Alert archive / Arizona / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 99, NWS Flagstaff, AZ

September 15, 2001Yavapai County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Sep 15, 2001, 2:10 PM MST for Yavapai County, Arizona. It was in force for 35 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
Sep 15, 2001, 2:10 PM MST (21:10 UTC)
Expired
Sep 15, 2001, 2:45 PM MST
In force
35 min
Issued by
NWS Flagstaff, AZ
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Yavapai County, AZ

The radar

The Flagstaff radar (KFSX), 129 km from the middle of the area, began a volume at 21:13 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, 9.2 hours before the alert went out and 129 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 2001-09-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 29 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 2001-09-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 3 square meters per square second.19395878Sfc1 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
29 J/kg
Mixed-layer CIN
-114 J/kg
Mixed-layer LCL
1574 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
3 m²/s²
0-3 km storm-relative helicity
108 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.

624 
WUUS55 KFGZ 152112
SVRFLG
AZC025-152145-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
210 PM MST SAT SEP 15 2001

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTH CENTRAL YAVAPAI COUNTY IN ARIZONA
  THIS INCLUDES THE CITIES OF...WAGONER...PEEPLES VALLEY...WALNUT
  GROVE

* UNTIL 245 PM MST

* AT 210 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER WALNUT GROVE...MOVING NORTHWEST AT 5 MPH.

* THE SEVERE THUNDERSTORM WILL AFFECT OR PASS CLOSE TO...
  OVER WALNUT GROVE AT 220 PM MST
  8 MILES EAST OF PEEPLES VALLEY AT 245 PM MST

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

HEAVY RAINS MAY FLOOD LOW LYING AREAS AND  WASHES. 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 3414 11249 3430 11239 3443 11263 3423 11276
MAS

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 15, 9:49 AM MST, 4 hours 21 minutes earlier.

Area forecast discussion, Sep 15, 9:49 AM MST, 4 hours 21 minutes before
NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
949 AM MST SAT SEP 15 2001

.SYNOPSIS...ABUNDANT SUBTROPICAL MOISTURE ACROSS THE REGION WILL
BRING ANOTHER ROUND OF THUNDERSTORMS TO THE REGION TODAY. SOME OF
THE STORMS WILL PRODUCE HEAVY RAINFALL...ESPECIALLY OVER CENTRAL
ARIZONA. A CHANCE OF SHOWERS AND THUNDERSTORMS WILL RETURN SUNDAY
AND MONDAY. MUCH DRIER WESTERLY FLOW WILL TAKE HOLD BY TUESDAY...
WITH DRY AND WARM CONDITIONS EXPECTED THE REMAINDER OF THE WEEK.

.DISCUSSION...GOOD FORECAST FROM THE EARLY MORNING PACKAGE. MAIN
HIGHLIGHTS .4 INCH PRECIP WATER ALONG THE UTAH AND ARIZONA BORDER
INCREASING TO AROUND AND INCH SOUTHERN YAVAPAI AND NORTHERN GILA
COUNTIES. SOUNDING FROM THE MESO ETA SHOWING INVERTED V SOUNDINGS TO
THE NORTH...DYNAMIC FORCING (DIVQ AND OMEGA) WEAK SO THUNDERSTORMS
ROUGHLY NORTH OF I-40 WILL HAVE THE POTENTIAL OF PRODUCING SOME
STRONG GUSTY WIND AND SMALL HAIL. TO THE SOUTH OF INTERSTATE 40
MOISTURE IS DEEPER...MESO ETA SOUNDINGS SUGGEST STEEPER LAPSE
RATES...FLOW IS WEAK AS WELL AS THE DYNAMIC FORCING DOWN IN THE
NOISE LEVEL...SO THE STORMS ALONG AND SOUTH OF I-40 WILL BE
STRONG PULSE AND TERRAIN DRIVEN...WITH THE MAIN THREAT...LOCALIZED
HEAVY RAINFALL.

CLEMMONS
.FGZ...NONE.

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 15, 4:37 PM MSTFlash Flood WarningFGZCoconino113 min

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; radar from the NEXRAD Level II archive.