Alert archive / Arizona / Flash Flood Warnings in 2003

Flash Flood Warning 12, NWS Flagstaff, AZ

August 21, 2003Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 21, 2003, 12:13 PM MST for Coconino County, Arizona. It was in force for 77 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, 12:13 PM MST (19:13 UTC)
Expired
Aug 21, 2003, 1:30 PM MST
In force
77 min
Issued by
NWS Flagstaff, AZ
Area
Counties, with a storm outline in the text

County Coconino County, AZ

The radar

The Cedar City radar (KICX), 157 km from the middle of the area, began a volume at 19:16 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 flash flood 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, 7.2 hours before the alert went out and 150 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, Flgstf/Belemont, AZ at 12:00Z on 2003-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 109 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, Flgstf/Belemont, AZ at 12:00Z on 2003-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 5 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
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

Open this sounding in Storm Lab

The text

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

000 
WGUS55 KFGZ 211917
FFWFGZ
AZC005-212115-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1213 PM MST THU AUG 21 2003

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WEST CENTRAL COCONINO COUNTY IN NORTH CENTRAL ARIZONA

* UNTIL 230 PM MST

* AT 1208 PM MST...WEATHER SERVICE DOPPLER RADAR INDICATED VERY HEAVY
  RAIN OVER WEST CENTRAL COCONINO COUNTY...OR ABOUT 15 MILES WEST    
  OF SUPAI...MOVING NORTHEAST AT 10 MPH.

MOHAWK CANYON AND NATIONAL CANYON ARE LOCATED WITHIN THE HEAVY RAIN 
AREA.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE. IF YOUR VEHICLE STALLS, ABANDON IT IMMEDIATELY AND SEEK
HIGHER GROUND.

TO REPORT SEVERE WEATHER HAVE THE NEAREST LAW ENFORCEMENT AGENCY
RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN
FLAGSTAFF.

LAT...LON 3617 11312 3603 11295 3619 11278 3633 11295

What forecasters said that day

The local office's own words before this flash flood 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 flash flood warning went out at Aug 21, 10:15 AM MST, 1 hour 58 minutes earlier.

Area forecast discussion, Aug 21, 10:15 AM MST, 1 hour 58 minutes before
NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1015 AM MST THU AUG 21 2003

.SYNOPSIS...TROPICAL MOISTURE WILL REMAIN ACROSS NORTHERN ARIZONA
INTO EARLY NEXT WEEK. AS A RESULT...EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS EACH DAY.

.DISCUSSION...HIGH PRESSURE REMAINS OVER THE CENTRAL ROCKY MTNS WITH
A RIDGE AXIS EXTENDING SWWD ACROSS AZ. THIS CIRC PATTERN WILL
CONTINUE 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. 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 MORNING.
PW VALUES REMAIN VERY HIGH ACROSS THE STATE. FINALLY... MORNING
RAOBS SHOW MODERATE WINDS ALOFT AND CURRENT WAVE CLOUD ACTIVITY OVER
NRN AZ INDICATES THESE WINDS STILL PRESENT. THUS...SOME INGREDIENTS
NOW IN PLACE FOR STRONGER AND ORGANIZED STORMS TO DEVELOP ACROSS THE
WRN PORTIONS OF NRN AZ TODAY. WILL MAKE SOME ADJUSTMENTS TO POPS IN
WRN ZONES...OTHERWISE ZFP IN GOOD SHAPE.  DB

.CODED TEMPERATURES/POPS FOR SELECTED CITIES IN NORTHERN ARIZONA

FLAGSTAFF        079/052 079/052 077/051      040 030 050 040 050 020
WINSLOW          092/064 092/064 090/063      030 020 040 030 040 020
PRESCOTT         087/062 087/062 085/061      040 030 040 030 040 020
PAGE             094/070 094/070 092/069      020 020 030 020 030 020
WINDOW ROCK      086/050 086/050 084/049      040 020 040 030 040 020
CANYON DE CHELLY 092/063 092/063 090/062      030 020 040 030 040 020
COTTONWOOD       096/070 096/070 094/069      030 020 040 030 040 020
GRAND CANYON     082/052 082/052 080/051      030 020 040 030 040 020
GREER            074/046 074/046 072/045      050 030 060 050 060 030
HEBER            084/054 084/054 082/053      040 030 050 040 050 020
JACOB LAKE       077/052 077/052 075/051      030 030 040 030 040 020
NAVAJO N.M.      086/055 086/055 084/054      030 020 040 030 040 020
PAYSON           091/064 091/064 089/063      030 030 040 030 040 030
SEDONA           094/063 094/063 092/064      040 020 040 030 040 020
SELIGMAN         090/061 090/061 088/060      030 030 030 030 030 020
SHOW LOW         084/060 084/060 082/059      040 030 050 040 050 020
ST. JOHNS        091/059 091/059 089/058      040 030 040 030 040 020
WUPATKI N.M.     094/065 094/065 092/064      030 020 040 030 040 020
Hazardous weather outlook, Aug 21, 10:35 AM MST, 1 hour 38 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.

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 4:33 PM MSTSevere Thunderstorm WarningFGZCoconino57 min

Nearby

Flash Flood Warnings in Arizona, 2003Every flash flood 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.