Alert archive / Arizona / Severe Thunderstorm Warnings in 1990
Severe Thunderstorm Warning 40, NWS Phoenix, AZ
NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 21, 1990, 8:21 PM MST for Graham County, Arizona. It was in force for 2 hr.
The area
The counties it named.
The facts
- Issued
- Aug 21, 1990, 8:21 PM MST (03:21 UTC)
- Expired
- Aug 21, 1990, 10:30 PM MST
- In force
- 2 hr
- Issued by
- NWS Phoenix, AZ
- Area
- Whole counties
County Graham County, AZ
The radar
The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.
The nearest sounding before it
Winslow (Autob), AZ (KINW), launched 00:00Z, 3.4 hours before the alert went out and 244 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 3400 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 5 m²/s²
- 0-3 km storm-relative helicity
- 4 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 KPHX 220321 SVRPHX AZC009-220530- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM AND FLASH FLOOD WARNING NATIONAL WEATHER SERVICE PHOENIX ARIZONA 821 PM MST TUE AUG 21 1990 THE NATIONAL WEATHER SERVICE IN PHOENIX ARIZONA HAS ISSUED A SEVERE THUNDERSTORM AND FLASH FLOOD WARNING EFFECTIVE UNTIL 1030 PM MST FOR THE FOLLOWING LOCATIONS...... IN SOUTHEAST ARIZONA ...CENTRAL GRAHAM COUNTY AT 820 PM RADAR AT PHOENIX INDICATED A SEVERE THUNDERSTORM WITH VERY HEAVY RAIN...DAMAGING WINDS AND LARGE HAIL OVER CENTRAL GRAHAM COUNTY. THE STORM WAS CENTERED OVER THE MOUNTAINS NORTH OF PIMA...BUT HAD SPREAD SOUTH AND WEST TO THE PIMA...FORT THOMAS AREA. THIS THUNDERSTORM MAY CAUSE WINDS IN EXCESS OF 70 MPH AND HAILSTONES UP TO 2 INCHES IN DIAMETER...AS WELL AS FLASH FLOODING. THIS WARNING INCLUDES SAFFORD AND POINTS WEST TO THE TOWN OF FORT THOMAS AND BYLAS...ALONG HIGHWAY 70. SEVERE THUNDERSTORMS CAUSE DAMAGING WINDS...LARGE HAIL AND DEADLY LIGHTNING. MOVE INSIDE A REINFORCED BUILDING OR STORM SHELTER. GO TO AN INTERIOR ROOM OR HALLWAY ON THE LOWEST FLOOR. STAY AWAY FROM WINDOWS. WATCH OUT FOR FLASH FLOODING. STAY AWAY FROM STREAMS AND AVOID NARROW STEEP WALLED CANYONS. DONT DRIVE ACROSS FLOODED STREAMS OR WASHES... OR INTO FLOODED CITY STREETS OR UNDERPASSES. TENHARKEL
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, Aug 21, 7:37 PM MST, 44 minutes before
AZC009-220545- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PHOENIX ARIZONA 737 PM MST TUE AUG 21 1990 ...STRONG THUNDERSTORMS NORTHERN GRAHAM COUNTY... RADAR AT PHOENIX SPOTTED A GROUP OF STRONG THUNDERSTORMS ABOUT 10 TO 15 MILES NORTH OF SAFFORD AT 730 PM MST THIS EVENING. THE STORMS WERE MOVING TOWARD THE NORTH...AWAY FROM POPULATED AREAS...SO THEY WERE NOT CONSIDERED A THREAT TO CAUSE WIND OR HAIL DAMAGE. BUT THEY MAY RESULT IN RUNOFF IN DESERT WASHES ON THE NORTH SIDE OF THE GILA RIVER VALLEY ...NORTH OF THE GILA RIVER. THEY COULD ALSO CAUSE AN INCREASE IN THE FLOW OF BONITA CREEK...NORTHEAST OF SAFFORD...SO ANYONE CAMPED IN THIS REMOTE CANYON SHOULD BE SURE THEY ARE ON HIGH GROUND...WELL AWAY FROM THE STREAM. TENHARKEL
The office that day
Everything else NWS Phoenix, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 21, 8:21 PM MST | Flash Flood Warning | PSR | Graham | 2 hr |
Nearby
Severe Thunderstorm Warnings in Arizona, 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; the sounding from the Mesonet's radiosonde archive.