Alert archive / California / Severe Thunderstorm Warnings in 1990
Severe Thunderstorm Warning 2, NWS Sacramento, CA
NWS Sacramento, CA issued this severe thunderstorm warning at Jul 18, 1990, 6:44 PM PDT for Siskiyou County, Trinity County, California. It was in force for 2 hr. 1 report came from inside the area while it was in force.
The area
The counties it named, with what was reported inside it.
The facts
- Issued
- Jul 18, 1990, 6:44 PM PDT (01:44 UTC)
- Expired
- Jul 18, 1990, 8:45 PM PDT
- In force
- 2 hr
- Issued by
- NWS Sacramento, CA
- Area
- Whole counties
Counties Siskiyou County, CA, Trinity County, CA
The radar
The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 18, 8:00 PM PDT | Hail 1 | Trinity, CA |
NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.
The nearest sounding before it
Medford/Jackson, OR (KMFR), launched 00:00Z, 1.7 hours before the alert went out and 139 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
- 157 J/kg
- Mixed-layer CIN
- -94 J/kg
- Mixed-layer LCL
- 3185 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- -6 m²/s²
- 0-3 km storm-relative helicity
- 48 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KRDD 190145 SVRRDD CAC089-093-105-190345- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE REDDING CA 644 PM PDT WED JUL 18 1990 THE NATIONAL WEATHER SERVICE IN REDDING HAS ISSUED A SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 845 PM PDT FOR PEOPLE IN THE FOLLOWING LOCATIONS...S... IN NORTH CALIFORNIA ...WESTERN SHASTA COUNTY...SOUTHWESTERN SISKIYOU COUNTY IN NORTHWEST CALIFORNIA ...TRINITY COUNTY MEDFORD WEATHER RADAR REPORTS A VIP LEVEL 5 THUNDERSTORM LOCATED IN THE VICINITY OF HAYFORK IN TRINITY COUNTY. LOCAL AUTHORITIES HAVE REPORTED HAIL TO 1 INCH IN DIAMETER AS WELL AS HEAVY RAIN IN THE HAYFORK, BIG BAR RANGER STATION, AND BIG FLAT AREAS. THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH YOU SHOULD PREPARE FOR DAMAGING WIND IN EXCESS OF 55 MPH...LARGE HAIL...AND DEADLY LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER... PREFERABLY INSIDE A STRONG BUILDING BUT STAY AWAY FROM WINDOWS. GARRETT
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.
In the hours before
Special weather statement, Jul 18, 4:35 PM PDT, 2 hours 9 minutes before
CAZ006>009-190330
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE REDDING CA
430 PM PDT WED JUL 18 1990
...STRONG THUNDERSTORMS IN THE NORTH VALLEY AND
NORTHERN MOUNTAINS...
SACREMENTO RADAR HAS DETECTED SEVERAL AREAS OF THUNDERSTORMS OVER THE
SURROUNDING MOUNTAINS OF THE NORTHERN SACRAMENTO VALLEY. IN AN AREA
OF THUNDERSTORMS LOCATED ABOUT 25 MILES WEST OF RED BLUFF GROUND
OBSERVERS REPORTED SEEING LIGHTNING...BUT AT THE PRESENT TIME
THERE HAVE BEEN NO REPORTS OF ANY HAIL OR HEAVY RAIN. THESE STORMS
ARE EXPECTED TO MOVE TOWARD THE NORTHEAST AND MAY REACH THE REDDDING
AREA LATER THIS AFTERNOON AND EVENING.
THESE THUNDERSTORMS MAY CAUSE STRONG WINDS...SMALL HAIL...AND HEAVY
RAIN...AS WELL AS THE EVER-PRESENT DANGERS FROM LIGHTNING. SEEK
SHELTER INSIDE A BUILDING IF THESE STORMS MOVE INTO YOUR AREA.
MOISTURE MOVING NORTHWARD FROM THE TROPICS IS RESPONSIBLE FOR THE
INCREASE IN THUNDERSTORM ACTIVITY. THESE CONDITIONS ARE EXPECTED TO
CONTINUE THROUGH THE END OF THE WEEK. SCATTERED MOUNTAIN
THUNDERSTORMS ARE FORECAST THROUGH THE WEEKEND BUT THUNDERSTROM
ACTIVITY SHOULD BE MOSTLY CONFINED TO THE NORTHERN SIERRAS AND
CASCADES AFTER WEDNESDAY.
TRAVELERS TO THE MOUNTAINS SHOULD BE ESPECIALLY WARY OF THUNDERSTORMS
AND STAY AWAY FROM EXPOSED HIGH GROUND, TREES ON RIDGES, AND
BUILDINGS ON RIDGES.
GARRETTThe office that day
Everything else NWS Sacramento, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 18, 6:44 PM PDT | Severe Thunderstorm Warning | STO | Shasta | 2 hr |
Nearby
Severe Thunderstorm Warnings in California, 1990Every severe thunderstorm warning in 1990
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.