Alert archive / Arizona / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 17, NWS Phoenix, AZ

August 7, 2001Yuma County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 7, 2001, 4:15 PM MST for Yuma County, Arizona. It was in force for 45 min. 1 report came from 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, with what was reported inside it.

The facts

Issued
Aug 7, 2001, 4:15 PM MST (23:15 UTC)
Expired
Aug 7, 2001, 5:00 PM MST
In force
45 min
Issued by
NWS Phoenix, AZ
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Yuma County, AZ

What was reported inside it

TimeReportWhereRemark
Aug 7, 4:40 PM MSTThunderstorm Wind 60 EWellton, AZSevere thunderstorm wind gusts blew down several electric power poles and uprooted many small trees.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Yuma Prvg Ground, AZ (K1Y7), launched 12:00Z, 11.3 hours before the alert went out and 21 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, Yuma Prvg Ground, AZ at 12:00Z on 2001-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 194 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, Yuma Prvg Ground, AZ at 12:00Z on 2001-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 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
194 J/kg
Mixed-layer CIN
-343 J/kg
Mixed-layer LCL
3008 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
78 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.

291 
WUUS55 KPSR 072318
SVRPHX
AZC027-080000-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
415 PM MST TUE AUG 7 2001

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WEST CENTRAL YUMA COUNTY IN SOUTHWEST ARIZONA...
  ALONG PORTIONS OF INTERSTATE 8 BETWEEN THE TOWNS OF
  LIGURTA AND WELLTON.

* UNTIL 500 PM MST

* AT 406 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR DETECTED  
  SEVERE THUNDERSTORMS 6 MILES SOUTHEAST OF LIGURTA...OR ABOUT 11
  MILES EAST OF FORTUNA FOOTHILLS...MOVING NORTHWEST AT 5 MPH.
  
  DENSE BLOWING DUST WITH VISIBILITIES NEAR ZERO IS POSSIBLE.
  
DAMAGING MICROBURST WINDS ARE LIKELY WITH THIS STORM. VERY HEAVY RAIN
WITH LOCALIZED FLOODING IS ALSO POSSIBLE. TAKE COVER IN A 
SUBSTANTIAL SHELTER UNTIL THE STORM PASSES.

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

LAT...LON 3267 11441 3250 11422 3264 11407 3273 11413

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 Phoenix, AZ wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 7, 3:10 PM MST, 1 hour 5 minutes earlier.

Area forecast discussion, Aug 7, 3:10 PM MST, 1 hour 5 minutes before
AZZ020>028-CAZ030>033-080545-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
310 PM MST TUE AUG 7 2001

.SYNOPSIS...
A STRONG WEATHER DISTURBANCE WILL BECOME NEARLY STATIONARY ACROSS
FAR EASTERN ARIZONA THE NEXT COUPLE OF DAYS. THIS SYSTEM WILL HELP
TO TRIGGER SHOWERS AND THUNDERSTORMS OVER MAINLY SOUTH-CENTRAL
ARIZONA THROUGH WEDNESDAY NIGHT. SOUTHWEST ARIZONA AND FAR SOUTHEAST
CALIFORNIA WILL REMAIN RELATIVELY DRY. AFTER THIS...THERE WILL BE A
TEMPORARY LULL IN THE THUNDERSTORM THREAT ON THURSDAY BEFORE THE
UPPER HIGH SHIFTS BACK TO OUR NORTH. THIS SHIFT WILL BRING RENEWED
CHANCES OF THUNDERSTORMS OVER SOUTH-CENTRAL ARIZONA BY THE END OF
THE WEEK.

.DISCUSSION...
FAIRLY ACTIVE DAY ACROSS MUCH OF CWFA...WITH ISOLATED STORMS EVEN
RUMBLING ACROSS SE CA ZONES. DESERT SFC TEMP/DEWPOINT DEPRESSIONS IN
THE 40 TO 60 DEG F RANGE STILL GIVING THE SOUNDINGS AN INVERTED V
LOOK...ALTHOUGH KIWA RADAR ALSO ESTIMATING SOME ISOLATED HEFTY
RAINFALL AMOUNTS. CHECK OF 18Z MESO-ETA SHOWS WE ARE UNDERGOING SOME
DYNAMICAL INFLUENCE FROM VORT MAX MOVING IN FROM THE 4 CORNERS AREA.
AND...WITH STEERING FLOWS OUT OF THE ENE...BELIEVE SOUTH-CENTRAL
DESERTS SHOULD CONTINUE WITH A THREAT OF STORMS WELL INTO THE NIGHT.
AFTER TONIGHT...MODELS SETTLE VORT TROUGH ALONG THE AZ/NM BORDER.
THIS POSITION WILL PROBABLY KEEP MUCH OF ERN CWFA UNDER THE GUN FOR
STORMS THRU TOMORROW. PRESENCE OF DEBRIS CLOUDS FROM TONIGHTS TSTM
ACTIVITY COULD SERVE TO PUT A DAMPER ON RENEWED STORMS WEDNESDAY.
BECAUSE OF THIS...WILL JUST KEEP LOW GRADE CHANCE POPS IN PLACE INTO
TOMORROW NIGHT FOR MARICOPA COUNTY EWD. BY THURSDAY...AZ/NM VORT
TROF GETS NUDGED FURTHER TO THE E. THIS SHOULD RESULT IN A TEMPORARY
LULL IN STORMS FOR THURSDAY...EXCEPT OVER HIGHER TERRAIN OF ZONE 24.
BELIEVE WRN PORTION OF CWFA WILL SEE LESS ACTION THROUGH TOMORROW...
WITH HIGH PRESSURE RIGHT OVERHEAD PUTTING A CAP ON CONVECTION. TEMPS
OBVIOUSLY WILL BE COOLER NEXT COUPLE OF DAYS IN WAKE OF TSTM
ACTIVITY.

TURNING TO THE EXTENDED...MEDIUM RANGE MODELS DISAGREE SOMEWHAT IN
PLACEMENT OF UPPER RIDGE. WILL GO MORE IN LINE WITH NOGAPS/UKMET
WHICH PUTS HIGH BACK INTO FAVORABLE POSITION ALONG UT BORDER. SO...
WILL OPT TO MAINTAIN CHANCE POPS SOUTH-CENTRAL ARIZONA DURING THE
EXTENDED...KEEPING WRN CWFA DRY.     ESTLE

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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.