Alert archive / California / Tornado Warnings in 2011
Tornado Warning 1, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this tornado warning at Mar 18, 2011, 11:02 AM PDT for San Mateo County, California. It was in force for 28 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Mar 18, 2011, 11:02 AM PDT (18:02 UTC)
- Expired
- Mar 18, 2011, 11:30 AM PDT
- In force
- 28 min
- Issued by
- NWS San Francisco Bay Area, CA
- Area
- Storm-based polygon
County San Mateo County, CA
The radar
The San Francisco radar (KMUX), 59 km from the middle of the area, began a volume at 18:02 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
Oakland, CA (KOAK), launched 12:00Z, 6.0 hours before the alert went out and 23 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
- 21 J/kg
- Mixed-layer CIN
- -28 J/kg
- Mixed-layer LCL
- 757 m above ground
- 0-6 km bulk shear
- 68 kt
- 0-1 km storm-relative helicity
- 203 m²/s²
- 0-3 km storm-relative helicity
- 285 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
219
WFUS56 KMTR 181802
TORMTR
CAC081-181830-
/O.NEW.KMTR.TO.W.0001.110318T1802Z-110318T1830Z/
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1102 AM PDT FRI MAR 18 2011
THE NATIONAL WEATHER SERVICE IN THE SAN FRANCISCO BAY AREA HAS
ISSUED A
* TORNADO WARNING FOR...
SAN MATEO COUNTY IN WESTERN CALIFORNIA...
THIS INCLUDES THE CITIES OF...SAN MATEO...SAN CARLOS...REDWOOD
CITY...MILLBRAE...FOSTER CITY...BURLINGAME...BELMONT...
* UNTIL 1130 AM PDT
* AT 1058 AM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR HALF MOON
BAY...OR 10 MILES WEST OF BELMONT...MOVING NORTHEAST AT 30 MPH.
* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
HILLSBOROUGH AND HALF MOON BAY
PRECAUTIONARY/PREPAREDNESS ACTIONS...
IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER IN A NEARBY REINFORCED
BUILDING. AS A LAST RESORT...SEEK SHELTER IN A CULVERT...DITCH OR LOW
SPOT AND COVER YOUR HEAD WITH YOUR HANDS.
THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.
IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.
&&
LAT...LON 3765 12237 3761 12234 3760 12230 3758 12229
3759 12224 3755 12222 3754 12218 3752 12216
3738 12241 3748 12245 3750 12250 3754 12252
TIME...MOT...LOC 1801Z 233DEG 27KT 3747 12244
$$
RILEY1 follow-up statement
392
WWUS56 KMTR 181815
SVSMTR
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1115 AM PDT FRI MAR 18 2011
CAC081-181830-
/O.CON.KMTR.TO.W.0001.000000T0000Z-110318T1830Z/
SAN MATEO CA-
1115 AM PDT FRI MAR 18 2011
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1130 AM PDT FOR SAN
MATEO COUNTY...
AT 1111 AM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO. THIS TORNADO WAS LOCATED NEAR BELMONT...MOVING
NORTHEAST AT 40 MPH.
OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO FOSTER
CITY AND REDWOOD CITY
PRECAUTIONARY/PREPAREDNESS ACTIONS...
THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.
IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.
&&
LAT...LON 3759 12242 3762 12235 3761 12234 3760 12230
3758 12229 3759 12224 3755 12222 3754 12218
3752 12216 3742 12233
TIME...MOT...LOC 1815Z 246DEG 34KT 3754 12227
$$
RILEYThe office that day
Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 18, 9:49 AM PDT | High Wind Watch | MTR | Alameda, Contra Costa, Marin, Monterey, Napa, San Benito and 5 more | 28 hr |
| Mar 18, 11:43 AM PDT | Special Weather Statement | MTR | San Mateo | 47 min |
Nearby
Tornado Warnings in California, 2011Every tornado warning in 2011Tornadoes in 2011
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.