Alert archive / Arizona / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 11, NWS Phoenix, AZ

July 25, 2001Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 25, 2001, 5:34 AM MST for Maricopa County, Arizona. It was in force for 41 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
Jul 25, 2001, 5:34 AM MST (12:34 UTC)
Expired
Jul 25, 2001, 6:15 AM MST
In force
41 min
Issued by
NWS Phoenix, AZ
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 71 km from the middle of the area, began a volume at 12:36 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

Phoenix, AZ (KPSR), launched 12:00Z, 0.6 hours before the alert went out and 53 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 2001-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1475 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 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 2001-07-25The 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
1475 J/kg
Mixed-layer CIN
-57 J/kg
Mixed-layer LCL
1652 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.

000 
WUUS55 KPSR 251235
SVRPHX

AZC013-251315-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
534 AM MST WED JUL 25 2001

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN MARICOPA COUNTY IN SOUTH CENTRAL ARIZONA

* UNTIL 615 AM MST

* AT 526 AM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER CAVE CREEK...OR ABOUT 10 MILES NORTHWEST
  OF SCOTTSDALE...MOVING NORTHEAST AT 25 MPH.

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.

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

LAT...LON 3382 11208 3371 11191 3402 11160 3415 11181

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 Jul 25, 2:59 AM MST, 2 hours 35 minutes earlier.

Area forecast discussion, Jul 25, 2:59 AM MST, 2 hours 35 minutes before
AZZ020>028-CAZ030>033-251745-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
259 AM MST WED JUL 25 2001

.SYNOPSIS...
A DRY SOUTHWEST FLOW IS EXPECTED TO CONTINUE IN PLACE OVER SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...WHILE SOUTH-CENTRAL ARIZONA WILL
REMAIN ON THE EDGE OF RELATIVELY HUMID AIR TO ITS SOUTH AND EAST...
WITH MOSTLY ISOLATED THUNDERSTORMS...MAINLY OVER THE HIGHER TERRAIN
...DURING THE AFTERNOONS AND EVENINGS. OTHERWISE...THE ATMOSPHERE IS
FORECAST TO REMAIN RELATIVELY DRY AND STABLE THROUGH EARLY NEXT WEEK
...LIMITING THUNDERSTORM ACTIVITY GENERALLY TO THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA.

.DISCUSSION...
A CUTOFF LOW PRESSURE SYSTEM CONTINUED TO SLOWLY MOV EWD OVR SRN CA
THIS MORNING. THIS SYSTEM HAS ACTED TO PULL SOME MID-LEVEL MOISTURE
NWWD INTO CNTRL AND NRN AZ THIS MORNING...LENDING SOME CREDENCE TO
OUR EXPANDED AREA OF POSSIBLE TSTMS FOR TODAY AND TONIGHT. LOOK FOR
GENERAL CONVECTIVE ACTIVITY OVR MARICOPA COUNTY AND EWD...ESPECIALLY
ALONG THE EDGE OF THE MONSOON BOUNDARY...THIS AFTERNOON AND EVENING.
CONVECTION SHOULD BEGIN ON THE HIGHER TERRAIN...MOVING TO THE LOWER
DESERTS IN THE LATE AFTERNOON AND EVENING. THE MAIN CONCERN WE WILL
HAVE IS GUSTY WIND ASSOCIATED WITH DOWNBURSTS. THE SUB-CLOUD LAYERS
REMAIN QUITE DRY AND INVERTED VEE SOUNDING PROFILES SHOULD BE THE
RULE. IT HAS BEEN QUITE DRY ON THE DESERTS FOR AWHILE...SO BLOWING
DUST WILL BE ANOTHER CONCERN. A DUST STORM WARNING HAD TO BE ISSUED
LAST EVENING FOR THE CNTRL DESERTS...AND THAT WILL BE VERY POSSIBLE
AGAIN LATE THIS AFTERNOON OR EARLY THIS EVENING. NO SIGNS OF A GULF
SURGE DUE TO PROXIMITY OF TS DALILA AS YET. THOUGHT WE MIGHT SEE ONE
THIS MORNING...BUT VWP AT KYUX SHOWS SELY WINDS ARE DIMINISHING AND
BEING OVERRUN BY WLYS. HOWEVER...PHX DEWPOINT WAS 61 DEG AT 09Z AS A
RESULT OF TSTM OUTFLOWS FROM THE SE LAST EVENING. THE YUMA DEWPOINT
WAS AT 64 DEG THIS MORNING...BUT BLH WAS 37 DEG. NO SURGE. GENERALLY
KEEPING THE SAME FORECAST GOING...JUST RAISED THE ZONE 24 POPS A BIT
FOR TODAY...TO 20 PCT...AND SHOWED A BIT OF COOLING IN THE EXTENDED
FORECAST DUE TO THE NEXT TROUGH KNOCKING THE HEIGHTS DOWN BY EARLY
NEXT WEEK.  WILT

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 25, 2:20 PM MSTFlash Flood WarningPSRPinal40 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.