Alert archive / Arizona / Flash Flood Warnings in 1998

Flash Flood Warning 2, NWS Flagstaff, AZ

July 21, 1998Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 21, 1998, 1:06 AM MST for Coconino County, Arizona. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 21, 1998, 1:06 AM MST (08:06 UTC)
Expired: Jul 21, 1998, 4:00 AM MST
In force: 3 hr
Issued by: NWS Flagstaff, AZ
Area: Whole counties

County Coconino County, AZ

The radar

The Flagstaff radar (KFSX), 150 km from the middle of the area, began a volume at 08:06 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.

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 00:00Z, 8.1 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: 534 J/kg
Mixed-layer CIN: -46 J/kg
Mixed-layer LCL: 1738 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: -12 m²/s²
0-3 km storm-relative helicity: 85 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 210807
FFWFLG
AZC005-211100-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
106 AM MST TUE JUL 21 1998

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF HAS ISSUED A

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

* UNTIL 400 AM MST

* A LINE OF THUNDERSTORMS HAS PRODUCED OVER AN INCH AND A HALF OF
  RAIN...WITH HEAVY RAIN STILL FALLING. THESE STORMS ARE SLOWLY
  MOVING TO THE NORTHWEST...NORTH OF INTERSTATE 40 BETWEEN COSNINO
  AND LEUPP CORNER.

* THESE STORMS WILL CONTINUE PRODUCING HEAVY RAIN...WITH RUNOFF
  CAUSING FLOODING ALONG INDIAN ROUTE 15...FROM THE
  TOWNSEND-WINONA JUNCTION TO LEUPP. FLOODING IS ALSO LIKELY ALONG
  STATE ROUTE 99 FROM LEUPP CORNER TO LEUPP.

DO NOT DRIVE ACROSS WATER COVERED ROADS. AVOID ALL AREAS SUBJECT
TO FLOODING.

RIGGS/PEREZ

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 Jul 20, 8:30 PM MST, 4 hours 36 minutes earlier.

Area forecast discussion, Jul 20, 8:30 PM MST, 4 hours 36 minutes before

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
830 PM MST MON JUL 20 1998

SYNOPSIS...AN AREA OF HIGH PRESSURE NORTH OF THE STATE WILL CONTINUE
TO GENERATE A RELATIVELY MOIST SOUTHEASTERLY FLOW OVER ARIZONA THE
NEXT FEW DAYS. THIS WILL RESULT IN A CONTINUED CHANCE OF AFTERNOON
AND EVENING THUNDERSTORMS...PARTICULARLY OVER THE MOGOLLON RIM AND
WHITE MOUNTAINS.

DISCUSSION...BUSY EVE THO NOT NEARLY AS BAD AS LAST NIGHT.  EASTERLY
WAVE RESPONSIBLE FOR YESTERDAY/S ACTIVE WEATHER NOW IN EXTREME SERN
CA.  THUS...DYNAMICS ACROSS NRN AZ DOWN FROM YESTERDAY THO PLENTY OF
MOISTURE INTERACTING WITH FAVORABLE THERMODYNAMIC PROFILES FOR DECENT
AMOUNT OF ACTIVITY TONIGHT NONETHELESS.  NOT MUCH CHANCE TO LOOK AT
NEW DATA THO SEE NO REASON FOR ANY SIGNIFICANT CHANGES NEXT FEW DAYS.
WILL TAKE A LOOK AT THE FIRST PD AND MAKE ANY NECESSARY ADJUSTMENTS.
KHW

FLG 2424  INW 2111
FLG...NONE.

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 20, 7:14 PM MST	Severe Thunderstorm Warning	FGZ	Gila	46 min
Jul 20, 8:04 PM MST	Severe Thunderstorm Warning	FGZ	Gila	46 min
Jul 20, 8:40 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	45 min

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; radar from the NEXRAD Level II archive.