Alert archive / Arizona / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 94, NWS Flagstaff, AZ

August 30, 2001Navajo County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Aug 30, 2001, 1:58 PM MDT for Navajo County, Arizona. It was in force for 32 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued
Aug 30, 2001, 1:58 PM MDT (19:58 UTC)
Expired
Aug 30, 2001, 2:30 PM MDT
In force
32 min
Issued by
NWS Flagstaff, AZ
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Navajo County, AZ

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 8.0 hours before the alert went out and 163 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 2001-08-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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 2001-08-30The 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
1 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1536 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
80 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.

293 
WUUS55 KFGZ 302000
SVRFLG
AZC017-302030-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1258 PM MST THU AUG 30 2001

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTH CENTRAL NAVAJO COUNTY IN ARIZONA
  THIS INCLUDES THE CITIES OF...ARIPINE...CLAY SPRINGS...PINEDALE

* UNTIL 130 PM MST

* AT 1258 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER CLAY SPRINGS. THE STORM WAS NEARLY
  STATIONARY.

* THE SEVERE THUNDERSTORM WILL AFFECT OR PASS CLOSE TO CLAY SPRINGS 
AND 5 MILES WEST OF PINEDALE AT 130 PM MST.

IF SEVERE WEATHER APPROACHES YOUR AREA...GO INSIDE A STURDY SHELTER
AWAY FROM CREEK BEDS AND OTHER FLOOD-PRONE AREAS. REMEMBER...A SEVERE
THUNDERSTORM CAN PRODUCE LARGE DAMAGING HAIL...DAMAGING WINDS IN
EXCESS OF 58 MPH...DEADLY LIGHTNING...AND VERY HEAVY RAIN.

VERY LARGE HAIL IS POSSIBLE WITH THIS SEVERE THUNDERSTORM. IF YOU ARE
IN THE PATH OF THE STORM...PUT YOUR CAR IN A GARAGE AND MOVE TO A
SUBSTANTIAL SHELTER.

HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS WASHES AND UNDERPASSES.
AVOID THESE AREAS AND DO NOT CROSS FLOODED ROADS AS THEY MAY BE
WASHED OUT. WATER LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE...
THEREFORE SEEK HIGHER GROUND IF THREATENED BY FLOOD WATERS.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE.

LAT...LON 3445 11044 3428 11052 3418 11028 3439 11018

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 30, 9:45 AM MDT, 4 hours 13 minutes earlier.

Area forecast discussion, Aug 30, 9:45 AM MDT, 4 hours 13 minutes before
NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
845 AM MST THU AUG 30 2001

.SYNOPSIS...DRIER AND MORE STABLE AIR HAS MOVED INTO THE WESTERN TWO
THIRDS OF ARIZONA SINCE YESTERDAY. THE BEST CHANCE FOR SHOWERS AND
THUNDERSTORMS TODAY WILL MAINLY BE EAST OF WINSLOW. MOISTURE WILL BE
FURTHER LIMITED ON FRIDAY...ANY THUNDERSTORM ACTIVITY WILL BE WIDELY
SCATTERED...AND LIKELY CONFINED TO THE HIGHER TERRAIN. AN INCREASE
IN MOISTURE IS FORECAST FOR THE LABOR DAY WEEKEND...WITH CHANCES OF
SHOWER AND THUNDERSTORM ACTIVITY INCREASING SATURDAY INTO MONDAY
ACROSS NORTHERN ARIZONA.

.DISCUSSION...SOME DRYING HAS OCCURRED SINCE YESTERDAY...THE MOST
SIGNIFICANT DRYING FROM FLAGSTAFF WESTWARD. THE LOWER HALF OF THE
MORNING SOUNDINGS HAVE COOLED...THUS STABILIZING THE AIRMASS A BIT
MORE THAN WEDNESDAY. DEEPEST MOISTURE LIES ACROSS THE EASTERN
QUARTER OF THE STATE...12Z MESO-ETA DEPICTION OF 700 MB THETA-E
RIDGE MATCHES THIS WELL. THIS IS MOST LIKELY WHERE THE MAJORITY OF
THE STORMS WILL BE TODAY...DOUBT MUCH OF ANYTHING WILL DEVELOP WEST
OF WINSLOW. MORE OF THE SAME FRIDAY...WITH A BIT MORE IN THE WAY OF
DRYING. WEEKEND AND REST OF EXTENDED STILL A QUESTION MARK...WILL
SEE IF THE 12Z AVN IS MAKING ANY CHANGES. CURRENT ZONE PACKAGE IS
REPRESENTATIVE OF THIS THINKING...NO UPDATES NEEDED THIS MORNING.
PETERSON.

.FGZ...NONE.

In the hours before

Special weather statement, Aug 30, 9:50 AM MDT, 4 hours 8 minutes before
AZZ004>018-037>040-301930-
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
850 AM MST THU AUG 30 2001

...SCATTERED THUNDERSTORMS OVER THE NORTHEAST PLATEAUS AND WHITE
   MOUNTAINS WITH LOCALLY HEAVY RAINFALL POSSIBLE...

...ISOLATED THUNDERSTORMS FROM THE KAIBAB PLATEAU TO THE WESTERN
   MOGOLLON RIM...

SCATTERED THUNDERSTORMS ARE EXPECTED TODAY FROM THE NORTHEAST
PLATEAUS SOUTH INTO THE WHITE MOUNTAINS AND THE EASTERN MOGOLLON
RIM. THE MOISTURE IS A LITTLE DEEPER OVER EASTERN PARTS OF THE
STATE...EXPECT LOCALLY HEAVY RAINFALL OF 1 TO 2 INCHES. A FEW OF THE
STORMS MAY PRODUCE STRONG...GUSTY WINDS TO 45 MPH.

ONLY ISOLATED THUNDERSTORMS ARE EXPECTED FROM THE KAIBAB PLATEAU TO
THE WESTERN MOGOLLON RIM TODAY. MOISTURE AND INSTABILITY IS LIMITED
OVER THESE AREAS...EXPECT BRIEF HEAVY RAIN AND SMALL HAIL FROM SOME
OF THESE STORMS.

Nearby

Severe Thunderstorm Warnings in Arizona, 2001Every severe thunderstorm warning in 2001

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.