Alert archive / Arizona / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 3, NWS Flagstaff, AZ

April 11, 1997Coconino County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Apr 11, 1997, 12:19 AM MST for Coconino County, Arizona. It was in force for 31 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
Apr 11, 1997, 12:19 AM MST (07:19 UTC)
Expired
Apr 11, 1997, 12:50 AM MST
In force
31 min
Issued by
NWS Flagstaff, AZ
Area
Whole counties

County Coconino County, AZ

The radar

The Flagstaff radar (KFSX), 150 km from the middle of the area, began a volume at 07:21 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

Flgstf/Belemont, AZ (KFGZ), launched 00:00Z, 7.3 hours before the alert went out and 68 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, Flgstf/Belemont, AZ at 00:00Z on 1997-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 23 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 00:00Z on 1997-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 square meters per square second.193958Sfc1 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
23 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
1417 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
-23 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.

264 
WUUS1 KFLG 111919
SVRFLG
AZC005-110750-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1219 AM MST FRI APR 11 1997

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1250 AM MST
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN NORTH CENTRAL ARIZONA

   ...EAST CENTRAL COCONINO COUNTY
 
AT 1215 PM MST...DOPPLER RADAR SHOWED A SEVERE THUNDERSTORM 20
MILES NORTHEAST OF FLAGSTAFF...NEAR WUPATKI NATIONAL MONUMENT.
AT 1210 PM...NATIONAL PARKS OFFICIALS AT WUPATKI REPORTED ONE HALF
INCH DIAMETER HAIL COVERING THE GROUND.

THIS THUNDERSTORM WAS MOVING EAST AT 15 MILES AN HOUR.
 
IF YOU ARE IN THE PATH OF THIS STORM AND ARE CAUGHT OUTSIDE...
FIND SHELTER IN A STRONG BUILDING AND STAY AWAY FROM WINDOWS UNTIL
THE STORM HAS PASSED. SEVERE THUNDERSTORMS PRODUCE DAMAGING
WIND...LARGE HAIL...VERY HEAVY RAIN AND DEADLY LIGHTNING.

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 Flagstaff, AZ wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 10, 8:38 PM MST, 3 hours 41 minutes earlier.

Area forecast discussion, Apr 10, 8:38 PM MST, 3 hours 41 minutes before
NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
830 PM MST THU APR 10 1997

00Z ETA-NGM PACKAGE INITIALIZED FAIRLY WELL THIS EVENING.  88D
BEGINNING TO SHOW LESS RETURNS FROM AROUND THE CWA...AS DAYTIME
INSTABILITY SHOWERS BEGIN TO WEAKEN. WILL UPDATE TO DROP MENTION OF
SHOWER ACTIVITY FOR MOST AREAS. BROAD 5H TROUGH...WITH ASSOCIATED
AXIS TO CONTINUE TO SLIDE SLOWLY EASTWARD THE NEXT FEW DAYS.  A FEW
WEAK IMPULSES TO SWING THROUGH CWA AS VORT LOBES CONTINUE TO ROTATE
AROUND TROUGH.  ENOUGH LOW LEVEL MOISTURE AROUND TO KEEP MENTION OF
A FEW SHOWERS IN THE FORECAST...ESPECIALLY IN THE AFTERNOON AS
ANOTHER BOUT OF INSTABILITY SHOWERS ON TAP.  HOWEVER...LIKELY TO BE
ONLY AT HIGHER ELEVATIONS...AND NOT AS ACTIVE AS TODAY.  DAY 2 WILL
BEGIN TO SEE A SLIGHT JUMP IN HEIGHTS AND THICKNESS...SO A COUPLE OF
DEGREES IN WARMING IN ORDER. CURRENT PACKAGE HAS TEMP HANDLED WELL.

FLG 3100  INW 0000
MCGRATH
FLG...NONE.

The office that day

Everything else NWS Flagstaff, AZ issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 11, 12:19 PM MSTSevere Thunderstorm WarningFGZCoconino31 min
Apr 11, 12:29 PM MSTSevere Thunderstorm WarningFGZCoconino21 min

Nearby

Severe Thunderstorm Warnings in Arizona, 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.