Alert archive / Arizona / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 41, NWS Phoenix, AZ

August 14, 2003Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 14, 2003, 7:29 PM MST for Maricopa County, Arizona. It was in force for 61 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 14, 2003, 7:29 PM MST (02:29 UTC)
Expired: Aug 14, 2003, 8:30 PM MST
In force: 61 min
Issued by: NWS Phoenix, AZ
Area: Counties, with a storm outline in the text

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 34 km from the middle of the area, began a volume at 02:32 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Aug 14, 1:45 PM MST	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Phoenix, AZ (KPSR), launched 00:00Z, 2.5 hours before the alert went out and 29 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 485 J/kg
Mixed-layer CIN: -55 J/kg
Mixed-layer LCL: 2530 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: -18 m²/s²
0-3 km storm-relative helicity: -7 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WUUS55 KPSR 150229
SVRPSR
AZC013-150330-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
728 PM MST THU AUG 14 2003

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

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

* UNTIL 830 PM MST

* AT 727 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 13 MILES NORTHEAST OF FOUNTAIN HILLS...MOVING
  SOUTHEAST AT 395 MPH.

DAMAGING MICROBURST WINDS UP TO 60 MPH ARE LIKELY WITH THIS STORM. 
VERY HEAVY RAIN IS ALSO POSSIBLE. TAKE COVER IN A SUBSTANTIAL 
SHELTER UNTIL THE STORM PASSES.

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

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM MST
THURSDAY EVENING FOR SOUTHEASTERN ARIZONA.

LAT...LON 3355 11211 3403 11211 3402 11171 3375 11136
          3360 11121 3347 11137 3347 11157 3323 11158
          3324 11206

$$

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 14, 3:20 PM MST, 4 hours 9 minutes earlier.

Area forecast discussion, Aug 14, 3:20 PM MST, 4 hours 9 minutes before

AZZ020>028-CAZ030>033-150545-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
320 PM MST THU AUG 14 2003

.SYNOPSIS...
VERY UNSETTLED WEATHER WILL BE THE RULE ACROSS SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA INTO THE WEEKEND AS AN UPPER LOW DRIFTS OVER
THE REGION FROM THE EAST. STRONG THUNDERSTORMS WILL RUMBLE ACROSS
SOUTH-CENTRAL ARIZONA THIS EVENING...WITH THE POTENTIAL FOR SEVERE
WEATHER. AFTER TONIGHT...A CHANCE OF SHOWERS AND THUNDERSTORMS WILL
CONTINUE...WITH ACTIVITY EXPECTED TO DECREASE SOMEWHAT OVER THE
UPCOMING WEEKEND. TEMPERATURES WILL BE WELL BELOW NORMAL ACROSS
SOUTH-CENTRAL ARIZONA ON FRIDAY DUE TO THE RAIN-COOLED AIR...WITH
READINGS EXPECTED TO REBOUND OVER THE WEEKEND. THE WEATHER WILL
RETURN TO A MORE NORMAL MONSOON PATTERN THE FIRST PART OF NEXT WEEK.

.DISCUSSION...
LOTS OF PARAMETERS COMING TOGETHER FOR A VERY ACTIVE EVENING ACROSS
MAINLY ERN CWFA. THESE FACTORS INCLUDE A VERY MOIST...UNSTABLE
AIRMASS...A FAVORABLE NELY STEERING FLOW WITH LOTS OF SHEER IN THE
0-6KM LAYER...DIVERGENCE ALOFT WITH LARGE SCALE MID LEVEL CONVERGENCE
...DYNAMICS WITH APPROACHING INVERTED TROF...IE JUST ABOUT ALL ONE
COULD ASK FOR TO ENSURE LOTS OF WEATHER. AS A RESULT...HAVE GONE
WITH VERY HIGH POPS FOR SCNTRL AZ TONIGHT INTO FRIDAY MORNING WITH
LOWER NUMBERS FURTHER W. SPC ISSUED A SEVERE THUNDERSTORM WATCH
EARLIER THIS AFTERNOON FOR BASICALLY SOUTH-CENTRAL INTO NE AZ TIL
04Z. IN ADDITION...HEAVY RAIN THREAT HAS PROMPTED US TO ISSUE FLASH
FLOOD WATCH FOR SCTNRL AZ UNTIL 12Z FRIDAY.

AFTER TONIGHT...INVERTED TROF MOVES INTO AZ AND THEN MEANDERS NWD
DURING THE WEEKEND. COOLER AIR ALOFT WILL SERVE TO DESTABLIZE THE
AMS EVEN FURTHER FRIDAY AND SATURDAY...ALTHOUGH IF TONIGHT IS ACTIVE
...WE WOULD HAVE LOTS OF CONVECTIVE INHIBITION TO OVERCOME IN THE
ABSENCE OF MORE UPPER FORCING. WE MAY HAVE SOME OF THAT BOTH FRIDAY
AND SATURDAY AS ADDITIONAL VORT MAXIMA ROTATE AROUND TROUGH. SO...
WILL BASICALLY KEEP CHANCE TYPE POPS GOING INTO SATURDAY...LOWERING
POPS A BIT ON SUNDAY...WITH A LOW GRADE MONSOON FORECAST MAINTAINED
MONDAY THRU THURSDAY.

.PSR...SVR TSTM WATCH SCNTRL AZ...ZONES 22...23...24...27 AND
       28 TIL 04Z.
       FLASH FLOOD WATCH SAME ZONES 00Z-12Z.

Hazardous weather outlook, Aug 14, 6:19 AM MST, 13 hours 10 minutes before

AZZ020>028-CAZ030>033-150100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
619 AM MST THU AUG 14 2003

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

.DAY ONE...TODAY

THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS IN SOUTHWEST AND
SOUTH CENTRAL ARIZONA. THE STRONGEST STORMS WILL OCCUR LATE THIS
AFTERNOON AND EVENING. THUNDERSTORMS ARE CAPABLE OF PRODUCING STRONG
POSSIBLY DAMAGING WINDS...DENSE BLOWING DUST...AND LOCALLY HEAVY
RAIN.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

AN UNUSUALLY STRONG LOW PRESSURE SYSTEM MOVING FROM TEXAS INTO
ARIZONA WILL CONTINUE THE UNSETTLED WEATHER ON FRIDAY. A CHANCE FOR
SHOWERS AND THUNDERSTORMS CAN BE EXPECTED ACROSS PARTS OF SOUTHEAST
CALIFORNIA...AND SOUTHWEST AND SOUTH CENTRAL ARIZONA.  THUNDERSTORMS
ARE CAPABLE OF PRODUCING STRONG POSSIBLY DAMAGING WINDS...DENSE
BLOWING DUST...AND HEAVY RAINFALL.

DECREASING THREATS FOR SHOWERS AND THUNDERSTORMS ARE EXPECTED
THIS WEEKEND AND EARLY NEXT WEEK.

.INSTRUCTIONS TO SPOTTERS...
WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

In the hours before

Local storm report, Aug 14, 6:07 PM MST, 1 hour 22 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX, AZ
607 PM MST THU AUG 14 2003

TIME(MST)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0530 PM    5 E SACATON               AZ   FLASH FLOODS
08/14/03   PINAL                          FLOODING REPORTED ON STATE
                                          HIGHWAY 87 NEAR MILE MARKER
                                          147. ROAD REPORTED AS
                                          IMPASSIBLE. REPORTED BY LAW
                                          ENFORCEMENT

FOWLE

Local storm report, Aug 14, 6:37 PM MST, 52 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX, AZ
637 PM MST THU AUG 14 2003

TIME(MST)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0615 PM    QUEEN CREEK               AZ   60 MPH TSTM WIND GUST
08/14/03   MARICOPA                       ESTIMATED WIND GUST
                                          MEASURED BY STORM SPOTTER.

FOWLE

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 14, 5:10 PM MST	Flash Flood Warning	PSR	Pinal	50 min
Aug 14, 5:17 PM MST	Severe Thunderstorm Warning	PSR	Pinal	58 min
Aug 14, 6:06 PM MST	Severe Thunderstorm Warning	PSR	Gila	54 min
Aug 14, 6:07 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	53 min
Aug 14, 6:35 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	55 min
Aug 14, 7:33 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	57 min
Aug 14, 8:23 PM MST	Flash Flood Warning	PSR	Maricopa	37 min
Aug 14, 8:28 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	62 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2003 Every 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.