Alert archive / California / Winter Storm Watches in 2012

Winter Storm Watch 6, NWS San Diego, CA

April 12, 2012San Diego County, California

NWS San Diego, CA issued this winter storm watch at Apr 12, 2012, 9:25 AM PDT for San Diego County, California. It took effect at Apr 13, 2012, 2:00 PM PDT. It was in force for .

The area

The counties it named.

The facts

Issued
Apr 12, 2012, 9:25 AM PDT (16:25 UTC)
In effect from
Apr 13, 2012, 2:00 PM PDT
Expired
Apr 12, 2012, 1:08 PM PDT
In force
Issued by
NWS San Diego, CA

County San Diego County, CA

The radar

The San Diego radar (KNKX), 28 km from the middle of the area, began a volume at 16:26 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, 4.4 hours before the alert went out and 47 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 12:00Z on 2012-04-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 41 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, San Diego, CA at 12:00Z on 2012-04-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 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
41 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
579 m above ground
0-6 km bulk shear
62 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
5 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 winter storm 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 winter storm watch went out at Apr 12, 3:45 AM PDT, 5 hours 40 minutes earlier.

Area forecast discussion, Apr 12, 3:45 AM PDT, 5 hours 40 minutes before
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Hazardous weather outlook, Apr 12, 4:32 AM PDT, 4 hours 53 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN DIEGO CA
432 AM PDT THU APR 12 2012

CAZ042-043-048-050-057-058-PZZ750-775-131145-
ORANGE COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS-
SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-
SAN DIEGO COUNTY VALLEYS-SANTA ANA MOUNTAINS AND FOOTHILLS-
SAN DIEGO COUNTY MOUNTAINS-
COASTAL WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER AND OUT
30 NM-
WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER EXTENDING 30 TO
60 NM OUT INCLUDING SAN CLEMENTE ISLAND-
432 AM PDT THU APR 12 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EXTREME
SOUTHWESTERN CALIFORNIA.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY
A WINTER STORM WILL MOVE ACROSS THE AREA FRIDAY THROUGH SATURDAY
MORNING. GUSTY WINDS AND MODERATE TO HEAVY PRECIPITATION IS LIKELY
SMALL CRAFT ADVISORIES MAY BE IN EFFECT ALONG WITH ADVISORIES FOR
URBAN AND SMALL STREAM FLOODING.

FOR SUNDAY NIGHT THROUGH TUESDAY...GUSTY NORTHEAST WINDS ARE
POSSIBLE THROUGH AND BELOW CANYONS AND PASSES.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY.

CAZ060>062-131145-
APPLE AND LUCERNE VALLEYS-COACHELLA VALLEY-
SAN DIEGO COUNTY DESERTS-
432 AM PDT THU APR 12 2012

...HIGH WIND WATCH IN EFFECT FROM FRIDAY MORNING THROUGH FRIDAY
EVENING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EXTREME
SOUTHWESTERN CALIFORNIA.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY
DAMAGING WINDS AND AREAS OF BLOWING SAND WITH VISIBILITY NEAR ZERO
ARE POSSIBLE FROM LATE FRIDAY MORNING THROUGH FRIDAY EVENING
AHEAD OF A COLD FRONT.

FOR FRIDAY NIGHT THROUGH NEXT TUESDAY...NORMALLY DRY WASHES WILL
BE FLOWING DUE TO A COMBINATION OF RUNOFF HEAVY RAINS OVER THE
MOUNTAINS FRIDAY NIGHT AND MELTING SNOW AS TEMPERATURES RAPIDLY
WARM TO ABOVE NORMAL SUNDAY THROUGH TUESDAY.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY.

CAZ055-056-131145-
SAN BERNARDINO COUNTY MOUNTAINS-RIVERSIDE COUNTY MOUNTAINS-
432 AM PDT THU APR 12 2012

...WINTER STORM WATCH IN EFFECT FROM LATE TONIGHT THROUGH LATE
FRIDAY NIGHT...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EXTREME
SOUTHWESTERN CALIFORNIA.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED TODAY.

LIGHT RAIN WITH SNOW ABOVE 5000 FEET SHOULD BEGIN THIS EVENING.
HEAVY RAIN AND SNOW IS FORECAST FOR LATE TONIGHT OVER THE SAN
GABRIEL MOUNTAINS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY
HEAVY SNOW SPREADING EAST ACROSS THE SAN BERNARDINO MOUNTAINS
FRIDAY MORNING...REACHING THE SAN JACINTO MOUNTAINS BY NOON
FRIDAY. PERIODS OF HEAVY SNOW MAY CONTINUE INTO FRIDAY NIGHT.

FOR SUNDAY NIGHT THROUGH TUESDAY...WEAK TO MODERATE STRENGTH
NORTHEAST WINDS EXPECTED THROUGH MOUNTAINS PASSES AND CANYONS AS
HIGH PRESSURE BUILDS TO THE NORTH.

.SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE
NEEDED TODAY.

BALFOUR

In the hours before

Special weather statement, Apr 12, 4:39 AM PDT, 4 hours 46 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Apr 12, 2:40 AM PDTWinter Storm WatchSGXRiverside, San Bernardino7 hr
Apr 12, 2:55 AM PDTHigh Wind WatchSGXRiverside, San Bernardino, San Diego11 hr
Apr 12, 9:25 AM PDTWinter Storm WarningSGXRiverside, San Bernardino, San Diego52 hr
Apr 12, 12:01 PM PDTSmall Craft AdvisorySGX57 hr
Apr 12, 1:36 PM PDTHigh Wind WarningSGXRiverside, San Bernardino, San Diego33 hr

Nearby

Winter Storm Watches in California, 2012Every winter storm watch in 2012

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.