Alert archive / California / Severe Thunderstorm Warnings in 2014

Severe Thunderstorm Warning 21, NWS Medford, OR

August 4, 2014Siskiyou County, California

NWS Medford, OR issued this severe thunderstorm warning at Aug 4, 2014, 8:47 PM PDT for Siskiyou County, California. It was in force for 20 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
Aug 4, 2014, 8:47 PM PDT (03:47 UTC)
Expired
Aug 4, 2014, 9:07 PM PDT
In force
20 min
Issued by
NWS Medford, OR
Area
Storm-based polygon

County Siskiyou County, CA

The radar

The Medford radar (KMAX), 51 km from the middle of the area, began a volume at 03:49 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

Medford/Jackson, OR (KMFR), launched 00:00Z, 3.8 hours before the alert went out and 78 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, Medford/Jackson, OR at 00:00Z on 2014-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 907 joules per kilogram.LCLLFCEL10008507005003002001001 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, Medford/Jackson, OR at 00:00Z on 2014-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -7 square meters per square second.1939Sfc1 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
907 J/kg
Mixed-layer CIN
-148 J/kg
Mixed-layer LCL
2195 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
-7 m²/s²
0-3 km storm-relative helicity
-24 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

778 
WUUS56 KMFR 050347
SVRMFR
CAC093-050430-
/O.NEW.KMFR.SV.W.0021.140805T0347Z-140805T0430Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MEDFORD OR
847 PM PDT MON AUG 4 2014

THE NATIONAL WEATHER SERVICE IN MEDFORD HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTH CENTRAL SISKIYOU COUNTY IN NORTHERN CALIFORNIA...

* UNTIL 930 PM PDT

* AT 844 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 6 MILES
  NORTHWEST OF JUANITA LAKE CAMPGROUND...OR 24 MILES NORTHEAST OF
  YREKA...AND MOVING SOUTH AT 10 MPH. IN ADDITION...THIS STORM WILL  
  PRODUCE VERY HEAVY RAINFALL.

* THE SEVERE THUNDERSTORM WILL OTHERWISE REMAIN OVER MAINLY RURAL
  AREAS OF THE INDICATED COUNTY.

LAT...LON 4174 12211 4181 12240 4194 12224 4192 12212
TIME...MOT...LOC 0347Z 018DEG 8KT 4187 12221

$$

WRIGHT
1 follow-up statement
152 
WWUS56 KMFR 050407
SVSMFR

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MEDFORD OR
907 PM PDT MON AUG 4 2014

CAC093-050417-
/O.CAN.KMFR.SV.W.0021.000000T0000Z-140805T0430Z/
SISKIYOU CA-
907 PM PDT MON AUG 4 2014

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL SISKIYOU COUNTY
IS CANCELLED...

THE THUNDERSTORMS HAS WEAKENED BELOW SEVERE LEVELS...HOWEVER HEAVY 
RAIN AND OCCASIONAL LIGHTNING WILL CONTINUE OVER THE AREA FOR THE 
NEXT HALF HOUR.

LAT...LON 4174 12211 4181 12240 4194 12224 4192 12212
TIME...MOT...LOC 0407Z 018DEG 8KT 4183 12223

$$

WRIGHT

The office that day

Everything else NWS Medford, OR issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 4, 7:13 PM PDTSevere Thunderstorm WarningMFRModoc, Siskiyou30 min
Aug 4, 8:41 PM PDTSevere Thunderstorm WarningMFRSiskiyou34 min
Aug 5, 4:30 AM PDTRed Flag WarningMFRModoc, Siskiyou18 hr
Aug 5, 3:56 PM PDTSpecial Weather StatementMFRModoc49 min
Aug 5, 4:27 PM PDTSpecial Weather StatementMFRModoc48 min

Nearby

Severe Thunderstorm Warnings in California, 2014Every severe thunderstorm warning in 2014

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.