Alert archive / Arizona / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 99, NWS Flagstaff, AZ

September 20, 1997Apache County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Sep 20, 1997, 2:23 PM MST for Apache 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
Sep 20, 1997, 2:23 PM MST (21:23 UTC)
Expired
Sep 20, 1997, 3:25 PM MST
In force
62 min
Issued by
NWS Flagstaff, AZ
Area
Whole counties

County Apache County, AZ

The radar

The Flagstaff radar (KFSX), 181 km from the middle of the area, began a volume at 21:22 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, 9.4 hours before the alert went out and 210 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 1997-09-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 41 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 1997-09-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 80 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
41 J/kg
Mixed-layer CIN
-58 J/kg
Mixed-layer LCL
1352 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
140 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFLG 202124 RRA
SVRFLG
AZC001-202225-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
223 PM MST SAT SEP 20 1997

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF AZ HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 325 PM MST
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN NORTHEASTERN ARIZONA

   ...SOUTHERN APACHE COUNTY
 
AT 220 PM MST...A SEVERE THUNDERSTORM WAS INDICATED BY FLAGSTAFF
DOPPLER RADAR OVER THE COMMUNITY OF MAVERICK OR 21 MILES WEST
SOUTHWEST OF ALPINE MOVING NORTHEAST AT 30 MPH.

SOME LOCATIONS IN THE WARNING AREA INCLUDE... BIG LAKE AND ALPINE.
 
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 Sep 20, 2:06 PM MST, 17 minutes earlier.

Area forecast discussion, Sep 20, 2:06 PM MST, 17 minutes before
NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
205 PM MST SAT SEP 20 1997

FOCUS OF CONVECTIVE ACTIVITY TODAY IS ALONG THE NORTHERN AND EASTERN
BORDERS WITH SOME RATHER STRONG STORMS OVER SOUTHERN PORTIONS OF THE
WHITE MOUNTAINS.

THE 12Z MODELS ARE PRETTY MUCH IN AGREEMENT THROUGH THE PERIOD. UPPER
LOW TO CONTINUE ITS SLOW JOURNEY THROUGH THE GREAT BASIN. THIS SYSTEM
IS DOING A DECENT JOB SCOURING OUT MOISTURE AT H5 AND ABOVE IN MAINLY
WESTERN AND CENTRAL AREAS OF AZ. HOWEVER...LOW LEVEL RH WONT START TO
TAPER OFF IN WESTERN AND CENTRAL AREAS TIL MONDAY. AS A RESULT...
FOCUS OF CONVECTIVE ACTIVITY THROUGH THE PERIOD TO BE IN MORE MOIST
EASTERN AREAS...WITH A SLIGHT CHANCE OVER THE WESTERN RIM SUNDAY PER
THERMODYNAMICS AND ZERO CHANCE MONDAY AS H7 RH 30% OR LESS.

DEPRESSINGLY BREEZY TO WINDY AGAIN TODAY...AND EXPECT THE SAME
TOMORROW BEFORE GRADIENTS LOOSEN ON TUESDAY. GOT DOWN TO 39F AT THE
WX OFFICE LAST NIGHT. EXPECT MORE CHILLY TEMPS TONIGHT...ESPECIALLY
WIND SHELTERED AREAS. HELLO FALL.

NORA LOOMS IN THE EXTENDED. SEE HURRICANE CENTER PRODUCTS FOR
DETAILS. MRF HINTING THAT WEDNESDAY AND THURSDAY MAY BE PRETTY WET IN
EASTERN AREAS...THOUGH A LOT OF UNCERTAINTY STILL EXISTS.

FLG --00  INW --00

PASSETTI

FLG...NONE.

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.