

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.