Alert archive / Arizona / Flash Flood Warnings in 1998

Flash Flood Warning 12, NWS Flagstaff, AZ

August 23, 1998Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 23, 1998, 3:35 PM MST for Coconino County, Arizona. It was in force for 90 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Aug 23, 1998, 3:35 PM MST (22:35 UTC)
Expired: Aug 23, 1998, 5:05 PM MST
In force: 90 min
Issued by: NWS Flagstaff, AZ
Area: Whole counties

County Coconino County, AZ

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 10.6 hours before the alert went out and 68 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: 121 J/kg
Mixed-layer CIN: -214 J/kg
Mixed-layer LCL: 1725 m above ground
0-6 km bulk shear: 2 kt
0-1 km storm-relative helicity: 32 m²/s²
0-3 km storm-relative helicity: 55 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 
TTAA00 KFLG 232237
FFWFLG
AZC005-240005-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
335 PM MST SUN AUG 23 1998

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF HAS ISSUED A

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

* UNTIL 505 PM MST

* AT 335 PM MST...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING
  HEAVY RAIN ALONG THE SOUTH RIM OF THE GRAND CANYON FROM WEST OF
  DESERT VIEW TO THE GRAND VIEW TRAIL AREA.

* RAPID WATER RISES AND TRAIL FLOODING POSSIBLE IN THE VICINITY OF
  RED CANYON...INCLUDING THE RED CANYON TRAIL AND GRAND VIEW TRAIL.

IF YOU ARE IN THE WARNING AREA... MOVE TO HIGHER GROUND AT ONCE.
DO NOT DRIVE ACROSS WATER COVERED ROADS. AVOID ALL AREAS SUBJECT
TO FLOODING.

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 23, 2:10 PM MST, 1 hour 25 minutes earlier.

Area forecast discussion, Aug 23, 2:10 PM MST, 1 hour 25 minutes before

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
210 PM MST SUN AUG 23 1998

SYNOPSIS...HIGH PRESSURE WILL REMAIN OVER THE SOUTHWESTERN UNITED
STATES FOR THE NEXT FEW DAYS. LOW LEVEL MOISTURE WILL REMAIN OVER
NORTHERN ARIZONA INTO MONDAY...RESULTING IN MOSTLY SUNNY MORNINGS
WITH CLOUDS...SHOWERS AND THUNDERSTORMS DEVELOPING IN THE AFTERNOONS.

DISCUSSION...BROAD 5H RIDGE REMAINS OVER THE AREA WITH SEVERAL
FEATURES NOTED ON WV IMAGERY. FIRST...IS WEAK EASTERLY WAVE WORKING
ACROSS OLE MX...AND ANOTHER IS WEAK DEFORMATION ZONE WHICH IS ACROSS
THE SE PORTION OF THE CWA. THIS DEF ZONE NOT CONTRIBUTING MUCH TO
EARLY AFTERNOON CONVECTION...BUT IT MAY PLAY A MORE PROMINENT ROLE
LATER THIS EVENING. SFC DEW POINTS ALSO REMAINING QUITE HIGH ACROSS
THE AREA...WITH EVIDENCE OF A SURGE OCCURRING AT KYUX.

12Z MODELS INITIALIZED LARGE SCALE FLOW FAIRLY WELL. AS FAR AS
MOISTURE IS CONCERNED...AM LEANING TOWARDS THE NGM...AS IT HAS
INITIALIZED THE 700 MB FIELDS BETTER OVER THE ETA. APPEARS THAT LOW
LEVEL RH NOT GOING ANYWHERE THIS FCST PERIOD AND WILL KEEP STANDARD
MONSOON FCST. IN THE EXTENDED...TROUGH TO WORK INTO THE WESTERN US
OVER THE EXTENDED PERIOD AND FLOW TO BECOME MORE SOUTHWESTERLY.
HOWEVER...GRADIENTS STILL WEAK AND DO NOT EXPECT MUCH SCOURING TO
OCCUR THROUGH THE PERIOD. WILL KEEP CHANCE CATEGORY FOR THE EXTENDED
WITH A FEW DEGREES OF COOLING.   MCGRATH
FLG 3534 INW 2422
FLG...NONE.

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 23, 1:46 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	34 min
Aug 23, 3:02 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	33 min
Aug 23, 4:54 PM MST	Flash Flood Warning	FGZ	Coconino, Yavapai	2 hr

Nearby

Flash Flood Warnings in Arizona, 1998 Every flash flood warning in 1998

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.