Alert archive / California / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 16, NWS Medford, OR

July 30, 1997Siskiyou County, California

NWS Medford, OR issued this severe thunderstorm warning at Jul 30, 1997, 7:00 PM PDT for Siskiyou County, California. It was in force for 30 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 30, 1997, 7:00 PM PDT (02:00 UTC)
Expired
Jul 30, 1997, 7:30 PM PDT
In force
30 min
Issued by
NWS Medford, OR
Area
Whole counties

County Siskiyou County, CA

The radar

The Medford radar (KMAX), 56 km from the middle of the area, began a volume at 02:04 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, 2.0 hours before the alert went out and 89 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 1997-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 726 joules per kilogram.LCLLFCEL10008507005003002001001 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, Medford/Jackson, OR at 00:00Z on 1997-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 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
726 J/kg
Mixed-layer CIN
-107 J/kg
Mixed-layer LCL
2032 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
137 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMFR 310207 RRA
SVRMFR
CAC093-310230-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MEDFORD OR
700 PM PDT WED JUL 30 1997

THE NATIONAL WEATHER SERVICE IN MEDFORD OR HAS ISSUED A SEVERE
THUNDERSTORM WARNING EFFECTIVE UNTIL 730 PM PDT FOR PEOPLE IN THE
FOLLOWING LOCATIONS...

IN NORTH CENTRAL CALIFORNIA

  ...NORTH CENTRAL SISKIYOU COUNTY

<

...STRONG THUNDERSTORMS OVER THE NORTHERN SCOTT VALLEY...

AT 700 PM PDT...WEATHER RADAR INDICATED A SEVERE THUNDERSTORM 4 MILES
NORTH OF FORT JONES. THE THUNDERSTORM WAS MOVING NORTH AT 15 MPH.
THIS THUNDERSTORM WILL AFFECT EXTREME NORTH SCOTT VALLEY THROUGH 715
PM THEN MOVE OVER THE MOUNTAINS TOWARD I-5 AND THE TOWN OF HORNBROOK.

RADAR INDICATED THAT THIS THUNDERSTORM WAS CAPABLE OF PRODUCING
STRONG...GUSTY WINDS TO NEAR 60 MPH...3/4 INCH HAIL AND LOCALLY HEAVY
RAIN.

TAKE NECESSARY PRECAUTIONS FOR YOUR PROTECTION. ALSO...REMEMBER THAT
THUNDERSTORM RAINS CAN CAUSE  LOCALIZED FLOODING.

SARGEANT

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 Medford, OR wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 30, 2:30 PM PDT, 4 hours 30 minutes earlier.

Area forecast discussion, Jul 30, 2:30 PM PDT, 4 hours 30 minutes before
SOUTHWEST OREGON/NORTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
230 PM PDT WED JUL 30 1997

TSTM ACTIVITY DEVLOPG AS EXPCTD SO BUSY EVENG IN STORE AS SOME STORMS
MAY GO SVR DUE TO HAIL.  WL ALSO HV TO KP AN EYE ON PSBL FFW AS 88D
SHWG STORM MVMT 5-10KTS.  ACTIVITY OF CONCERN IN ORZ015 AND CAZ011-
012.  WL CONT TO INDC SLGT CHC EVENG TSTMS PARTS OF ZNS 7/8 AS MFR IS
ONLY 1 DEG FROM CPT.  EXPCT TO EXCEED AM CPT BY 3-4 DEGS.  AGAIN
PROGS SHWG LTL CHG THUR.  THEY CONT TO TRY AND STABLZ WSIDE LOCATIONS
DUE TO INCR ONSHR LLVL FLOW.  WL BUY INTO THAT FOR NOW.  ESIDE ZONES
AND CA ZONES CONT UNSTBL WITH SCTD AFTN/EVENG TSTMS.  MST ACTIVE AREA
THO SHUD BE NE OF CWA. EXTNDD MDLS ALL LIKE STRNGTHNG THE TROF JST
OFSHR FRI-SUN.  END RESULT MIGHT BE SLGT COOLG.  PDX SHOWG THIS IN
EXTNDD FCST SO EXTNDD PACKAGE LUKS GUD.  DDG

.MFR...NONE

.KMAX...VCP 32...OPERATING.

...SEE PDXCCFPDX FOR CODED CITIES FORECAST

MFR UU 059/091 059/090 060 031111
LMT UU 051/085 050/085 050 033333
RBG UU 058/085 057/083 057 03100-
4BK UU 052/065 053/069 052 030000
OTH UU 053/068 053/070 054 030000
YKA UU 050/091 049/091 049 032222
MHS UU 050/085 049/084 049 032222
S11 UU 046/089 045/089 045 033333

Nearby

Severe Thunderstorm Warnings in California, 1997Every severe thunderstorm warning in 1997

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.