Alert archive / Arizona / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 45, NWS Flagstaff, AZ

August 11, 1997Coconino County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Aug 11, 1997, 1:28 PM MST for Coconino County, Arizona. It was in force for 47 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
Aug 11, 1997, 1:28 PM MST (20:28 UTC)
Expired
Aug 11, 1997, 2:15 PM MST
In force
47 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 20:28 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 11, 12:45 PM MSTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 8.5 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 12:00Z on 1997-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 298 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 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 12:00Z on 1997-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 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
298 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
676 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
221 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.

150 
WUUS1 KFLG 112031 RRA
SVRFLG
AZC005-112115-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
128 PM MST MON AUG 11 1997

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF AZ HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 215 PM MST
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN NORTH CENTRAL ARIZONA

   ...EAST CENTRAL COCONINO COUNTY
 
AT 126 PM MST...A SEVERE THUNDERSTORM WAS INDICATED BY FLAGSTAFF
DOPPLER RADAR 10 MILES NORTHEAST OF WUPATKI NATIONAL MONUMENT OVER
OPEN COUNTRY MOVING EAST AT 15 MPH.
 
IF YOU ARE CAUGHT OUTSIDE...TRY TO FIND SHELTER IN A WELL
PROTECTED AREA UNTIL THE STORM HAS PASSED. SEVERE THUNDERSTORMS
PRODUCE DAMAGING WIND...LARGE HAIL...VERY HEAVY RAIN AND FREQUENT
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 Aug 11, 9:00 AM MST, 4 hours 28 minutes earlier.

Area forecast discussion, Aug 11, 9:00 AM MST, 4 hours 28 minutes before
NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
900 AM MST MON AUG 11 1997

SAT IR IMAGERY INDICATING JET STREAK CURRENT WORKING ACROSS CENTRAL
AZ...PLACING NW IN FAVORABLE LEFT FRONT QUAD. THIS HELPING TO KICK
OFF ISOLATED THUNDERSTORMS IN THE NW DESPITE MID LEVEL DRYING.
FORTUNATELY STORM MOTION IS AWAY FROM THE SUPAI AREA. SFC DEWPOINTS
AND MORNING SOUNDINGS FROM AROUND THE AREA STILL SHOWING CONSIDERABLE
LOW LEVEL MOISTURE. 12Z RUC BRINGING IN WEAK RIPPLE INTO WESTERN AZ
THIS AFTERNOON...THIS NOTED ON MORNING WATER VAPOR IMAGERY OVER
SOUTHERN CA IN ASSOCIATION WITH JET STREAK CURRENTLY WORKING ACROSS.
THIS MAY POSE A THREAT FOR THUNDERSTORM DEVELOPMENT OVER YAVAPAI
COUNTY WHERE SFC DEWPOINTS REMAIN IN THE MID 50S TO LOW 60S. 12Z
ETA...ALONG WITH 03Z MSO INDICATING SOME UPPER LEVEL DIVERGENCE
WORKING ACROSS THE NW...AND MODELS MAY BE A BIT TOO QUICK TO BRUSH IT
ACROSS. FOR NOW BROAD-BRUSHING FORECASTS APPEAR TO BE ON TRACK.
PLANNING NO UPDATES AT THIS TIME.
FLG 422 INW 422
FLG...NONE

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 10, 10:27 PM MSTFlash Flood WarningFGZCoconino2 hr
Aug 11, 12:22 PM MSTSevere Thunderstorm WarningFGZCoconino63 min
Aug 11, 12:33 PM MSTSevere Thunderstorm WarningFGZCoconino52 min
Aug 11, 12:35 PM MSTSevere Thunderstorm WarningFGZNavajo55 min
Aug 11, 1:43 PM MSTSevere Thunderstorm WarningFGZCoconino62 min
Aug 11, 2:47 PM MSTSevere Thunderstorm WarningFGZApache43 min
Aug 11, 3:13 PM MSTSevere Thunderstorm WarningFGZApache32 min
Aug 11, 3:46 PM MSTSevere Thunderstorm WarningFGZApache64 min
Aug 11, 3:56 PM MSTFlash Flood WarningFGZApache2 hr
Aug 11, 4:38 PM MSTSevere Thunderstorm WarningFGZCoconino37 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.