Alert archive / Arizona / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 19, NWS Phoenix, AZ

August 11, 2001Maricopa County, Pinal County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 11, 2001, 3:44 PM MST for Maricopa County, Pinal County, Arizona. It was in force for 31 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 11, 2001, 3:44 PM MST (22:44 UTC)
Expired
Aug 11, 2001, 4:15 PM MST
In force
31 min
Issued by
NWS Phoenix, AZ
Area
Whole counties; the outline is the Mesonet’s reconstruction

Counties Maricopa County, AZ, Pinal County, AZ

The radar

The Phoenix radar (KIWA), 16 km from the middle of the area, began a volume at 22:47 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.

What was reported inside it

TimeReportWhereRemark
Aug 11, 4:10 PM MSTThunderstorm Wind 60 EMesa, AZSevere thunderstorm wind gusts damage trees, tree limbs torn off 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

Phoenix, AZ (KPSR), launched 12:00Z, 10.7 hours before the alert went out and 30 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 2001-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 558 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 2001-08-11The 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
558 J/kg
Mixed-layer CIN
-162 J/kg
Mixed-layer LCL
1840 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.

288 
WUUS55 KPSR 112246
SVRPHX
AZC013-021-112315-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
344 PM MST SAT AUG 11 2001

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EAST CENTRAL MARICOPA COUNTY IN SOUTH CENTRAL ARIZONA
  EXTREME NORTH CENTRAL PINAL COUNTY IN SOUTH CENTRAL ARIZONA
  THIS INCLUDES EAST MESA. 

* UNTIL 415 PM MST

* AT 315 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  A  SEVERE THUNDERSTORM ABOUT 2 MILES NORTH OF APACHE               
  JUNCTION...MOVING WEST AT 5 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  MESA AT 415 PM MST

DAMAGING MICROBURST WINDS ARE LIKELY WITH THIS STORM. VERY HEAVY RAIN
IS ALSO POSSIBLE. TAKE COVER IN A SUBSTANTIAL SHELTER UNTIL THE STORM
PASSES.

INTENSE LIGHTNING IS OCCURRING WITH THIS STORM...MOVE INDOORS IF
POSSIBLE. WHEN INDOORS...STAY AWAY FROM WINDOWS AND DOORS. IF
TELEPHONE USE IS REQUIRED...USE A CELL PHONE. UNPLUG ANY UNNECESSARY
ELECTRICAL APPLIANCES BEFORE THE STORM ARRIVES. IF OUTDOORS...AVOID
ISOLATED TALL OBJECTS SUCH AS TREES.

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 3334 11153 3352 11150 3358 11182 3336 11185

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 11, 2:45 PM MST, 59 minutes earlier.

Area forecast discussion, Aug 11, 2:45 PM MST, 59 minutes before
AZZ020>028-CAZ030>033-120545-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
245 PM MST SAT AUG 11 2001

.SYNOPSIS...
A VERY MOIST AIRMASS WILL CONTINUE ACROSS SOUTH-CENTRAL ARIZONA THIS
WEEKEND AND INTO EARLY NEXT WEEK...WITH LESSER AMOUNTS OF MOISTURE
EXPECTED OVER FAR SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA. THIS
MEANS THAT THERE WILL BE A CHANCE OF THUNDERSTORMS OVER SOUTH-CENTRAL
ARIZONA...MAINLY DURING THE AFTERNOON AND EARLY NIGHTTIME HOURS.
HIGH PRESSURE WILL BECOME ESTABLISHED NEAR THE FOUR CORNERS EARLY
NEXT WEEK. THIS WILL GIVE A MORE EASTERLY FLOW ALOFT WHICH WILL
SERVE TO PUSH DEEPER MOISTURE FURTHER WEST...FOR BETTER CHANCES OF
STORMS ALONG AND WEST OF THE COLORADO RIVER AFTER SUNDAY.

.DISCUSSION...
MODELS REMAIN IN AGREEMENT. UPPER HIGH OVER SOUTHERN CA HAS BEEN
MOVING NORTH TOWARD SOUTHERN NV TODAY AND WILL CONTINUE INTO 4
CORNERS REGION ON SUNDAY. UPPER FLOW TO SHIFT FROM NORTH TO
NORTHEASTERLY TONIGHT AS UPPER HIGH MOVES INTO SOUTHERN NV. AIRMASS
OVER SOUTH CENTRAL AZ REMAINS MOIST WITH MORNING PHX RAOB SHOWING A
LITTLE UNDER 2 INCHES OF P WATER...ONLY SLIGHT LESS THAN FRI. THUS
THERE WILL BE A CHANCE OF THUNDERSTORMS TONIGHT IN SOUTH CENTRAL AZ
AS ACTIVITY NOW OVER AND IN VICINITY OF THE RIM REGION MAY MOVE DOWN
INTO SOUTH CENTRAL AZ THIS EVENING AND TONIGHT AS THE FLOW BECOMES
NORTHEASTERLY. IN ADDITION...THERE IS A VORTMAX IN VICINITY OF WHITE
MOUNTAINS TONIGHT TO ENHANCE THUNDERSTORMS TOWARD SOUTH CENTRAL AZ.
PLUS A WAVE IN NORTHERN MEXICO INTO SE AZ. WITH THE DEEP MOISTURE
OVER SOUTHERN GILA COUNTY SOME STORMS MAY PRODUCE LOCALLY HEAVY
RAINFALL.  DRIER WESTERLY FLOW OVER SE CA TO KEEP THAT AREA MOSTLY
CLEAR TONIGHT AND SUNDAY. FLOW TO BECOME MORE EAST TO SOUTHEASTERLY
SUNDAY AS UPPER HIGH REACHES 4 CORNERS AREA. WITH MOIST AIRMASS OVER
NM...THE EAST FLOW WILL KEEP SOUTH CENTRAL AZ MOIST ALONG WITH
CHANCE OF THUNDERSTORMS. THIS MOIST EAST FLOW EXPECTED TO REACH SE
CA BY LATE SUNDAY/MONDAY FOR PARTLY CLOUDY SKIES AND CHANCE OF
THUNDERSTORMS BY MONDAY AND THEREAFTER. IN ADDITION AVN MOVES
NORTHERN MEXICAN WAVE WESTWARD ALONG AZ SOUTHERN BORDER INTO THE
NORTHERN GULF BY SUNDAY NIGHT / MONDAY. THIS ALONG WITH THE WESTWARD
PUSH OF MOISTURE WILL BRING A CHANCE FOR THUNDERSTORMS INTO FAR SW
AZ AND SE CA.   EXTENDED MRF SHOWS LITTLE CHANGE AS MOIST FLOW TO
REMAIN THROUGH EXTENDED PERIOD FOR PARTLY CLOUDY SKIES AND CHANCE OF
THUNDERSTORMS OVER REGION. DKS

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; radar from the NEXRAD Level II archive.