Alert archive / California / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 6, NWS San Diego, CA

February 17, 2017San Diego County, California

NWS San Diego, CA issued this severe thunderstorm warning at Feb 17, 2017, 5:43 PM PST for San Diego County, California. It was in force for 62 min. 3 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Feb 17, 2017, 5:43 PM PST (01:43 UTC)
Expired: Feb 17, 2017, 6:45 PM PST
In force: 62 min
Issued by: NWS San Diego, CA
Area: Storm-based polygon

County San Diego County, CA

The radar

The San Diego radar (KNKX), 32 km from the middle of the area, began a volume at 01:46 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
Feb 17, 5:55 PM PST	NON-TSTM WND DMG	3 Ne San Diego, CA	* 1 FATAL * TREE DOWN ON VEHICLE WITH ONE FATALITY ON NORTHBOUND 15 NEAR INTERSTATE 805 IN CITY HEIGHTS. .
Feb 17, 6:10 PM PST	NON-TSTM WND DMG	7 Sw Poway, CA	TREE DOWN ON VEHICLE NEAR CANYON LAKE DR. AT SCRIPPS RANCH.
Feb 17, 6:48 PM PST	NON-TSTM WND DMG	1 E San Diego, CA	TREE FELL ONTO APT COMPLEX NEXT TO 2650 BROADWAY ST, 30+ FT TALL AND12 IN DIAMETER.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

San Diego, CA (KNKX), launched 00:00Z, 1.7 hours before the alert went out and 36 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: 14 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 1020 m above ground
0-6 km bulk shear: 63 kt
0-1 km storm-relative helicity: 307 m²/s²
0-3 km storm-relative helicity: 383 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

103 
WUUS56 KSGX 180143
SVRSGX
CAC073-180245-
/O.NEW.KSGX.SV.W.0006.170218T0143Z-170218T0245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service San Diego CA
543 PM PST FRI FEB 17 2017

The National Weather Service in San Diego has issued a

* Severe Thunderstorm Warning for...
  Western San Diego County in southwestern California...

* Until 645 PM PST

* At 541 PM PST, National Weather Service doppler radar indicated a
  line of severe thunderstorms capable of producing damaging winds
  in excess of 60 mph. These storms were located along a line extending
  from 20 miles southwest of Laguna Beach to 40 miles southwest of Point
  Loma, and moving east at 25 mph. This intense line of heavy rain and
  high wind will move into coastal cities between 600 and 630 pm.

* Locations impacted include...
  Chula Vista, Oceanside, Carlsbad, El Cajon, Vista, Encinitas,
  National City, La Mesa, Poway, North Park, Point Loma, Hillcrest,
  Midway District Including Lindbergh Field, Downtown San Diego and
  La Jolla.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Severe thunderstorms produce damaging winds, destructive hail, deadly
lightning and very heavy rain. For your protection, move to an
interior room on the lowest floor of your home or business. Heavy
rains flood roads quickly so do not drive into areas where water
covers the road.

&&

LAT...LON 3265 11716 3267 11724 3282 11729 3293 11727
      3310 11732 3327 11745 3339 11759 3345 11758
      3347 11751 3351 11751 3350 11741 3347 11736
      3343 11724 3342 11715 3257 11677 3254 11713
TIME...MOT...LOC 0141Z 047DEG 9KT 3334 11775 3238 11757 

$$
Tardy

1 follow-up statement

206 
WWUS56 KSGX 180235
SVSSGX

Severe Weather Statement
National Weather Service San Diego CA
635 PM PST FRI FEB 17 2017

CAC073-180245-
/O.CON.KSGX.SV.W.0006.000000T0000Z-170218T0245Z/
San Diego CA-
635 PM PST FRI FEB 17 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM PST
FOR WESTERN SAN DIEGO COUNTY...

At 631 PM PST, National Weather Service doppler radar indicated a line of 
severe storms capable of producing damaging winds in excess of 60 mph. The 
highest threat is from La Jolla to Del Mar and areas a few miles inland.
These storms were located along a line extending along the San Diego coast
to Point Loma, moving east at 15 mph. Very heavy rain is associated with
these storms with rainfall up to 0.50 inches per hour. 

Locations impacted include...
Chula Vista, Oceanside, Carlsbad, El Cajon, Vista, Encinitas,
National City, La Mesa, Poway, North Park, Point Loma, Hillcrest,
Midway District Including Lindbergh Field, Downtown San Diego and La
Jolla.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Severe thunderstorms produce damaging winds, destructive hail, deadly
lightning and very heavy rain. For your protection move to an
interior room on the lowest floor of your home or business. Heavy
rains flood roads quickly so do not drive into areas where water
covers the road.

&&

LAT...LON 3265 11716 3267 11724 3282 11729 3293 11727
      3310 11732 3327 11745 3339 11759 3345 11758
      3347 11751 3351 11751 3350 11741 3347 11736
      3343 11724 3342 11715 3257 11677 3254 11713
TIME...MOT...LOC 0231Z 047DEG 9KT 3327 11784 3231 11766 

$$

Tardy

What forecasters said that day

The local office's own words before this severe thunderstorm 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 severe thunderstorm warning went out at Feb 17, 2:41 PM PST, 3 hours 2 minutes earlier.

Area forecast discussion, Feb 17, 2:41 PM PST, 3 hours 2 minutes before

Area Forecast Discussion
National Weather Service San Diego CA
241 PM PST Fri Feb 17 2017

...Major Pacific storm system to greatly impact the region with
damaging wind gusts and flooding this afternoon and evening...

.SYNOPSIS...
A powerful Pacific storm will bring bring damaging winds, flooding
and heavy mountain snow to the region this afternoon and evening.
Winds will decrease as heavy rain turns to showers tonight. Showers
will continue tonight through Sunday morning. Dry weather returns
Sunday, but a small chance of light rain is forecast Monday
through Wednesday.

&&

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

We are confident that major impacts will occur with this storm
system...possibly the strongest storm we've seen this winter.

A band of moderate to heavy rain is currently moving into Orange
and San Bernardino Counties this afternoon. Already strong winds
will increase even more as the rain band gradually tracks through
the region this afternoon and evening. Gusts along the coast will
exceed 50 mph and gusts in parts of the mountains and deserts will
exceed 70 mph. This will be a widespread strong wind event! Plan
for widespread urban flooding, small stream flooding in the
backcountry, and particularly for burn areas. Also expect the wind
to knock down trees and power lines, and the resulting damage and
power outages.

Heaviest rainfall amounts will be over Orange and San Bernardino
Counties. With very high atmospheric moisture in place rainfall
rates of one-half to up to 1 inch per hour will be possible during
the height of the rain event with highest rates along favorable
SSW facing slopes. This amount of short-duration rainfall will
likely lead to significant flooding issues in urbanized areas and
flash flooding in the mountains. Thunderstorms are remotely
possible and may bring briefly intense bursts of rain.

...Rainfall forecast through tonight...

ORANGE COUNTY..............2.5 to 4.5 inches (highest totals in
the Santa Ana Mountains).
SAN BERNARDINO MOUNTAINS...3 TO 8 inches (highest along SSW slopes).
RIVERSIDE COUNTY...........1.5 TO 3 inches.
SAN DIEGO COUNTY...........1.5 TO 2.5 inches.
UPPER AND LOWER DESERTS....0.25 to 1.5 inches.

Snow levels will be around 6500 feet during the heaviest
precipitation, and then lower to about 5000 feet Saturday
morning. Snow showers will continue Saturday and Saturday night.
Total Snowfall forecast is for 4 to 12 inches between 6000 to
7000 feet, 1 to 2 feet between 7000 to 8000 feet, with isolated
amounts of 2 to 3 feet possible above 8000 feet. An inch or two
could fall as low as 5000 feet...bringing winter impacts to the
mountain passes.

After about 9 pm the winds will quickly diminish and the heavy
rain will turn to showers. Showers and isolated thunderstorms
will continue through Saturday and Saturday night.

A ridge of high pressure will bring dry weather Sunday, but
our region will remain on the southern fringes of a stream of
moisture for several days. That will mean small chances of light
showers Monday through Wednesday. A trough of low pressure on
Wednesday will bring more winds. Dry weather appears to follow
Thursday heading into next weekend.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...High Wind Warning until 2 AM PST Saturday for Apple and Lucerne
     Valleys-Coachella Valley-Orange County Coastal Areas-Orange
     County Inland Areas-San Bernardino and Riverside County
     Valleys-The Inland Empire-San Diego County Coastal Areas-
     San Diego County Deserts-San Diego County Mountains-San
     Diego County Valleys-San Gorgonio Pass Near Banning-Santa
     Ana Mountains and Foothills.

     Flash Flood Watch through Saturday afternoon for Apple and
     Lucerne Valleys-Coachella Valley-Orange County Coastal
     Areas-Orange County Inland Areas-Riverside County Mountains-
     San Bernardino County Mountains-San Bernardino and
     Riverside County Valleys-The Inland Empire-San Diego County
     Coastal Areas-San Diego County Deserts-San Diego County
     Mountains-San Diego County Valleys-San Gorgonio Pass Near
     Banning-Santa Ana Mountains and Foothills.

     Winter Storm Warning until 7 AM PST Saturday for Riverside
     County Mountains-San Bernardino County Mountains.

     High Surf Warning until 10 PM PST Sunday for Orange County
     Coastal Areas-San Diego County Coastal Areas.

PZ...Gale Warning until 10 PM PST Sunday for Coastal Waters from San
     Mateo Point to the Mexican Border and out to 30 nm-Waters
     from San Mateo point to the Mexican Border Extending 30 to
     60 nm out including San Clemente Island.

&&

PUBLIC...MM
AVIATION/MARINE/BEACHES...Harrison

In the hours before

Local storm report, Feb 17, 4:52 PM PST, 51 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
452 PM PST FRI FEB 17 2017

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

0442 PM     NON-TSTM WND DMG 2 NNW LA MESA           32.80N 117.03W
02/17/2017                   SAN DIEGO          CA   LAW ENFORCEMENT

            TREE FELL ON VEHICLE IN THE PARKING LOT IN
            FRONT OF THE COWLS MOUNTAIN VISITORS CENTER
            AT 7000 GOLFCREST DR. TREE APPROX. 15-20
            FEET LONG, 1 FOOT IN DIAMETER, BLOCKING THE
            PARKING AREA.

&&

LJ

Local storm report, Feb 17, 5:02 PM PST, 41 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
502 PM PST FRI FEB 17 2017

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

0347 PM     NON-TSTM WND DMG 2 N SAN DIEGO           32.75N 117.16W
02/17/2017                   SAN DIEGO          CA   DEPT OF HIGHWAYS

            FULL CLOSURE OF HWY 63 NORTH BOUND AFTER A
            LARGE EUCALYPTUS TREE FELL ON A VEHICLE.

&&

LJ

Local storm report, Feb 17, 5:05 PM PST, 38 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
505 PM PST FRI FEB 17 2017

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

0445 PM     NON-TSTM WND DMG 1 N SANTA ANA           33.75N 117.88W
02/17/2017                   ORANGE             CA   LAW ENFORCEMENT

            TREE DOWN, POLE DOWN & LIVE WIRE! STREET
            CLOSED FROM 1300-1400 BLOCK WEST 6TH STREET.
            .

&&

LJ

Local storm report, Feb 17, 5:17 PM PST, 26 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
517 PM PST FRI FEB 17 2017

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

0505 PM     NON-TSTM WND DMG 3 N SAN DIEGO           32.76N 117.15W
02/17/2017                   SAN DIEGO          CA   PUBLIC

            HUGE TREE DOWN ON HOUSE ON MARYLAND STREET
            NEAR MADISON AVE. .

&&

LJ

Local storm report, Feb 17, 5:22 PM PST, 21 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
522 PM PST FRI FEB 17 2017

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

0500 PM     NON-TSTM WND DMG 8 SW POWAY              32.90N 117.11W
02/17/2017                   SAN DIEGO          CA   PUBLIC

            TREE FALLEN ON APARTMENT, GARAGE BUILDING ON
            CAMINITO RIO BRANCO ROAD. .

&&

LJ

Local storm report, Feb 17, 5:33 PM PST, 10 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
533 PM PST FRI FEB 17 2017

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

0520 PM     NON-TSTM WND DMG 4 NNE SAN DIEGO         32.77N 117.12W
02/17/2017                   SAN DIEGO          CA   LAW ENFORCEMENT

            TREE DOWN , POSSIBLY 100 FT TALL, 4 FEET
            DIAMETER/ 2 TELEPHONE POLES ARE ALSO DOWN,
            SPARKING, POWER LINES ARE DOWN.

&&

LJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 17, 4:51 PM PST	Severe Thunderstorm Warning	SGX	Orange	54 min
Feb 17, 5:11 PM PST	Special Marine Warning	SGX		94 min
Feb 17, 5:12 PM PST	Flash Flood Warning	SGX	Orange, Riverside, San Bernardino	4 hr
Feb 17, 5:48 PM PST	Areal Flood Advisory	SGX	San Diego	5 hr
Feb 17, 5:48 PM PST	Severe Thunderstorm Warning	SGX	Orange	57 min
Feb 17, 6:21 PM PST	Flash Flood Warning	SGX	San Bernardino	4 hr
Feb 17, 9:00 PM PST	Small Craft Advisory	SGX		49 hr
Feb 17, 10:15 PM PST	Areal Flood Warning	SGX	Riverside, San Bernardino	9 hr
Feb 17, 10:50 PM PST	Areal Flood Advisory	SGX	Orange, Riverside, San Diego	7 hr

Nearby

Severe Thunderstorm Warnings in California, 2017 Every severe thunderstorm warning in 2017

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.