Alert archive / Arizona / Severe Thunderstorm Warnings in 2003
Severe Thunderstorm Warning 52, NWS Flagstaff, AZ
NWS Flagstaff, AZ issued this severe thunderstorm warning at Aug 21, 2003, 4:33 PM MST for Coconino County, Arizona. It was in force for 57 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, 4:33 PM MST (23:33 UTC)
- Expired
- Aug 21, 2003, 5:30 PM MST
- In force
- 57 min
- Issued by
- NWS Flagstaff, AZ
- Area
- Counties, with a storm outline in the text
County Coconino County, AZ
The radar
The Las Vegas radar (KESX), 152 km from the middle of the area, began a volume at 23:37 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
Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 11.6 hours before the alert went out and 143 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.
- Mixed-layer CAPE
- 109 J/kg
- Mixed-layer CIN
- -106 J/kg
- Mixed-layer LCL
- 1474 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 5 m²/s²
- 0-3 km storm-relative helicity
- 11 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 WUUS55 KFGZ 212333 SVRFGZ AZC005-220000- BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE FLAGSTAFF AZ 431 PM MST THU AUG 21 2003 THE NATIONAL WEATHER SERVICE IN FLAGSTAFF HAS ISSUED A * SEVERE THUNDERSTORM WARNING AND FLOOD FLASH WARNING FOR... WEST CENTRAL COCONINO COUNTY IN NORTH CENTRAL ARIZONA * UNTIL 530 PM MST * AT 423 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 6 MILES WEST OF FRAZIERS WELL...MOVING NORTHWEST AT 20 MPH. RADAR INDICATED LARGE HAIL AND HEAVY RAINFALL WITH IS STORM. REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN FLAGSTAFF. LAT...LON 3565 11321 3577 11299 3606 11321 3597 11343
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 Flagstaff, AZ wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 21, 2:30 PM MST, 2 hours 3 minutes earlier.
Area forecast discussion, Aug 21, 2:30 PM MST, 2 hours 3 minutes before
NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 PM MST THU AUG 21 2003
.SYNOPSIS...A WEAK WEATHER DISTURBANCE WILL INTERACT WITH TROPICAL
MOISTURE ACROSS NORTHERN ARIZONA THIS AFTERNOON AND EVENING...
PRODUCING NUMEROUS SHOWERS IN THE WEST...AND SCATTERED SHOWERS IN
THE EAST. EXPECT AFTERNOON AND EVENING SHOWERS TO CONTINUE EACH DAY
THROUGH THE WEEKEND.
.DISCUSSION...HIGH PRESSURE REMAINS OVER THE CENTRAL ROCKY MTNS WITH
A RIDGE AXIS EXTENDING SWWD ACROSS AZ. THIS CIRC PATTERN CONTINUES
TO BRING A MOIST SUBTROPICAL FLOW NORTHWARD ACROSS THE STATE. A
CLOSED LOW IS IN PLACE OVER THE EPAC CENTERED NEAR 33N 128W. TO THE
EAST OF THIS SYSTEM A S/W TROUGH WAS EJECTING TO THE NE OVER NV.
THIS FEATURE CAN BE SEEN IN THE WV IMAGERY...AND WAS ALSO
INITIALIZED WELL IN THE MODEL DATA. WV IMAGERY ALSO SHOWS THE
LEADING EDGE OF DRIER AIR ALOFT ADVECTING ACROSS CA/AZ THIS
AFTERNOON. PW VALUES REMAIN VERY HIGH ACROSS THE STATE. SCATTERED
CONVECTION HAS DEVELOPED ACROSS MOST OF NRN AZ THIS AFTERNOON.
SHOWERS IN THE WEST HAVE BEEN PRODUCING COPIOUS RAINFALL AMOUNTS AND
ARE BEGINNING TO SHOW SIGNS OF ECHO TRAINING. WILL PUSH POPS UP A
BIT IN THE WESTERN ZONES FOR TONIGHT SINCE THIS ACTIVITY IS EXPECTED
TO CONTINUE WELL INTO THE EVENING.
UPPER LOW IN THE EPAC SHOULD BEGIN TO EJECT TO THE NE ON FRIDAY. AS
IT DOES...EXPECT GRADIENTS TO TIGHTEN ACROSS NW AZ. COMBINATION OF
ENHANCED SHEAR AND HIGH PW VALUES WILL RESULT IN STRONG CONVECTION
DEVELOPING AGAIN OVER THIS REGION. BY SATURDAY...GRADIENT RELAXES
AND HIGH RE-ESTABLISHES ITSELF WITH LIGHT WINDS ACROSS NRN AZ...THUS
EXPECT JUST A NORMAL MONSOON TYPE OF PATTERN FOR SAT/SUN.
.EXTENDED...MOIST AND UNSTABLE AIR MASS REMAINS OVER AZ FOR MORE
AFTERNOON AND EVENING THUNDERSTORMS. RIDGE SLOWLY SHIFTS TO THE
SOUTH SO THERE SHOULD BE SOME MODULATION IN THE PATTERN. WILL GO
WITH CLIMATOLOGICAL POP VALUES FOR NOW. DB
.CODED TEMPERATURES/POPS FOR SELECTED CITIES IN NORTHERN ARIZONA
CITY TEMPERATURES LO/HI PROBABILITY OF PRECIP
TON FRI SAT SUN TON FRI SAT SUN
FLAGSTAFF 053/078 052/077 050/076 030 050 040 050 020 040
WINSLOW 065/091 064/091 061/089 030 040 030 040 020 030
PRESCOTT 060/087 059/087 061/086 030 040 030 040 020 040
PAGE 070/093 071/093 068/091 030 030 020 030 020 020
WINDOW ROCK 053/083 054/083 050/082 030 040 030 040 020 040
CANYON DE CHELLY 061/089 062/089 058/088 030 040 030 040 020 030
COTTONWOOD 068/098 067/098 069/097 030 040 030 040 020 030
GRAND CANYON 053/082 052/083 050/081 030 040 030 040 020 030
GREER 050/073 049/072 047/071 040 060 050 050 030 060
HEBER 055/083 054/082 052/081 030 050 040 050 020 040
JACOB LAKE 053/076 052/075 050/074 040 040 030 040 020 040
NAVAJO N.M. 058/083 059/083 055/082 030 040 030 040 020 030
PAYSON 061/091 060/091 062/090 030 040 030 040 030 040
SEDONA 066/095 065/095 067/094 030 040 030 040 020 030
SELIGMAN 059/090 058/090 060/089 030 030 030 030 020 020
SHOW LOW 061/083 060/082 058/081 030 050 040 050 020 040
ST. JOHNS 065/091 064/090 064/089 030 040 030 040 020 040
WUPATKI N.M. 066/093 065/093 062/091 030 040 030 040 020 030Hazardous weather outlook, Aug 21, 10:35 AM MST, 5 hours 58 minutes before
AZZ004>018-037>040-220200- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE FLAGSTAFF AZ 700 AM MST THU AUG 21 2003 THIS HAZARDOUS WEATHER OUTLOOK IS FOR APACHE...COCONINO...NORTHERN GILA...NAVAJO...AND YAVAPAI COUNTIES IN NORTHERN ARIZONA. .DAY ONE...TODAY HIGH PRESSURE REMAINS OVER THE CENTRAL ROCKY MOUNTAINS PRODUCING A MOIST AND UNSTABLE SOUTHERLY FLOW OVER ARIZONA. A WEAK DISTURBANCE WILL MOVE ACROSS ARIZONA THIS AFTERNOON. THIS FEATURE SHOULD ENHANCE THUNDERSTORM POTENTIAL TODAY...ESPECIALLY IN WESTERN ARIZONA. SOME OF THESE STORMS WILL PRODUCE LOCALLY HEAVY RAIN...SMALL HAIL...AND STRONG GUSTY WINDS. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY A MOIST AND UNSTABLE AIR MASS WILL REMAIN OVER ARIZONA RESULTING IN A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. DEFINITION OF HAZARDOUS WEATHER...A WEATHER EVENT POSING A THREAT TO LIFE AND PROPERTY.
In the hours before
Local storm report, Aug 21, 2:26 PM MST, 2 hours 7 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
0226 PM MST THU AUG 21 2003
TIME(MST) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0145 PM 10 NE PRESCOTT AZ 0.75 IN HAIL
08/21/03 YAVAPAI
0215 PM PRESCOTT VALLEY AZ FLASH FLOOD
08/21/03 YAVAPAI 1-2 FEET OF WATER IN
STREETS. POWER OUTAGES.The office that day
Everything else NWS Flagstaff, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 21, 12:13 PM MST | Flash Flood Warning | FGZ | Coconino | 77 min |
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.