Alert archive / Arizona / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 10, NWS Phoenix, AZ

July 17, 2001Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 17, 2001, 4:01 PM MST for Maricopa County, Arizona. It was in force for 44 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Jul 17, 2001, 4:01 PM MST (23:01 UTC)
Expired
Jul 17, 2001, 4:45 PM MST
In force
44 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

County Maricopa County, AZ

What was reported inside it

TimeReportWhereRemark
Jul 17, 4:15 PM MSTThunderstorm Wind 60 EScottsdale, AZLarge tree downed power pole snapped by thunderstorm winds.

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, 11.0 hours before the alert went out and 49 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 2001-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 26 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 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 2001-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 26 square meters per square second.193958Sfc1 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
26 J/kg
Mixed-layer CIN
-228 J/kg
Mixed-layer LCL
2096 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
26 m²/s²
0-3 km storm-relative helicity
81 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 172303
SVRPHX

AZC013-172345-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
401 PM MST TUE JUL 17 2001

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

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

* UNTIL 445 PM MST

* AT 4 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  A SEVERE THUNDERSTORM OVER NORTH TEMPE...MOVING NORTHEAST AT 20    
  MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  PARADISE VALLEY AT 410 PM MST
  FOUNTAIN HILLS AT 440 PM MST
  SCOTTSDALE AT 410 PM MST

INTENSE RAIN AND STRONG DAMAGING WINDS ARE LIKELY WITH THIS STORM. 
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 3345 11210 3334 11193 3358 11162 3374 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 17, 3:35 PM MST, 26 minutes earlier.

Area forecast discussion, Jul 17, 3:35 PM MST, 26 minutes before
AZZ020>028-CAZ030>033-180545-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
335 PM MST TUE JUL 17 2001

.SYNOPSIS...
ARIZONA REMAINS BETWEEN LOW PRESSURE ALONG THE WEST COAST AND A HIGH
PRESSURE SYSTEM OVER THE GREAT PLAINS. A LOW PRESSURE SYSTEM FROM
NORTHWEST MEXICO MOVING NORTH MEANS SCATTERED SHOWERS AND
THUNDERSTORMS IN SOUTH-CENTRAL ARIZONA TONIGHT...WITH SOME CLOUDS
SPREADING OVER SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA. DRIER AIR
FROM THE SOUTHWEST IS EXPECTED TO DECREASE THE CHANCE OF SHOWERS AND
THUNDERSTORMS OVER SOUTH-CENTRAL ARIZONA BY FRIDAY AND SATURDAY.

.DISCUSSION...
AN INCREASE IN SHOWERS AND THUNDERSTORMS WAS TAKING PLACE IN
SOUTH-CENTRAL ARIZONA EARLIER THAN EXPECTED THIS AFTERNOON. A
HAZARDOUS WEATHER OUTLOOK WAS ISSUED EARLIER THIS AFTERNOON TO COVER
THE POSSIBILITY OF STRONG THUNDERSTORMS LATE THIS AFTERNOON AND
TONIGHT. A WEAK LOW PRESSURE SYSTEM IN NORTHWEST MEXICO MOVING NORTH
IS RESPONSIBLE FOR THIS INCREASE IN SHOWERS AND THUNDERSTORMS. HAVE
WORDED THE FORECAST WITH MAINLY EVENING SHOWERS AND THUNDERSTORMS IN
SOUTH-CENTRAL ARIZONA...BUT THERE IS STILL A POSSIBILITY OF SHOWERS
AND THUNDERSTORMS AT LEAST OVERNIGHT AND WEDNESDAY AS THE LOW
PRESSURE SYSTEM CONTINUES APPROACHING FROM THE SOUTH. DRIER AIR FROM
THE SOUTHWEST IS EXPECTED TO DECREASE THE CHANCE OF SHOWERS AND
THUNDERSTORMS OVER SOUTH-CENTRAL ARIZONA BY FRIDAY AND SATURDAY.
BEYOND THAT...THERE COULD BE AN INCREASE IN MOISTURE AGAIN. HOWEVER
...WITH SO MUCH UNCERTAINTY IN TIMING OF DRY AIR VERSES MORE HUMID
AIR...HAVE CONTINUED SAME IDEA AS PREVIOUS FORECASTER FOR THE
EXTENDED FORECAST...THAT IS A BROAD BRUSH OF MOSTLY CLEAR SKIES FOR
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA...AND PARTLY CLOUDY SKIES
FOR SOUTH-CENTRAL ARIZONA WITH A CHANCE OF AFTERNOON AND EARLY
EVENING SHOWERS AND THUNDERSTORMS OVER THE HIGHER TERRAIN.

ELLIS

In the hours before

Special weather statement, Jul 17, 1:37 PM MST, 2 hours 24 minutes before
AZZ022>024-027-028-180700-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
137 PM MST TUE JUL 17 2001

...ISOLATED STRONG THUNDERSTORMS ARE POSSIBLE OVER SOUTH-CENTRAL
ARIZONA LATE THIS AFTERNOON THROUGH TONIGHT...

COUNTIES IN THE RISK AREA INCLUDE:
     IN ARIZONA...MARICOPA...NORTHWEST PINAL...AND SOUTHERN GILA.

THE PRIMARY HAZARDOUS WEATHER RISKS INCLUDE:
     LOW VISIBILITIES DUE TO BLOWING DUST...GUSTY WINDS UP< TO 50 MPH
     ...BRIEF HEAVY RAIN...AND DANGEROUS CLOUD TO GROUND LIGHTNING.

STORM SPOTTER ACTIVATION MAY BE NECESSARY LATE THIS AFTERNOON
THROUGH TONIGHT.

CRAIG ELLIS

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.