Alert archive / Arizona / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 74, NWS Flagstaff, AZ

August 19, 2001Gila County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Aug 19, 2001, 4:59 PM MST for Gila County, Arizona. It was in force for 31 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 19, 2001, 4:59 PM MST (23:59 UTC)
Expired
Aug 19, 2001, 5:30 PM MST
In force
31 min
Issued by
NWS Flagstaff, AZ
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Gila County, AZ

The nearest sounding before it

Phoenix, AZ (KPSR), launched 12:00Z, 12.0 hours before the alert went out and 107 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, Phoenix, AZ at 12:00Z on 2001-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 748 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, Phoenix, AZ at 12:00Z on 2001-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 0 square meters per square second.1939Sfc1 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
748 J/kg
Mixed-layer CIN
-283 J/kg
Mixed-layer LCL
2037 m above ground
0-6 km bulk shear
0 kt
0-1 km storm-relative helicity
0 m²/s²
0-3 km storm-relative helicity
0 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.

432 
WUUS55 KFGZ 200000
SVRFLG
AZC007-200030-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
459 PM MST SUN AUG 19 2001

THE NATIONAL WEATHER SERVICE HAS EXTENDED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHWESTERN GILA COUNTY IN ARIZONA
  THIS INCLUDES THE COMMUNITIES OF...PAYSON...STAR VALLEY

* UNTIL 530 PM MST

* AT 459 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 2 MILES SOUTHEAST OF STAR VALLEY...MOVING      
  NORTHWEST AT 10 MPH. THEREFORE THE PREVIOUS SEVERE THUNDERSTORM    
  WARNING HAS BEEN EXTENDED FOR THIS AREA UNTIL 530 PM MST.

* THE SEVERE THUNDERSTORM WILL AFFECT OR PASS CLOSE TO...  
STAR VALLEY AROUND 500 PM MST
PAYSON AROUND 505 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.

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

LAT...LON 3407 11118 3423 11108 3439 11136 3420 11150

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 19, 2:30 PM MST, 2 hours 29 minutes earlier.

Area forecast discussion, Aug 19, 2:30 PM MST, 2 hours 29 minutes before
NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 PM MST SUN AUG 19 2001

.SYNOPSIS...HIGH PRESSURE CURRENTLY OVER NORTHEAST ARIZONA WILL
CONTINUE TO MOVE EASTWARD TONIGHT. AS A RESULT...SOUTHERLY FLOW
ALOFT WILL BRING AN INCREASE IN MONSOONAL MOISTURE TO THE STATE. AN
UPPER LEVEL DISTURBANCE EMBEDDED IN THE FLOW WILL RESULT IN AN
UPSWING IN SHOWERS AND THUNDERSTORMS AND COOLER DAYTIME TEMPERATURES
TOMORROW. A WESTERLY FLOW ALOFT WILL BRING DRIER AND WARMER WEATHER
TO THE STATE BY THE MIDDLE OF NEXT WEEK.

.DISCUSSION...CONVECTION OFF TO A LATE START TODAY WITH COVERAGE
JUST BECOMING SCATTERED ATTM.  A COUPLE OF SYNOPTIC FEATURES
INDICATE AN UPSWING IN THUNDERSTORM ACTIVITY OVER THE NEXT 24 HOURS.
HIGH PRESSURE OVER NORTHEAST AZ TODAY WILL CONTINUE TO MOVE EASTWARD
TONIGHT. THIS WILL RESULT IN THE LOWER TROPOSPHERIC FLOW BECOMING
MORE SOUTHERLY WITH TIME AND AN INCREASE IN MOISTURE TRANSPORT
ACROSS AZ. THE OTHER FEATURE OF INTEREST IS A WEAK DISTURBANCE
EMBEDDED IN THE FLOW ALONG THE AZ/MEXICO BORDER. MESOETA HAS BEST
HANDLE ON THIS FEATURE AND MOVES IT NORTHWARD INTO SOUTH CENTRAL AZ
TONIGHT AND INTO NORTHERN AZ EARLY TOMORROW. FLOW BECOMES WESTERLY
LATE MONDAY INTO TUESDAY AS A TROF OF LOW PRESSURE MOVES INTO THE
WEST COAST AND BEGINS TO ADVECT DRIER AIR INTO THE STATE. ETA/AVN
SHOWS AN ATTENDANT 50 KT JET WITH THIS TROF WHICH CLIPS THE
NORTHWEST PART OF THE STATE ON TUESDAY. THIS FEATURE BEARS WATCHING
AS ENERGETICS INTERACT WITH RESIDUAL MOISTURE AND SHEAR PROFILE
BECOMES FAVORABLE FOR POSSIBLE SVR WX DAY ON TUESDAY. ETA/AVN THEN
SWEEP THE MOISTURE OUT OF ALL BUT FAR EASTERN AZ ON WEDNESDAY.

IN THE EXTENDED...DRY AIR REMAINS OVER THE FORECAST AREA THROUGH THE
PERIOD. PER CONSENSUS WITH NEARBY OFFICES DURING COORDINATION
CALL...WILL KEEP CHANCE SHOWERS ALONG THE EASTERN AZ/NM BORDER ZONES ON
WEDNESDAY...THEN DRY CONDITIONS/MOSTLY CLEAR FORECAST THROUGH
SUNDAY.  TW

.FGZ...NONE.

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 19, 2:29 PM MSTSevere Thunderstorm WarningFGZCoconino31 min
Aug 19, 3:05 PM MSTSevere Thunderstorm WarningFGZCoconino25 min
Aug 19, 4:26 PM MSTSevere Thunderstorm WarningFGZGila34 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.