Alert archive / Arizona / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 48, NWS Phoenix, AZ

August 21, 2003Gila County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 21, 2003, 7:20 PM MST for Gila County, Arizona. It was in force for 25 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 21, 2003, 7:20 PM MST (02:20 UTC)
Expired
Aug 21, 2003, 7:45 PM MST
In force
25 min
Issued by
NWS Phoenix, AZ
Area
Counties, with a storm outline in the text

County Gila County, AZ

The radar

The Phoenix radar (KIWA), 104 km from the middle of the area, began a volume at 02:22 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Phoenix, AZ (KPSR), launched 00:00Z, 2.3 hours before the alert went out and 128 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 00:00Z on 2003-08-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 911 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 00:00Z on 2003-08-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -11 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
911 J/kg
Mixed-layer CIN
-135 J/kg
Mixed-layer LCL
2185 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-11 m²/s²
0-3 km storm-relative helicity
38 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 220220
SVRPSR
AZC007-220245-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
716 PM MST THU AUG 21 2003

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR LARGE HAIL...
  CENTRAL GILA COUNTY IN EAST CENTRAL ARIZONA

* UNTIL 745 PM MST

* AT 707 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER CENTRAL GILA COUNTY...OR ABOUT 14 MILES
  NORTHEAST OF GLOBE...MOVING NORTHWEST AT 15 MPH.

THIS SEVERE THUNDERSTORM WITH LARGE HAIL AND VERY HEAVY RAIN WILL
CROSS HIGHWAY 60...ABOUT 14 MILES NORTHEAST OF GLOBE AROUND 730 PM.
MOTORISTS DRIVING HIGHWAY 60 NORTHEAST OF GLOBE SHOULD BE ALERT
FOR THE DANGERS OF HAIL.

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 3353 11075 3340 11053 3355 11033 3370 11062

$$

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 21, 2:55 PM MST, 4 hours 25 minutes earlier.

Area forecast discussion, Aug 21, 2:55 PM MST, 4 hours 25 minutes before
AZZ020>028-CAZ030>033-220545-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
WEATHER SERVICE PHOENIX AZ
255 PM MST THU AUG 21 2003

.SYNOPSIS...
UPPER LEVEL LOW PRESSURE OFF THE SOUTHERN CALIFORNIA COAST WILL MOVE
TOWARD NORTHERN CALIFORNIA BY EARLY SATURDAY. AT THE SAME TIME HIGH
PRESSURE ALOFT WILL BUILD OVER ARIZONA AND THE SOUTHERN ROCKIES.
THIS MEANS A CONTINUED MOIST AND UNSTABLE PATTERN. IN ADDITION...A
STRONGER DISTURBANCE IS EXPECTED TO FORM IN NORTHERN MEXICO AND
MIGRATE INTO SOUTHERN ARIZONA BY EARLY SATURDAY...ENHANCING THE
POTENTIAL FOR PRECIPITATION. THE BEST CHANCE OF RAIN STILL APPEARS
TO BE OVER THE HIGHER TERRAIN OF SOUTH-CENTRAL ARIZONA.

.DISCUSSION...
AN AREA OF TOWERING CUMULUS SPOTTED NORTH OF YUMA PROVING GROUNDS
THIS AFTERNOON...WHILE GOES TOTAL PRECIP WATER LOOP SHOWED OVERALL
DECREASE IN VALUES EARLY THIS AFTN...MAINLY ACROSS WRN ZONES. THE
LARGE COMPLEX IN NORTHERN MEX DISSIPATED MUCH EARLIER...AND SOME
DEBRIS CLOUDS STILL LINGERING. RADAR ALSO SHOWED CELLS TO THE NORTH
OF OUR CWA THAT WERE BACK-BUILDING TOWARD MARICOPA CTY LINE.

WILL CONTINUE WITH A MOIST AND UNSTABLE AIRMASS TONIGHT...WITH NOT A
WHOLE LOT OF JET DYNAMICS ACROSS OUR AREA.  MODELS HAVE BEEN
ADVERTISING THE RIDGE TO SHARPEN UP A BIT TOMORROW AND INTO SATURDAY.
ALONG WITH A SHARPER RIDGE...AND ELEVATED RH VALUES...STRONG UPWARD
MOTIONS ARE PROGGED WITH AT LEAST ONE DISTURBANCE ROTATING AROUND
THE BASE OF THE RIDGE FRIDAY NIGHT AND INTO SATURDAY. 500MB OMEGA
BULLSEYE IS DEPICTED ABOUT OVER YUMA-TUCSON BY 12Z SATURDAY. THE
NEIGHBORING WFOS AGREE ON AN INCREASE IN POPS FROM TONIGHT TO
FRIDAY NIGHT. TIMING OF ACTIVITY ON SATURDAY WILL BE TRICKY.

TEMPERATURES HELD DOWN A BIT THIS AFTERNOON DUE TO MID LEVEL CLOUD
COVER. THIS MAY ALSO KEEP MAX TEMPS IN PHX DOWN A DEG OR 2.
CONVECTION SHOULD FIRE FROM NORTHERN GULF AND WRN SONORA...INTO
SOUTHWEST AND SOUTH-CENTRAL AZ...AND SPREAD NORTH TONIGHT. SO...A
MUCH SLOWER ONSET OF STORMS TODAY...COUPLED WITH LESS MOISTURE TO
WORK WITH...SO NO WIDESPREAD HEAVY PRECIP OUTBREAKS TONIGHT.
SIPPLE

.PSR...NONE.
Hazardous weather outlook, Aug 21, 6:00 AM MST, 13 hours 20 minutes before
AZZ020>028-CAZ030>033-220100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
600 AM MST THU AUG 21 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHWEST AND
SOUTH-CENTRAL ARIZONA...AND SOUTHEAST CALIFORNIA.

.DAY ONE...TODAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

Nearby

Severe Thunderstorm Warnings in Arizona, 2003Every severe thunderstorm warning in 2003

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.