Alert archive / Arizona / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 46, NWS Flagstaff, AZ

August 11, 1997Coconino County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Aug 11, 1997, 1:43 PM MST for Coconino County, Arizona. It was in force for 62 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, 1:43 PM MST (20:43 UTC)
Expired: Aug 11, 1997, 2:45 PM MST
In force: 62 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 20:43 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.

Issued	Product	Office	Lasted
Aug 11, 12:45 PM MST	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 8.7 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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.

000 
TTAA00 KFLG 112045 RRA
SVRFLG
AZC005-112145-

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

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF AZ HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 245 PM MST
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN NORTH CENTRAL ARIZONA

   ...SOUTH CENTRAL COCONINO COUNTY
 
AT 139 PM MST...A SEVERE THUNDERSTORM WAS INDICATED BY FLAGSTAFF
DOPPLER RADAR 5 MILES SOUTHWEST OF METEOR CITY OR 20 MILES
SOUTHWEST OF WINSLOW MOVING NORTHEAST AT 15 MPH.

PEOPLE NEAR OR IN THE PATH OF THIS SEVERE STORM SHOULD FIND
SHELTER.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60
MPH...DESTRUCTIVE HAIL...FREQUENT LIGHTNING...AND VERY HEAVY
RAIN.  FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST
FLOOR OF YOUR HOME OR BUSINESS.

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 43 minutes earlier.

Area forecast discussion, Aug 11, 9:00 AM MST, 4 hours 43 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.

Issued	Product	Office	Counties	Lasted
Aug 10, 10:27 PM MST	Flash Flood Warning	FGZ	Coconino	2 hr
Aug 11, 12:22 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	63 min
Aug 11, 12:33 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	52 min
Aug 11, 12:35 PM MST	Severe Thunderstorm Warning	FGZ	Navajo	55 min
Aug 11, 1:28 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	47 min
Aug 11, 2:47 PM MST	Severe Thunderstorm Warning	FGZ	Apache	43 min
Aug 11, 3:13 PM MST	Severe Thunderstorm Warning	FGZ	Apache	32 min
Aug 11, 3:46 PM MST	Severe Thunderstorm Warning	FGZ	Apache	64 min
Aug 11, 3:56 PM MST	Flash Flood Warning	FGZ	Apache	2 hr
Aug 11, 4:38 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	37 min

Nearby

Severe Thunderstorm Warnings in Arizona, 1997 Every 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.