Alert archive / Arizona / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 41, NWS Flagstaff, AZ

August 10, 1997Coconino County, Yavapai County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Aug 10, 1997, 12:45 PM MST for Coconino County, Yavapai County, Arizona. It was in force for 50 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 10, 1997, 12:45 PM MST (19:45 UTC)
Expired
Aug 10, 1997, 1:35 PM MST
In force
50 min
Issued by
NWS Flagstaff, AZ
Area
Whole counties

Counties Coconino County, AZ, Yavapai County, AZ

The radar

The Flagstaff radar (KFSX), 113 km from the middle of the area, began a volume at 19:45 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 12:00Z, 7.8 hours before the alert went out and 33 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 1997-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 558 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 12:00Z on 1997-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 115 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
558 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
662 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
115 m²/s²
0-3 km storm-relative helicity
122 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

680 
WUUS1 KFLG 101946 RRA
SVRFLG
AZC005-025-102035-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1245 PM MST SUN AUG 10 1997

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF AZ HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 135 PM MST
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN NORTH CENTRAL ARIZONA

   ...SOUTH CENTRAL COCONINO COUNTY

IN CENTRAL ARIZONA

   ...NORTH CENTRAL YAVAPAI COUNTY
 
AT 1244 PM MST...A SEVERE THUNDERSTORM WAS INDICATED BY FLAGSTAFF
DOPPLER RADAR 26 MILES SOUTHWEST OF FLAGSTAFF OR 14 MILES NORTH
NORTHEAST OF CLARKDALE MOVING NORTHEAST AT 20 MPH.

PEOPLE NEAR OR IN THE PATH OF THIS SEVERE STORM SHOULD FIND
SHELTER IMMEDIATELY.
 
IF YOU 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 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 10, 9:00 AM MST, 3 hours 45 minutes earlier.

Area forecast discussion, Aug 10, 9:00 AM MST, 3 hours 45 minutes before
NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
900 AM MST SUN AUG 10 1997

NICE LOOKING COMPLEX OVER NW AZ AT THIS TIME WORKING INTO FLG CWA.
7H-5H TROUGH TO CONTINUE TO SPREAD SOME UVV INTO THE NW OVER THE NEXT
12 HRS. MOISTURE COMBINED WITH DAYTIME HEATING SHOULD ALLOW FOR SOME
DECENT CONVECTIVE DEVELOPMENT TODAY. ANOTHER THING TO WATCH IS CAA
ALOFT.  5H TEMPS TO TAKE A DIP BY A DEGREE OR TWO AS TROUGH
APPROACHES...WHILE THE REMAINDER OF THE CWA STILL HAS SFC DEW POINTS
RUNNING ABOVE 50. 12Z FGZ SOUNDING HAS DESTABILIZED FROM PAST 24
HRS...AND WHEN MODIFIED TO REFLECT AFTERNOON CONDITIONS...CAPES
RUNNING CLOSE TO 3K...A GOOD INDICATOR THAT ANY STORMS THAT DO
DEVELOP TODAY MAY BE CAPABLE OF PRODUCING LARGE HAIL. WILL BE MAKING
SOME UPDATES FOR THE REST OF THE PACKAGE TO JUICE POPS A BIT TO
REFLECT CURRENT CONDITIONS.
FLG 723 INW 523
FLG...NONE

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 10, 10:16 AM MSTSevere Thunderstorm WarningFGZCoconino54 min
Aug 10, 10:25 AM MSTFlash Flood WarningFGZCoconino45 min
Aug 10, 10:25 AM MSTSevere Thunderstorm WarningFGZCoconino45 min
Aug 10, 11:07 AM MSTFlash Flood WarningFGZCoconino3 hr

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.